Herpesvirus papio 2, an SA8-like α-herpesvirus of baboons

Abstract

Several SA8 isolates obtained from baboons were compared to the prototype SA8 herpesvirus of African green monkeys. SDS-PAGE and restriction enzyme analyses revealed definite differences between green monkey and baboon isolates. DNA and amino acid sequences of the gB, gD and gJ glycoprotein genes exhibited substantial differences in variable regions. For the gB and gD, the amount of amino acid substitutions between SA8 and the baboon viruses was comparable to levels observed between analogous genes of SA8 & B virus or HSV1 & HSV2. Although a high degree of antigenic cross-reactivity was apparent, virus-specific antigenic determinants were also readily detected. Phylogenetic analyses supported separation of the baboon isolates and SA8 as distinct viruses. Taken together these results suggest that although closely related to SA8, the baboon viruses represent a distinct simian alpha-herpesvirus which we propose be designated Herpesvirus papio 2.

The genome of herpesvirus papio 2 is closely related to the genomes of human herpes simplex viruses

“…Furthermore, these results provide extensive supporting evidence that the genomes of HVP-2 and HSV are closely related. The results of these studies combined with previous genetic, pathogenic, and serologic analyses further demonstrate the close relationship between HVP-2 and HSV (Bigger & Martin, 2002;Eberle et al, 1995Eberle et al, , 1997Eberle et al, , 1998Levin et al, 1988).…”

“…In 1985 an epizootic outbreak of a simplex-like virus occurred in a captive baboon colony (Eberle et al, 1995;Levin et al, 1988). The virus associated with this outbreak was serologically similar to simian herpesvirus SA8.…”

“…However, DNA sequence analysis of genes predicted to encode glycoproteins B, D and J (gB, gD and gJ) revealed that this virus was genetically distinct from SA8. As a result, the baboon isolates were designated herpesvirus papio 2 (HVP-2) (Eberle et al, 1995). HVP-2 infection of baboons produces a disease that is clinically similar to herpes simplex virus (HSV) infection of humans.…”

Pathogenicity of Different Baboon Herpesvirus Papio 2 Isolates Is Characterized by either Extreme Neurovirulence or Complete Apathogenicity

“…For many years the baboon virus HVP2 was assumed to be identical to SA8 (9,11,12,17). However, more recent studies show that, while very closely related to SA8, baboon isolates represent a distinct virus (1,7). Similar to the case for BV in macaques, more than 90% of adult baboons show serological evidence of infection with HVP2, and clinically evident disease due to HVP2 is uncommon (6,27).…”

“…Because of the similarity between HVP2 and the apathogenic SA8 and the lack of any reported human infections, baboon HVP2 has largely been considered unimportant from a zoonotic standpoint. However, during the production of immune-phase sera in mice, rapid-onset death was observed in mice inoculated intraperitoneally with one isolate of HVP2 (7). In a recent study comparing SA8 and HVP2 to HSV1 in a mouse model, two strains of HVP2 were found to readily invade the central nervous system (CNS) following peripheral intramuscular in-oculation (which most closely resembles a bite or scratch), producing paralysis and death (22).…”