Follicular and extrafollicular tetramer+ SIV-specific CD8 T cells in relation to Foxp3+ cells during early SIV infection.

(A) Representative lymph node section stained with Mamu-A*001:01/Gag CM9 tetramers (red), IgM (blue), and Foxp3 (green) showing a tetramer+ cell in contact with a Foxp3+ cells. Confocal images were collected with a 20X objective and the scale bar is 100 μm and 10 μm in low- and high-magnification images respectively. (B) Representative image a showing tetramer+ Foxp3+. (C) Percentages of follicular tetramer+ SIV-specific CD8 T cells that were in direct contact with Foxp3+ cells tend to be lower than extrafollicular tetramer+ SIV-specific CD8 T cells (95% CI: -13.9, 1.57; p = 0.0956). (D) There was no significant difference between percentages of tetramer+ SIV-specific CD8+ T cells inside and outside follicle that were Foxp3+ (95% CI: -2.1, 3.4; p = 0.5676). (E) Representative image showing the distribution of Foxp3+ cells in lymph node. Scale bar is 100 μm. (F) Frequencies of Foxp3+ cells inside follicles were 67% (95% CI: 51%, 77%) lower than outside of follicle (p = 0.0007).