FIG. 4.

SIV RNA⁺ cells in LN samples taken at 2 weeks p.i. from a Δnef-infected (Mm16) and a SIVmac239-infected (Mm18) rhesus macaque. (A and B) Mm16; (C and D) Mm18. Serially sectioned tissue specimens were stained either by in situ hybridization with antisense SIVmac239 RNA (A and C) or with an anti-CD20 antibody (B and D) to stain B cells. SIV RNA⁺ cells (blue) were localized in a region rich in CD20⁺ B cells (brown) in LNs of rhesus macaques infected with Δnef. By contrast, SIV RNA⁺ cells were localized outside a region rich in CD20⁺ B cells in LNs of rhesus macaques infected with SIVmac239.