Proliferative Response of Hamster CD4+ T Cells after Different Mitogenic Stimulation
The measurement of effector cells involved in immune responses is an important parameter in various fields of lymphocyte research using the Syrian Golden hamster as the experimental model. The aim of the present study was to identify the percentage of peripheral hamster CD4+ cells that undergo proliferation and the number of cell divisions induced by four different mitogenic compounds: phorbol-myristate acetate plus ionomycin (PMA/ionomycin), concanavalin A (Con A), phytohaemagglutinin (PHA) and the superantigen Staphylococcal enterotoxin B (SEB). The proliferative response was investigated by the use of the cross-reactive mouse anti-CD4 antibody (clone H129.9) and analyzed by flow cytometry using the dye carboxyfluorescein diacetate succinimydil ester (CFSE). PMA/ionomycin induced the highest proliferative response of CD4+ cells. Interestingly, the down-regulation in the CD4 expression described after PMA/ ionomycin activation both in human and in mouse lymphocytes was not seen in hamster cells. Stimulation with SEB and with Con A also induced up to 6 to 7 proliferation cycles in cells, whereas PHA induced the lowest proliferation. These results provide useful tools for the study of CD4+ cells in the hamster model.