Immune Response to Mycobacteria

摘要

Abstract: The immune response to mycobacteria is a complex process, varying according to the infection or disease ninvolved and to its acute or chronic nature; it is not yet fully understood. A better understanding is essential for definitive ndiagnosis and the development of new vaccines. The immune response involves a wide range of molecular and Th1-nmodel cellular components: antigen-presenting cells (macrophages and dendritic cells); T lymphocytes (CD4, CD8, NK nand u0003u0002); cytokines such as IL-2, IFN-u0002, IL-18 and TNF-u0001; and the chemokines RANTES, MCP-1, MIP-1u0001 and IL-8, nwhich play a key role in granuloma formation in M. tuberculosis and atypical mycobacterial infection. The immune nresponse also involves epithelial and natural killer (NK) cells, several signaling proteins (costimulatory molecules and ntranscription factors) that participate in regulating T-cell activation, toll-like receptors and major histocompatibility ncomplex Class 1 molecules. M. tuberculosis-secreted antigens that reportedly induce the secretion of mediators associated nwith protection against M. tuberculosis infection include CPF-10, ESAT-6, 27kDa and 38 kDa, which induce production nof IFN-u0003, TNF-u0001 and nitric oxide. The immune response to M. leprae infection involves the Th-1 model in tuberculoid nleprosy and the Th-2 model in lepromatous leprosy, with the production of IL-4, IL-5 and IL-13 or IL-10 (Th-3 response).