Human CD4⁺ CD25^high 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.