Relationship between Vδ1 T-cell expansion, microbial translocation, and CD4 T-cell depletion. (A) Frequencies of CD4 T cells in peripheral blood (red), spleen (yellow), peripheral lymph nodes (blue), mesenteric lymph nodes (green), small intestine (pink), large intestine (black), and BAL (orange) in uninfected (squares) and chronically SIV-infected (circles) RMs. (B) Correlation between CD4 T-cell frequencies and activation of CD4 T cells at different anatomical sites. (C) Correlation between CD4 T-cell depletion and Vδ1 T-cell frequencies at different anatomical sites. (D) Correlation between CD4 T-cell depletion and Vδ2 T-cell frequencies at different anatomical sites. (E) Correlation between translocated microbial products (E coli) in lymph nodes and Vδ1 T-cell frequencies. (F) Correlation between E coli in lymph nodes and Vδ2 T-cell frequencies. P values were calculated using the Mann-Whitney U test, and correlations were determined using the Spearman rank test.