CELLULAR IMMUNITY OF RATS TO TULAREMIA

Abstract

Mononuclear leucocytes harvested from the peritoneal cavities of rats recovered from infection with Pasteurella tularensis, and from those immunized with a killed vaccine, conferred significant resistance against this organism when transferred to normal recipients. It was determined that a minimum of 3.7 × 10⁷ leucocytes/rat was required for protection and that only intact cells were effective in providing immunity. The immune response was shown to be specific for tularemia, and was of the passive type, disappearing between 15 and 18 days following cell transfer.