A simplified method for the production of murine T-cell growth factor free of lectin

A simple and rapid method for the production of TCGF free of lectin (LF-TCGF) is described. Murine splenocytes are exposed to 10--20 micrograms/ml Con A for 2 h before washing the cells and incubating them in medium for an additional 20 h. This procedure leads to the same titers of TCGF activity obtained when Con A is presented throughout the incubation time. The resulting TCGF preparation is free of Con A as evidenced by its inability to activate fresh resting lymphoid cells and by measurements using [3H]Con A in tracer amounts. The LF-TCGF is capable of growing activated but not resting lymphocytes and can lead to greater than 50-fold increase in the generation of cytotoxic cells in in vitro sensitizations to alloantigens.