Suppression of humoral immune response against herpes simplex virus induced by defective strains, ts- and TK- mutants.

Suppression of humoral antibody formation against HSV is not only induced by replicating Herpes simplex virus type 2 (HSV-2) but also by the defective strain ANG and the deletion mutant 1301 of Herpes simplex virus type 1 (HSV-1). Moreover, ts-mutants A, H, K, S, 1201 and 1208 of HSV-1 as well as some ts-mutants of HSV-2 and "defective-interfering" particles of HSV-1 after high multiplicity of infection-passages induced suppression. Treatment of infected mice with ACG reduced antibody-formation but did not result in suppression. UV-irradiation of the antibody producing strain Len of HSV-1 strongly reduces antibody formation and induces suppression. Experiments using a series of intertypic recombinants showed the suppressing activity to be spread over the whole genome of HSV-2. It is concluded that suppression is induced by more than one region of the genome of HSV-2 and by incomplete replication of HSV-1 and 2.