Mortality of Chick Embryos upon Injection of Homologous Adult Cells.

Abstract

Injection of certain types of adult chicken cells into 14-16 day chick embryos of another breed has been found to cause death of the embryos, usually 5-7 days after injection. This degree of mortality was not obtained by injection of normal contaminants of the cell preparations such as serum, heparinized plasma, or citrated plasma. The cells causing from 67-81% of deaths were the adult, circulating white cells and the upper centrifugal layer of bone marrow cells. Invariably the embryos injected with these cells died with greatly-enlarged spleens. Cells causing 25-30% deaths were the adult red blood cells, the lower centrifugal layer of bone marrow cells, and embryonic blood. Previous studies have shown that only a 15-20% mortality is to be expected after injection of blood from 1 embryo. The types of cells found to be responsible for death seem to agree with the hypothesis of Billingham, Brent and Simonsen, that such deaths are due to the "graft vs. host" reaction in which the injected cells consider the embryo to be a homograft and thus react against it.