Non-M3, MHC Ib-restricted CD8⁺ T cells contribute to protective immunity against Mtb.

Abstract

<p>C57BL/6, K^b-/-D^b-/-, K^b-/-D^b-/-M3^-/- and β₂m^-/- mice were infected with aerosolic Mtb H37Rv (~200 CFU) and sacrificed at indicated time-points. (A) Representative dot-plots depict CD8⁺ and CD4⁺ T cell populations from indicated mice before infection or at day 30 post-infection. Numbers indicate the percentage of cells in each quadrant in the TCRβ⁺ population. (B, C) Bar graphs depict the mean ± SEM of the percentage (B) and total number (C) of CD8⁺ T cells in the lung and spleen of indicated mice at day 30 post-infection. Data shown are from one of three independent experiments with 3 mice in each group. (D, E) Comparison of CFU between C57BL/6 (n = 5–8), K^b-/-D^b-/- (n = 9–14), K^b-/-D^b-/-M3^-/- (n = 7–15) and β₂m^-/- (n = 4–6) mice in the lung (D) and spleen (E) at day 14, 30 and 60 post-infection. Data shown are pooled from three independent experiments. (F) Bacterial burden in the lung of K^b-/-D^b-/-M3^-/- mice received CD8 depleting mAb or control IgG at day 28 post-infection. Data shown are the mean ± SEM from 9 mice per group. *<i>P</i> <0.05, **<i>P</i> <0.01, ***<i>P</i> <0.001, ns, no statistical significance.</p