B cells and HSV-specific antibodies respond to HSV-2 reactivation in skin

Tissue-based T cells increasingly have been shown to be important effectors in the control and prevention of mucosal viral infections - less is known about tissue-based B cells. We demonstrate that B cells and antibody-secreting cells (ASCs) are present in skin biopsies of persons with symptomatic HSV-2 reactivation. CD20+ B cells are observed in inflammatory infiltrates at greatest density at the time of symptomatic reactivation; HSV-2-specific antibodies to HSV-2 surface antigens are also detected. The concentrations of HSV-2-specific antibodies in tissue biopsies vary over the course of HSV-2 reactivation and healing, unlike serum where concentrations remain static over time. B cells and HSV-specific antibody were rarely present in biopsies of unaffected skin. Investigation of serial biopsies over the course of lesion healing suggests that B cells follow a more migratory than resident pattern of infiltration in HSV-affected genital skin, in contrast to T cells. Together, these observations may suggest a functional and distinct role of tissue-based B cells in the local immune response to HSV-2.