HIV virions and HIV infection in vitro are unaffected by human granzymes Aand B

Granzymes are a family of serine proteinases commonly found in the granules of CD8(+) T cells. In HIV infection, CD8(+) cells show cytotoxic and noncy totoxic antiviral activities. The latter is mediated, at least in part, by a secreted CD8(+) cell antiviral factor, CAF. Because of the antiviral natu re of CD8(+) cells, we examined the potential anti-HIV activity of free gra nzymes that can be found in CD8(+) cell culture fluids. Pretreatment of CD4 (+) T cells with granzyme A or granzyme B had no effect on their susceptibi lity to infection with HIV, nor did incubation of the granzymes with HIV vi rions alter their infectivity. Continuous culture of acutely infected CD4() T cells with granzyme A or B showed no effect on cell viability or the re plication of HIV. The findings of this study suggest that free granzymes do not control HIV infection and spread in CD4(+) T cells.