RESUMO
Cell cultures of monkey prepuce (Rhfs) and African green monkey kidney (BSC-1) were infected once with simian Mason-Pfizer virus (MPV) and virus expression in the course of establishment of chronic infection was studied. The productive infection was characterized by changes in the cell metabolism (DNA synthesis increased 2-3-fold as early as the "zero" passage), the appearance of gs-antigen, formation of virions of type D and high activity of RNA-dependent DNA-polymerase. Multinuclear giant cells appeared only in the infected Rhfs cell culture most sensitive to MPV. In human embryo kidney culture (HEK) productive infection was also established however, HEK cultures did not survive after 3-4 passages. No signs of transformation could be found in any of the cultures studied.