In order to induce the primary antibody response to sheep erythrocytes in vitro in murine lymphocytes, the cells are usually cultured in RPMI-1640 medium containing 10% fetal calf serum (FCS). When FCS was replaced by calf serum (CS) or newborn bovine serum (NBS), the antibody response was poor compared with that obtained with FCS. However, a comparable response was induced when CS or NBS was added at 1% to the culture medium in combination with 500 micrograms/ml beta-cyclodextrin (beta-CD). In the presence of beta-CD, the response was the highest when CS or NBS was added at 1%. An important observation was that all the lots of CS (5 lots) and NBS (2 lots) tested supported the response equally in the presence of beta-CD. The anti-sheep erythrocytes response induced by 1% CS or NBS in the presence of beta-CD was shown to be completely dependent on the added antigen, suggesting that beta-CD is not a polyclonal activator. beta-CD showed neither mitogenic nor cytotoxic effects on murine lymphocytes. These results indicate that beta-CD is a useful additive for inducing the primary antibody response in vitro in the culture medium containing CS or NBS which is usually less supportive but less expensive than FCS.

Abstract--We have devised a new culture medium that is made of RPMI-1640 medium, 500 ag/ml (3-cyclodextrin ((3-CD) and 1% fetal calf serum (FCS) (13-CD medium). Murine lymphocytes stimulated with sheep erythrocytes in vitro de veloped antibody-forming cells in (3-CD medium as efficiently as in 10% FCS containing RPMI-1 640 medium (1 OF medium). Immunostimulating agents (SA96 and levamisole) and immunosuppressive agents (hydrocortisone and D-penicilla mine) showed similar immunomodulating effects on the antibody responses in both media. In addition, the enhancing effect of levamisole varied drastically depending on the lot of FCS used in 1OF medium, but a clear enhancement was always observed in /3-CD medium containing any lot of FCS tested.