Development of a serum-free medium for in vitro immune responses by using beta-cyclodextrin. Demonstration of the requirements for polyamines.

A serum-free medium has been developed which is able to support primary antibody responses by cultured murine lymphocytes. This medium is based on RPMI 1640 that is supplemented with beta-cyclodextrin, insulin, transferrin, albumin, low density lipoprotein, putrescine and L-alanine as substitutes for fetal calf serum. Omission of anyone of these components resulted in a marked decrease of antibody responses. By employing the serum-free culture conditions, it was clearly demonstrated that polyamines such as putrescine, spermidine and spermine had positive effects on the development of antibody-forming cells. This serum-free medium supported the antibody response to sheep erythrocytes, trinitrophenyl (TNP)-Ficoll or TNP-lipopolysaccharide as efficiently as 10% fetal calf serum-containing medium. In addition, murine lymphocytes proliferated in response to an antigen or a mitogen equally well in these two types of medium.