Background: CD48, CD150 and CD244.2 are the signaling lymphocytic activation molecules (SLAM) of hematopoietic population expressed on the T cells, B cells, monocytes, macrophages and play an important role in adaptive immune response. Aim: The present study aims at evaluating the individual circulating levels of these SLAM markers in response to electron beam radiation and the protective effects of Carica papaya (L.) and DADS intervention. Methods and Material: The mice were fed orally with 100mg/kg body weight of papaya leaf extract and 10mg/kg body weight of DADS. The extract and DADS were administered to individual groups for 5 consecutive days with respective control groups and exposed to 6Gy of electrons radiation. Results: The present study indicated significant rise in the CD244.2 levels in irradiation control and a near normal levels in groups with C.papaya and DADS intervention. A significant decrease in the CD48 expression of granulocytes is seen in radiation control group on comparison to the normal control group. A significant rise is seen in the CD48 expression of granulocytes with DADS treatment prior irradiation when compared to DADS control. A significant increase in the granulocyte CD150 expression with DADS treatment prior irradiation group is seen when compared to the DADS control group. In DADS treatment prior irradiation compared to radiation control the CD244.2 expression in granulocytes is significantly lowered. Conclusion: Study suggests a potential increase in the percentage of CD244.2+ lymphocytes in response to electron beam radiation and a comparative decrease in the percentage of CD244.2+ lymphocytes in C.papaya leaf extract and DADS intervention.
Key words: SLAM markers, Immune suppression, Hematopoietic progenitors, CD48, CD150, CD244.2, NK cell, Cytotoxicity.