KINETICS OF PRIMARY SIV INFECTION IN LYMPH-NODES

The very early stages of SIV infection in lymph nodes of rhesus monkey s were characterized by in situ hybridization. Massive viral replicati on was detected in macrophages and lymphocytes during the first week o f infection. In a second phase, SIV RNA concentrated in the developing germinal centers, and colocalized with the follicular dendritic cells . The down-regulation of the viral load in lymph nodes varied dependin g on the animal, indicating early differences in the susceptibility to SIV infection.