Depressed CCL5 Expression in Human Pulmonary Tuberculosis

CCL5/regulated on activation, normal T expressed and secreted production (RANTES) is a principal CC chemokine, and can activate macrophages and Th1 lymphocytes, however, little is known about the CCL5 profiles associated with active tuberculosis (TB). In this study, we investigated the production of CCL5 by the peripheral blood mononuclear cells (PBMCs) of patients with active pulmonary TB after stimulation with Triton X-100 soluble proteins (TSP) or the 30-kDa antigen. The profiles of cytokines/chemokines [CXCL8/interleukin (IL)-8, IL-12 p40, and interferon (IFN)-gamma] were also examined by PBMCs from TB patients, and compared with those obtained from healthy tuberculin reactors (HTR). Concordant with earlier studies, IFN-gamma production was significantly depressed in the PBMCs from TB patients compared with those from HTR. In addition, the CCL5, but not CXCL8, levels in the PBMCs from TB patients were significantly depressed after stimulation for 18 hr compared to those in the PBMCs from HTRs. The CCL5 release was not significantly correlated with the release of IFN-gamma in the cells from TB patients and HTRs. Further, inhibitor studies show that the 30-kDa- or TSP-induced CCL5 mRNA expression is sensitive to inhibitors of mitogen-activated protein kinase kinase (MEK) 1/2 and Janus kinase (JAK) 2, but not p38, pathway activation, suggesting a MEK1/2- or JAK2-based mechanism is responsible for modulating of the CCL5 expression in human PBMCs. Collectively, these data suggest that TB patients show depressed production of CCL5 secretion, which can be modulated by MEK- and JAK2-based transcriptional regulatory mechanisms, in response to the mycobacterial antigens.

Elevated Levels of Interferon-inducible Protein-10 (IP)-10/CXCL10, but not of Interferon-gamma, in Patients with Pulmonary Tuberculosis

Mycobacterial strains are potent inducers of cytokines/chemokines by mononuclear phagocytes, which constitute an important cellular component of the first line of defense in the innate immune system. Interferon (IFN)-gamma-inducible protein (IP-10 or CXCL10) is a potent chemoattractant; however, little is known about the IP-10 profiles attributable to the Th1 regulation associated with active tuberculosis (TB). In this study, we investigated the production of IP-10, interleukin (IL)-12 p40, and IFN-gamma by the peripheral blood mononuclear cells (PBMCs) of patients with active pulmonary TB in response to in vitro stimulation with Triton X-100 soluble proteins (TSPs) or the 30-kDa antigen. The TSP antigens used in the present study were isolated and purified from Mycobacterium tuberculosis H37Rv (virulent strain), M. tuberculosis H37Ra (avirulent strain), and Mycobacterium bovis BCG. The results were compared with those obtained for healthy tuberculin reactors (HTRs). Concordant with earlier studies, IFN-gamma production was significantly depressed in the PBMCs from TB patients compared with those in the HTR group. However, the IP-10 levels in the PBMCs from TB patients were significantly elevated 18 h after stimulation compared to those in the PBMCs from HTRs. IP-10 release was correlated in a significant manner with the release of IFN-gamma in the HTRs, but this was not the case for the TB patients. Collectively, these data suggest that TB patients show altered regulation of Th1-driving cytokine and chemokine production in response to a variety of mycobacterial antigens.

Induction of TNF-alpha, IL-12, IL-10, MCP-1 and IL-8 in Human Peripheral Blood Monocytes in Response to the Cell Wall-Associated Triton X-100 Soluble Protein (TSP) Antigens of Mycobacterium tuberculosis

Mycobacterium tuberculosis is a potent inducer of cytokine production by mononuclear phagocytes, which are an important cellular component in the first line immune defence. In this study, the cell wall-associated Triton X-100 soluble protein (TSP) antigens, TSP-H37Rv, TSP-H37Ra, TSP-K, and TSP-BCG, were isolated from M. tuberculosis H37Rv, M. tuberculosis H37Ra, M. tuberculosis K-strain, and M. bovis BCG, respectively. The monocytes were isolated from the peripheral blood mononuclear cells of healthy individuals and were co-cultured with each TSP antigens and the secretory proteins of M. tuberculosis (PPD and 30-kDa antigen) to measure the production of cytokines; tumor necrosis factor (TNF)-a, interleukin (IL)-12, IL-8 and monocyte chemotactic protein-1 (MCP-1). The TSP-H37Rv antigen- stimulated monocytes showed higher level of TNF-a and IL-12 production compared to those of other TSP antigens and PPD. Especially, IL-12 production in response to the TSP-H37Rv antigen was significantly elevated in comparison with that of PPD-stimulated monocytes (TSP-H37Rv, 255.5+/-256.9 pg/ml; PPD, 55.7+/-55.4 pg/ml). However, the 30-kDa antigen did not induce TNF-alpha expression and also showed the lowest level of cytokine and chemokine production by monocytes. MCP-1 and IL-8 production were similarly increased in response to all TSP antigens and the PPD antigen. The production of IL-12 by the TSP-H37Rv antigen stimulation was significantly increased in PPD reactors than that in the non-reactor group, while the levels of other cytokines stimulated with each TSP antigens, 30-kDa and PPD antigen were not significantly different between the tuberculin reactor and the non-reactor groups. These results suggest that the cell wall-associated TSP antigen isolated from M. tuberculosis H37Rv acts as a more potent IL-12 inducer than the PPD antigen in innate immune response and thus it could further activate the Th1-mediated immune responses effectively against M. tuberculosis infection.

Isolation of a Specific Antigen from the Triton X-100 Soluble Protein (TSP) Of Mycobacterium tuberculosis

Tremendous efforts have been made to develop better vaccines and diagnostic markers for the effective control of tuberculosis. Recently, we reported that the Triton X-100 soluble protein (TSP) of Mycobacterium tuberculosis induced strong T-cell proliferation and IFN-gamma production in humans, and also conferred a significant level of protection against tuberculosis in a mouse model. In this study, the TSP was prepared by Triton X-100 extraction of Mycobacterium tuberculosis bacilli, which was followed by Triton X-114 phase partitioning. Western blot analysis using sera of 177 active pulmonary tuberculosis patients and 323 healthy individuals revealed that the TSP contained a immunodominant 40-kDa antigen specifically reacting with some sera from pulmonary tuberculosis patients. The 40-kDa antigen was purified by ion-exchange chromatography, and partially characterized by two-dimensional gel electrophoresis and N-terminal sequencing. Results of this study suggest that 40-kDa molecule of the TSP antigen from the cell suface of Mycobacterium tuberculosis can be used as a serodiagnostic marker as well as a potential vaccine candidate against tuberculosis.

Macrophage Activation after In vitro Stimulation with the TSP Antigen of Mycobacterium tuberculosis H37Rv / 대한면역학회지

Present study aimed to investigate the immunological activities of cell wall associated protein antigen solubilized with Triton X-100 (TSP) from Mycobacterium tuberculosis H37Rv and conducted on 43 patients with pulmonary tuberculosis (newly diagnosed, medicated within 12 months and chronic refractory patients) and 17 normal healthy controls. These immunological responses were compared with those induced by the PPD or 30 kDa antigen from M, tuberculosis H37Rv culture filtrates, identified as biologically important secreted proteins. Proliferative responses to mycobacterial antigens were compared in peripheral blood mononuclear cells (PBMC) of healthy subjects and pulmonary tuberculosis patients. Signiticant blastogenic responses to the TSP were observed in healthy tuberculin reactors, newly diagnosed and some of antituberculosis drug-medicated patients by H-thymidine incorporation assay. IL-12 p40 and IFN-r mRNA expressions to the TSP were markedly increased, whereas IL-10 and TNF-a mRNA expressions were decreased at a 5 day-stimulation by PBMC in healthy tuberculin reactors, newly diagnosed and medicated patients. However, patients with chronic refractory tuberculosis exhibited more depressed IL-12 p40 and IFN-r mRNA expressions to all of the antigens than another groups. Interestingly, very low IL-10 and TNF-a mRNA expressions cultured with the TSP were also shown. These data suggest that the TSP may be involved in the macrophage activation by induction of Th1 stimulatory signals, such as IL-12, and suppression of Th1 inhibitory cytokine, IL-10.