Using adoptive transfer models we determined that an adeno-associated viral vector of serotype 2 (AAV2) induces in mice proliferation of CD8+ T cells that recognize an epitope within the viral capsid. Proliferation to an endogenous epitope within viral protein (VP)3 could be observed for at least 3 weeks while a foreign epitope placed at multiple copies within VP2 elicited CD8+ T cell expansion for at least 10 weeks. These data show that capsid antigens of AAV2 degrade slowly over a period of weeks and during this period provide targets to CD8+ T cells. [ABSTRACT FROM AUTHOR]