CN116679062A - Application of GPD2 protein in preparation of products for treating or diagnosing diseases caused by macrophage-mediated pneumococcal infection - Google Patents

Abstract

The application belongs to the field of biology, and particularly relates to application of GPD2 protein in preparation of a product for treating or diagnosing diseases caused by pneumococcal infection mediated by macrophages, wherein GPD2 expression in the pneumococcal infection macrophages is increased, and by knocking down the expression level of the GPD2 protein in cells, secretion of inflammatory factors can be effectively reduced, occurrence and development of inflammatory reactions are reduced, so that a new target for treating the diseases caused by pneumococcal infection is facilitated to be found.

Description

GPD2 protein is used in the preparation for treatment or diagnosis of macrophage-mediated pneumococcal infection application of the product resulting in a disease

technical field

The invention belongs to the field of biotechnology, and specifically relates to the application of GPD2 protein in the preparation of products for treating or diagnosing diseases caused by macrophage-mediated pneumococcal infection.

Background technique

Pneumococcus (Streptococcus pneumoniae, S.pn), also known as Streptococcus pneumoniae, belongs to the genus Streptococcus in the bacterial kingdom Firmicutes, Bacillus, Lactobacillus, Streptococcus. Pneumococcus is a Gram-positive coccus with a diameter of about 1 μm, usually in double arrangement, and some virulent strains form capsules in vivo. The capsule is not stained by ordinary staining, and it appears as a transparent ring around the bacteria, without flagella, and does not form spores. When the bacteria are senescent, or after the bacteria are lysed due to the production of autolysin, Gram staining can be negative. Pneumococcus is highly pathogenic, and among pyogenic cocci, its pathogenicity is second only to Staphylococcus aureus. Pneumolysin and Jiamo are the main pathogenic substances of Streptococcus pneumoniae. Among them, Jiamo is the main pathogenic factor, which helps the bacteria resist host phagocytosis, promotes its massive replication in the host and invades host cells.

Pneumococcus can cause pneumonia, meningitis, pleurisy, bacteremia, otitis media, mastoiditis, endocarditis, sepsis and other diseases. As a highly invasive pathogen, under special circumstances, pneumococcus can cause severe invasive diseases in humans, especially in immunocompromised populations.

Contents of the invention

In view of this, the present invention provides the application of GPD2 protein in the preparation of products for treating or diagnosing diseases caused by pneumococcal infection mediated by macrophages.

To achieve the above object, the technical solution of the present invention is:

In the first aspect, the present application provides GPD2 protein (GPD2 protein is an intermediate metabolic enzyme located outside the inner membrane of mitochondria) as a target in the preparation of products for the treatment or diagnosis of diseases caused by macrophage-mediated pneumococcal infection application.

Further, the product is medicine, kit, health product or cosmetic.

Further, the drug refers to a drug that reduces the expression level of GPD2 protein.

Further, the kit refers to a kit for detecting the expression level of GPD2 protein.

Further, the diseases include pneumonia, meningitis, pleurisy, bacteremia, otitis media, mastoiditis, endocarditis, and sepsis.

In the second aspect, the present application provides the application of GPD2 gene in the preparation of products for treating or diagnosing diseases caused by pneumococcal infection mediated by macrophages.

In a third aspect, the present application provides the use of an inhibitor of GPD2 protein in the preparation of products for treating or preventing diseases caused by macrophage-mediated pneumococcal infection.

In the fourth aspect, the present application provides the application of GPD2 gene inhibitors in the preparation of products for treating or preventing diseases caused by macrophage-mediated pneumococcal infection.

The present invention has the following beneficial effects:

The present invention finds for the first time that the expression of GPD2 protein in pneumococcal-infected macrophages increases, and by knocking down the expression level of GPD2 protein in cells, it can effectively reduce the secretion of inflammatory factors and reduce the occurrence and development of inflammatory reactions. The results show that, GPD2 protein can regulate the inflammatory response caused by pneumococcal infection, which is helpful to find new targets for the treatment of diseases caused by pneumococcal infection.

Description of drawings

Figure 1 shows the expression of GPD2 protein in different cells after pneumococcal infection, in which, the left picture of Figure 1A shows the expression level of GPD2 protein detected by western blot method in RAW264.7 cells, and the right picture of Figure 1A shows the western blot bar of the left picture The results of quantitative analysis of the bands, Fold Change is the fold increase; Figure 1B is the GPD2 mRNA level detected by qRT-PCR in RAW264.7 cells; the left picture of Figure 1C is the expression of GPD2 protein in BMDM cells, and the right picture of Figure 1C is Quantitative analysis results of western blot bands in the left figure; Figure 1D shows the level of GPD2 mRNA in BMDM cells, where NC is a negative control and normalized by Gapdh and β-actin;

Figure 2 shows the results of HE staining, body weight changes and the expression of GPD2 in the lung tissue of mice after pneumococcal infection. Figure 2A shows the body weight changes of mice after pneumococcal infection, and Relative body weight is the relative body weight; HE staining results of post-infection mice. Figure 2C shows the level of GPD2 mRNA detected by qRT-PCR in the homogenate of mouse lung tissue after pneumococcal infection; the left figure of Figure 2D shows the expression level of GPD2 protein detected by western blot; The right figure shows the quantitative analysis results of western blot bands, NC is the negative control, and Gapdh and β-actin are used for normalization;

Figure 3 shows the expression of GPD2 protein after siRNA interferes with cells and the secretion of inflammatory factors after siRNA targets GPD2 in cells. The left figure of Figure 3A shows the expression level of GPD2 protein after siRNA interferes with RAW264.7 cells; the right figure of Figure 3A is the left Figure 3B shows the quantitative analysis results of western blot bands; the left picture of Figure 3B shows the expression level of GPD2 protein after siRNA interferes with BMDM cells; the right picture of Figure 3B shows the quantitative analysis results of western blot bands in the left picture; Figure 3C left picture shows siRNA interference with RAW264 The level of GPD2 mRNA after .7 cells, the right figure of Figure 3C is the level of GPD2 mRNA after siRNA interferes with BMDM cells; the left figure of Figure 3E is the relative expression of inflammatory factor IL-1β after GPD2 in cells after siRNA targets RAW264.7 cells, Figure 3C The middle picture of 3E shows the relative expression level of inflammatory factor IL-6 after GPD2 in cells after siRNA targeting RAW264.7 cells, and the right picture of Figure 3E shows the relative expression level of inflammatory factor TNF-α after GPD2 in cells after siRNA targeting RAW264.7 cells Expression level; Figure 3F is the expression level of inflammatory factor IL-6 after GPD2 in cells after siRNA targeting RAW264.7 cells; Figure 3H left panel is the relative expression of inflammatory factor IL-1β after GPD2 in cells after siRNA targeting BMDM cells The middle picture in Figure 3H shows the relative expression of the inflammatory factor IL-6 after GPD2 in the cells after siRNA targeting BMDM cells, and the right picture in Figure 3H shows the relative expression of the inflammatory factor TNF-α in the cells after GPD2 in the cells after siRNA targeting BMDM cells The left figure of Figure 3I is the expression level of the inflammatory factor IL-1β after GPD2 in the cells after siRNA targeting BMDM cells, and the right figure of Figure 3I is the expression level of the inflammatory factor TNF-α after GPD2 in the cells after siRNA targeting BMDM cells, Relative mRNA expression of IL-6 is the IL-6 mRNA level detected by qRT-PCR; Relative mRNA expression of IL-1β is the IL-1β mRNA level detected by qRT-PCR; Relative mRNA expression of TNF-α is the TNF-α mRNA detected by qRT-PCR Levels, where NC is negative control and PC is positive control, normalized by Gapdh and β-actin.

Detailed ways

The present invention is further described through specific examples below, but it should be pointed out that the specific material proportions, process conditions and results described in the embodiments of the present invention are only used to illustrate the present invention, and cannot be limited thereto In the protection scope of the present invention, all equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

This application provides the application of GPD2 protein in the preparation of products for the treatment or diagnosis of diseases caused by macrophage-mediated pneumococcal infection. The products are medicines, kits, health products or cosmetics. The medicine refers to reducing the expression level of GPD2 protein The drug, the kit refers to the kit for detecting the expression level of GPD2 protein, and the diseases include pneumonia, meningitis, pleurisy, bacteremia, otitis media, mastoiditis, endocarditis, and sepsis.

The present application also provides the application of the GPD2 gene in the preparation of products for treating or diagnosing diseases caused by pneumococcal infection mediated by macrophages.

The present application also provides the application of the GPD2 protein inhibitor in the preparation of products for treating or preventing diseases caused by pneumococcal infection mediated by macrophages.

The present application also provides the application of the GPD2 gene inhibitor in the preparation of products for treating or preventing diseases caused by pneumococcal infection mediated by macrophages.

The solutions of the present invention are illustrated below through specific examples. It should also be understood that the following examples are only used to specifically illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention all belong to this invention. protection scope of the invention. The specific process parameters and the like in the following examples are only an example of the appropriate range, that is, those skilled in the art can make a selection within the appropriate range through the description herein, and are not limited to the specific values exemplified below.

(1) Expression level test of GPD2 protein after pneumococcus infection of different macrophages

1. Experimental method

1.1 Culture of RWA264.7 cells

RAW264.7 cells are mouse mononuclear macrophage leukemia cell lines, which were purchased from the Shanghai Cell Bank of the Chinese Academy of Sciences. They were cultured in DMEM containing 10% South American fetal bovine serum and 1% penicillin-streptomycin solution in high glucose at 37°C. Culture in a 5% CO ₂ incubator, change the medium every day, and observe the state of the cells.

1.2 Extraction and culture of BMDM cells

BMDM cells are bone marrow derived macrophages (bone marrow derived macrophage BMDM). Select 8-week-old C57BL/6 mice, kill them by neck dislocation, and immerse them in 75% (volume concentration) alcohol for disinfection; For the femur of the hind leg, remove the excess meat on the femur and cut off both ends of the bone, flush the bone marrow into a 50ml centrifuge tube with PBS (containing 2% FBS, 1% PS), filter the residue with a 75-mesh filter, and collect by centrifugation The cells in the filtrate were resuspended with DMEM high-glucose medium (containing 10% FBS, 1% penicillin-streptomycin antibody, M-CSF factor (20ug/ml) after removing red blood cells with red blood cell lysate, and then spread into 10cm culture dishes 4 hours after plating, the adherent cells were removed, and the cell suspension was continuously spread into a 10cm culture dish, and placed in a 37°C incubator for seven days. The medium was changed on the third and fifth day, and trypsin was used on the seventh day. The cells were digested and spread into a 6-well plate (3×10 ⁶ /well) for later use.

1.3qRT-PCR detection of the expression level of GPD2 protein in cells

(1) RNA extraction: Collect the cultured RWA264.7 cells and BMDM cells respectively, remove the supernatant, wash with PBS buffer 3 times, add 500 μL RNA extraction reagent RNAiso plus, mix well, and let stand at 4°C for 8 minutes. Collect the cells in EP tubes, shake and mix well, and let stand on ice for 10 minutes; then, add RNAiso plus 1/5 volume of chloroform, mix up and down, stand on ice for 5 minutes, and then centrifuge at 13000rpm×20min at 4°C ;Pipe the supernatant solution into a pre-cooled new enzyme-free EP tube, add the same volume of isopropanol as the supernatant, mix up and down, let stand on ice for 10min, and centrifuge at 13000rpm×40min at 4°C; discard the supernatant , add 1ml of freshly prepared 75% ethanol solution (volume concentration), wash the precipitate, centrifuge at 13000g×10min at 4°C, repeat the washing twice; discard the supernatant, and after the ethanol is completely volatilized, add 30 μL RNase free ddH according to the amount of precipitation ₂ O; finally, the RNA concentration and purity were measured on the machine.

(2) Reverse transcription: Calculate the required volume according to the RNA concentration of 1000ng, and perform reverse transcription. The sample loading system is shown in Table 1 (20 μL reaction system):

Table 1 Reverse transcription system

Reagent Dosage 5×Primer Script Buffer 4μL Oligod T primer 1μL Primer Script RT Enyme MiX 1μL Random 6mers 1μL Total RNA 1000ng/RNA concentration RNase Free ddH ₂ O up to 20 μL

Note: 5×Primer Script Buffer, OligodT primer, Primer Script RT EnymeMiX and Random 6mers were purchased from TAKARA Company.

The reaction conditions were as follows: react at 37°C for 15 minutes, then react at 85°C for 5 seconds, and then store at 4°C for future use.

(3) qRT-PCR: The qRT-PCR method was used to amplify the reverse transcription product. The sequences of the primers used were shown in Table 2, and the reaction system was shown in Table 3.

Table 2 Primer Sequence

Table 3 Reagents of Reaction System Dosage cDNA 1μL TB GreenTM Premix Ex TaqTMⅡ(Tli RNase H Plus) 5μL upstream amplification primer 0.4μL downstream amplification primers 0.4μL ddH ₂ O 3.2μL

Note: TB GreenTM Premix Ex TaqTMⅡ (Tli RNase H Plus) was purchased from TAKARA Company, and the primers were synthesized by Sangon Bioengineering (Shanghai) Co., Ltd.

Reaction conditions: pre-denaturation at 95°C for 7min; then denaturation at 94°C for 10s, then annealing at 58°C for 20s, then fully extending at 72°C for 20s, collecting fluorescence, a total of 40 cycles, melting curve Conditions: (65-95°C) Fluorescence is collected every 0.5°C rise.

1.4 Western blotting to detect the expression level of GPD2 protein in cells

(1) Protein extraction: collect the cells, remove the supernatant, wash 3 times with PBS buffer, add 1mL PBS buffer to scrape off the cells, centrifuge at 13000rpm×10min at 4°C, remove the supernatant, retain the cell pellet, add Proper amount of RIPA protein lysate containing protease inhibitors (RIPA:PMSF=100:1), resuspend and mix well; lyse cells on ice for 30 minutes, vortex every 5 minutes, repeat 6 times, 13000rpm×30min at 4°C Centrifuge; draw the supernatant solution into a new EP tube, detect the protein concentration by BCA method, add the remaining protein sample to the loading buffer (5×loading buffer), boil and denature it, and store it at -40°C.

(2) SDS PAGE gel electrophoresis: Prepare 10% separating gel according to the instructions of the PAGE gel rapid preparation kit (10%) and pour the gel slowly and uniformly, slowly add an appropriate amount of absolute ethanol to the surface of the gel, and let it stand at room temperature for 15 minutes; Discard the absolute ethanol, pour the prepared 5% stacking gel into the upper layer of the completely solidified separation gel, insert the toothed comb, and let it stand at room temperature for 10 minutes; carefully pull out the toothed comb, add 1×SDS electrophoresis buffer to cover the gel Sample well; add 30 μg boiled and denatured protein sample to the sample well, and add protein marker as a molecular weight reference; after filling the glass plate with electrophoresis buffer, separate the protein by electrophoresis in two steps: the first step, voltage 80V , current 100mA, 40min; second step, electrophoresis 120V, current 100mA, 90min.

(3) Membrane transfer: After the electrophoresis is over, firstly, according to the molecular weight of the protein to be tested, cut an appropriate gel and cut a matching polyvinylidene fluoride (PVDF) membrane, soak the cut gel in a pre- In the cold wet transfer buffer, soak the cut PVDF membrane in methanol for 30s, wash in ddH ₂ O for 2min, then soak the PVDF membrane and filter paper in the pre-cooled wet transfer buffer, and finally transfer the positive electrode to the Place the sponge, filter paper, PVDF membrane and gel in sequence in the direction of the negative electrode, and transfer the membrane by electrophoresis at a constant current of 250V and 210mA for 70min.

(4) Sealing: After the membrane transfer, put the PVDF membrane into 5% skimmed milk powder, and seal at room temperature for 2 hours on a shaker.

(5) Antibody incubation: first wash the remaining blocking solution on the membrane with TBST, blot the remaining liquid on the membrane with qualitative filter paper, place the membrane on a wax plate, and add the pre-diluted primary antibody working solution (GPD2 stock solution: a Anti-dilution solution = 1:6000, β-actin stock solution: primary antibody dilution solution = 1:1000) evenly cover the PVDF membrane, incubate overnight at 4°C; wash 3 times in TBST, 10min each time; finally, add the pre-diluted spicy The root peroxidase-labeled secondary antibody (antibody stock solution: secondary antibody diluent = 1:8000) was placed on the PVDF membrane, incubated at room temperature for 1 h, washed 3 times with TBST, 10 min each time.

(6) Color development and imaging: In the dark room, put the PVDF film on the wax plate, and then add the pre-configured chemiluminescent reagent ECL luminescence solution (A liquid: B liquid = 1:1) to evenly cover the PVDF film, and place it on the imaging system The image is displayed in .

2. Experimental results

In order to detect the expression level of GPD2 protein after pneumococcal infection of different macrophages, the same amount of RAW264.7 cells and BMDM cells were taken to stimulate RAW264.7 cells and BMDM cells with S.pn D39 and D39Δply (MOI=50) respectively. Cells, the specific steps are: spread RAW264.7 cells and BMDM cells into six-well plates (to collect cells to extract RNA) and 3mm culture dishes (to collect cells to extract protein), and group them into: NC, S.pn D39 (MOI= 50), D39Δply (MOI=50), stimulate the cells for 3h-9h, collect the cells, extract RNA and protein, and detect the mRNA and protein expression levels of GPD2 by qRT-PCR and western blot.

Extract RNA and protein, the specific steps are the same as above;

The expression level of GPD2 was detected by qRT-PCR and Western blotting, and the specific steps were the same as above;

As shown in Figure 1A-D, the expression of GPD2 was increased in the S.pn D39 stimulation group, which indicated that the expression of GPD2 protein was changed after S.pn D39 stimulation.

(2) Constructing a pneumonia model to detect the expression level of GPD2 protein in vivo after pneumococcus infection in C57 mice

1. Experimental method

1.1 Construction of mouse pneumonia model

(1) Mouse nasal infection: Pick 5 typical colonies from the Columbia blood agar plate and inoculate them into C+Y medium, incubate at 37°C, 5% CO ₂ for 3 hours, collect the bacteria by centrifugation, resuspend in PBS buffer, and multiply After diluting and detecting its OD value to 0.5, after calculating the required volume of bacterial solution, the wild-type C57BL/6 mice were anesthetized by intraperitoneal injection of about 100 μL of 1.5% pentobarbital, and intranasally dripped with 40 μL of PBS, S. pn D39, D39Δply (1×10 ⁸ CFU), 20 μL for each of the left and right noses; pay attention to observe the breathing situation of the mice after nasal instillation, and continue to observe for 5 minutes. The recovery of consciousness and activities, and the recovery of mice with activities were considered as successful infection.

(2) The mice successfully infected were sacrificed, and the lung tissues were collected.

(3) After the lung tissue was isolated, it was washed with sterile PBS and fixed with 10% formaldehyde solution. The specific steps were as follows: ① Separation and fixation of the lung tissue: anesthetized the treated mice with 100 μL 0.5% pentobarbital, and collected blood from the heart. Afterwards, perfuse the lungs from the trachea

500 μL of 4% paraformaldehyde. The lung tissue filled with paraformaldehyde was isolated and soaked in 4% paraformaldehyde, and fixed overnight at 4°C. ② Preparation of lung tissue paraffin sections: The fixed lung tissue was made into paraffin-embedded tissue wax blocks, and the paraffin blocks were cut into about 6 μm thick continuous paraffin sections with a microtome. ③ Dewaxing: Place paraffin sections in xylene, dewax for 10 min, repeat 3 times. Put them into 100%, 95% and 70% alcohol for dehydration for 5 minutes, and repeat the operation twice for each concentration of alcohol. Rinse with tap water for 2 minutes and then stand in double distilled water for 5 minutes.

Subsequent sectioning and HE staining were performed, and the sections were grouped and marked for subsequent hematoxylin-eosin (H&E) staining. The pathological changes of the lungs were observed under a microscope.

1.2qRT-PCR and Western blotting: the method is the same as above.

2. Experimental results

In order to construct a pneumonia model and detect the expression level of GPD2 protein in C57 mice infected with pneumococcus, the C57BL/6J mice were treated with intranasal drops of PBS, D39 whole bacteria, and D39Δply-deficient bacteria (1×10 ⁸ CFU). The pathological changes of the lungs of the mice and the body weight changes within 0-5 days are shown in Figure 2A-D.

It can be seen from Figure 2A and Figure 2B that compared with the PBS group, the alveoli of the lung tissues of the mice treated with D39 whole bacteria and D39Δply-deficient bacteria were squeezed, accompanied by a large number of inflammatory cell infiltration, and the degree of the D39Δply group was lighter than that of the D39 group ; Weight loss, of which the weight loss is most obvious on the first 1-2 days.

It can be seen from Figure 2C and Figure 2D that the expression of GPD2 protein in the D39 treatment group was increased, which was consistent with the results of cell in vitro experiments, which indicated that GPD2 protein was related to pneumococcal infection.

(3) The effect of interfering with the expression of GPD2 protein on the inflammatory response of different macrophages infected by pneumococcus

experimental method

1.1 Small interfering RNA (Small interfering RNA; siRNA) carrier interferes with the expression of GPD2 in RAW264.7 and BMDM cells

Synthesis of siRNA carrier: Entrust Shanghai Gemma Pharmaceutical Technology Co., Ltd. to synthesize siRNA carrier targeting GPD2. The sequence of the siRNA vector is shown in Table 4.

Table 4 Primer Sequence

(2) Cell transfection: Inoculate the cells in a new 6-well plate to ensure a density of about 1×10 ⁶ cells per well; then discard the medium and add only medium to each well; use 250 μL of only medium Dilute 5 μL siRNA stock solution (20 μM), mix well; dilute 3 μL GP with 250 μL culture medium only, mix well; let stand for 5 minutes, mix diluted siRNA and GP, let stand at room temperature for 20 minutes; add 500 μL of the above mixture to the corresponding well , mix well, culture at 37°C, 5% CO ₂ incubator for 4-6h, discard the medium, add fresh complete medium containing FBS, culture at 37°C, 5% CO ₂ incubator for subsequent experiments .

(3) Cell RNA collection, the specific steps are: after cell transfection, stimulate the cells with S.pn D39 (MOI=50), D39Δply (MOI=50) for 6 hours, collect the cells, remove the supernatant, and wash with PBS buffer 3 times, add 500 μL RNA extraction reagent RNAiso plus, mix well, let stand at 4°C for 8 minutes, collect cells in EP tube, shake and mix well, let stand on ice for 10 minutes; then, add 1/5 volume of RNAiso plus in chloroform , upside down and mix well, after standing on ice for 5min, centrifuge at 13000rpm×20min at 4°C; pipette the supernatant solution into a new pre-cooled enzyme-free EP tube, add isopropanol equal to the volume of the supernatant, and mix up and down Mix well, let stand on ice for 10min, centrifuge at 13000rpm×40min at 4°C; discard the supernatant, add 1ml of freshly prepared 75% ethanol solution (volume concentration), wash the precipitate, and centrifuge at 13000g×10min at 4°C, repeat Wash twice; discard the supernatant, and after the ethanol evaporates completely, add 10 μL-30 μL RNasefree ddH ₂ O to dissolve according to the amount of precipitation; finally, measure the concentration and purity of RNA on the machine.

1.2 qPT-PCR: The method is the same as above, and the primers used are shown in Table 5.

Table 5 Primer Sequence

1.3 Enzyme linked immunosorbent assay (ELISA) to detect the expression levels of inflammatory factors in macrophages

(1) Collect the supernatant: After RAW264.7 cells and BMDM cells are treated, collect the cell supernatant and store it in a -40°C refrigerator. The supernatant should be tested within two weeks. ;

(2) ELISA detection: ELISA method was used to detect the levels of inflammatory factors in the cells respectively. The specific test steps were carried out according to the corresponding ELISA kit instructions (Biolegend). A standard curve was made and the corresponding concentration values of each well were calculated. The results are shown in Figure 3 Show.

2. Experimental results

It can be seen from Figures 3A-3D that after siRNA interference, the expression levels of GPD2 protein in RAW264.7 cells and BMDM cells were reduced. As shown in Figures 3E, 3F, 3H and 3I, after siRNA targeted GPD2 in RAW264.7 cells and BMDM cells, the secretion of inflammatory factors in the D39 treatment group decreased. The results indicated that by reducing the expression level of GPD2 protein in BMDM cells, the inflammatory response caused by pneumococcal infected cells was reduced, that is, GPD2 protein can regulate the inflammatory response of macrophages caused by pneumococcal infection.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (8)

1. Application of GPD2 protein in the preparation of products for treating or diagnosing diseases caused by macrophage-mediated pneumococcal infection. 2. The application according to claim 1, wherein the product is a medicine, a test kit, a health product or a cosmetic. 3. The application according to claim 2, wherein the drug refers to a drug that reduces the expression level of GPD2 protein. 4. The application according to claim 2, wherein the kit refers to a kit for detecting the expression level of GPD2 protein. 5. The application according to claim 1, characterized in that the diseases include pneumonia, meningitis, pleurisy, bacteremia, otitis media, mastoiditis, endocarditis, and sepsis. 6. Application of GPD2 gene in the preparation of products for treating or diagnosing diseases caused by macrophage-mediated pneumococcal infection. 7. Application of an inhibitor of GPD2 protein in the preparation of products for treating or preventing diseases caused by macrophage-mediated pneumococcal infection. 8. Application of an inhibitor of GPD2 gene in the preparation of products for treating or preventing diseases caused by macrophage-mediated pneumococcal infection.