Identification of the Type of Blood-cell Responsible for the Graft-versus-Host Reaction in Chicks

Abstract

An attempt has been made to identify the cell responsible for the splenic enlargement caused by the injection of adult homologous blood and spleen cell suspensions into embryonic or newborn chicks. Adult chicken blood lymphocytes 99–100 per cent, pure produced marked splenic enlargement when injected intravenously into chick embryos of a different breed or strain. As little as 30,000 lymphocytes could produce a detectable effect. Adult chicken spleen-cells also produced enlargement of the embryonic spleen. Adult monocytes and thymocytes did not cause significant enlargement. Evidence is presented that the development of inflammatory nodules after the local intracutaneous injection of cells from adult homologous donors is, like splenic enlargement, principally the result of a reaction of the grafted cells against the host. Adult blood lymphocytes when injected intracutaneously were shown to cause the production of a nodule in 3–5 days. Monocytes and thymocytes did not cause the formation of these nodules. From these experiments it is concluded that, in chickens, cells of the peripheral blood lymphocyte family are immunologically competent, and are capable of producing an iso-immune reaction against antigens present in their embryonic or juvenile host.