Passive cutaneous anaphylaxis in the chicken. Biological fractionation of the mediating antibody population.

The studies reported here demonstrated that adult chickens, when immunized with bovine serum albumin, respond with the production of serum antibodies which will mediate passive cutaneous anaphylactic (PCA) reactions in 10-day-old chicks but not in adults. This difference is at least in part due to differences in histamine sensitivity between chicks and adults. The molecule responsible for this PCA activity was indistinguishable from the predominant 7S chicken immunoglobulin antigenically and by a combination of gel filtration on Sephadex G-200 and ion exchange chromatography on DEAE-cellulose. However, the PCA activity is apparently biologically separable from portions of the 7S serum immunoglobulin population since this activity has never been elicited by immunoglobulins derived from yolk. On the basis of stability to denaturing treatments and short tissue fixation time periods, the chicken PCA-mediating antibodies appear to resemble the γG1 homocytotrophic antibodies of mice and guinea-pigs instead of the IgE-type reagins found in some mammals. Therefore, PCA-mediating antibodies appear to be a subpopulation of the chicken 7S immunoglobulins, distinguishable by its inability to pass into the egg yolk but indistinguishable by standard chemical and immunochemical criteria.