ENHANCEMENT OF ANTIGEN PRESENTATION OF INFLUENZA-VIRUS HEMAGGLUTININ BY THE NATURAL HUMAN ANTI-GAL ANTIBODY

Immunogenicity of inactivated virus or subviral vaccines may be enhanc ed by complexing with an IgG antibody. Such antibody would increase th e uptake, processing and presentation of the vaccine's antigens by ant igen presenting cells (APC), via the adhesion of the antibody-vaccine complex to Fc-receptors on macrophages and other APC. A natural antibo dy in humans, which may be generally exploited for this purpose, is th e natural anti-Gal antibody, This antibody is ubiquitously produced as 1% of circulating IgG in humans and Old World primates, and it intera cts specifically with the carbohydrate epitope Gal alpha 1-3 Gal beta 1-4GlcNAc-R (termed the alpha-galactosyl epitope). This epitope is syn thesized in large amounts in cells of nonprimate mammals and New World monkeys by the glycosylation enzyme alpha 1,3 galactosyltransferase. Here we describe in vitro studies on the ability of anti-Gal to bind t o alpha-galactosyl epitopes on influenza virus propagated in mammalian cells, and to enhance presentation by APC of viral hemagglutinin anti genic determinants to specific helper T cell clones. The various appro aches for achieving alpha-galactosyl epitope expression on virion and subviral vaccines ave discussed. Copyright (C) 1996 Elsevier Science L td.