Application of KAT8 and related substances thereof in resisting mycobacterial infection

Abstract

The invention relates to the field of biological medicine, and provides application of KAT8 and related substances thereof in resisting mycobacterial infection. In particular to application of a KAT8 protein, a nucleic acid molecule for coding the protein and a KAT8 accelerant in preparation of products for preventing and / or treating mycobacterium tuberculosis and related non-mycobacterium tuberculosis (NTM) infection diseases. The KAT8 can inhibit intracellular proliferation of mycobacteria and relieve inflammation and damage of tissues, provides a new target spot for treatment of mycobacterium infection, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedicine, and relates to the application of acetyltransferase KAT8 and related substances in the preparation of anti-mycobacterial infection drugs. Background Art

[0002] Tuberculosis is an infectious disease caused by infection with Mycobacterium tuberculosis (Mtb). According to the World Health Organization, there are about 10 million new cases of tuberculosis each year in the world, and the number of deaths from tuberculosis is as high as 1.5 million. The main reasons for the severe tuberculosis epidemic include: 1) a single vaccine with limited preventive effect; 2) the prevalence of drug-resistant tuberculosis and low treatment success rate; 3) complex treatment regimens and long courses of treatment. Solving the above problems requires us to have a deep understanding of the interaction mechanism between Mtb and the host immune system, and provide a theoretical basis for finding new treatment strategies.

[0003] The emergence and development of host-directed therapy (HDT) can be used as an adjuvant therapy for multidrug-resistant strains. Its mechanism is to intervene in the expression and function of host genes, enhance the host's protective immune response, improve its ability to kill Mycobacterium tuberculosis, and reduce the inflammatory response to reduce inflammation and pathological damage caused by bacterial infection, thereby synergizing with anti-tuberculosis drugs to achieve better therapeutic effects. Unlike anti-tuberculosis drugs that directly target Mycobacterium tuberculosis, HDT has the following advantages: first, it is effective against both susceptible and resistant tuberculosis bacteria; second, the risk of inducing tuberculosis resistance is low; third, it can shorten the duration of antibiotic treatment by targeting multiple components and signaling pathways of the host immune system.

[0004] Infectious droplets containing tuberculosis enter the lungs through the oral cavity, nasal cavity, upper respiratory tract and bronchi, and eventually reach the alveoli, where they are engulfed by pulmonary macrophages and trigger inflammatory cell infiltration to form granuloma structures. Macrophages play an important role in the process of tuberculosis infection. They are not only the main host cells of tuberculosis in the host, but also the main effector cells that kill tuberculosis. The "game" between tuberculosis and macrophages determines the direction of the occurrence and development of tuberculosis.

[0005] After tuberculosis is engulfed by macrophages into phagosomes, the macrophage phagosomes fuse with lysosomes to form acidified phagosome-lysosomes. Lysosomes contain a large number of hydrolases that can quickly change the lumen environment of the phagosomes to limit the growth of pathogens. However, tuberculosis also acts on host signal transduction by secreting virulence proteins such as phosphatases SapM, PtpA, PtpB and Coronin-1a, inhibiting the acidification of macrophage phagosomes and helping the bacteria to survive temporarily in the phagosomes. Tuberculosis can also rupture cell phagosomes to enter the cytoplasm to absorb cytoplasmic nutrients and further proliferate in the cells. When the phagosome is damaged, the bacteria are transferred from the phagosome to the cytoplasm. At this time, macrophages recognize and target the phagosome fragments and bacteria exposed to the cytoplasm through selective autophagy. Autophagy includes five steps: initiation, nucleation, extension, fusion and degradation. In this process, tuberculosis inhibits the selective autophagy of macrophages on the ruptured phagosome membrane by secreting effector proteins, helping the bacteria escape the host's killing.

[0006] Atg5 is one of the core autophagy genes, and mice lacking Atg5 in bone marrow cells die faster during tuberculosis infection. Studies have found that chromatin H3K18 and H4K16 acetylation associated with the ATG5 promoter are increased during tuberculosis infection, which is consistent with the observations of Fullgrabe et al. that H4K16 deacetylation is associated with the downregulation of autophagy-related genes, and the expression of histone acetyltransferase KAT8 can induce autophagy by increasing the level of H4K16ac.

[0007] Histone acetyltransferase KAT8 is a member of the MYST family of proteins, with a highly conserved lysine acetyltransferase domain. It is the main enzyme that catalyzes H4K16 acetylation in mammalian cells. Studies on mammalian cells have shown that the loss of KAT8 and the resulting loss of H4K16 acetylation can lead to a variety of phenotypes, including defective DNA damage response, reduced fatty acid oxidation and mitochondrial respiration, cell death, apoptosis, and autophagy. We speculate that KAT8 is involved in regulating the acetylation level of Atg5, thereby regulating macrophage autophagy, and this regulation plays a role in resisting infection during mycobacterial infection.

[0008] In summary, there is an urgent need in the art to develop an active substance that can effectively block mycobacterial invasion, effectively resist mycobacterial infection and control tissue inflammatory damage caused by mycobacterial infection, so as to control mycobacterial infectious diseases and their related symptoms and / or other complications. Summary of the invention

[0009] The present invention is based on the above research and studies the application of acetyltransferase KAT8 and related substances in the preparation of anti-mycobacterial infection drugs.

[0010] The present invention first re-analyzed the public data of peripheral blood PBMC transcriptome of tuberculosis patients and found that the transcription level of KAT8 in the immune cells of active tuberculosis patients was significantly reduced. This result was also verified in the macrophage cell line, suggesting that KAT8 plays a role in the interaction between tuberculosis and the host. The proliferation of tuberculosis in peritoneal macrophages and bone marrow-derived macrophages of KAT8 knockout mice was further detected, and it was found that the proliferation of tuberculosis in macrophages increased significantly after KAT8 knockout, thus confirming that KAT8 plays an important role in resisting mycobacterial invasion and infection.

[0011] Based on the above research, the technical solution to be protected by the present invention is as follows:

[0012] One of the main purposes of the present invention is to provide the use of KAT8 in resisting mycobacterial infection, and further provide their use in treating mycobacterial infectious diseases and related diseases or symptoms. The medicine or pharmaceutical composition of the present invention can be used to effectively resist mycobacterial infection and control the occurrence of infectious diseases.

[0013] In the first aspect disclosed in the present invention, there is provided use of KAT8, nucleic acid molecules encoding the protein, and promoters thereof in preparing products for preventing and / or treating mycobacterial infectious diseases and / or diseases and / or symptoms associated with infection.

[0014] In the second aspect of the present invention, a product is provided which has KAT8, a nucleic acid molecule encoding the protein, and a promoter thereof as active ingredients.

[0015] In the third aspect disclosed in the present invention, a method for treating infectious diseases and / or diseases and / or symptoms associated with infection is provided, the method comprising administering to a subject in need thereof a therapeutically effective amount of KAT8, a nucleic acid molecule encoding the protein, a promoter thereof, or a recombinant expression vector thereof.

[0016] In a fourth aspect of the present invention, there is provided a use of KAT8 in preparing a mycobacterium detection kit or an antibacterial drug screening kit for mycobacterium detection or antimycobacterial drug screening.

[0017] Preferably, the mycobacterium is selected from one or more of the following groups: Mycobacterium tuberculosis, Mycobacterium marinum, Mycobacterium avium-intracellulare complex, Mycobacterium kansasii, Mycobacterium simianum, Mycobacterium toadense, Mycobacterium gordonii, Mycobacterium terrestris, and Mycobacterium paraterrestris.

[0018] The diseases or symptoms associated with mycobacterium infection are selected from one or more of the following groups: pathological tissue damage caused by mycobacterium infection; insufficient or excessive cytokine production after infection; inflammatory damage to organs; and multiple organ failure, for example, the organs are selected from the group consisting of lungs, kidneys, brain, stomach and intestines.

[0019] KAT8 is selected from Kat8 protein, a nucleic acid molecule encoding the protein, a promoter thereof or a recombinant expression vector thereof, and is also selected from mRNA, cDNA or precursor of Kat8.

[0020] Further preferably, the Kat8 promoter is selected from any one or more of the following: exogenous Kat8 protein or nucleic acid encoding it, a substance that promotes the expression or active function of Kat8 protein, a substance that promotes the overexpression of nucleic acid molecules encoding Kat8 protein, or a liposome or nanomaterial that encapsulates the nucleic acid encoding Kat8 protein.

[0021] In a preferred embodiment of the present invention, the Kat8 protein is selected from any of the following situations:

[0022] (a), a polypeptide having an amino acid sequence as shown in SEQ ID NO.2;

[0023] (b) a substance having homology or sequence identity with the amino acid sequence shown in SEQ ID NO.2 and having the function of promoting KAT8;

[0024] (c) A substance having a KAT8-promoting function, wherein one or more amino acids are substituted, deleted or added in the amino acid sequence of (a) or (b), or a protein or polypeptide derived from (a) or (b),

[0025] The nucleic acid molecule encoding Kat8 protein is selected from any of the following situations:

[0026] (i) a nucleic acid molecule having the nucleotide sequence shown in SEQ ID NO.1;

[0027] (ii) a molecule that hybridizes to the nucleotide sequence defined in (i) under stringent conditions;

[0028] (iii) a nucleic acid molecule homologous to or having sequence identity with the nucleotide sequence shown in SEQ ID NO.1;

[0029] (iv) A nucleic acid molecule in which one or more nucleotides are substituted, deleted or added in the nucleotide sequence of (i), (ii) or (iii).

[0030] In some embodiments, the Kat8 protein is: a naturally purified protein, a chemically synthesized product, or produced from a prokaryotic or eukaryotic host using recombinant technology. The host is selected from: bacteria, yeast, higher animals and mammalian cells, preferably human KAT8.

[0031] Furthermore, the present invention also provides a Kat8 recombinant expression vector, comprising an expression vector and a nucleic acid molecule encoding the Kat8 protein inserted into the expression vector, wherein the nucleic acid molecule encoding the Kat8 protein is as described above.

[0032] Wherein, the expression vector is a conventional vector such as a plasmid vector, a cosmid vector, a phage vector or a viral vector, and the specific type is selected from the prior art according to the actual situation. The "viral vector" includes adeno-associated virus and lentivirus. Suitable viral vectors are well known to those of ordinary skill in the art. The remaining "non-viral vectors" include liposomes or lipid complexes, cationic polymers, chitosan polymers and nanoparticle vectors. Suitable non-viral vectors are well known to those of ordinary skill in the art.

[0033] In the second and third aspects of the present invention, an anti-mycobacterial product is provided, which is a pharmaceutical composition or a kit, for example, a pharmaceutical composition or a kit in a form suitable for administration by a method selected from the following group: oral administration, injection (for example, direct naked DNA or protein injection, liposome-encapsulated DNA or protein injection), gold-coated gene gun bombardment, reproduction-defective bacteria carrying plasmid DNA, replication-defective adeno-associated virus carrying target DNA, or nasal administration, pulmonary administration, oral administration or transdermal administration of a protein encoded by a target gene.

[0034] Preferably, the pharmaceutical composition or kit of the present invention comprises:

[0035] (A) a therapeutically or preventively effective amount of KAT8, a nucleic acid molecule encoding the protein, and / or a promoter thereof;

[0036] (B) a pharmaceutically or immunologically acceptable carrier or excipient;

[0037] (C) optionally, one or more other active substances for preventing or treating mycobacterial infectious diseases and their related conditions and / or symptoms.

[0038] Generally, liquid preparations can be kept stable for at least one year at 2°C-8°C, and freeze-dried preparations can be kept stable for at least six months at 30°C. The preparations can be suspensions, water injections, freeze-dried preparations and other preparations commonly used in the pharmaceutical field.

[0039] When the composition of the present invention is administered to animals including humans, the dosage varies depending on the patient's age and weight, disease characteristics and severity, and administration route. The results of animal experiments and various circumstances can be referred to, and the total dosage cannot exceed a certain range.

[0040] A fourth aspect of the present invention provides use of a reagent for detecting the expression level of KAT8 in preparing a mycobacterium detection kit or an antimicrobial drug screening kit, and a corresponding kit product.

[0041] The experimental results showed that the expression of KAT8 was significantly downregulated in patients with mycobacterium infection, suggesting that it is an inhibitory factor of mycobacterium infection and has the effect of inhibiting the occurrence and development of mycobacteria. Based on this, it can be inferred that KAT8 can be used as a marker for mycobacterium detection or antibacterial drug screening.

[0042] The reagent for detecting the expression level of KAT8 is selected from the reagent for detecting the expression level of Kat8 protein, and may also be the reagent for detecting the expression level of Kat8 gene.

[0043] The method for drug screening using KAT8 as a marker is as follows:

[0044] (A) treating cells, tissues or animals infected with mycobacteria or simulating infection symptoms with the candidate substance;

[0045] (B) detecting the level of Kat8 protein or a nucleic acid molecule encoding the protein in the cell, tissue or animal;

[0046] (C) After treatment with the candidate substance, if the level of Kat8 protein or the nucleic acid molecule encoding the protein is higher than the expression level in the tissue or cell of the infection model, it indicates that the candidate substance has the effect of treating mycobacterial infection by promoting Kat8.

[0047] In a sixth aspect of the present invention, a mycobacterium detection kit or an antimicrobial drug screening kit is provided, which comprises a reagent for detecting the expression level of Kat8 in a biological sample, and is composed of a reverse transcription system, a primer system, and an amplification system. By detecting the nucleic acid expression level of RetSat, diagnosis or drug screening is achieved.

[0048] Among them, the primer sequences with specificity for detecting Kat8 in biological samples are shown in SEQ ID NOs. 3 and 4 below:

[0049] RetSat-F: 5'-ACGAGGCGATCACCAAAGTG-3' (SEQ ID NO. 3);

[0050] RetSat-R: 5'-AAGCGGTAGCTCTCTCGAAC-3' (SEQ ID NO. 4).

[0051] Beneficial protection and effects of the present invention:

[0052] The present invention provides the use of KAT8 in products for treating mycobacterial infectious diseases and / or diseases and / or symptoms associated with mycobacterial infection. Experiments have confirmed that KAT8 knockout promotes mycobacterial invasion and infection of cells, suggesting that KAT8 is a protective factor for mycobacterial infection and has the effect of inhibiting mycobacterial invasion and infection. KAT8 overexpression can inhibit mycobacterial infection, which is manifested as inhibiting the proliferation ability of mycobacteria in macrophages, thereby achieving the treatment of mycobacterial infectious diseases. Therefore, the present invention provides a new target for the treatment of mycobacterial infectious diseases by overexpression or functional promotion of KAT8, and has broad clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present disclosure will be further described below in conjunction with the accompanying drawings, wherein these drawings are only for illustrating the embodiments of the present disclosure rather than for limiting the scope of the present disclosure.

[0054] Figure 1 The results showed that the expression level of KAT8 in the immune cells of patients with active tuberculosis was significantly reduced: A, the mRNA level of Kat8 was significantly reduced in the peripheral blood immune cells of patients with active tuberculosis; B, the expression of KAT8 in THP-1 cells infected with Mycobacterium tuberculosis was downregulated in a time-dependent manner compared with that in uninfected cells (****, P<0.0001, ***, P<0.001; *, P<0.05, ns, no significance, UI: uninfected).

[0055] Figure 2 The results showed that the proliferation of Mycobacterium tuberculosis in macrophages of Kat8 knockout mice was significantly increased. Mycobacterium tuberculosis was infected with bone marrow-derived macrophages and peritoneal macrophages of Kat8 knockout mice and control mice at MOI = 1 and 3, and the results showed that the proliferation of Mycobacterium tuberculosis in these two macrophages of Kat8 knockout was significantly increased (****, P < 0.0001, ***, P < 0.001; **, P < 0.01, ns, no significance).

[0056] Figure 3 It shows that overexpression of Kat8 can inhibit the proliferation of tuberculosis in macrophages. Tuberculosis was infected with Kat8-overexpressing RAW 264.7 cells and control RAW 264.7 cells at MOI=1, and the results showed that the number of tuberculosis in Kat8-overexpressing cells was significantly reduced (***, P<0.001, ns, no significance). DETAILED DESCRIPTION

[0057] The following examples and experimental examples further illustrate the present invention and should not be construed as limiting the present invention. The examples do not include a detailed description of conventional methods, such as methods for constructing vectors and plasmids, methods for inserting protein-encoding genes into vectors and plasmids, or methods for introducing plasmids into host cells. Such methods are well known to those skilled in the art and are described in many publications.

[0058] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein can be applied to the present invention, and the preferred implementation methods and materials described in the specific implementation methods are for demonstration purposes only.

[0059] Example 1: The expression level of KAT8 in immune cells of patients with active tuberculosis is significantly reduced

[0060] 1. Reanalysis of transcriptome data

[0061] Using published transcriptome data, bioinformatics tools (such as DESeq2 or EdgeR) were used to normalize the data and perform differential expression analysis. The differential expression of the Kat8 gene between active tuberculosis patients and healthy controls was evaluated.

[0062] 2. Detection of Kat8 gene expression level

[0063] (1) Cell infection: THP-1 cell line was used and divided into two groups: one group was an uninfected control group and the other group was a tuberculosis-infected group. THP-1 cells were infected with an appropriate tuberculosis infection dose MOI = 1, and cell samples were collected at different time points (e.g., 0, 24, 48, 72 hours).

[0064] (2) RNA extraction and quantitative PCR: TRIzol reagent was used to extract total cell RNA, and cDNA was synthesized by reverse transcription. Real-time quantitative PCR (qPCR) technology was used to detect the expression level of the Kat8 gene using specific primers, and β-actin was used as an internal reference gene for standardization.

[0065] The results are as follows Figure 1 As shown, published transcriptome data were reanalyzed to evaluate Kat8 gene expression levels, and Kat8 mRNA levels were significantly reduced in peripheral blood immune cells of patients with active tuberculosis ( Figure 1 A); Compared with uninfected cells, the expression of KAT8 in THP-1 cells infected with Mycobacterium tuberculosis showed a decreasing trend at 24h, 48h, and 72h, showing a time-dependent downregulation ( Figure 1 B).

[0066] Example 2: The proliferation of tuberculosis bacteria in macrophages of Kat8 knockout mice is significantly increased

[0067] 1. Construction of mouse model

[0068] Kat8 knockout mice (genotype: Kat8 - / - ) and corresponding control mice (wild type, genotype: Kat8 + / + ). Ensure that the mice are housed under the same environmental conditions and acclimate for at least one week before the experiment.

[0069] 2. Isolation and culture of bone marrow-derived macrophages

[0070] Cells were extracted from the bone marrow of Kat8 knockout mice and control mice. The bone marrow cells were inoculated in a medium containing M-CSF (macrophage colony stimulating factor) and cultured for 7 days to induce macrophage differentiation.

[0071] 3. Isolation of peritoneal macrophages

[0072] Peritoneal macrophages from Kat8 knockout mice and control mice were collected by intraperitoneal injection of broth culture medium. Three days later, the peritoneal fluid was collected, centrifuged and the cells were resuspended in culture medium. After counting, they were plated in 24-well cell culture plates.

[0073] 4. Bacterial infection

[0074] Tuberculosis was used for infection, and the infection dose was set at MOI 1 and MOI 3. The isolated bone marrow-derived macrophages and peritoneal macrophages were inoculated in 24-well plates, respectively, and cultured at 32°C and 5% CO2 after infection. Cell samples were collected at different time points (48 hours and 72 hours) after infection to evaluate the proliferation of tuberculosis.

[0075] 5. Bacterial proliferation assessment

[0076] The plate count method was used to assess the proliferation of tuberculosis bacteria: at an appropriate time point after infection, cells were collected and lysed to release the bacteria. The bacterial suspension was diluted and inoculated on a suitable medium and cultured for 10 days to form colonies. The number of colonies on each plate was counted to calculate the proliferation level of tuberculosis bacteria in each sample.

[0077] 6. Data Analysis

[0078] Data analysis was performed using statistical software (e.g., GraphPad Prism) to compare the proliferation of tuberculosis bacteria in Kat8 knockout mice and control mice. The significance of the differences between groups was assessed using t-test, and P values ​​< 0.05 were considered statistically significant.

[0079] The results are as follows Figure 2As shown in the figure, the proliferation of tuberculosis in macrophages of Kat8 knockout mice increased significantly. When tuberculosis was infected with bone marrow-derived macrophages of Kat8 knockout mice and control mice at MOI=1 and 3, there was no difference in the infection amount of tuberculosis in the two groups of macrophages within 6 hours of the initial infection. As time went on, at 2 days of infection, the infection amount of tuberculosis in macrophages of Kat8 knockout mice increased dramatically, which was significantly higher than that of bone marrow-derived macrophages of control mice ( Figure 2 A and Figure 2 B); The situation in peritoneal macrophages is similar. When Mycobacterium tuberculosis infects peritoneal macrophages of Kat8 knockout mice and control mice at MOI=1 and 3, there is no difference in the amount of Mycobacterium tuberculosis infection in the macrophages of the two groups within 6 hours of infection. As time goes by, the difference between the two groups becomes more and more obvious. On the second day of infection, the amount of Mycobacterium tuberculosis infection in the macrophages of Kat8 knockout mice is significantly different from that of the control group. On the third day, the difference is even more significant ( Figure 2 C and Figure 2 D).

[0080] Example 3: Overexpression of Kat8 inhibits tuberculosis proliferation in macrophages

[0081] 1. Preparation of Kat8 overexpression lentivirus

[0082] Amplify the DNA fragment of Kat8 gene and insert it into lentiviral overexpression plasmid. Transfect lentiviral overexpression plasmid lenti-Kat8 and auxiliary packaging plasmid into 293T cells, and package control empty virus lenti-control at the same time. Collect the virus after 48 hours and store it at -80℃.

[0083] 2. Construction of Kat8-overexpressing RAW 264.7 cells

[0084] Macrophage RAW 264.7 cells were cultured and infected with lenti-Kat8 and control empty virus lentis-control, respectively.

[0085] 3. Bacterial infection

[0086] Kat8-overexpressing RAW 264.7 cells and control RAW 264.7 cells were infected with Mycobacterium tuberculosis at an infection dose of MOI 1. After infection, the cells were cultured at 32°C and 5% CO2. Cell samples were collected 48 hours after infection to evaluate the intracellular proliferation of Mycobacterium tuberculosis.

[0087] 4. Bacterial proliferation assessment

[0088] The proliferation of tuberculosis bacteria was assessed by plate count method: 48 hours after infection, cells were collected and lysed to release bacteria. The bacterial suspension was diluted and inoculated on a suitable medium and cultured for 10 days to form colonies. The number of colonies on each plate was counted to calculate the proliferation level of tuberculosis bacteria.

[0089] 5. Data Analysis

[0090] Data analysis was performed using statistical software (e.g., GraphPad Prism) to compare the proliferation of tuberculosis bacteria in Kat8-overexpressing RAW 264.7 cells and control RAW 264.7 cells. The t-test was used to evaluate the significance of the differences between the groups, and a P value < 0.05 was considered statistically significant ( Figure 3 ).

[0091] The results are as follows Figure 3 As shown in the figure, the proliferation of tuberculosis bacteria in Kat8-overexpressing RAW 264.7 cells was significantly reduced. Tuberculosis bacteria were infected with Kat8-overexpressing RAW 264.7 cells and control RAW 264.7 cells at MOI = 1. There was no difference in the number of tuberculosis bacteria in macrophages of the two groups 6 hours after infection. As time went by, the number of tuberculosis bacteria in Kat8-overexpressing cells decreased significantly after 2 days of infection, which was significantly lower than that of the control group ( Figure 3 ). The results showed that overexpression of KAT8 could inhibit the proliferation of tuberculosis bacteria in macrophages, suggesting that KAT8 plays an important role in resisting tuberculosis infection.

[0092] The nucleotide sequence encoding KAT8 protein is shown in SEQ ID NO.1:

[0093]

[0094] The amino acid sequence of KAT8 protein is shown in SEQ ID NO.2:

[0095] MAAQGAAAAVAAGTSGVAGEGEPGPGENAAAEGTAPSPGRVSPPTPARGEPEVTVEIGETYLCRRPDSTWHSAEVIQSRVNDQEGREEFYVHYVGFNRRLDEWVDKNRLALTKT VKDAVQKNSEKYLSELAEQPERKITRNQKRKHDEINHVQKTYAEMDPTTAALEKEHEAITKVKYVDKIHIGNYEIDAWYFSPFPEDYGKQPKLWLCEYCLKYMKYEKSYRFHLGQ CQWRQPPGKEIYRKSNISVYEVDGKDHKIYCQNLCLLAKLFLDHKTLYFDVEPFVFYILTEVDRQGAHIVGYFSKEKESPDGNNVACILTLPPYQRRGYGKFLIAFSYELSKLE STVGSPEKPLSDLGKLSYRSYWSWVLLEILRDFRGTLSIKDLSQMTSITQNDIISTLQSLNMVKYWKGQHVICVTPKLVEEHLKSAQYKKPPITVDSVCLKWAPPKHKQVKLSKK

[0096] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all within the scope defined by the claims of this application.

Claims

1. Use of KAT8 in the preparation of a product for preventing and / or treating mycobacterial infectious diseases and / or diseases and / or symptoms associated with infection.

2. The use according to claim 1, characterized in that The mycobacterium is selected from one or more of the following groups: Mycobacterium tuberculosis, Mycobacterium marinum, Mycobacterium avium-intracellulare complex, Mycobacterium kansasii, Mycobacterium simianum, Mycobacterium toadense, Mycobacterium gordonii, Mycobacterium terrestris, Mycobacterium paraterrestris; The diseases or symptoms associated with mycobacterium infection are selected from one or more of the following groups: pathological tissue damage caused by mycobacterium infection, insufficient or excessive cytokine production after infection, inflammatory damage to organs, and multiple organ failure; KAT8 is selected from Kat8 protein, a nucleic acid molecule encoding the protein, a promoter thereof or a recombinant expression vector thereof, and is also selected from mRNA, cDNA or precursor of Kat8.

3. The use according to claim 2, characterized in that: The Kat8 promoter is selected from any one or more of the following: exogenous Kat8 protein or nucleic acid encoding it, a substance that promotes the expression or active function of Kat8 protein, a substance that promotes the overexpression of nucleic acid molecules encoding Kat8 protein, or a liposome or nanomaterial that encapsulates Kat8 protein encoding nucleic acid.

4. The use according to claim 3, Features: in, The Kat8 protein is selected from any of the following situations: (a), a polypeptide having an amino acid sequence as shown in SEQ ID NO.2; (b) a substance having homology or sequence identity with the amino acid sequence shown in SEQ ID NO.2 and having the function of promoting KAT8; (c) A substance having a KAT8-promoting function, wherein one or more amino acids are substituted, deleted or added in the amino acid sequence of (a) or (b), or a protein or polypeptide derived from (a) or (b), The nucleic acid molecule encoding Kat8 protein is selected from any of the following situations: (i) a nucleic acid molecule having the nucleotide sequence shown in SEQ ID NO.1; (ii) a molecule that hybridizes to the nucleotide sequence defined in (i) under stringent conditions; (iii) a nucleic acid molecule homologous to or having sequence identity with the nucleotide sequence shown in SEQ ID NO.1; (iv) A nucleic acid molecule in which one or more nucleotides are substituted, deleted or added in the nucleotide sequence of (i), (ii) or (iii).

5. A Kat8 recombinant expression vector, characterized in that: The recombinant vector includes an expression vector and a nucleic acid molecule encoding Kat8 protein inserted into the expression vector, and the nucleic acid molecule encoding Kat8 protein is shown in SEQ ID NO.

1.

6. The Kat8 recombinant expression vector according to claim 5, characterized in that: in, The expression vector is a plasmid vector, a cosmid vector, a phage vector or a viral vector, and the viral vector is selected from adeno-associated virus or lentivirus.

7. An anti-mycobacterial infection preparation, characterized in that: The active component thereof comprises the KAT8 described in any one of claims 1 to 4.

8. The anti-mycobacterial infection preparation according to claim 7, characterized in that The anti-mycobacterial infection preparation is used in combination with other mycobacterial therapeutic drugs.

9. Use of a reagent for detecting KAT8 expression level in the preparation of a mycobacterium detection kit or an antibacterial drug screening kit, characterized in that: The kit contains primers with detection specificity for the KAT8 gene, and the primer sequences are shown in SEQ ID NOs. 3 and 4.

10. A mycobacterium detection kit or an antimicrobial drug screening kit, the kit comprising primers with detection specificity for the KAT8 gene, the primer sequences being as shown in SEQ ID NOs. 3 and 4.

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