Primary cytotoxic response of bovine peripheral blood leukocytes to parainfluenza type 3 virus infection.

Peripheral blood mononuclear cells were isolated from calves following Parainfluenza Type-3 (PI-3) virus infection and incubated with autologous and non-autologous PI-3 virus-infected muscle cells in a 4 h chromium release assay. Peaks of cytotoxicity, which ranged from 12% to 53% were observed between Days 6 and 9 post infection, with an effector to target cell ratio of 100:1. Killing of PI-3 virus-infected or uninfected mismatched muscle cells was never more than 5%.