IgA Anti-Dextran B1355 Responses

Abstract

Injection of mice bearing the Ig-1^a allotype with dextran Bl355 results in an IgM antibody response that is generally regarded as thymus independent. Moreover, the antibody is directed to α[1,3] determinants on dextran Bl355 and shares cross-reacting idiotypic determinants with a λ₁ IgA (J558) myeloma protein as well as a λ₁ IgM (MOPC 104E) myeloma protein. In this study, we show that BALB/c (Ig-1^a) mice injected with dextran Bl355 produced highly significant IgA anti-dextran responses with specificity directed to the α[1,3] epitope. Kinetics of the IgA anti-dextran response in BALB/c mice paralleled kinetics of the IgM response. However, the magnitude of the IgA response was markedly T cell dependent and age dependent.