Pathogenesis of SIVmac infection in Chinese and Indian rhesus macaques: effects of splenectomy on virus burden.

The spleen and lymph nodes are the predominant sites of viral replication in SIV and HIV infections. We studied splenectomized and control unsplenectomized rhesus macaques of both the Indian and the Chinese subspecies of Macaca mulatta. All animals were inoculated with SIVmac239, a molecularly cloned strain of SIV. Our data showed: (1) splenectomized animals, particularly among the Indian subspecies, had a lower virus burden and longer survival than unsplenectomized controls, (2) the Chinese macaques controlled virus replication more effectively than did the Indian animals, and (3) that a higher infectious virus burden was present in LN/spleen than in blood in both splenectomized and control animals.