pDCs are recruited to the colorectum after SIV infection. (A) Frequency of pDCs and mDCs in the colorectum of uninfected and SIV-infected RMs at indicated times PI. ART-treated macaques received 22 weeks of therapy at 18 weeks PI. FACS plots depict representative data from an uninfected and SIV-infected animal. (B) Frequency of pDCs in the blood and colorectum of SIV− or SIV+ SMs. (C) Affymetrix GeneChip heat map with linear fold change values of MX1, MX2, and OAS2 gene expression in the colorectum of uninfected and chronically SIV-infected RMs and SMs. Numbers indicate individual animals. SIV+ RMs were at 11 weeks PI and SIV+ SMs were naturally infected for at least 1 year. Genes represented here are considered significant if they were regulated at least 1.5-fold and have a P value cut-off of .05 (adjusted for multiple hypothesis testing using the Benjamini-Hochberg false discovery rate method). Color scale represents level of gene expression, where −1 indicates very low level of expression, 0 indicates median level of expression, and +1 indicates high level of expression. Fold change values were calculated against uninfected RMs or uninfected SMs.