Influence of dextran polymer particles (Sephadex G-200) on humoral immune responses.

Dextran polymer particles (Sephadex G-200) mixed with bovine serum albumin (BSA) or sheep red blood cells (SRBC) were injected intraperitoneally (i.p.) into mice and the number of antibody-forming cells in spleen and antibody titers in sera were determined. Antibody formation following the first and the booster immunization to BSA was enhanced to a similar degree by Sephadex G-200 and incomplete Freund's adjuvant. When SRBC were injected in a suboptimal dose of 5X10(6) cells, Sephadex G-200 enhanced the maximum of the primary immune response. In contrast, the polymer inhibited the primary and secondary immune response when 5X10(8) SRBC were given.