Studies in experimental eosinophilia. III. The induction of peritoneal eosinophilia by the passive transfer of serum antibody.

Experimental eosinophilia is readily induced by repeated injections of foreign protein; a single injection results in little, if any, response (1-6). Although it seems evident that some intermediate changes must occur in the host which prepare it to develop substantial eosinophilia in response to subsequent injections of foreign protein, no details are known regarding either the sequence of reactions or the reactants involved in this response. Previous studies (7) have sho~m that peritoneal eosinophitia may be induced by the transfer of tissues, tissue extracts or serum. Such transfers were most often successful when both the donor and recipient had each been prepared by a series of injections with a different non-cress-reacting protein, and when the transferred material was accompanied by the protein which had been used to prepare the donor. These experiments suggested that antibody might mediate eosinophilia. This paper presents evidence that the active material which can be passively transferred does have the properties of antibody and that the active material in vivo is an immune complex.