FIG 3.

SIV RNA⁺ cells in inguinal LN and foreskin. Cells containing vRNA (brown) were detected in tissue sections using in situ hybridization with antisense SIV-specific riboprobes. The interval between the time of SIV inoculation and the time of tissue collection is indicated for each row. (A, B, and E to H) Sections of tissue from animals inoculated with SIVmac251 hybridized with antisense SIV-specific riboprobes. (C and D) Sections of tissue from an animal inoculated with AT-2-inactivated SIV and necropsied at 1 day p.i. (C) A normally processed section hybridized with antisense SIV-specific riboprobes. (D) RNase treatment prior to hybridization with antisense SIV-specific riboprobes. Arrowheads in panel C, areas in the section with abundant vRNA staining in a faint reticular pattern that is consistent with extracellular SIV virion RNA; arrowheads in panel G, 3 of the few SIV RNA⁺ cells within the T cell zone of the LN. Bars = 20 μm (A to E), 50 μm (F, H), and 100 μm (G). A DAB label and hematoxylin counterstain were used.