Protective immunity against herpes simplex virus generated by DNA vaccination compared to natural infection

To evaluate the utility of plasmid DNA vaccination against disease caused b y herpes simplex virus (HSV), we compared the strength of protection agains t lethal challenge following natural virus infection with that following va ccination with a plasmid encoding HSV glycoprotein go (gD-DNA). We further determined the cellular basis of each type of protection using lymphocyte d eficient knockout mice. Establishment of immunity to HSV using live virus i mmunization required CD8 (+) T cells and B cells, but not CD4(+) or gamma/d elta (+) T cells, and was related to specific antibody levels: surprisingly , CD4 knockout mice had large quantities of IgG anti-HSV serum antibodies. Establishment of immunity to HSV using gD-DNA immunization approached the s trength of that generated following sublethal infection, but was dependent on alpha/beta (+) CD4(+) T cells, CD8(+). T cells, B cells, and even partia lly on gamma/delta (+) T cells, and not strictly correlated with antibody l evels. (C) 2001 Elsevier Science Ltd. All rights reserved.