Herpes simplex virus type-1 and human lymphocytes: virus expression and the response to infection of adult and foetal cells.

The growth of Herpes simplex virus type I (HSV-I) in human lymphocytes of adult and foetal origin was studied. Virus DNA synthesis, antigen and particle production and the yield of infectious progeny were determined in cultured lymphocytes with or without exposure to stimulating concentrations of the mitogens phytohaemagglutinin and pokeweed mitogen. Separated sub-populations of cells were examined and the conclusion reached that only the stimulated T-lymphoblast was permissive for full virus expression. Stimulation of cell DNA synthesis in response to infection was observed in cultures of adult and foetal lymphocytes under conditions which were nonpermissive for virus growth. Morphological change and prolonged culture survival were a feature of foetal lymphocytes exposed to u.v. irradiated HSV-I.