Sheep, rabbit and chicken antisera against a human VH fragment: reactivity with immunoglobulins and lymphocytes

Antisera against a human VH fragment obtained from an IgG3, VH II, kappa protein (KUP) were raised in rabbits, sheep and chicken. The three types of anti-VH antisera reacted equally well with both intact immunoglobulin molecules and isolated heavy chains. The antisera did not detect any free heavy chain specific antigens by sensitive enzyme-linked immunosorbent assay (ELISA) tests although they reacted with some antigens which were more or less hidden on intact immunoglobulin molecules but well expressed on isolated heavy chains. The antisera reacted with more than 90% of IgG, IgA and IgM present in normal pooled serum. Experiments with T cells from normal peripheral blood indicated that the sheep and rabbit anti-VH antisera reacted with a 70,000 mol.wt T-cell surface antigen.