الملخص

ABSTRACT The present study was investigated the immunological effects of the lipopolysaccharide extracted from Klebsiella pneumoniae against experimental infection with toxoplasmosis in mice. Immunological changes in treated mice were compared with the +ve (mice infected with T.gondii but not treated with LPS) and -ve (mice not infected with T.gondii and not treated with LPS) group at 3,14 and 30 days post infection with tissue cysts of T.gondii in the peritoneal cavity. Total and differential WBC count of peripheral blood and innate immune response represented by the phagocytic index were the criteria taken into consideration. Results showed a significant increase in the total WBC count in mice treated with LPS after infection with T.gondii, compared with –ve and +ve control groups. For differential WBC count, an increase in lymphocytes and decrease in monocytes, neutrophils and eosinophils was noticed. Basophils were not considered because of their low number.For phagocytic index, an increase was noticed in treated mice compared with –ve and +ve control groups, and the highest rate was observed in cncentration 500 µg / 20 gm body weight at 30 days post infection. It is concluded that, LPS extracted from K.pneumoniae may well be used as a active and non toxic immunomodulator against infection with toxoplasmosis in mice.