INTESTINAL RESPONSE OF SHEEP TO INTRA-PERITONEAL IMMUNIZATION

Abstract

An immunization procedure which centrally stimulated the Ig[immunoglobulin]A system of sheep with the release of antibody-containing cells (ACC) of the IgA class into intestinal lymph was developed. Injection (i.p.) of ovalbumin resulted in a substantial output of ACC in intestinal lymph. ACC of the IgA class reached a peak 8-9 days after i.p. injection when they comprised 1.4% of cells in lymph. ACC of the IgM and IgG1 classes comprised 3.5 and 2.9% of cells in lymph. The output of ACC of the IgA, IgM and IgG1 classes in lymph at the peak of the response was, respectively, 3.7 .times. 106, 9.8 .times. 106 and 8 .times. 106 cells/h. In marked contrast to rats, virtually no ACC appeared in intestinal lymph of sheep following intraduodenal infusion of ovalbumin in animals primed 2 wk earlier by i.p. injection of antigen in Freund''s complete adjuvant (CFA).