To screen new antigens for novel tuberculosis(TB)vaccine research,we used bioinformatics to predict the B and T cell epitopes of Rv2318,and evaluated the immunogenicity of Rv2318 and its T/B epitope peptides(Rv2318p).The recombinant plas-mids pET32a-Rv2318 and pET32a-Rv2318p were constructed through gene synthesis methods.The recombinant proteins were ex-pressed in a prokaryotic system and purified with nickel affinity chromatography.Proteins were identified with SDS-PAGE and western blotting.BALB/c mice were immunized subcutaneously with the recombinant proteins to evaluate immunogenicity.Sera were collected,and antigen specific antibody titers were evaluated with ELISA.Splenocytes were isolated,and cytokines and T cell proliferation were analyzed with ELISA and flow cytometry,respectively.Rv2318 included two epitope fragments,aa10-130 and 350-410.SDS-PAGE and western blotting indicated that the target proteins were expressed and purified correctly,and their relative molecular weights were-approximately 68 kD and 42 kD,respectively.Rv2318 and Rv2318p induced stronger humoral immune responses than observed in the control groups(P<0.000 1,n=6).Compared with Rv2318,Rv2318p showed significantly greater enhancement of specific IgG and IgG subclass antibodies(P<0.000 1,n=6).In addition,Rv2318p increased the ratio of IgG2a/IgG1,thus indicating that it primarily induced a cellular immune response biased toward the Th1 type.Cytokine experiments revealed that IFN-γ,IL-2,IL-6,and IL-4 significantly increased after immunization with Rv2318p(P all<0.01,n=6),particularly Th1 type cytokines(IFN-γ and IL-2).Furthermore,Rv2318 increased the expression of only IL-2 and IL-6,particularly IL-6(P all<0.01,n=6).Although Rv2318 in-duced more IFN-γ,we observed no significant difference between Rv2318 and PBS immunized mice.Importantly,Rv2318p stimu-lated mice to express IFN-γ at 842 pg/mL,approximately 3 times the level elicited by Rv2318.Whereas both proteins increased the proportions of CD4+and CD8+T cells,Rv2318p promoted greater proliferation of T lymphocytes.These data indicated that both Rv2318 and its epitope peptides enhanced humoral and cellular immune responses,whereas the epitope peptides notably triggered a stronger Th1 type cellular response.In conclusion,the recombinant protein Rv2318 and its epitope peptides showed favorable immunogenicity,and the immunogenicity of Rv2318p was superior to that of Rv2318.This study provides a theoretical basis for TB vaccine development.

This study was aimed at analyzing the epidemiological and drug resistance characteristics of tuberculosis at a desig-nated tuberculosis hospital in Hunan Province in 2024.Patients diagnosed with TB at the hospital between April and October 2024 were included in the study.Demographic data,clinical information,and drug sensitivity test results were collected from the hospital′s electronic medical record system.Descriptive statistics,the chi-square test,and logistic regression were used to analyze the epidemic characteristics,drug resistance characteristics,and factors influencing tuberculosis.Whole genome sequencing of isolates was per-formed,and lineage classification and drug resistance gene mutations were detected with TB-Profiler.The male-to-female ratio was 2.72∶1,and the median age was 56(IQR:43-66)years.Among the 391 patients,most were farmers(46.8%,183/391)and were pri-marily from Changsha(41.1%,162/391).Significant differences were observed in sex and occupation between pulmonary tuberculosis(PTB)and extrapulmonary tuberculosis(EPTB).The overall prevalence of any type of drug resistance of tuberculosis was 33.25%,and the multidrug resistance TB(MDR-TB)and poly-drug resistance(PR-TB)rates were 14.23%and 4.35%,respectively.The re-sistance rates to rifampicin(RIF),isoniazid(INH),ethambutol(EMB),and streptomycin(SM)were 17.90%,22.25%,6.39%,and 20.20%,respectively.Multivariable logistic regression analysis indicated that both diabetes(OR:2.295,95%CI:1.082-4.866)and retreatment(OR:17.822,95%CI:8.343-38.072)were risk factors for developing MDR-TB.Lineage 2(L2)strains accounted for 64.40%(136/191),whereas lineage 4(L4)accounted for 28.80%(55/191).The most common drug resistance mutations were katG Ser315Thr(62.50%,20/32)for INH,rpoB Ser450Leu(50.00%,12/24)for RIF,embB Met306Val(55.56%,5/9)for EMB,and rpsL Lys43Arg(80.95%,34/42)for SM.In conclusion,TB drug resistance was found to be a serious problem at a designated tu-berculosis hospital in Hunan in 2024.Strengthening the treatment and management of patients infected with L2 strains,those with co-morbid diabetes,and retreatment cases is crucial for preventing and controlling the emergence of drug-resistant TB.

To screen new antigens for novel tuberculosis(TB)vaccine research,we used bioinformatics to predict the B and T cell epitopes of Rv2318,and evaluated the immunogenicity of Rv2318 and its T/B epitope peptides(Rv2318p).The recombinant plas-mids pET32a-Rv2318 and pET32a-Rv2318p were constructed through gene synthesis methods.The recombinant proteins were ex-pressed in a prokaryotic system and purified with nickel affinity chromatography.Proteins were identified with SDS-PAGE and western blotting.BALB/c mice were immunized subcutaneously with the recombinant proteins to evaluate immunogenicity.Sera were collected,and antigen specific antibody titers were evaluated with ELISA.Splenocytes were isolated,and cytokines and T cell proliferation were analyzed with ELISA and flow cytometry,respectively.Rv2318 included two epitope fragments,aa10-130 and 350-410.SDS-PAGE and western blotting indicated that the target proteins were expressed and purified correctly,and their relative molecular weights were-approximately 68 kD and 42 kD,respectively.Rv2318 and Rv2318p induced stronger humoral immune responses than observed in the control groups(P<0.000 1,n=6).Compared with Rv2318,Rv2318p showed significantly greater enhancement of specific IgG and IgG subclass antibodies(P<0.000 1,n=6).In addition,Rv2318p increased the ratio of IgG2a/IgG1,thus indicating that it primarily induced a cellular immune response biased toward the Th1 type.Cytokine experiments revealed that IFN-γ,IL-2,IL-6,and IL-4 significantly increased after immunization with Rv2318p(P all<0.01,n=6),particularly Th1 type cytokines(IFN-γ and IL-2).Furthermore,Rv2318 increased the expression of only IL-2 and IL-6,particularly IL-6(P all<0.01,n=6).Although Rv2318 in-duced more IFN-γ,we observed no significant difference between Rv2318 and PBS immunized mice.Importantly,Rv2318p stimu-lated mice to express IFN-γ at 842 pg/mL,approximately 3 times the level elicited by Rv2318.Whereas both proteins increased the proportions of CD4+and CD8+T cells,Rv2318p promoted greater proliferation of T lymphocytes.These data indicated that both Rv2318 and its epitope peptides enhanced humoral and cellular immune responses,whereas the epitope peptides notably triggered a stronger Th1 type cellular response.In conclusion,the recombinant protein Rv2318 and its epitope peptides showed favorable immunogenicity,and the immunogenicity of Rv2318p was superior to that of Rv2318.This study provides a theoretical basis for TB vaccine development.

This study was aimed at analyzing the epidemiological and drug resistance characteristics of tuberculosis at a desig-nated tuberculosis hospital in Hunan Province in 2024.Patients diagnosed with TB at the hospital between April and October 2024 were included in the study.Demographic data,clinical information,and drug sensitivity test results were collected from the hospital′s electronic medical record system.Descriptive statistics,the chi-square test,and logistic regression were used to analyze the epidemic characteristics,drug resistance characteristics,and factors influencing tuberculosis.Whole genome sequencing of isolates was per-formed,and lineage classification and drug resistance gene mutations were detected with TB-Profiler.The male-to-female ratio was 2.72∶1,and the median age was 56(IQR:43-66)years.Among the 391 patients,most were farmers(46.8%,183/391)and were pri-marily from Changsha(41.1%,162/391).Significant differences were observed in sex and occupation between pulmonary tuberculosis(PTB)and extrapulmonary tuberculosis(EPTB).The overall prevalence of any type of drug resistance of tuberculosis was 33.25%,and the multidrug resistance TB(MDR-TB)and poly-drug resistance(PR-TB)rates were 14.23%and 4.35%,respectively.The re-sistance rates to rifampicin(RIF),isoniazid(INH),ethambutol(EMB),and streptomycin(SM)were 17.90%,22.25%,6.39%,and 20.20%,respectively.Multivariable logistic regression analysis indicated that both diabetes(OR:2.295,95%CI:1.082-4.866)and retreatment(OR:17.822,95%CI:8.343-38.072)were risk factors for developing MDR-TB.Lineage 2(L2)strains accounted for 64.40%(136/191),whereas lineage 4(L4)accounted for 28.80%(55/191).The most common drug resistance mutations were katG Ser315Thr(62.50%,20/32)for INH,rpoB Ser450Leu(50.00%,12/24)for RIF,embB Met306Val(55.56%,5/9)for EMB,and rpsL Lys43Arg(80.95%,34/42)for SM.In conclusion,TB drug resistance was found to be a serious problem at a designated tu-berculosis hospital in Hunan in 2024.Strengthening the treatment and management of patients infected with L2 strains,those with co-morbid diabetes,and retreatment cases is crucial for preventing and controlling the emergence of drug-resistant TB.

Objective:To preliminarily evaluate the immunogenicity and efficacy of two novel tuberculosis vaccine candidates (a fusion multicomponent protein EPDPA015f and a mixed multicomponent protein EPDPA015m) and to provide a new antigen combination for the development of tuberculosis vaccines.Methods:Recombinant plasmids for the expression of EPDPA015f and EPDPA015m proteins were constructed. Six-week-old BALB/c mice were immunized with EPDPA015f or EPDPA015m in combination with aluminium adjuvant (50 μg/mouse) for three times with an interval of 10 d. The mice were sacrificed 10 d after the last immunization to collect blood and spleen samples. Serum antibody titers and cytokine levels were measured by ELISA, Luminex technique and enzyme-linked immunospot assay (ELISPOT). Mycobacterial growth inhibition assay (MGIA) was used to detect the ability of mouse splenocytes to inhibit the growth of Mtb in vitro. One-way analysis of variance and t-test were used for statistical analysis. Results:Both EPDPA015f and EPDPA015m could induce the production of various cytokines and IgG antibodies at a high level. The levels of cytokines related to Th1 (IL-2, TNF-α, IFN-γ), Th2 (IL-4, IL-6, IL-10) and Th17 (IL-17) as well as other proinflammatory cytokines (GM-CSF, IL-12) were higher in the EPDPA015f group than in the adjuvant group ( P<0.05). The titer of IgG antibody induced by EPDPA015f was as high as 1∶4×10 6. The results of MGIA showed that the numbers of Mtb (lgCFU) in the PBS, adjuvant, EPDPA015f and EPDPA015m groups were 3.46±0.11, 3.51±0.06, 2.98±0.09 and 3.19±0.08, respectively. The number of colonies in the EPDPA015f group was the least as compared with that in the other three groups ( P<0.001, P<0.001, P<0.01). Conclusions:The vaccine candidate EPDPA015f could elicit more comprehensive and high-level cellular and humoral immune responses, and exhibited superior in vitro inhibitory activity against the growth of Mtb. EPDPA015f had the potential to be used as a preventive vaccine or a booster vaccine

Objective:To evaluate the immunogenicity and protective effect of a multicomponent recombinant protein vaccine EPRHP014 constructed independently and provide a scientific basis for developing new tuberculosis (TB) vaccine and effective prevention and control of TB.Methods:Three full-length Mycobacterium ( M.) tuberculosis protein antigens (EsxH, Rv2628, and HspX) and two epitope-predicted and optimized epitope-dominant protein antigens (nPPE18 and nPstS1) were selected, from which five protein antigens were used to construct a protein antigen composition EPRHP014, including a fusion expression multi-component protein antigen (EPRHP014f) and a multi-component mixed protein antigen (EPRHP014m) formed with the five single protein using clone, purification, and purification respectively. Multicomponent protein vaccines EPRHP014f and EPRHP014m were prepared with aluminum adjuvant, and the BCG vaccine was used as a control. ELISA detected the titer of serum-specific antibodies, the secretion of various cytokines was detected by ELISpot and Luminex, and immune protection was observed by the M.tuberculosis growth inhibition test in vitro. The results were statistically analyzed by t-test or rank sum test, and P<0.05 was considered a statistically significant difference. Results:Mice Immunized with EPRHP014m and EPRHP014f could produce highly effective IgG antibodies and their subtypes IgG1 and IgG2a, and the antibody titers were similar to those of mice immunized with BCG, with no statistical significance ( P>0.05). The number of spot-forming cells (SFC) secreting IFN-γ and IL-4 induced by EPRHP014f group was significantly higher than those by EPRHP014m group and BCG group ( P<0.05), but there was no significant difference in the number of SFC for IFN-γ and IL-4 induced between EPRHP014m group and BCG group ( P>0.05). The secretion levels of GM-CSF and IL-12p70 induced by the EPRHP014m group were higher than those of the BCG group ( P<0.05), but there was no significant difference in the levels of IL-6 and IL-10 induced between EPRHP014m group and BCG group ( P>0.05). There was no significant difference in the secretions of IL-6, IL-10, IL-12, and GM-CSF between the EPRHP014f and BCG groups ( P>0.05). EPRHP014m group, EPRHP014f group, and BCG group had obvious antibacterial effects in vitro, and the difference was insignificant ( P>0.05). Conclusion:Both EPRHP014f and EPRHP014m can induce strong humoral and cellular immune responses in mice after immunization, and have a strong ability to inhibit the growth of M. tuberculosis in vitro, indicating that the antigen composition EPRHP014 has good potential in the development and application of TB vaccine.

Objective: To examine the association between the cross-resistance to ethionamide (Eto) and isoniazid (INH) and mutations of drug resistant genes in Mycobacterium tuberculosis (MTB), so as to provide the evidence for clinical diagnosis and treatment for multidrug-resistant (MDR) tuberculosis. Methods: Totally 126 MTB clinical isolates were selected, including 88 MDR-MTB clinical isolates and 38 INH- and rifampicin (RFP)-sensitive isolates. The resistance to INH and Eto was tested in MTB clinical isolates using the drug susceptibility test, and the mutations in the spacer region of INH and Eto resistance-related katG, inhA, ethA, mshA, ndh, spacer region of oxyR-ahpC and inhA promoter were detected using PCR assay. The phenotypic resistance served as a gold standard, and the sensitivity, specificity and accuracy of gene mutation tests were calculated for detection of MTB clinical isolates cross-resistant to INH and Eto. Results: Of the 126 MTB clinical isolates, there were 37 isolates cross-resistant to INH and Eto (29.37%), 51 isolates with resistance to INH and susceptibility to Eto (40.48%), 4 isolates with susceptibility to INH and resistance to Eto (3.17%) and 34 isolates with susceptibility to INH and Eto (26.98%). Among the 41 Eto-resistant MTB clinical isolates, there were 37 isolates with resistance to INH (90.24%). There were 64 MTB clinical isolates detected with katG mutations (50.79%), 4 isolates with mutation in the spacer region of oxyR-ahpC (3.17%), 2 isolates with inhA mutations (1.59%), and these isolates were all resistant to INH. There were 11 MTB clinical isolates detected with mutation in the inhA promoter (8.73%) and one isolate with ndh mutation, and all these isolates were cross-resistant to INH and Eto. There were 23 MTB clinical isolates detected with ethA mutations (18.25%) and 40 isolates with mshA mutations (31.75%), in which Eto-susceptible and -resistant isolates were detected. The diagnostic sensitivity, specificity and accuracy of inhA promoter tests for detection of cross-resistance to INH and Eto were 29.73% (95%CI: 16.44%-47.17%), 100.00% (95%CI: 87.36%-100.00%) and 63.38% (95%CI: 51.76%-73.63%) in MTB clinical isolates. Conclusions The prevalence of INH resistance is high in Eto-resistant MTB clinical isolates. Mutation in the inhA promoter region correlates with the cross-resistance to INH and Eto in MTB clinical isolates, and detection of mutation in the inhA promoter may be feasible to detect the cross-resistance to INH and Eto in MTB clinical isolates.

Objective:To evaluate the humoral and cellular immunoreactivity of recombinant Mycobacterium tuberculosis ( M. tuberculosis) PstS1 and HspX protein antigens in order to provide reference for immunodiagnosis of tuberculosis and screening of candidates for vaccine antigens. Methods:Purified recombinant M. tuberculosis PstS1 and HspX proteins were obtained using molecular cloning expression and Ni 2+ affinity chromatography. Blood samples and epidemiological data of healthy individuals and patients with M. tuberculosis infection were collected. Specific IgG antibodies and IFN-γ-producing antigen-specific T cells were respectively detected by enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT) with the recombinant proteins used as antigens. The humoral and cellular immunoreactivity of the recombinant PstS1 and HspX proteins were assessed with statistical analysis of data. Results:Both the recombinant PstS1 and HspX proteins could induce the secretion of IFN-γ by more specific effector T cells in patient with M. tuberculosis infection, and the differences between the infection and healthy control groups were statistically significant ( P<0.05). The specificity and sensitivity of the recombinant PstS1 and HspX as the diagnostic antigens of ELISPOT were 92.11% (35/38) and 65.96% (31/47), and 68.42% (26/38) and 91.49% (43/47), respectively. The two proteins also possessed some humoral immunoreactivity, but statistically significant difference was only observed in the HspX-specific antibody level between the two groups ( P<0.05). Conclusions:Both the recombinant PstS1 and HspX proteins had good cellular immunoreactivity and were the immunodominant antigens of cellular immunity. They performed well in cellular immunodiagnosis and were good potential candidate antigens for anti-tuberculosis vaccines.

Objective:The cellular immunity of 5 Mycobacterium tuberculosis recombinant proteins and their compositions was evaluated.Method:A total of 88 fresh venous blood from peripheral heparin anticoagulant population, 42 of which were from tuberculosis patients treated by The Tuberculosis Prevention and Treatment Center of Changping District, Beijing, and 46 of healthy volunteers were provided by the Infection Diseases of Chinese Center for Disease Control and Prevention. Healthy volunteers without a history of tuberculosis exposure and any clinical signs and symptoms. Using the Mycobacterium tuberculosis standard strain H37Rv DNA as a template, complete genes of the selected 5 recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c by PCR amplified; 5 recombinant proteins were cloned, expressed and purified as stimulants by genetic recombination and protein purification techniques, and the effector T cell enzyme-linked immunospot assay (ELISPOT) was used to detect cellular immunity in the population.Results:The recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c were successfully cloned, expressed and purified; And the sensitivities were 50.00%, 71.43%, 69.04%, 73.81% and 76.19%, and the specificities were 86.96%, 76.09%, 71.74%, 39.13% and 36.96%. In addition, the positive predictive value, negative predictive value, area under the curve and Youden index were 52.46% to 77.78%, 62.96% to 74.47%, 0.511 to 0.754 and 0.129 to 0.475, respectively. Except for Rv1411c and Rv3418c, the number of spot-forming cell (SFC) detected by Rv3874, Rv3875 and Rv2031c in tuberculosis patients was higher than healthy volunteers, and the differences were statistically significant ( P<0.001). Among the 26 compositions composed of 5 recombinant proteins, the sensitivity was 80.95% to 95.24%, and the specificity was 68.89% to 24.44%. As the number of recombinant proteins in the composition increases, the sensitivity gradually increased, but the specificity decreased. Conclusion:The recombinant proteins of Mycobacterium tuberculosis Rv3874, Rv3875 and Rv2031c have strong ability to stimulate T cells to produce immune response, and have certain antigenicity. The efficacy of Rv1411c and Rv3418c alone as diagnostic antigens is not ideal, and the composition composed of multi-component antigens has certain application value. This article provides experimental evidence for the immune diagnosis of tuberculosis and the preparation of new anti-tuberculosis vaccines.

Objective:The cellular immunity of 5 Mycobacterium tuberculosis recombinant proteins and their compositions was evaluated.Method:A total of 88 fresh venous blood from peripheral heparin anticoagulant population, 42 of which were from tuberculosis patients treated by The Tuberculosis Prevention and Treatment Center of Changping District, Beijing, and 46 of healthy volunteers were provided by the Infection Diseases of Chinese Center for Disease Control and Prevention. Healthy volunteers without a history of tuberculosis exposure and any clinical signs and symptoms. Using the Mycobacterium tuberculosis standard strain H37Rv DNA as a template, complete genes of the selected 5 recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c by PCR amplified; 5 recombinant proteins were cloned, expressed and purified as stimulants by genetic recombination and protein purification techniques, and the effector T cell enzyme-linked immunospot assay (ELISPOT) was used to detect cellular immunity in the population.Results:The recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c were successfully cloned, expressed and purified; And the sensitivities were 50.00%, 71.43%, 69.04%, 73.81% and 76.19%, and the specificities were 86.96%, 76.09%, 71.74%, 39.13% and 36.96%. In addition, the positive predictive value, negative predictive value, area under the curve and Youden index were 52.46% to 77.78%, 62.96% to 74.47%, 0.511 to 0.754 and 0.129 to 0.475, respectively. Except for Rv1411c and Rv3418c, the number of spot-forming cell (SFC) detected by Rv3874, Rv3875 and Rv2031c in tuberculosis patients was higher than healthy volunteers, and the differences were statistically significant ( P<0.001). Among the 26 compositions composed of 5 recombinant proteins, the sensitivity was 80.95% to 95.24%, and the specificity was 68.89% to 24.44%. As the number of recombinant proteins in the composition increases, the sensitivity gradually increased, but the specificity decreased. Conclusion:The recombinant proteins of Mycobacterium tuberculosis Rv3874, Rv3875 and Rv2031c have strong ability to stimulate T cells to produce immune response, and have certain antigenicity. The efficacy of Rv1411c and Rv3418c alone as diagnostic antigens is not ideal, and the composition composed of multi-component antigens has certain application value. This article provides experimental evidence for the immune diagnosis of tuberculosis and the preparation of new anti-tuberculosis vaccines.