The immunosuppressive effect of mycoplasma infection. I. Effect on the humoral and cellular response.

Mycoplasma-induced immunosuppression in rats was demonstrated with strain PN. Immunosuppression involving the humoral antibody response was complete or partial when mycoplasma was injected concurrently with the antigen. Mycoplasma did not interfere with the antibody response when injected after primary immunization. Inhibition of blast transformation was shown to occur in lymphocytes derived from rats infected with the above mycoplasma. The inhibition was partial or complete depending on the interval between the infection and the time when the lymphocytes were taken from the animal, and blast transformation reverted to normal when the infection was over. Although the question of mechanism remains open, it was concluded that immunosuppression might be the result of the effect of on a particular population of cells.