Modification of humoral immune response in C57Bl/6 mice with a complex of alpha-fetoprotein and retinoid acid derivatives.

Amides of all trans-retinoic acid and O-phospho-L-threonine, O-phospho-L-tyrosine, and O-phosphoethanolamine injected intravenously in a dose of 6.8 microg/kg 1.5-3.4-fold increased the count of antibody-producing cells in the spleen of C57Bl/6 mice (primary immune response to sheep erythrocytes). Activity of the complex containing alpha-fetoprotein and L-threonine ligand did not differ from that of free retinoid. This complex holds much promise as a prototype of immunomodulators with a wide range of activity.