The major innate immune cell types involved in tuberculosis(TB)infection are macrophages,dendritic cells(DCs),neutrophils and natural killer(NK)cells.These immune cells recognize the TB-causing pathogen Mycobacterium ...The major innate immune cell types involved in tuberculosis(TB)infection are macrophages,dendritic cells(DCs),neutrophils and natural killer(NK)cells.These immune cells recognize the TB-causing pathogen Mycobacterium tuberculosis(Mtb)through various pattern recognition receptors(PRRs),including but not limited to Toll-like receptors(TLRs),Nod-like receptors(NLRs)and C-type lectin receptors(CLRs).Upon infection by Mtb,the host orchestrates multiple signaling cascades via the PRRs to launch a variety of innate immune defense functions such as phagocytosis,autophagy,apoptosis and inflammasome activation.In contrast,Mtb utilizes numerous exquisite strategies to evade or circumvent host innate immunity.Here we discuss recent research on major host innate immune cells,PRR signaling,and the cellular functions involved in Mtb infection,with a specific focus on the host’s innate immune defense and Mtb immune evasion.A better understanding of the molecular mechanisms underlying host–pathogen interactions could provide a rational basis for the development of effective anti-TB therapeutics.展开更多
Background China is one of the high burden countries of Mycobacterium tuberculosis （TB） infection globally, with high incidence and mortality. We studied the molecular characteristics of rifampin （RIF） and isoniaz...Background China is one of the high burden countries of Mycobacterium tuberculosis （TB） infection globally, with high incidence and mortality. We studied the molecular characteristics of rifampin （RIF） and isoniazid （INH） resistant Mycobacterium tuberculosis strains from Beijing, China, in order to find out the genetic marker for rapid detection of specific drug resistance.Methods Forty pansusceptible and 81 resistant strains of Mycobacterium tuberculosis isolated from Beijing, China during 2002-2005 were analyzed. The modified rifampin oligonucleotide （RIFO） assay based on reverse line blot hybridization was used to detect mutations in the 81 bp hot-spot region of rpoB gene, which is associated with RIF resistance. The INH resistance associated genes, regulatory region mab-inhA （-15C/T） and structural gene katG S315T were detected by reverse line blot hybridization and PCR-restriction fragment length polymorphism （RFLP） method respectively. All the strains were typed by spoligotying and the Beijing genotype was further subdivided by NTF locus analysis. The distribution of drug resistance associated mutations in the above genes was compared in these groups. Results Sixty-five （91.5%） of 71 RIF resistant and 52 （92.9%） of 56 multidrug-resistant （MDR, i.e. resistant to at least RIF and INH） strains were found to harbor mutations in the rpoB hot-spot region. No mutation was detected in RIF sensitive strains. The specificity and sensitivity of the modified RIFO assay were 100% and 91.5%, respectively, katG315 AGC〉ACC and inhA-15C〉T mutations were found in 40 （60.6%） and 10 （15.2%） of 66 INH resistant strains, respectively; 7.6% of INH-resistant strains had mutations in both of these genes. Therefore, a combined use of both katG315 and inhA-15 identified 68.2% of INH-resistant strains. The Beijing genotype accounted for 91.7% of total strains and was further subdivided into ＂modern＂ （76.6%） and ＂ancestral＂ （23.4%） group. There is no significant difference展开更多
Although it has been known that γδ T cells may play an important role in the immune response to infection of Mycobacterium tuberculosis （M. tb）, the mechanisms by which the γδ T cells participate in the innate a...Although it has been known that γδ T cells may play an important role in the immune response to infection of Mycobacterium tuberculosis （M. tb）, the mechanisms by which the γδ T cells participate in the innate and/or acquired immunity to tuberculosis （TB） have not been full elucidated. In the present study, 27 patients with active pulmonary TB and 16 healthy donors （HD） were performed. We found that proportion of IL-17-producing cells among lymphocyte was similar between TB patients and HD, whereas the proportions of γδ T cells in IL-17-producing cells （59.2%） and IL-17-producing cells in γδ T cells （19.4%） in peripheral blood were markedly increased in TB patients when compared to those in HD （43.9% and 7.7%, respectively）. In addition, the proportions of IFN-T-producing γδ T cells in TB patients were obviously lower than that in HD. Upon re-stimulated with M. tb heat-treated antigen （M. tb-HAg） in vitro, fewer IL-17-producing γδ T cells were generated from HD and TB patients, whereas IFN-T-producing γδ T cells were increased in TB patients compared to that in HD. Our findings in TB patients and healthy human were consistent with other murine investigation that the IL-17- producing γδ T cells were main source of IL-17 in mouse model of BCG infection, suggesting that γδ T cells might be involved in the formation of tubercular granuloma in pulmonary TB patients, but need further identification.展开更多
As the first line of immune defense for Mycobacterium tuberculosis （Mtb）, macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant ...As the first line of immune defense for Mycobacterium tuberculosis （Mtb）, macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant since ancient times. Triggered upon Mtb infection, multiple cellular pathways in macrophages are activated to initiate a tailored immune response toward the invading pathogen and regulate the cellular fates of the host as well. Toll-like receptors （TLRs） expressed on macrophages can recognize pathopatterns （PAMPs） on Mtb and mediate the production of immune-regulatory cytokines such as tumor necrosis factor （TNF） and type I Interferons （IFNs）. In addition, Vitamin D receptor （VDR） and Vitamin D-1- hydroxylase are up-regulated in Mtb-infected macrophages, by which Vitamin D participates in innate immune respon- ses. The signaling pathways that involve TNF, type I IFNs and Vitamin D are inter-connected, which play critical roles in the regulation of necroptosis, apoptosis, and autophagy of the infected macrophages. This review article summarizes cur- rent knowledge about the interactions between Mtb and macrophages, focusing on cellular fates of the Mtb-infected macrophages and the regulatory molecules and cellular pathways involved in those processes.展开更多
AIM:To define the parameters that positively predict diagnosis of Crohn's disease (CD) and differentiate it from gastrointestinal tuberculosis (GITB). METHODS:This prospective study over 3 years was carried out in...AIM:To define the parameters that positively predict diagnosis of Crohn's disease (CD) and differentiate it from gastrointestinal tuberculosis (GITB). METHODS:This prospective study over 3 years was carried out in the consecutive Indian patients with definite diagnosis of CD and equal numbers of patients with definite diagnosis of GITB. Demographic, clinical, laboratory, morphological and histological features were noted in all the patients. Serological tests such as p-ANCA, c-ANCA, IgA ASCA and IgG ASCA, were performed. Endoscopic biopsy and/or surgical tissue specimens were subjected to smear and culture for acid-fast bacilli (AFB) and tissue polymerase chain reaction for tuberculosis (TB PCR). Diagnosis of CD and GITB was based on the standard criteria. Data were analyzed using univariate Chi-square test and multiple logistic regression (MLR). RESULTS:The study is comprised of 26 patients with CD (age 36.6 ± 8.6 year, male:female, 16:10) and 26 patients with GITB (age 37.2 ± 9.6 year, male:female, 15:11). The following clinical variables between the two groups (CD vs TB) were significant in univariate analysis:duration of symptoms (58.1 ± 9.8 vs 7.2 ± 3.4 mo), diarrhoea (69.2% vs 34.6%), bleeding per rectum (30.7% vs 3.8%), fever (23.1% vs 69.2%), ascites (7.7% vs 34.6%) and extra-intestinal manifestations of inflammatory bowel disease (61.5% vs 23.1%). Of these, all except ascites and extra-colonic manifestations were found statistically significant by MLR. Accuracy of predicting CD was 84.62% based on the fever, bleeding P/R, diarrhoea and duration of symptoms while it was 63.4% when histology was reported as inflammatory bowel disease and 42.3% when there was recurrence of disease after surgery. Accuracy of predicting GITB was 73.1% when there was co-existing pulmonary lesions and/or abdominal lymphadenopathy;75% when tuberculosis was reported in histology;63.4% when granuloma was found in histology;82.6% when TB PCR was positive;and 61.5% when smear and/ or culture was positive for AFB. Serological tes展开更多
基金the National Key Research and Development Program of China(Grant Nos.2017YFA0505900 and 2017YFD0500300)the National Basic Research Programs of China(Grant No.2014CB74440)+2 种基金the National Natural Science Foundation of China(Grant Nos.81371769 and 81571954)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDPB03)the Youth Innovation Promotion Association CAS(Grant No.Y12A027BB2).
文摘The major innate immune cell types involved in tuberculosis(TB)infection are macrophages,dendritic cells(DCs),neutrophils and natural killer(NK)cells.These immune cells recognize the TB-causing pathogen Mycobacterium tuberculosis(Mtb)through various pattern recognition receptors(PRRs),including but not limited to Toll-like receptors(TLRs),Nod-like receptors(NLRs)and C-type lectin receptors(CLRs).Upon infection by Mtb,the host orchestrates multiple signaling cascades via the PRRs to launch a variety of innate immune defense functions such as phagocytosis,autophagy,apoptosis and inflammasome activation.In contrast,Mtb utilizes numerous exquisite strategies to evade or circumvent host innate immunity.Here we discuss recent research on major host innate immune cells,PRR signaling,and the cellular functions involved in Mtb infection,with a specific focus on the host’s innate immune defense and Mtb immune evasion.A better understanding of the molecular mechanisms underlying host–pathogen interactions could provide a rational basis for the development of effective anti-TB therapeutics.
基金This study was supported by a grant from the National Natural Science Foundation of China(No.30471841).
文摘Background China is one of the high burden countries of Mycobacterium tuberculosis （TB） infection globally, with high incidence and mortality. We studied the molecular characteristics of rifampin （RIF） and isoniazid （INH） resistant Mycobacterium tuberculosis strains from Beijing, China, in order to find out the genetic marker for rapid detection of specific drug resistance.Methods Forty pansusceptible and 81 resistant strains of Mycobacterium tuberculosis isolated from Beijing, China during 2002-2005 were analyzed. The modified rifampin oligonucleotide （RIFO） assay based on reverse line blot hybridization was used to detect mutations in the 81 bp hot-spot region of rpoB gene, which is associated with RIF resistance. The INH resistance associated genes, regulatory region mab-inhA （-15C/T） and structural gene katG S315T were detected by reverse line blot hybridization and PCR-restriction fragment length polymorphism （RFLP） method respectively. All the strains were typed by spoligotying and the Beijing genotype was further subdivided by NTF locus analysis. The distribution of drug resistance associated mutations in the above genes was compared in these groups. Results Sixty-five （91.5%） of 71 RIF resistant and 52 （92.9%） of 56 multidrug-resistant （MDR, i.e. resistant to at least RIF and INH） strains were found to harbor mutations in the rpoB hot-spot region. No mutation was detected in RIF sensitive strains. The specificity and sensitivity of the modified RIFO assay were 100% and 91.5%, respectively, katG315 AGC〉ACC and inhA-15C〉T mutations were found in 40 （60.6%） and 10 （15.2%） of 66 INH resistant strains, respectively; 7.6% of INH-resistant strains had mutations in both of these genes. Therefore, a combined use of both katG315 and inhA-15 identified 68.2% of INH-resistant strains. The Beijing genotype accounted for 91.7% of total strains and was further subdivided into ＂modern＂ （76.6%） and ＂ancestral＂ （23.4%） group. There is no significant difference
文摘Although it has been known that γδ T cells may play an important role in the immune response to infection of Mycobacterium tuberculosis （M. tb）, the mechanisms by which the γδ T cells participate in the innate and/or acquired immunity to tuberculosis （TB） have not been full elucidated. In the present study, 27 patients with active pulmonary TB and 16 healthy donors （HD） were performed. We found that proportion of IL-17-producing cells among lymphocyte was similar between TB patients and HD, whereas the proportions of γδ T cells in IL-17-producing cells （59.2%） and IL-17-producing cells in γδ T cells （19.4%） in peripheral blood were markedly increased in TB patients when compared to those in HD （43.9% and 7.7%, respectively）. In addition, the proportions of IFN-T-producing γδ T cells in TB patients were obviously lower than that in HD. Upon re-stimulated with M. tb heat-treated antigen （M. tb-HAg） in vitro, fewer IL-17-producing γδ T cells were generated from HD and TB patients, whereas IFN-T-producing γδ T cells were increased in TB patients compared to that in HD. Our findings in TB patients and healthy human were consistent with other murine investigation that the IL-17- producing γδ T cells were main source of IL-17 in mouse model of BCG infection, suggesting that γδ T cells might be involved in the formation of tubercular granuloma in pulmonary TB patients, but need further identification.
文摘As the first line of immune defense for Mycobacterium tuberculosis （Mtb）, macrophages also provide a major habitat for Mtb to reside in the host for years. The battles between Mtb and macrophages have been constant since ancient times. Triggered upon Mtb infection, multiple cellular pathways in macrophages are activated to initiate a tailored immune response toward the invading pathogen and regulate the cellular fates of the host as well. Toll-like receptors （TLRs） expressed on macrophages can recognize pathopatterns （PAMPs） on Mtb and mediate the production of immune-regulatory cytokines such as tumor necrosis factor （TNF） and type I Interferons （IFNs）. In addition, Vitamin D receptor （VDR） and Vitamin D-1- hydroxylase are up-regulated in Mtb-infected macrophages, by which Vitamin D participates in innate immune respon- ses. The signaling pathways that involve TNF, type I IFNs and Vitamin D are inter-connected, which play critical roles in the regulation of necroptosis, apoptosis, and autophagy of the infected macrophages. This review article summarizes cur- rent knowledge about the interactions between Mtb and macrophages, focusing on cellular fates of the Mtb-infected macrophages and the regulatory molecules and cellular pathways involved in those processes.
文摘AIM:To define the parameters that positively predict diagnosis of Crohn's disease (CD) and differentiate it from gastrointestinal tuberculosis (GITB). METHODS:This prospective study over 3 years was carried out in the consecutive Indian patients with definite diagnosis of CD and equal numbers of patients with definite diagnosis of GITB. Demographic, clinical, laboratory, morphological and histological features were noted in all the patients. Serological tests such as p-ANCA, c-ANCA, IgA ASCA and IgG ASCA, were performed. Endoscopic biopsy and/or surgical tissue specimens were subjected to smear and culture for acid-fast bacilli (AFB) and tissue polymerase chain reaction for tuberculosis (TB PCR). Diagnosis of CD and GITB was based on the standard criteria. Data were analyzed using univariate Chi-square test and multiple logistic regression (MLR). RESULTS:The study is comprised of 26 patients with CD (age 36.6 ± 8.6 year, male:female, 16:10) and 26 patients with GITB (age 37.2 ± 9.6 year, male:female, 15:11). The following clinical variables between the two groups (CD vs TB) were significant in univariate analysis:duration of symptoms (58.1 ± 9.8 vs 7.2 ± 3.4 mo), diarrhoea (69.2% vs 34.6%), bleeding per rectum (30.7% vs 3.8%), fever (23.1% vs 69.2%), ascites (7.7% vs 34.6%) and extra-intestinal manifestations of inflammatory bowel disease (61.5% vs 23.1%). Of these, all except ascites and extra-colonic manifestations were found statistically significant by MLR. Accuracy of predicting CD was 84.62% based on the fever, bleeding P/R, diarrhoea and duration of symptoms while it was 63.4% when histology was reported as inflammatory bowel disease and 42.3% when there was recurrence of disease after surgery. Accuracy of predicting GITB was 73.1% when there was co-existing pulmonary lesions and/or abdominal lymphadenopathy;75% when tuberculosis was reported in histology;63.4% when granuloma was found in histology;82.6% when TB PCR was positive;and 61.5% when smear and/ or culture was positive for AFB. Serological tes
