Immunity of babesia divergens in the rat: histology of the infected liver and Its possibil role in removing PRBC'S

ABSTRACT

The possible removal of B. divergens PREC's by the livers of immune splenectomized rats was investigated. The clearance of Cr51 labeled B. divergens infected erythrocytes was followed in splenectomized rats to test whether Cr51 labeled PREC's are cleared from the circulation of immune rats through the uptake and the phagocytosis by the liver. No significant difference was observed between the clearance radioactivity from the circulation as well as the liver uptake in the immune rats and the controls. The injection of irradiated parasites into the same rats showed that they were able to clear PRBC's from the blood stream and immunity was not specifically directed at merozoites. It was speculated that the parasites inside the red cells are removed by lysis or phagocytosis. Histological studies on livers collected from immune rats showed that lymphocytes are accumulated in the liver; therefore, those consisting of B and T cells leukocytes accumulating in the liver might be very important in the development of acquired immunity to B. divergens in splenectomized rats