Human CD4+ CD25high cells suppress proliferative memory lymphocyte responses to herpes simplex virus type 2

Lymphocytes with the regulatory CD4(+) CD25(+) phenotype frequently suppress memory T-cell responses. Murine herpes simplex virus type 1 (HSV-1) models have shown that CD4(+) CD25(+) cells can limit immunity-mediated corneal damage but slow viral clearance. We investigated the effect of CD4(+) CD25(+) cells from healthy HSV-2-infected humans on recall proliferative (CD4) responses to HSV-2. Depletion and reconstitution experiments were consistent with a suppressive effect of autologous blood-derived CD4(+) CD25(+) cells for whole HSV-2 antigen. Regulatory T cells may modulate human CD4 memory responses to HSV-2 and influence their antiviral and inflammatory functions.