IDCs from lymph nodes of monkeys with AIDS have markedly reduced expression of CD83.

(A-B) Lymph node cells were stained with mAb to HLA-DR and p55 to identify IDCs. (A) Representative dot plots of cells from a healthy monkey stained with mAb to HLA-DR and either control IgG (left) or p55 (right), showing the HLA-DR^hi p55⁺ IDC (R1). (B) On the left the proportion of HLA-DR^hi p55⁺IDCs in unseparated lymph node cells from normal, healthy monkeys (N, n = 5) and monkeys with acute SIV infection (A, n = 5) or AIDS (n = 5) is shown. IDCs are reduced in lymph nodes of monkeys with AIDS relative to normal animals (P = .05). On the right, the expression of CD83 on the HLA-DR^hip55⁺ IDCs is shown. Expression of CD83 is reduced in monkeys with AIDS compared to normal animals (P < .0005). Each circle represents a different animal, and horizontal bars represent the mean. (C-E) Lymph node sections from a healthy monkey (C) and monkeys with acute SIV infection (D) or AIDS (E) were labeled by in situ hybridization for CD83 RNA (black) and immunohistochemistry for p55 protein (brown). Double-labeled IDCs in lymph nodes of the healthy monkey and monkey with acute SIV infection are highlighted by arrows. Ab staining was detected using streptavidin-peroxidase with diaminobenzidine substrate. Tissues were counterstained with hematoxylin. Original magnification × 600.