Passive Cutaneous Anaphylaxis Induced in Mice with Rabbit 5S Antibody Fragments. ∗

Abstract

Summary

γG-immunoglobulin, obtained from rabbit anti-bovine serum albumin serum, was treated with pepsin and subsequently reduced and alkylated to yield fractions containing 5S and 3.5S Fab fragments, respectively. The 5S fraction had precipitating antibody activity and induced passive cutaneous anaphylaxis (PCA) in mice. Such sen-sitization has not been demonstrated in the guinea pig. With respect to the dosage and the length of the latent period required, there was a marked difference in the abilities of the 5S antibody fractions and the γG-antibody to provoke PCA in the mouse. The 3.5S Fab fragments possessed “univalent” antibody activity but failed to induce PCA. However, 3.5 S Fab fragments inhibited the PCA reaction in the mouse, but failed to block the reaction in guinea pigs. Hybrid 5S fragments had the same properties as Fab fragments. These results point out additional differences between the PCA reaction of guinea pigs and mice. The findings also show that PCA in the mouse demands functionally bivalent antibodies.

We wish to express our appreciation to Dr. T. B. Tomasi, Jr. and Miss Jane Wark (formerly of the Dept. of Exp. Med., University of Vermont) for perfoming the analiytical ultracentrifugation and to Mrs. Patricia McEntee for technical assistance.