Ontogeny of Circulating Immunoglobulins in Normal, Bursectomized and Irradiated Chickens

Abstract

Normal chickens develop peak levels of IgM earlier than they develop peak levels of IgG. Despite its suppressive effect on primary antibody responses, bursectomy at hatching has no effect on the early rise in circulating IgM. This treatment delays but does not prevent the normal increase with age of plasma IgG concentrations. Near-lethal whole body irradiation on the 2nd day of life does not suppress the development of circulating immunoglobulins. Early bursectomy and irradiation prevented synthesis of detectable IgM and IgG over an 8-week period in 59% of birds so treated. The observations suggest that circulating γ globulin levels may bear no direct relationship to the number of stem cells of the plasma cell line.