Heterogeneity in the Properties of 7 S and 19 S Rabbit-Neutralizing Antibodies to Herpes Simplex Virus

Summary The 7 S and 19 S rabbit antibodies to herpes simplex virus (HSV) from early and late (hyperimmune) sera differed in their ability to sensitize virus for subsequent neutralization by either complement (C′) or anti-γ-globulin (GAR). The early 7 S and 19 S antibodies showed low to negligible neutralizing activity in the absence of C′ or GAR. When C′ was added, however, both of these antibodies showed enhanced neutralizing activity. The early 7 S but not the early 19 S antibody was also capable of sensitizing virus for subsequent neutralization by GAR. The late 19 S antibody could neutralize virus in the absence of C′ or GAR, but its activity was enhanced in the presence of C′ or GAR. The late 7 S antibody showed high neutralizing activity in the absence of C′ or GAR. In the presence of C′, the neutralization rate constants (K) but not the neutralization titers of the late 7 S antibody were enhanced. In contrast, the neutralization titers of the late 7 S antibody were enhanced approximately threefold with GAR. The neutralizing activity of the early and late 19 S antibodies with C′ or GAR was sensitive to inactivation by 2-ME. Similarly, the neutralizing activity with C′ of the early 7 S antibody and the enhanced rate of neutralization with C′ of the late 7 S antibody were sensitive to inactivation by 2-ME. In contrast, 2-ME did not reduce the neutralization titers of the early and late 7 S antibodies in the presence of GAR.