MECHANISMS OF PROTECTION INDUCED BY ATTENUATED SIMIAN IMMUNODEFICIENCY VIRUS .4. PROTECTION AGAINST CHALLENGE WITH VIRUS GROWN IN AUTOLOGOUS SIMIAN CELLS

Attenuated simian immunodeficiency virus (SIV) induces potent protecti on against infection with wild-type virus, but the mechanism of this i mmunity remains obscure. Allogeneic antibodies, which arise within ani mals as a result of SIV infection, might protect against challenge wit h exogenous SIV grown in allogeneic cells. To test this hypothesis, ei ght macaques were infected with attenuated SIV and subsequently challe nged with wild-type SIV grown in autologous cells or heterologous cell s. The results clearly demonstrated that animals infected with attenua ted SIV are protected against wild-type SIV grown in autologous or het erologous cells. Thus, the hypothesis that live attenuated SIV protect s by the induction of allogeneic antibodies is not tenable.