HK1226665A1 - Enhancer of survival of transplanted organ - Google Patents

Abstract

The present invention provides enhancer of survival of transplanted organ. Provided are: an enhancer of the survival of a transplanted organ, which can prevent the occurrence of any rejection reaction without requiring the use of any existing immunosuppressing agent; an organ preservation solution which enables the preservation of the freshness of an organ after the excision of the organ from a donor; and others. Prepared are: an enhancer of the survival of a transplanted organ, which contains 5-aminolevulinic acid (ALA) or a derivative or salt thereof and an iron compound as active ingredients; and an organ preservation solution. Preferred examples of the ALA compound include ALA, esters thereof including a methyl ester, an ethyl ester, a propyl ester, a butyl ester, a pentyl ester and the like thereof, and hydrochloric acid salts, phosphoric acid salts and sulfuric acid salts of ALA and the esters. A preferred example of the iron compound is sodium ferrous citrate.

Description

Survival promoter for transplanted organ

The present application is a divisional application of chinese patent application 201280050051.4(PCT application No. PCT/JP2012/005782) having an application date of 9/12/2012, and entitled "promoter of survival of transplanted organ".

Technical Field

The present invention relates to a transplanted organ survival promoter (hereinafter, also referred to as "ALA") containing 5-aminolevulinic acid (ALA ") or a derivative thereof or a salt thereof and a metal-containing compound such as an iron compound, and also relates to a preservative for an organ removed from a donor, which comprises the transplanted organ survival promoter.

Background

In organ transplantation, the immune mechanism originally used to protect the organism against bacteria, viruses, etc. generates rejection reactions by recognizing the transplanted organ as a "foreign body". It is not to be said that the success of transplant therapy depends on the degree to which rejection can be controlled. As a method for regulating rejection, there are a method for locally controlling rejection of a transplanted organ and a method for regulating rejection itself of a whole body, and the latter is the method mainly performed at present, and it is known that administration of a calcineurin inhibitor such as cyclosporine and tacrolimus or a steroid drug can inhibit rejection after transplantation, and therefore, they are widely used, but side effects are also many.

In recent years, in order to reduce the amount of a drug to be administered, a method of extracting T cells from a donor or recipient, culturing the extracted T cells in a mixture with a specific antibody, and returning the cultured T cells to the body has been developed as a method of artificially inducing immune tolerance. For example, the following are proposed: a renal transplant rejection inhibitor containing, as an active ingredient, the above recipient-derived T cells obtained by stimulating T cells collected from a recipient undergoing renal transplantation with alloantigens of a donor of kidney in the presence of an anti-CD 80 antibody or an antigen-binding fragment thereof and a CD86 antibody or an antigen-binding fragment thereof (see, for example, patent document 1); a method for reducing the effect of graft-versus-host disease, the method comprising the step of extracting a sample comprising peripheral blood mononuclear cells containing CD4+ CD25+ regulatory T cells from a human donor, the step of generating concentrated CD4+ CD25+ regulatory T cells by concentrating the CD4+ CD25+ regulatory T cells in the sample, the step of proliferating the concentrated group of CD4+ CD25+ regulatory T cells, and the step of administering a part of the proliferated CD4+ CD25+ regulatory T cells to a human to treat graft-versus-host disease (see, for example, patent document 2); a method for inducing recipient cells to reduce transplant rejection, said method comprising a) isolating peripheral blood mononuclear cells from a recipient and a donor, b) mixing the cells of the donor and the recipient in vitro, c) treating the cells with a regulatory composition, d) increasing the cells, and e) introducing the cells into the recipient (see, for example, patent document 3).

In addition, an organ preservation solution containing flavonoids (see, for example, patent document 4), an organ preservation agent containing 1, 5-anhydrofructose or a derivative thereof (see, for example, patent document 5), an organ preservation agent containing fullerenes (see, for example, patent document 6), an organ preservation solution containing Hepatocyte Growth Factor (HGF) (see, for example, patent document 7), an organ preservation solution containing lecithin-induced superoxide dismutase (see, for example, patent document 8), an organ preservation solution containing glucosyl-L-ascorbic acid or a salt thereof (see, for example, patent document 9), and the like are known.

On the other hand, ALA is known as an intermediate of tetrapyrrole biosynthetic pathways widely present in animals, plants, and fungi, and is generally biosynthesized from succinyl CoA and glycine using a 5-aminolevulinic acid synthase. Photodynamic therapy or photodynamic therapy (hereinafter also referred to as "ALA-PDT") using ALA has also been developed, and has attracted attention as a therapeutic method that is less invasive and can maintain QOL, and tumor diagnosis and treatment agents using ALA and the like have also been reported. ALA is known to be useful as an agent for improving or treating adult diseases, cancers, and male infertility (see, for example, patent documents 10 to 12).

Patent document 1: japanese laid-open patent publication No. 2007-131598

Patent document 2: japanese Kokai publication 2011-505378

Patent document 3: japanese Kokai publication Hei-2003-530101

Patent document 4: japanese laid-open patent publication No. 2009-221128

Patent document 5: japanese laid-open patent publication No. 2008-115089

Patent document 6: japanese patent laid-open No. 2006 and 316000

Patent document 7: japanese patent laid-open publication No. 2005-306749

Patent document 8: japanese patent laid-open publication No. 2002-60301

Patent document 9: japanese patent laid-open publication No. 2000-191401

Patent document 10: international publication WO2010/050179

Patent document 11: japanese patent laid-open publication No. 2011-

Patent document 12: international publication WO2009/139156

Disclosure of Invention

Rejection is the largest cause of functional disuse of transplanted organs after transplantation, and in order to prevent rejection, long-term administration of immunosuppressive agents is necessary. However, long-term administration of immunosuppressive agents may cause serious side effects such as infection, kidney damage, diabetes, lymphoproliferation, malignant tumor, cardiovascular complications, and the like, and strict management is required. Although artificial immune tolerance induction methods such as the method of extracting T cells, culturing the T cells in a mixture with a specific antibody, and returning the cells to the body may reduce the amount of immunosuppressive agent to be used, they have not been widely used because they require several weeks of cell culture time, require complicated steps, and have side effects such as alopecia. In addition, various tolerance-inducing systems have been developed experimentally, but have not been used clinically at all.

The present invention addresses the problem of providing a transplanted organ survival promoter which is safe and has a different mechanism of action from conventional drugs and which can promote the survival of a transplanted organ during organ transplantation, and an organ preservation solution which can maintain the freshness of an organ removed from a donor.

The present inventors have continuously conducted various studies on the application of ALA to medical treatment, and have found that ALA has an action of promoting the survival of a transplanted organ when suppressing rejection in organ transplantation. Further, it has been found that, by administering ALA alone or a composition containing an ALA group and an iron compound to a donor before a transplant operation and also to a recipient transplanted with an organ excised from the donor, the survival rate of the transplanted organ is remarkably increased, unlike the conventional administration of an immunosuppressive agent for organ transplantation alone to a recipient. It has also been found that when an organ excised from a donor is transplanted while spleen cells of the recipient after the organ transplantation are administered to another recipient, a so-called secondary immune tolerance-inducing effect of promoting the survival of the transplanted organ is exerted even without administration of ALA. ALA has also been found to be effective as a preservative for organs removed from donors.

In addition, it has been found that an iron compound cooperates with ALA to enhance the survival promoting effect of a transplanted organ, the secondary immune tolerance inducing effect, and the freshness retaining effect of an organ after extirpation from a donor. When the iron compound is sufficiently present or when the iron compound is taken separately, there is a case where there is no problem in the case where ALA is administered alone. For japanese people who have a lower red meat intake than other countries, iron in minerals is often insufficient. Therefore, although iron is added simultaneously in some examples conducted by japanese, it is not necessary to use an artificial subject having sufficient storage iron. Further, although it is widely known that ALA is metabolized into porphyrin and PDT and PDD activities are exhibited under light irradiation, light is not essential for the promoter of transplanted organ survival of the present invention.

The present inventors further studied the administration method and the administration amount and established a promoter of the survival of transplanted organs containing ALA alone or ALA and an iron compound as the active ingredients, thereby completing the present invention.

Namely, the present invention relates to:

(1) a promoter for promoting the survival of transplanted organs, which comprises a compound represented by the following formula (I) or a salt thereof,

in the formula, R¹Represents a hydrogen atom or an acyl group, R²Represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aralkyl group or an aryl group.

(2) The promoter for promoting survival of transplanted organ according to the above (1), wherein R is¹And R²Is a hydrogen atom.

(3) The promoter for promoting survival of a transplanted organ according to the above (1) or (2), further comprising an iron compound.

(4) The promoter for promoting survival of a transplanted organ according to the above (3), the iron compound is one or more compounds selected from the group consisting of iron chloride, iron sesquioxide, iron sulfate, ferrous pyrophosphate, ferrous citrate, iron sodium citrate, iron ammonium citrate, iron pyrophosphate, iron lactate, ferrous gluconate, iron sodium diethylenetriamine pentaacetate, iron ammonium diethylenetriamine pentaacetate, iron sodium ethylenediamine tetraacetate, iron ammonium ethylenediamine tetraacetate, iron sodium dicarboxymethylglutamate, iron ammonium dicarboxymethylglutamate, iron ferrous fumarate, iron acetate, iron oxalate, iron succinate, iron sodium citrate succinate, iron heme, iron dextran, iron triethylenetetramine, iron lactoferrin, iron transferrin, iron chlorophyll, iron proteinate, iron oxysulfide, and iron glycinate sulfate.

(5) The promoter for promoting survival of transplanted organs according to (3), wherein the iron compound is sodium ferrous citrate.

(6) A method for promoting survival of a transplanted organ in organ transplantation, which comprises administering the promoter for promoting survival of a transplanted organ according to any one of (1) to (5) above to a recipient before and/or after organ transplantation.

(7) A method for promoting survival of a transplanted organ in organ transplantation, which comprises administering the promoter for promoting survival of a transplanted organ according to any one of the above (1) to (5) to a donor before organ transplantation and a recipient before organ transplantation and/or after organ transplantation.

(8) A transplant organ survival promotion kit comprising:

a) a compound represented by the above formula (I) or a salt thereof, and

b) an iron compound.

(9) A method for promoting survival of a transplanted organ, comprising administering to a subject simultaneously or sequentially:

a) a compound represented by the above formula (I) or a salt thereof, and

b) an iron compound.

(10) A combination of transplant organ survival promoting agents comprising:

a) a compound represented by the above formula (I) or a salt thereof,

b) an iron compound, and

c) organ transplantation immunosuppressive drugs.

(11) A combination of transplant organ survival promoting agents comprising:

a) the promoter for promoting survival of transplanted organ according to any one of (1) to (5) above, and

b) organ transplantation immunosuppressive drugs.

(12) An isolated immune cell derived from a recipient to which the promoter for promoting survival of a transplanted organ of any one of (1) to (5) above has been administered before and/or after organ transplantation.

(13) An isolated immune cell derived from a recipient to which a donor before organ transplantation or a recipient before organ transplantation and/or after organ transplantation has been administered the promoter for transplanted organ survival according to any one of (1) to (5) above.

(14) The isolated immune cell according to (12) or (13) above, which is a regulatory T cell.

(15) A method for inducing secondary immune tolerance, which comprises administering the immune cell of any one of (12) to (14) above to the same receptor and/or another receptor from which the cell was collected.

(16) A method for preserving a transplant organ, which comprises administering the transplant organ survival promoter of any one of (1) to (5) above to an organ removed from a donor or a preservation solution for the organ.

(17) The preservation method according to (16) above, wherein the organ is derived from a donor to which the promoter for promoting survival of a transplanted organ according to any one of (1) to (5) above has been previously administered.

(18) A preservative for organs removed from donors, which comprises the promoter for promoting survival of transplanted organs according to any one of (1) to (5) above.

(19) A compound represented by the above formula (I) or a salt thereof for improving the survival rate of a transplanted organ.

(20) A compound represented by the above formula (I) or a salt thereof, and an iron compound for improving the survival rate of a transplanted organ.

(21) Use of a compound represented by the above formula (I) or a salt thereof for producing a promoter of transplanted organ survival.

(22) Use of a compound represented by the above formula (I) or a salt thereof, and an iron compound for the production of a promoter for promoting the survival of a transplanted organ.

(23) A compound represented by the above formula (I) or a salt thereof for use as a preservative for organs after extirpation from donors.

(24) A compound represented by the above formula (I) or a salt thereof, and an iron compound, which are useful as a preservative for organs after removal from a donor.

(25) Use of a compound represented by the above formula (I) or a salt thereof for producing a preservative for organs removed from a donor.

(26) Use of a compound represented by the above formula (I) or a salt thereof, and an iron compound for the production of a preservative for organs removed from a donor.

The promoter for promoting the survival of transplanted organs can protect the transplanted organs against stress, maintain the freshness of the transplanted organs, inhibit rejection reaction accompanying organ transplantation and improve the survival rate of the transplanted organs. The present invention is completely different from the existing immunosuppressive agents or artificial immune tolerance induction methods such as a method of extracting T cells and mixing and culturing the T cells with a special antibody and returning the T cells to the body, and the present invention basically has no side effect, does not need to take medicines for a long time, and is extremely effective as a transplant organ survival promoter in organ transplantation. Further, since the mechanism of action is different from that of conventional immunosuppressants and the like, it is expected that the effect can be further improved by combining with existing drugs. In addition, the organ preservation agent of the present invention can maintain the freshness of the organ removed from the donor.

Drawings

FIG. 1 shows an example of a schematic representation of different systems of mouse heart transplantation experiments.

FIG. 2 is a diagram showing the outline of heart transplantation in a mouse of different systems using the promoter for promoting the survival of transplanted organs of the present invention and the procedure after the transplantation. The vertical axis represents the heart beat rate.

FIG. 3 is a diagram showing an outline of heart transplantation and the passage after transplantation of another type of different system mice using the promoter for promoting the survival of transplanted organs of the present invention. The vertical axis represents the heart beat rate.

FIG. 4 is a graph showing the results of heart survival in transplanted heart, which shows the survival rate of heart transplantation in the case where the transplanted organ survival promoter of the present invention is administered to a donor mouse before organ transplantation, a recipient mouse and a recipient mouse after organ transplantation, spleen cells derived from the recipient are transplanted to the same system recipient mouse, and the same system recipient mouse is subjected to heart transplantation in a different system mouse.

FIG. 5 is a photograph showing a donor mouse before organ transplantation, a recipient mouse and a recipient mouse after organ transplantation, wherein the transplanted organ survival promoter of the present invention is administered to the donor mouse, the recipient mouse and the recipient mouse after organ transplantation, spleen cells derived from the recipient are transplanted to the recipient mouse of the same system, and skin transplantation is performed to the recipient mouse of the same system using a different system.

FIG. 6 is a graph showing the results of measuring the number of regulatory T cells in recipient-derived spleen cells by administering the transplanted organ survival promoter of the present invention to a donor mouse before organ transplantation, a recipient mouse and a recipient mouse after organ transplantation.

Fig. 7 is a graph showing the results of investigation of the effectiveness of ALA-containing preservatives on organs removed from donors, as investigated by the time (seconds) required for a heart whose beating has ceased during storage to restart beating after transplantation.

Detailed Description

The transplant organ survival promoter of the present invention is not particularly limited as long as it contains a compound represented by the above formula (I) or a salt thereof (hereinafter, these may be collectively referred to as "ALA group" in some cases) as an active ingredient, but preferably contains an iron compound in addition to ALA group. By administering the above-mentioned transplant organ survival promoter of the present invention, particularly a transplant organ survival promoter containing ALA-based and iron compounds, to a subject such as a human, livestock, poultry, or pet, the promotion of transplant organ survival in organ transplantation can be performed. In the present invention, promotion of survival of a transplanted organ means suppression of rejection reaction in organ transplantation (including tissue transplantation) and improvement of survival rate (which is a rate at which the transplanted organ (tissue) continues to function in a living body).

The transplant organ survival promoting kit of the present invention is not particularly limited as long as it is a kit containing ALA compounds and iron compounds as active ingredients and in the form of a single drug, and when the transplant organ survival promoting kit is used, the transplant organ survival promoting kit can be used for promoting the transplant organ survival in organ transplantation in human, livestock, poultry, pets, and the like. The above-mentioned kit for promoting the survival of a transplanted organ may contain an attachment such as an instruction manual.

The organ to be transplanted is not particularly limited as long as it can be transplanted, and is not limited to an organ removed from a donor, and may be a graft or cell prepared in vitro, a tissue or organ artificially constructed by a regenerative medical technique, an organ prepared from a universal cell, and the like. Further, as the kind of the organ, kidney, liver, heart, pancreas, lung, small intestine, eyeball, cornea, hair, skin, and the like can be exemplified, wherein kidney, liver, heart, pancreas, lung, small intestine can be preferably exemplified.

The combinations of the promoter for promoting the survival of a transplanted organ of the present invention include, but are not limited to, the combinations of the above-mentioned promoter for promoting the survival of a transplanted organ of the present invention and an immunosuppressive drug for organ transplantation, and the combinations of ALA and an iron compound and an immunosuppressive drug for organ transplantation can be administered to promote the survival of a transplanted organ. Examples of the immunosuppressive agents for organ transplantation include metabolic antagonists such as Azathioprine (Azathioprine), mercaptopurine, methotrexate, mycophenolic acid (mycophenolic acid) and Leflunomide (Leflunomide), alkylating agents such as cyclophosphamide, calcineurin inhibitors such as cyclosporine and tacrolimus, and drugs such as steroids. Since the mechanism of action of the transplant survival promoter and the transplant survival promoter kit of the present invention is different from that of conventional immunosuppressive drugs for organ transplantation, when the combination of the transplant survival promoter of the present invention is used, a synergistic effect can be expected, and in some cases, a synergistic effect can be expected.

The compound usable as an active ingredient of the promoter for promoting the survival of a transplanted organ of the present invention can be exemplified by a compound represented by the formula (I) or a salt thereof (hereinafter, sometimes collectively referred to as "ALA group"). ALA, also known as aminolevulinic acid, is one of the amino acids, which is R of formula (I)¹And R²Both in the case of hydrogen atoms. As ALA derivatives, there may be mentioned R of the formula (I)¹Is a hydrogen atom or an acyl group, R of formula (I)²A compound other than ALA, which is a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.

Among the ALAs mentioned above, R of the formula (I) is preferably exemplified¹And R²ALA or its salt when both are hydrogen atoms. ALA is an amino acid, also known as aminolevulinic acid. Further, as ALA derivatives, R of the formula (I)¹Is a hydrogen atom or an acyl group, R of formula (I)²A compound other than ALA, which is a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.

Examples of the acyl group in the formula (I) include straight-chain or branched alkanoyl groups having 1 to 8 carbon atoms such as formyl group, acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, pivaloyl group, hexanoyl group, octanoyl group, and benzylcarbonyl group, and aroyl groups having 7 to 14 carbon atoms such as benzoyl group, 1-naphthoyl group, and 2-naphthoyl group.

Examples of the alkyl group in the formula (I) include straight-chain or branched alkyl groups having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, a heptyl group, and an octyl group.

Examples of the cycloalkyl group in the formula (I) include a cycloalkyl group having 3 to 8 carbon atoms which is saturated or may have a part of unsaturated bonds, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclododecyl group, and a 1-cyclohexenyl group.

Examples of the aryl group in the formula (I) include aryl groups having 6 to 14 carbon atoms such as a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group.

The aralkyl group in the formula (I) may have an aryl moiety as in the case of the aryl group and an alkyl moiety as in the case of the alkyl group, and specific examples thereof include aralkyl groups having 7 to 15 carbon atoms such as a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, a benzhydryl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

As the ALA derivative, R is preferable¹A compound represented by formyl, acetyl, propionyl, butyryl or the like, R²Is a compound of methyl, ethyl, propyl, butyl, pentyl, etc., the above-mentioned R¹And R²Combinations of (b) can be preferably exemplified by combinations of formyl group and methyl group, acetyl group and methyl group, propionyl group and methyl group, butyryl group and methyl group, formyl group and ethyl group, acetyl group and ethyl group, propionyl group and ethyl group, butyryl group and ethyl group, and the like.

ALA may be administered in vivo as an active ingredient in the form of ALA of formula (I) or a derivative thereof, and may be administered as various salts, esters or prodrugs (precursors) that are decomposable by enzymes in vivo, depending on the form of administration, in order to improve solubility. Examples of the salt of ANA or a derivative thereof include a pharmacologically acceptable acid addition salt, a metal salt, an ammonium salt, an organic amine addition salt, and the like. Examples of the acid addition salts include inorganic acid salts such as hydrochloride, hydrobromide, hydroiodide, phosphate, nitrate and sulfate, and organic acid addition salts such as formate, acetate, propionate, toluenesulfonate, succinate, oxalate, lactate, tartrate, glycolate, methanesulfonate, butyrate, valerate, citrate, fumarate, maleate and malate. Examples of the metal salt include alkali metal salts such as lithium salt, sodium salt and potassium salt, alkaline earth metal salts such as magnesium salt and calcium salt, and metal salts such as aluminum salt and zinc salt. Examples of the ammonium salt include alkyl ammonium salts such as ammonium salt and tetramethylammonium salt. Examples of the organic amine salt include triethylamine salt, piperidine salt, morpholine salt, and toluidine salt. These salts may be used in the form of a solution at the time of use.

Among the above ALAs, preferred are ALA, ALA methyl ester, ALA ethyl ester, ALA propyl ester, ALA butyl ester, ALA pentyl ester and other esters, and hydrochloride, phosphate and sulfate salts thereof, and ALA hydrochloride and ALA phosphate are particularly preferred.

The ALA can be produced by any known method of chemical synthesis, production by a microorganism, or production by an enzyme. The ALA may form a hydrate or solvate, and may be used alone or in combination of two or more kinds as appropriate.

The iron compound may be an organic salt or an inorganic salt, and the inorganic salt may include ferric chloride, ferric oxide, ferric sulfate, and ferrous pyrophosphate, and the organic salt may include a carboxylate such as a citrate salt such as ferrous citrate, ferric sodium citrate, ferrous sodium citrate, ferric ammonium citrate, ferric iron pyrophosphate, ferric lactate, ferrous gluconate, diethylenetriamine pentaacetic acid sodium iron ammonium salt, diethylenetriamine pentaacetic acid iron ammonium salt, ethylenediamine tetraacetic acid iron sodium salt, ethylenediamine tetraacetic acid iron ammonium salt, dicarboxymethyl glutamic acid iron sodium salt, dicarboxymethyl glutamic acid iron ammonium salt, ferrous fumarate, ferric acetate, ferric oxalate, ferrous succinate, succinic acid iron sodium citrate, and organic acid salts such as heme iron, iron anhydride, triethylenetetramine iron, lactoferrin, transferrin iron, sodium chlorophyllin, ferritin iron, Contains saccharide iron oxide and ferrous sulfate glycinate, preferably ferrous sodium citrate and ferric sodium citrate.

The iron compounds may be used alone or in combination of two or more. The molar ratio of the amount of the iron compound to the amount of the ALA compound to be administered (in terms of ALA) may be 0.01 to 100 times, preferably 0.05 to 10 times, and more preferably 0.1 to 8 times.

The promoter for promoting the survival of a transplanted organ of the present invention may contain other metal compounds instead of or in addition to the iron compound within a range that does not cause excessive symptoms. Examples of the metal compound include a magnesium compound, a zinc compound, a nickel compound, a vanadium compound, a cobalt compound, a copper compound, a chromium compound, and a molybdenum compound.

In the method for promoting the survival of a transplanted organ of the present invention, it is preferable to administer ALA and an iron compound in combination. In this case, administration may be in the form of a composition comprising the ALA group and the iron compound, or may be each administered separately, simultaneously or sequentially. In the case of separate administration, preferably simultaneous administration, and in the case of separate administration sequentially, administration is preferably such that the administration of the ALA group and the iron compound produces a synergistic effect, preferably a synergistic effect.

The promoter for promoting the survival of a transplanted organ of the present invention may be administered only to a recipient to which the following organs are transplanted: from the viewpoint of improving the survival rate, it is preferable to further administer the organ before the organ is removed, the organ obtained by temporarily storing the organ removed from the donor in a preservation solution, the organ prepared by using a regenerative medical technique for autologous transplantation, the organ obtained by immersing the organ in ALA, or the like. Thus, it is a major feature of the present invention that the survival rate can be improved by administering the promoter for promoting the survival of a transplanted organ or the promoter kit for promoting the survival of a transplanted organ of the present invention to a donor before organ transplantation and a recipient after or before organ transplantation.

If necessary, by proliferating an isolated immune cell derived from a recipient (the recipient being a recipient to whom the transplant/organ survival promoter or transplant/organ survival promoter kit of the present invention has been administered to a recipient before organ transplantation and/or after organ transplantation), or an isolated immune cell derived from a recipient (the recipient being a recipient to whom the transplant/organ survival promoter or transplant/organ survival promoter kit of the present invention has been administered to a donor before organ transplantation and/or a recipient before organ transplantation) and/or after organ transplantation), and administering the same recipient or another recipient from which the immune cell has been collected, thereby administering the recipient to which the immune cell has been administered, even without administration of the transplant organ survival promoting agent or transplant organ survival promoting kit of the present invention, immune tolerance at an individual level is induced to be promoted (induction of secondary immune tolerance is promoted). This promotion of induction of secondary immune tolerance shows that promotion of survival of a transplanted organ is achieved by induction of immune tolerance, and can be applied to adoptive immunotherapy of cells. For example, if immune cells are taken out from a person who has once been induced to have immune tolerance and stored, when immune tolerance is relieved (for example, when a transplanted organ is not received), the state of immune tolerance can be restored by transplanting the cells without administering the promoter for survival of a transplanted organ of the present invention. This induction of secondary immune tolerance is a particularly great feature of the present invention.

The immune cells include, in addition to spleen cells, macrophages, dendritic cells, T cells, B cells, NK cells, neutrophils, eosinophils, myeloid-derived suppressor cells (MDSCs), and the like, and preferably regulatory T cells and spleen cells.

The routes of administration of the components of the transplant organ survival promoting agent and transplant organ survival promoting kit of the present invention include oral administration including sublingual administration, or non-oral administration such as nasal drop administration, inhalation administration, intravenous administration including infusion, transdermal administration using cataplasm or the like, suppository, or administration using forced enteral nutrition using a nasogastric tube, nasointestinal tube, gastric fistula or intestinal fistula, but oral administration is preferred.

The dosage form of each component of the transplant organ survival promoting agent and transplant organ survival promoting kit of the present invention can be determined appropriately according to the administration route, and examples thereof include an aqueous solution such as an injection, nasal drops, infusion solution, tablets, capsules, fine granules, powder, liquid, syrup, etc., a cataplasm, a suppository, and the like. The components of the transplant organ survival promoting agent and the transplant organ survival promoting kit of the present invention may be administered in the form of a supplement such as a tablet or a capsule, in addition to the medical use. In particular, in the case of elderly persons or infants with difficulty in swallowing, a disintegrating agent showing rapid disintegration in the mouth and a liquid preparation suitable for administration through a nasogastric tube are preferable.

In order to prepare the promoter for promoting the survival of a transplanted organ and the kit for promoting the survival of a transplanted organ of the present invention, pharmacologically acceptable carriers, excipients, diluents, additives, disintegrants, binders, coating agents, lubricants, glidants, lubricants, flavoring agents, sweeteners, solubilizers, solvents, gelling agents, nutrients and the like may be added as necessary, and specifically, water, physiological saline, animal fats and oils, vegetable oils, lactose, starch, gelatin, crystalline cellulose, gum (gum), talc, magnesium stearate, hydroxypropyl cellulose, polyalkylene glycol, polyvinyl alcohol, glycerin may be exemplified. In the case where the promoter for promoting the survival of a transplanted organ and the kit for promoting the survival of a transplanted organ of the present invention are prepared as an aqueous solution, it is necessary to pay attention not to make the aqueous solution alkaline in order to prevent the decomposition of ALA species, but to prevent the decomposition by removing oxygen even in the case where the aqueous solution is alkaline.

The promoter for promoting the survival of a transplanted organ of the present invention is useful in the following respects: capable of suppressing an immune response on the recipient side which is induced in the case of transplanting an extirpated donor organ to a recipient; inhibiting rejection associated with organ transplantation; improving the survival rate of transplanted organs. It can be used as a preservative for organs removed from donors, and can be added to conventional organ preservation solutions to enhance the effect of promoting the survival of transplanted organs in organ transplantation. Examples of the rejection include hyperacute rejection, acute rejection, and chronic rejection after organ transplantation.

The hyperacute rejection is a strong rejection occurring within 24 hours from just after transplantation, and can be determined as a criterion for the presence or absence of hyperacute rejection by suturing a blood vessel or by determining whether or not a thrombus is formed in an artery of a transplanted organ within minutes to hours after restoration of blood flow, and can be determined as a criterion for cardiac arrest within 24 hours from just after transplantation to after transplantation in the case of cardiac transplantation. The acute rejection is a rejection occurring three days to about one week after transplantation, and in the case of heart transplantation, cardiac arrest 24 hours after transplantation can be used as a criterion for judging the presence or absence of acute rejection. The chronic rejection is a rejection occurring 3 months after transplantation, and the detailed mechanism thereof is unknown, and in the case of heart transplantation, cardiac arrest may be used as a criterion for the presence or absence of chronic rejection.

The donor and/or recipient in the present invention may be a mammal such as a human, baboon, cow, pig, dog, cat, rabbit, rat, or mouse, and the method of organ transplantation using the transplant organ survival promoter of the present invention is not particularly limited as long as the organ transplantation can be performed from the donor to the recipient, and examples thereof include an allogeneic organ transplantation such as a mouse to a mouse, a rat to a rat, a rabbit to rabbit, a dog to dog, a cat to cat, a pig to pig, a monkey to monkey, a baboon to baboon, a human to human, or a xenogeneic organ transplantation such as a pig to a human, a cow to human, a monkey to human, or a baboon to human.

The organ transplantation using the promoter for promoting the survival of a transplanted organ of the present invention can be performed by a usual method, and may be a homograft organ transplantation in which an organ corresponding to an organ supplied from a donor or the like is removed from a recipient and the organ supplied from the donor or the like is transplanted to the same site in the recipient, or a heterograft organ transplantation in which an organ supplied from a donor or the like is transplanted to another site in the recipient while the recipient organ remains.

The promoter for promoting the survival of a transplanted organ of the present invention needs to be administered to a recipient after organ transplantation, and specific administration periods include, for example, the following day to 10 days after the day of transplantation, preferably the following day to 15 days after the day of transplantation, more preferably the following day to 1 month after the day of transplantation, and particularly preferably the following day to a day when the survival of a transplanted organ is sufficiently confirmed on the day of transplantation.

As described above, in order to increase the survival rate, it is preferable to previously administer the transplant organ survival promoter of the present invention to a donor from which an organ is extracted. However, in particular, in the case where there is no sufficient time for the donor to be administered, such as in brain death transplantation, the same effects can be obtained by directly administering the organ removed from the donor, immersing the organ in a liquid containing the transplant organ survival promoter of the present invention, or administering the organ after removal, such as adding the transplant organ survival promoter of the present invention to a storage liquid in which the organ is stored. When an organ for autologous transplantation is prepared using regenerative medical technology, a means of adding the organ to a storage solution of the organ may be employed. Thus, the organ preservation agent after removal from a donor of the present invention includes a transplant organ survival promoter, and may be in a solid form such as powder, granule, or tablet, or in a liquid form. In the case of the solid form, a dispersant, a dissolving agent, and a pH adjusting agent may be blended in advance, if necessary. In the case of a liquid form, it preferably has a buffering capacity. In the case of a liquid form, the liquid may be prepared as a concentrated storage solution and used by diluting with physiological saline or the like.

When the promoter for promoting the survival of a transplanted organ of the present invention is administered to a donor of the present invention, it is necessary to administer the promoter for promoting the survival of a transplanted organ of the present invention during a predetermined period before the organ is removed, and specific administration periods include a period from one week before the current day of the organ removal operation to the current day of the removal operation, preferably from 5 days before the current day of the removal operation, more preferably from 3 days before the current day of the removal operation to the current day of the removal operation, and even more preferably from 2 days before the current day of the removal operation to the current day of the removal operation, and in cases where the organ must be transported after the removal operation of the organ, it is preferable to take measures such as storing the promoter for promoting.

The promoter of transplanted organ survival and the kit for promoting transplanted organ survival of the present invention can be used in the veterinary fields such as livestock, poultry, pets, etc., as described above, in addition to humans. The amount, frequency and period of administration of the above-mentioned promoter for promoting transplant organ survival and the like may vary depending on the age, body weight, symptoms and the like of a subject, and examples of the amount of administration of ALA in terms of the molar amount of ALA include 0.1 to 12 mmol/day, preferably 0.2 to 9 mmol/day, more preferably 0.3 to 6 mmol/day, still more preferably 0.35 mmol/day to 4 mmol/day per adult, and the frequency of administration may include administration once to several times a day or continuous administration by infusion or the like. The administration period can also be determined by a pharmacologist or clinician in the art according to known methods.

When the promoter for promoting the survival of a transplanted organ of the present invention is used in the form of an organ preservation solution, the concentration of ALA is 0.1. mu.M-100 mM, preferably 1. mu.M-10 mM, more preferably 5. mu.M-5 mM, most preferably 10. mu.M-1 mM.

The promoter for promoting the survival of a transplanted organ of the present invention can also be used in combination with other existing immunosuppressive methods for organ transplantation. Examples of conventional organ transplantation immunosuppressive methods include a method of inducing immune tolerance with immunosuppressive monoclonal antibodies using antibodies such as CD2, CD3, CD4, CD7, CD25, CD28, CD45, and B7. Since these drugs and methods are considered to be fundamentally different from the mechanism relating to the immunosuppressive effect of ALA in organ transplantation, additive effects can be expected, and synergistic effects can be expected in some cases. In addition, the effect of reducing side effects without reducing the amount of conventional immunosuppressive agents for organ transplantation can be expected.

The present invention will be described more specifically with reference to the following examples, but the technical scope of the present invention is not limited to these examples.

Example 1

[ preparation of heterogeneous Heart transplantation model mice ]

B10 mice (male, average 10-week-old, 20-25 g in body weight) were used as donor mice for providing transplanted hearts. CBA mice (male, average 10-week-old, 20-25 g in body weight) were used as recipient mice for transplantation of hearts removed from donors. The procedure for the allogenic heart transplantation of mice was carried out according to the protocol of section 2-1-5 "heart transplantation of mouse allogenic sites" in chapter 1 of the laboratory Manual of organ transplantation (Xiugui Co., Ltd.). The following shows an outline.

After anesthetizing the donor mice, the chest was opened, 1mL of cold physiological saline to which heparin was added was sufficiently perfused, and then the hearts were removed and stored in cold physiological saline to which heparin was added. After anesthetizing the recipient mouse, the abdomen was opened, and the heart removed from the donor mouse was transplanted into the great abdominal vein, thereby preparing a heterogeneous heart transplantation model mouse.

Example 2

[ survival efficiency of mouse allograft Heart (1) ]

The different part heart transplantation model mice were divided into the following groups of administration modes shown in (1) to (4) of table 1, and the oral administration experiment of the transplanted organ survival promoter of the present invention was performed. The test mice had free access to bait and water before and after the anesthetic treatment, except for the intake of the administered composition. The outline of the experiment is shown in FIG. 1.

[ Table 1]

The administration results of the groups (1) to (4) are shown below. Further, the relationship between the elapsed days and the heart beat rate is shown in fig. 2.

In the group (1) in which both donor mice and recipient mice were given sterile water, the transplanted heart was stopped for all the individuals by day 9, and there were no long-term beating individuals. More specifically, one transplanted heart stopped on day 6, two on day 7, two on day 8, and one on day 9 post-transplantation.

In the group (2) in which ALA (100mg/kg) + SFC (115mg/kg) was administered only to donor mice, all the individuals had transplanted cardiac arrest or the individuals died without long-term beating by day 8. On day 7, 4 and 2 transplanted hearts stopped on day 8.

In the group (3) in which ALA (100mg/kg) + SFC (115mg/kg) was administered only to recipient mice, individuals with long-term beating were found. In more detail, 2 transplanted hearts stopped on day 12. There were 1 individual whose transplanted heart continued to beat at the time point of 66 days and 1 individual whose transplanted heart continued to beat at the time point of 70 days.

In the group (4) in which ALA (100mg/kg) + SFC (115mg/kg) was administered to both donor and recipient mice, the number of individuals who continued beating for a long period was significantly large. In more detail, one transplanted heart stopped at day 8. 2 individuals who continued beating after the heart was transplanted at the time points of 66 days and 76 days, and 1 individual who continued beating after the heart was transplanted at the time points of 96 days and 106 days.

Since this experimental model was performed by a highly invasive surgery, it is expected that the death of the individual was caused to some extent by stress, regardless of whether ALA or iron compounds were administered. However, when ALA and an iron compound were orally administered to the donor before transplantation and the recipient after transplantation, the number of individuals who continued beating for a long period of time was large, and it was confirmed that the survival rate of organs was significantly improved by administering ALA and an iron compound. The mice of group (3) also had long-term beating individuals, and it was confirmed that the promoter for transplanted organ survival of the present invention was effective even when only the transplanted recipient was administered.

[ survival efficiency of mouse allograft Heart (2) ]

The different part allogeneic heart transplantation model mice were divided into the administration modes shown in the groups (a) to (e) in table 2 below, and the difference in the effect of the transplanted organ survival promoter of the present invention due to the amount of the iron compound was examined. The test mice had free access to bait and water before and after the anesthetic treatment, except for the intake of the administered composition.

[ Table 2]

The administration results of groups (a) to (e) are shown below. Further, the relationship between the elapsed days and the heart beat rate is shown in fig. 3.

In the group (a) in which both the donor mouse and the recipient mouse were given sterile water, the transplanted heart was stopped for all the individuals by day 9, and there were no long-term beating individuals. More specifically, 2 transplanted hearts stopped on day 6, 5 on day 7, and 2 on day 8 after transplantation.

In group (b) in which ALA (100mg/kg) was administered to both donor mice and recipient mice, the transplanted heart stopped for all individuals by day 8, and there were no long-term beating individuals. More specifically, 2 transplanted hearts stopped on day 7 and 3 stopped on day 8 after transplantation.

In the group (c) in which ALA (100mg/kg) + SFC (11.5mg/kg) was administered to both the donor mouse and the recipient mouse, there were long-term beating individuals. More specifically, although 1 transplanted heart stopped at 8 days after transplantation and 1 transplanted heart stopped at 12 days, 1 individual whose transplanted heart continued to beat at the time point of 25 days elapsed and 2 individuals whose transplanted heart continued to beat at the time point of 29 days elapsed.

In the group (d) to which ALA (100mg/kg) + SFC (115mg/kg) was administered to both donor and recipient mice, the number of individuals who lasted long-term pulsation was significantly large, and the number of individuals who survived long-term pulsation was large. In more detail, 2 individuals who continued beating after the heart transplantation at the time points of 63 days and 73 days passed each other. 1 individual whose heart continued beating at the time point of the lapse of 93 days and 103 days.

In group (e) in which ALA (100mg/kg) + SFC (115mg/kg) was administered to the recipient alone, there were long-term beating individuals. In more detail, although 1 transplanted heart stopped beating on day 15, 2 individuals continued to beat at the time point when 29 days passed.

Comparing group (b) with group (c) and group (d), it was confirmed that: when ALA is administered to a donor before transplantation and a recipient after transplantation, the immunosuppressive effect is significantly increased and the survival rate of the recipient is improved by administering ALA in combination with an iron compound as compared with the case where ALA is administered alone. In addition, it was confirmed that the group (d) to which 115mg/kg of sodium ferrous citrate was administered was preferable as the amount of the iron compound added. In addition, the mice in group (e) also had long-term beating individuals, and it was confirmed that it was effective to administer the promoter for promoting the survival of transplanted organs of the present invention only to the transplanted recipient.

Example 3

[ mechanism of survival of transplanted organ is immunological tolerance ]

ALA (100mg/kg) + SFC (115mg/kg) was administered to both donor and recipient mice from 2 days before the heart transplantation until the transplantation day, after the heart transplantation, only the recipient mice were administered 1 time per day until the 11 th day, splenocytes from one transplantation recipient mouse (CBA) that survived for a long period (>100 days) were isolated, and the splenocytes were intraperitoneally injected into another recipient system mouse (CBA), while the heart of the donor mouse (B10) that was the same system as that at the time of the one transplantation was transplanted into the recipient system mouse (CBA). The results are shown in FIG. 4. As a result, the survival rate of the heart secondary transplantation (induction of secondary immune tolerance) was promoted by the spleen cell transplantation that underwent the heart transplantation with ALA + SFC administration. That is, the survival rate of the heart of the mouse (B10) transplanted with both the heart of the donor mouse and the spleen cells derived from the recipient system mouse (CBA) transplanted once (tolerance; n ═ 5) was increased compared to the survival rate of the heart of the mouse (B10) transplanted with both the heart of the donor mouse and the spleen cells derived from the recipient system mouse (CBA) transplanted once (naive state; n ═ 5). The results show that the mechanism of survival of transplanted organs is immune tolerance.

[ immune tolerance of transplanted organ-surviving mice at the individual level ]

ALA (100mg/kg) + SFC (115mg/kg) was administered to both donor and recipient mice from 2 days before the heart transplantation was performed to the transplantation day, only recipient mice were administered 1 time per day 1 to 11 days after the heart transplantation, splenocytes from one transplantation recipient mouse (CBA) that survived for a long period (>100 days) were isolated, and the splenocytes were intraperitoneally injected into another recipient system mouse (CBA), while the skin of a donor mouse (B10) of the same system as the one transplantation was transplanted into the above recipient system mouse (CBA). The results 30 days after skin grafting are shown in fig. 5. As a result, it was observed that the skin graft survived through spleen cell transplantation which had undergone heart transplantation with ALA + SFC administration. The results show that transplanted organ-surviving mice develop immune tolerance at the individual level.

[ regulatory T cell number in spleen ]

The number of regulatory T cells in the spleen of receptor system mice (CBA) was determined by flow cytometry. The following groups were provided for testing, respectively: 1) group (2) group (n ═ 6) of recipient system mice administered with only sterile water, group (3) group (n ═ 6) of recipient system mice administered with ALA (100mg/kg) + SFC (115mg/kg), group (3) group (n ═ 6) of recipient system mice intraperitoneally injected with spleen cells derived from one heart transplant recipient mouse (CBA) administered with sterile water to both donor mice and recipient mice, group (4) group (n ═ 6) of recipient system mice intraperitoneally injected with spleen cells derived from one heart transplant recipient mouse (CBA) administered with ALA (100mg/kg) + SFC (115mg/kg) to both donor mice and recipient mice from 2 days before the heart transplant day to the transplant day, and group (n ═ 6) of recipient system mice administered with only one heart transplant recipient mouse (CBA) administered with 1 time after the heart transplant to the 11 th day. The results are shown in FIG. 6. As a result, it was found that the number of regulatory T cells in the receptor system mice of group 4) was significantly larger than that of group 3), and the proportion of regulatory T cells in the spleen was increased. The results show that administration of ALA + SFC induces immune tolerance.

Example 4

[ Effect of storing and transplanting ALA-containing storing liquid on Heart ]

The effectiveness of ALA-containing preservatives on organs removed from donors was investigated with respect to preservation of freshness of organs. The preservation of freshness of organs was examined by the time (seconds) required for the heart, which stopped beating during preservation, to restart beating after transplantation, i.e., the Re-beating time (Re-beating time). B10 mice (male, 7 to 10 weeks old, 20 to 25g in body weight) were used as donor mice for providing heart for preservation and transplantation.

As the preservation solutions, ALA was added to a base solution containing potassium chloride, sodium bicarbonate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate and glucose to a final concentration of 100 μ M, and iron sulfate was added to a final concentration of 5 μ M to obtain a preservation solution G6(+), and iron sulfate was added to the above base solution to a final concentration of 5 μ M to obtain a preservation solution G6(-), which were used for the test. As the ALA, ALA hydrochloride was used. The osmotic pressure of the test preservative fluid is 326-3630 sm/kg. Further, as a control, a commercially available organ preservation solution ("Viasan" manufactured by Astelas pharmaceutical Co., Ltd.; preservation solution UW) was used. The temperature of these storage solutions was set to ice-cold temperature, and the storage period was set to 24 hours.

The preservation solution G6(+), the preservation solution G6(-) and the preservation solution UW were used for the test, and the re-beating time was measured. The measurement of the time to re-pulsation was carried out according to the description of "mouse ectopic Heart transplantation" in chapter 2-1-5 of the laboratory Manual of organ transplantation (Xiugui Co., Ltd.) and the description of European Heart Journal (2011)32, 509-. The following shows an outline.

After anesthetizing the donor mouse, the chest was opened, 1mL of the preservation solution for test was sufficiently perfused, and then the heart was removed and stored in the preservation solution for test. After anesthetizing the recipient mouse, the abdomen was opened, and the heart removed from the donor mouse and stored was transplanted into the great abdominal vein to prepare a heterogeneous heart transplantation model mouse. At this time, the time required from the start of reperfusion of blood to the heart to the start of heart re-beating was measured and used as the re-beating time.

[ shortening of Rethrobbing time by ALA-containing preservation solution ]

After the heart of the mouse for transplantation was stored in the storage solution G6(+), the storage solution G6(-) and the storage solution UW for 24 hours, the allogenic heart was transplanted, and the time of re-beating (sec) was measured. The results are shown in FIG. 7. As a result, the average value of the re-pulsation time (seconds) of the storage solution G6(+) containing ALA (100. mu.M) + iron sulfate (5. mu.M) solution was 108 seconds, the average value of the re-pulsation time (seconds) of the storage solution G6(-) containing iron sulfate (5. mu.M) solution was 145 seconds, and the average value of the re-pulsation time (seconds) of the control storage solution UW was 229 seconds. It was confirmed that the use of the preserving solution G6(+) significantly shortened the re-beating time (t test; p ═ 0.0244) compared to the use of the preserving solution UW.

Industrial applicability

The promoter for promoting the survival of a transplanted organ of the present invention can be advantageously used in the fields of medicine and medical care.

Claims (12)

1. An isolated immune cell derived from a recipient to which a transplant organ survival promoter containing a compound represented by the following formula (I) or a salt thereof and which does not require irradiation with light is administered before and/or after organ transplantation,

in the formula, R¹Represents a hydrogen atom or an acyl group, R²Represents a hydrogen atom, straight chain or branchedAlkyl, cycloalkyl, aryl or aralkyl radicals of the chain.

2. The isolated immune cell of claim 1, wherein R is¹And R²Is a hydrogen atom.

3. The isolated immune cell of claim 1 or 2, wherein the promoter of transplant organ survival further comprises an iron compound.

4. The isolated immune cell of claim 3, the iron compound is one or more compounds selected from the group consisting of iron chloride, iron sesquioxide, iron sulfate, ferrous pyrophosphate, ferrous citrate, iron sodium citrate, iron ammonium citrate, iron pyrophosphate, iron lactate, ferrous gluconate, iron sodium diethylenetriamine pentaacetate, iron ammonium diethylenetriamine pentaacetate, iron sodium ethylenediamine tetraacetate, iron ammonium ethylenediamine tetraacetate, iron sodium dicarboxymethylglutamate, iron ammonium dicarboxymethylglutamate, iron ferrous fumarate, iron acetate, iron oxalate, iron succinate, iron sodium citrate succinate, iron heme, iron dextran, iron triethylenetetramine, iron lactoferrin, iron transferrin, iron chlorophyll, iron proteinate, iron oxysulfide, and iron glycinate sulfate.

5. The isolated immune cell of claim 3, wherein the iron compound is sodium ferrous citrate.

6. An isolated immune cell derived from a recipient to which a transplant organ survival promoter containing a compound represented by the following formula (I) or a salt thereof and not requiring light irradiation is administered to a donor before organ transplantation and a recipient before organ transplantation and/or after organ transplantation,

in the formula, R¹Represents a hydrogen atom or an acyl group, R²Represents a hydrogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.

7. The isolated immune cell of claim 6, wherein R is¹And R²Is a hydrogen atom.

8. The isolated immune cell of claim 6 or 7, wherein the promoter of transplant organ survival further comprises an iron compound.

9. The isolated immune cell of claim 8, the iron compound is one or more compounds selected from the group consisting of iron chloride, iron sesquioxide, iron sulfate, ferrous pyrophosphate, ferrous citrate, iron sodium citrate, iron ammonium citrate, iron pyrophosphate, iron lactate, ferrous gluconate, iron sodium diethylenetriamine pentaacetate, iron ammonium diethylenetriamine pentaacetate, iron sodium ethylenediamine tetraacetate, iron ammonium ethylenediamine tetraacetate, iron sodium dicarboxymethylglutamate, iron ammonium dicarboxymethylglutamate, iron ferrous fumarate, iron acetate, iron oxalate, iron succinate, iron sodium citrate succinate, iron heme, iron dextran, iron triethylenetetramine, iron lactoferrin, iron transferrin, iron chlorophyll, iron proteinate, iron oxysulfide, and iron glycinate sulfate.

10. The isolated immune cell of claim 8, wherein the iron compound is sodium ferrous citrate.

11. The isolated immune cell of any one of claims 1 to 10, which is a regulatory T cell.

12. Use of the immune cell according to any one of claims 1 to 11 for producing a promoter for inducing secondary immune tolerance.