Extended Data Fig. 8: Compromised accumulation of Tfh-like cells in macaques and mice lungs dampens vaccine mediated protection against Mtb.

Macaques were aerosol exposed to MtbΔsigH prior to challenge with virulent Mtb CDC1551 and received either CD20 depleting (n = 4 NHPs) or IgG isotype control antibodies (n = 2 NHPs). Clinical samples were collected throughout the study and at necropsy. (a) FACS profiles for detection of B cells in PBMCs (left panel), BAL (middle panel), and lung (right panels) in CD20-depleted (upper panels) and control macaques (lower panels). (b) The percentage of total peripheral blood B cells (flow cytometry) and (c) Levels of C-reactive protein (CRP) were determined from samples collected throughout the study. (d) FACS profile for detection of T cell subsets in macaque lungs. (e) ESAT6⁺ CD4⁺ T cells producing IFNγ, IL2, IL17 and TNFα in lung tissue were enumerated by flow cytometry at the final end-point. (f) CFP-10 specific antibody levels in serum (diluted 1:15) collected at indicated time points. Data represent mean + SD and statistical analysis was performed with two-sided Mann-Whitney U-test. ***, p≤0.0005. Bcl6^fl/fl and CD4^creBcl6^fl/fl mice (n = 4 to 7 mice/group) were mucosally vaccinated with BCG and rested for thirty days following which mice were infected with Mtb HN878. Mice were euthanized at 20 dpi. (g) Experimental scheme. Lungs were collected and bacterial burden was determined in (h) Bcl6^fl/fl and CD4^creBcl6^fl/fl mice. Data represent mean + SD and statistical analysis was performed with two-sided unpaired t-test. **, p ≤ 0.005.