Nef increases macrophage infiltration in tumors and promotes macrophage tissue accumulation. (A) Representative histological sections of (top) intestine mucosa villi, (middle) liver, and (bottom) medulla area of kidney of non-Tg and CD68/HIV^Nef-Tg mice stained with F4/80 antibodies (macrophages) and counterstained with hematoxylin (nuclei). Scale bars, 50 μm. (B) Intestine: percentage of the F4/80-stained surface relative to the villi surface, n = 5, 3 sections per mouse. Liver and kidney: quantification of the number of F4/80-positive cells, n = 7 and 8, respectively, 3 sections per mouse. Box without whisker plots (interquartile range) and all dot plots (gray) are shown with mean value (red line). (C) Representative flow cytometry analysis of C3L5 tumor-infiltrated hematopoietic cells stained for CD45.2, CD11b, F4/80, and Gr1. CD11b- and F4/80-positive cells are illustrated, after gating on CD45.2⁺/Gr1^low cells. (D) Number of F4/80-positive cells inside tumors: n = 14 for CD4C/HIV^Nef-Tg and n = 16 for non-Tg mice.