The effect of route of administration of antigen on the antibody-containing cell response in lymph of sheep.

The output and immunoglobulin class of antibody-containing cells (ACC) in lymph from different regions of adult sheep has been compared following intraperitoneal or subcutaneous injection of ovalbumin in Freund's complete adjuvant (FCA). Intraperitoneal injection of antigen in FCA elicited no response at all in popliteal lymph, but there were substantial responses in lymph from the hepatic, coeliac (which carries lymph mainly from the abomasum and anterior duodenum) and intestinal lymphatic ducts. A significant increase in the number of blast cells accompanied the ACC response. ACC reached a peak 7- days after injection when ACC comprised 3.7% +/- 0.7%, 2.3% +/- 0.7% and 3.3% +/- 0.6% of total lymphocytes in lymph from the hepatic, coeliac and intestinal ducts respectively. At this time ACC were distributed among three immunoglobulin classes IgM, IgG1 and IgA with the latter constituting 25%--40% of ACC in lymph from the three regions. ACC did not appear in intestinal lymph following subcutaneous injection of ovalbumin in FCA in the leg immediately below the tarsus. This contrasted with the vigorous response in popliteal lymph where 6 days after the injection ACC constituted 3.9% of cells in lymph. Most (83%) of the ACC were IgG1-specific at the peak of the response. The remaining ACC were distributed among the IgM, IgG2 and IgA classes with the latter comprising 3% of total ACC.