IN-VITRO PROLIFERATIVE RESPONSES OF HUMAN PERIPHERAL-BLOOD MONONUCLEAR-CELLS TO NON-RECALL ANTIGENS

Primary in vitro proliferative responses of naive T cells to antigens other than superantigens and alloantigens have been little studied. Tw o tissue culture techniques have been reported which support in vitro antigen priming of T cells. These methods require various degrees of c ellular manipulation and culture vessels other than standard microtitr e plates. We report here that primary proliferative responses to non-r ecall antigens can be readily obtained using unselected human PBMC pre pared from either adult or cord blood. Cells proliferate whether cultu red in 2 ml volumes, 200 mu l microcultures or 20 mu l hanging drops. The variation in the proliferative responses increases as the culture volume is decreased such that considerable errors are apparent when Te rasaki culture plates are used. The lowest stimulation indices are als o observed in the 20 mu l microcultures. Nevertheless, similar respons e patterns are noted for the differing culture vessels; generally, pro liferative responses reach peak magnitude only after 7 days of culture . The initial concentration of PBMC in culture influences the magnitud e of the reactions such that halving the cell numbers frequently leads to greater than 50% reduction in the measured responses. The results of this study indicate that neither a specialised culture vessel nor c omplex cellular manipulation are required for in vitro priming of T ce ll immunity. Consequently, this area of immunology should be readily a menable to further study.