The role of antigen-antibody complexes in mediating immunologic unresponsiveness in the chicken.

A significant suppression of an adoptive secondary response to either BSA or sheep red blood cells (SRBC) resulted when chicken spleen cells were incubated with BSA-antibody (Ab) complexes formed in antigen excess (molar ratio Ag1Ab1.1). Serum from 14-day old birds rendered unresponsive at hatching with large doses of BSA also produced suppression. In addition the in vitro response to SRBC was suppressed by the above treatment. Complexes formed at equivalence either had no effect on the subsequent responses of primed cells or produced an enhancement. The fact that both the homologous and heterologous responses were inhibited could indicate that both were suppressed via a common pathway.