Figure 5.

IFN-γ-expressing unconventional T cells elicited by infant BCG vaccination. (a) Representative flow cytometry plots depicting γδ TCR expressing CD3⁺lymphocytes (left) and IFN- γ expression in unstimulated and BCG-stimulated γδ T cells (right). (b) Frequencies of BCG-reactive γδ T cells expressing IFN-γ in BCG-vaccinated (dark blue) and unvaccinated (light blue) infants. (c) Representative flow cytometry plots of (left) CD26 and CD161 expression by CD3⁺lymphocytes to identify CD26⁺CD161⁺ T cells producing IFN-γ in unstimulated and BCG-stimulated infant blood samples (right). (d) Frequencies of BCG-reactive IFN-γ-expressing CD3⁺CD26⁺CD161⁺ T cells in BCG-vaccinated (dark blue) and unvaccinated (light blue) infants. (e) Representative flow cytometry plot depicting CD8 and CD4 staining and gating in CD3⁺CD26⁺CD161⁺ T cells (left). Plot depicting TRAV1-2 and IFN-γ staining among CD4+CD26+CD161+ T cells (right). (f) Proportions of BCG-reactive IFN-γ⁺CD3⁺CD26⁺CD161⁺ T cells that are CD8+, double negative for CD8 and CD4 or that are CD4+ in BCG-vaccinated (dark blue) and unvaccinated (light) infants. (g) Proportions of BCG-reactive IFN-γ⁺CD4⁺CD26⁺CD161⁺ T cells that express TRAV1–2 in BCG-vaccinated infants. The black dots represent the estimated median; the error bars represent 95% confidence intervals. Q-values are Bonferroni-adjusted p-values, with q < 0.05 considered statistically significant.