Influence of mercuric chloride on resistance to generalized infection with herpes simplex virus type 2 in mice

The effect of mercuric chloride on resistance to generalized infection with herpes simplex virus type 2 (HSV-2) in mice was studied. The severity of the infection was evaluated by the amount of infectious virus in the liver. Mercury at a single dose of 20 micrograms aggravated the infection, and neither increasing the single dose to 80 micrograms nor giving repeated doses of 20 micrograms further intensified the infection. Examination of the course of infection after mercury exposure revealed an increased virus replication and dissemination during the first days of the infection, indicating that the early, nonspecific defence mechanisms were affected. Virus clearance and elimination, which is mediated by specific immunity, seemed not to be influenced. Examination of cells from the peritoneal cavity and of livers from virus-infected mice showed that mercury detectable by autometallography was exclusively found in mature peritoneal macrophages and in Kupffer cells of the liver. Inflammatory cells, recruited to the peritoneal cavity or infiltrating the infectious foci of the liver, did not show any mercury deposits. Attempts to demonstrate an effect in vivo of mercury on potential antiviral macrophage functions like interferon-alpha/beta (IFN-alpha/beta) and tumour necrosis factor-alpha (TNF-alpha) secretion and oxidative burst capacity were not successful, possibly because recruited, inflammatory cells, which have not been exposed to the high mercury concentrations at the site of injection, take over these functions of intoxicated macrophages.