Pancreatic antigenic complex p64 69: involvement in regulation of insulin secretion and relation to glutamic acid decarboxylase.

The role of pancreatic beta-cell antigenic structures in modulation of insulin secretion in vitro was recently demonstrated by others. Here we report generation of a monoclonal antibody (mAB) ICA-1 to non-species specific beta-cell antigen(s) 64, 67 and 69 kDa. The mAB inhibits glucose stimulated insulin secretion in islet cell cultures. The ability of mAB ICA-1 to immunoprecipitate active glutamic acid decarboxylase from high speed supernatants of pancreatic and brain crude extracts was demonstrated. The 64, 67 and 69 kDa antigenic material was affinity purified from pancreatic islet cell high speed supernatants, active glutamic acid decarboxylase was found in the material. Immunoaffinity purification with mAB ICA-1 of GAD-like pancreatic beta-cell antigenic material has provided evidence of possible involvement of glutamic acid decarboxylase in modulation of insulin secretion.

[The effect of structural-chemical characteristics of water-soluble polyelectrolyte complexes of ovalbumin on their immunological properties]. / O vliianii strukturno-khimicheskikh osobennostei vodorastvorimykh poliélektrolitnykh kompleksov oval'bumina na ikh immunologicheskie svoistva.

Immunogenicity of soluble protein antigens in the complexes with synthetic polyions may be regarded as depending both on the nature of polymer carrier and the structure of the protein-polyelectrolyte complex. The immunogenicity of stable soluble complexes of ovalbumin (OA) with polycation - quaternized poly-4-vinylpyridine (C-1) and copolymer of acrylic acid and 2-methyl-5-vinylpyridine (C-2) have been evaluated. Immunization of mice by C-1 have induced a vigorous formation of the anti-OA IgG antibodies and IgE homocytotropic antibodies, while immunogenicity of OA in C-2 was comparable with that of OA alone. The analysis of the structural-chemical features of the complexes investigated has shown that enhanced immunogenicity of C-1 may be due to (1) the non-homogeneous distribution of protein globulae among polycation macromolecules and to (2) the formation of complex with an asymmetrical structure, to (3) the high ability of C-1 to adsorb on a surface of the lymphoid cells and to induce a formation of intercellular aggregates. An enhancing of a stability and a size of C-2 in the presence of Cu2+ shows no influence on a immunogenicity of OA. An immunogenicity of both types of complexes does not depend upon the access of determinants of OA to antibodies so far as it has been shown that complex formation in both cases are not accompanied by an alteration of antigenicity and allergenicity of OA.