Mycobacterium tuberculosislpdC, Rv0462, induces dendritic cell maturation and Th1 polarization.
ABSTRACT Mycobacterium tuberculosis, the etiological factor of pulmonary tuberculosis, causes significant morbidity and mortality worldwide. Activation of host immune responses for containment of mycobacterial infections involves participation of innate immune cells, such as dendritic cells (DCs). In this study, we demonstrated that the gene encoding lipoamide dehydrogenase C (lpdC) from M. tuberculosis, Rv0462, induce maturation and activation of DCs involved in the MAPKs signaling pathway. Moreover, Rv0462-treated DCs activated naïve T cells, polarized CD4(+) and CD8(+) T cells to secrete IFN-γ in syngeneic mixed lymphocyte reactions, which would be expected to contribute to Th1 polarization of the immune response. Our results suggest that Rv0462 can contribute to the innate and adaptive immune responses during tuberculosis infection, and thus modulate the clinical course of tuberculosis.
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ABSTRACT: Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is one of the world's leading infectious causes of morbidity and mortality. As a mucosal-transmitted pathogen, Mtb infects humans and animals mainly through the mucosal tissue of the respiratory tract. Apart from providing a physical barrier against the invasion of pathogen, the major function of the respiratory mucosa may be to serve as the inductive sites to initiate mucosal immune responses and sequentially provide the first line of defense for the host to defend against this pathogen. A large body of studies in the animals and humans have demonstrated that the mucosal immune system, rather than the systemic immune system, plays fundamental roles in the host's defense against Mtb infection. Therefore, the development of new vaccines and novel delivery routes capable of directly inducing respiratory mucosal immunity is emphasized for achieving enhanced protection from Mtb infection. In this paper, we outline the current state of knowledge regarding the mucosal immunity against Mtb infection, including the development of TB vaccines, and respiratory delivery routes to enhance mucosal immunity are discussed.Tuberculosis research and treatment. 01/2012; 2012:791728.
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ABSTRACT: Protein Nε-acetylation, a post-translational modification widespread in eukaryotes and prokaryotes, has been intensively explored due to its crucial roles in multitudinous physiologic events including transcriptional regulation, metabolic regulation, etc. The particular hotspot is the relationship between acetylation and metabolic regulation. Protein acetylation major types and functions thereof, prokaryotic acetyltransferase, deacetylases, and acetylation sites of enzymes related to glycometabolism, together with the cross-talk between acetylation and other modification, such as the phosphorylation were summarized, with emphases on those from Mycobacteria. J. Cell. Biochem. 113: 3601-3609, 2012. © 2012 Wiley Periodicals, Inc.Journal of Cellular Biochemistry 07/2012; 113(12):3601-9. · 3.06 Impact Factor
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ABSTRACT: Mycobacterium bovis is the etiological factor of bovine tuberculosis (BTB), posing a significant problem to domestic cattle. The bacterium is also zoonotic, affecting human health worldwide. Macrophage evasion of the bacterium involves mycobacterial molecules such as MB1684 (ornithine carbamoyltransferase). In this study, we confirmed a concentration-dependent decrease in proliferation of Ana-1 macrophages when treated with rMB1684 when compared with mycobacterium bovis purified protein derivative of tuberculosis (MbPPD) or phosphate buffer solution incubation groups. We examined the activation of nuclear factor-kappa B (NF-κB) upon exposure to MB1684, and its role in MB1684-induced upregulation of interferon (IFN)-γ and proinflammatory cytokines (interleukin [IL]-1β, IL-6, and tumor necrosis factor-α) in Ana-1 macrophages. The levels of proinflammatory cytokines and IFN-γ were significantly high in MB1684-treated Ana-1 macrophages. The treatment led to an increase in NF-κB activation and a high expression of the just mentioned proinflammatory cytokines. NF-κB inhibition significantly abrogated MB1684-induced upregulation of proinflammatory cytokine mRNA expression, which suggests that MB1684-induced activation of NF-κB in turn stimulates gene expression of IFN-γ and proinflammatory cytokines in Ana-1 macrophages. The experiment was repeated in bone marrow macrophages, a more in-vivo-like model system, and similar results validated our conclusion. Further, we identified the possibility of the application of MB1684 antigen for the detection of BTB in cattle serum.DNA and cell biology 02/2014; · 2.28 Impact Factor