Expression of HIV in lymph node cells of LAS patients. Immunohistology, in situ hybridization, and identification of target cells.

Monoclonal antibodies (MAb) anti-HIV core and envelope proteins and in situ hybridization, using cDNA HIV probe, were employed to determine which lymph node cells in LAS patients express viral antigens and viral nucleic acids. The results have been correlated with the histologic phases of LAS and with the germinal center lysis detected using DRC-1 MAb directed against follicular dendritic reticulum cells (FDRC). Viral antigens occasionally were detected on high endothelial cells of paracortical venules and frequently on germinal center FDR accessory cells; this last finding correlates well with the extent of FDRC lysis and of CD4+ and CD8+ lymphocyte infiltration in germinal centers. HIV replication, detected by in situ hybridization, was observed in mononucleated cells present in T and B areas and, in one case, in flat endothelium.