Effect of cross-immunization on monotypic antibody responses to herpes simplex virus types 1 and 2

New Zealand White rabbits were immunized subcutaneously with partially purified UV-inactivated preparations of herpes simplex virus (HSV-1 or HSV-2) in complete Freund's adjuvant. After the initial immunizations, designated groups of animals received additional amounts of either HSV-1 or HSV-2 at 35-day intervals. Sera were absorbed with lysates of cells infected with heterotypic virus and the residual monotypic antibodies were detected by 51Cr-release assay using HSV-infected target cells. A positive correlation was found between the ratio of neutralizing antibodies to HSV-1 and HSV-2 (II/I index) and the content of monotypic antibodies. Results showed that production of monotypic antibodies to HSV-1 And HSV-2, under the conditions employed, was independent of previous exposure to HSV.