Human immune sera were analyzed by an immunoblot procedure in order to identify which polypeptides of herpes simplex virus type 1 were recognized and to determine the relative concentrations of antibodies to individual viral antigens. The strongest reactivity in all immune sera examined was directed against the three major herpes simplex virus-specific glycoprotein antigens (gAB, gC, and gD) and a series of uncharacterized low-molecular-weight polypeptides. Titers of antibody to the gC and gD antigens varied among individuals and were often considerably lower than titers of antibody to the gAB antigen. Immune sera also recognized a number of nonglycosylated polypeptides, both structural and nonstructural. No consistent differences were noted between the recognition of particular viral polypeptides by sera from individuals with frequent, recurrent labial lesions and that by sera from individuals with infrequent, recurrent lesions. However, the ratio between the titer of antibody to the gAB antigen and that to the gC antigen did appear to be somewhat lower in sera from persons with a high recurrence rate.

Employing an immunoblotting technique, the polypeptide specificity and relative titers of anti-HSV IgG reactive with denaturation-resistant epitopes on HSV proteins were determined in patients experiencing primary HSV-1 infections at various anatomical sites. Early sera from previously seronegative patients with primary HSV-1 infections were found to have comparatively low levels of antibody directed against the major viral glycoprotein antigens (gB, gC, and gD) relative to titers present in sera of individuals with long-standing, latent orofacial HSV-1 infections. Patients with primary infections did however have high titers of antibody directed against a series of low molecular weight HSV polypeptide antigens. These antigens were found to be antigenically related to a structural component of virion nucleocapsids. At later times postinfection, titers of antibodies directed against other viral polypeptides including the major glycoproteins increased to levels more closely approximating those observed in latently infected individuals. These results indicate that the anti-HSV IgG detected by immunoblot analysis which appears earliest following primary infection is not directed against the known major infected cell or virion glycoprotein surface antigens but rather against an internal capsid protein of HSV.

SUMMARYRelative IgG titres to specific viral proteins in acute and convalescent sera from patients with primary and recurrent genital herpes simplex virus type 2 (HSV-2) infections were determined using an immunoblot assay. Patients with recurrent genital infections generally had high titres of antibody reactive with two of the three major viral glycoproteins (gD and gG) as well as with several viral capsid proteins in both acute and convalescent sera. In contrast, patients experiencing primary genital HSV-2 infections exhibited marked differences in the polypeptide reactivity profiles of acute and convalescent sera. Of particular interest was the observation that the earliest and strongest antibody response was directed not against the viral glycoproteins but rather to an internal capsid protein(s) of HSV-2.

Biological and biochemical properties of two neurotropic herpesviruses of New World monkeys--Herpesvirus saimiri type 1 (HVS-1) and Herpesvirus ateles type 1 (HVA-1)--were examined and compared. HVS-1 and HVA-1 both exhibited a time course of replication similar to another primate herpesvirus, SA 8. Both viruses grew rapidly and high titers of infectious virus were readily produced. HVS-1 and HVA-1 were also able to replicate efficiently in cell lines derived from a number of primate and non-primate species. Analysis of proteins synthesized in infected cells revealed the presence of over 30 virus-specific proteins ranging from less than 30,000 to over 200,000 daltons apparent molecular weight. Both viruses specified synthesis of a major capsid polypeptide of 148,000 daltons. Pulse labeling of cells during infection demonstrated temporal differences in the kinetics of synthesis of individual viral proteins and post-translational modification of a number of viral polypeptides. Glycosylated polypeptides synthesized in HVS-1 and HVA-1 infected cells were identified which ranged from approximately 49,000 to 120,000 daltons. Structural polypeptides of HVA-1 and HVS-1 virions were identified by SDS-PAGE analysis of purified virions. Taken together with clinical data on the diseases caused by these viruses, these studies indicate that HVS-1 and HVA-1 appear similar in many respects to both the human herpes simplex viruses and alphaherpesviruses of other primates.