Herpes Simplex Virus Type 2 Primes Mouse Macrophages for an Early and Genetically Determined Respiratory Burst Mediated by Interferon- /beta

The influence of infection by herpes simplex virus type 2 (HSV-2) on the respiratory burst capacity of mouse macrophages was studied by luminol-dependent chemiluminescence with phorbol myristate acetate (PMA) as trigger. Peritoneal cells from virus-infected mice were strongly primed for a respiratory burst during the acute phase of the infection. By 12 h after infection the response had increased 40-fold over control values. Most of the response was elicited by mononuclear phagocytes. When resting peritoneal macrophages were infected with HSV-2 in vitro a maximal priming effect was seen with 2 x 10(6) p.f.u./ml of virus after 8 h, but a significant response was obtained after 4 h of infection; after 12 h incubation with virus the response declined to reach background levels at 24 h. Peritoneal cells from C57BL/6 mice which are relatively resistant to HSV-2 showed a higher respiratory burst capacity after infection than cells from more susceptible BALB/c mice. Incubation of macrophages with crude niurine interferon (IFN)-alpha/beta produced by macrophages or purified murine IFN-alpha, in concentrations comparable to those obtained early (2 to 5 h) after infection of macrophage cultures with HSV-2 also augmented the respiratory burst. Addition of an IFN-alpha/beta-specific antiserum to HSV-2-infected cultures almost completely removed the response. We therefore conclude that HSV-2 induces an early and genetically determined activation of macrophages, mediated in an autocrine manner by IFN-alpha/beta secreted by the macrophages early during infection.