Immunomodulatory effect of various molecular-weight maleic anhydride-divinyl ethers and other agents in vivo.

Various molecular-weight maleic anhydride-divinyl ether copolymer polyanions were evaluated in six in vivo systems. Low- and high-molecular-weight MVE's were effective adjuvants with irradiated L1210 tumor cell vaccine. A high percentage of L1210-challenged survivors were refractory to a second challenge of tumor cells. Azimexon and Bacillus Calmette-Guérin were also effective adjuvants, but Bestatin was without adjuvant effect. All the MVE's demonstrated a marginal antitumor effect against the L1210 and LSTRA tumors. The MVW's, regardless of molecular weight differences, were effective in enhancing macrophage tumoricidal activity and retarding the development of M109 tumor growth in the lungs. Enhancement of delayed-type hypersensitivity by all six MVE's indicates their ability to stimulate T-cells.