Requirement of a combination of a saturated and an unsaturated free fatty acid and a fatty acid carrier protein for in vitro growth of lymphocytes.

Two FFA, 1 saturated and 1 unsaturated, and a FFA carrier protein are essential for in vitro growth of Con A-stimulated lymphocytes. Optimal growth was obtained with a combination of palmitic and oleic acid. As carrier proteins, serum albumin and beta-lactoglobulin served equally well. Palmitic and oleic acid could be replaced by other saturated and unsaturated FFA, respectively. The effectiveness of unsaturated FFA was influenced by the chain length, the number of double bonds, and the configuration at the double bond. The position of the double bond appeared to have no effect. 125I-HSA binds to lymphocytes in a specific and nonspecific way. beta-Iac competes with 125I-HSA for the SA-binding sites. The specific binding and the growth supporting ability of SA have a similar dose response.