Loss of the short-lived suppressive function of peripheral leukocytes in feline retrovirus-infected cats.

Normal feline peripheral blood mononuclear cells demonstrated increased phytomitogen blast transformation after a 24 hr delay in mitogen addition as compared to 0 hr mitogenesis. Increased stimulation after 24 hr which is not due to enhancing factors accumulating in the culture medium has been attributed to a short-lived suppressor cell which loses its effect after 24 hr in culture. This short-lived suppressive phenomenon was studied in normal specific-pathogen-free cats and compared to experimental animals infected with retrovirus (FeLV). Experimental cats demonstrated a subsequent loss of this function following acquisition of a persistent viremia.