Study of Immune Cytotoxicity with Herpesvirus hominis Infected Cells 1

Abstract

Summary

Immune cytotoxicity of herpesvirus-infected cells was studied by means of a direct cytotoxicity test which used failure to attach after treatment with antiviral serum and complement as a measure of cytotoxicity. Cells infected with herpesvirus, as well as uninfected cells, were found to settle out of suspension and attach to the surface of containers within one hour after suspension. Infected cells appeared to be damaged by serum-complement treatment and were unable to attach. Immune cytotoxicity was found to be complement-dependent, since either omission or heating of the normal rabbit serum used as a source of complement eliminated the cytotoxic effect. Cell susceptibility to cytotoxic effects was found to be directly related to viral multiplicity of infection and presumably, therefore, to the proportion of infected cells. Infected cells were not susceptible during the first four hours after viral infection, but developed this susceptibility within 5–6 hours after infection. Anti-serum produced by either corneal or intramuscular routes of inoculation exhibited cytotoxic activity. Cytotoxic titers of anti-serum were calculated as the log₁₀ of the highest dilution of serum producing a 50% reduction in cell attachment, and titers of eleven rabbit anti-sera varied from 1.2 to 2.5. The cytotoxic reaction was not type specific and anti-sera produced against either type 1 or type 2 herpesvirus exhibited cytotoxicity for cells infected with either type.