DAO 27:173-185 (1996)  -  doi:10.3354/dao027173

Polyclonal anti-idiotype (anti-Id) antibodies were prepared in rats against a monoclonal antibody (MAb AS-1) which defines a highly conserved neutralization epitope on virion protein 2 (VP2) of Serogroup A aquatic birnaviruses. Anti-mouse IgG cross-reactive antibodies were removed from rat sera by adsorption to an affinity column of normal mouse IgG and further purified by subsequent adsorption to and elution from an affinity column coupled with MAb AS-1. Confirmation that these anti-Id antibodies were directed against the paratope of MAb AS-1 and molecularly mimicked the virus epitope was demonstrated in a variety of assays. Anti-Id antibodies reacted in enzyme-linked immunosorbent assay (ELISA) with both whole MAb AS-1 IgG and F(ab)₂ fragments, but did not react with 2 unrelated mouse IgGs or F(ab)₂ fragments. Anti-Id antibodies blocked binding of virus to MAb AS-1 in a dose-dependent manner with 100% inhibition at the highest concentration. Similarly, virus inhibited anti-Id/idiotype binding by 60%. Furthermore, anti-Id antibodies inhibited the ability of MAb AS-1 to neutralize virus in plaque reduction assays. Anti-Id antibodies induced the production of virus neutralizing antibodies in mice. Anti-Id antibodies also were used to show that the AS-1 epitope is a presumptive cell attachment site on the virus which recognizes and binds to specific cell receptors. Anti-Id antibodies were shown to bind to a variety of both salmonid and non-salmonid fish cell cultures. Pretreatment of fish cell cultures with virus inhibited (28 to 50%) binding of anti-Id antibodies. Treatment of fish cell cultures with anti-Id antibodies also resulted in a decrease (98%) in the yield of progeny virus compared with replication of the virus in untreated cells or cells treated with normal rat immunoglobulin.

Anti-idiotype antibodies · Aquatic birnaviruses · Fish cells