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Updated: Aug 9, 2026

Protective Efficacy and Pulmonary Immune Response Following Subcutaneous and Intranasal BCG Administration in Mice
Published on: September 19, 2016
Cutting edge: major CD8 T cell response to live bacillus Calmette-Guérin is mediated by CD1 molecules
Tetsuo Kawashima1, Yoshihiko Norose, Yoshiyuki Watanabe
1Department of Microbiology and Immunology, Nippon Medical School, Tokyo, Japan.
Abstract:
MHC class I-restricted CD8(+) T cells are a crucial component of the host defense against mycobacterial infection in mice, but it has often proved very difficult to identify the CD8 T cell response in humans. Human group 1 CD1 molecules (CD1a, -b, -c) mediate MHC-independent presentation of mycobacteria-derived lipid and glycolipid Ags to CD8(+) T cells, and their intracellular localization to the endocytic system may favor efficient monitoring of phagosome-resident mycobacteria. Here, we show that bacillus Calmette-Guérin (BCG)-immunized subjects contain a significant circulating pool of CD8(+) T cells that recognize BCG-infected DCs in a CD1-dependent, but MHC-independent, manner. These CD1-restricted T cells efficiently detected live, rather than dead, BCG and produced IFN-gamma, an important cytokine for protection against mycobacterial infection. These results emphasize that lipid-reactive CD8(+) T cells may contribute to host defense against mycobacterial infection.
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