Increase in Gamma Interferon-Secreting CD8+, as Well as CD4+, T Cells in Lungs following Aerosol Infection with Mycobacterium tuberculosis

AUTOR(ES)
FONTE

American Society for Microbiology

RESUMO

Although it is well established that CD4+ T cells are required for the protective immune response against tuberculosis (TB), there is some evidence that CD8+ T cells are also involved in the host response to Mycobacterium tuberculosis. There is, however, a paucity of information on the pulmonary CD8+ T-cell response during infection. We therefore have compared the changes in both CD8+ and CD4+ T cells following aerosol infection with M. tuberculosis. There was an observed delay between the peak of infection and the activated T-cell response in the lung. The kinetics of CD8+ and CD4+ T-cell responses in the lung were identical, both peaking at week 8, 4 weeks later than the peak of cellular response in draining lymph nodes. Similar changes in activation/memory phenotypes occurred on the pulmonary CD8+ and CD4+ T cells. Following in vitro restimulation, both subsets synthesized gamma interferon, a cytokine essential for controlling M. tuberculosis infection. Since lung CD8+ T cells are actively expanded during aerosol M. tuberculosis infection, it is important that both CD8+ and CD4+ T cells be targeted in the design of future TB vaccines.

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