Genetic variation of in vitro cytolytic activity and in vivo rejection potential of non‐immunized semi‐syngeneic mice against a mouse lymphoma line

Abstract

Spleens of normal young mice of certain genotypes contain lymphocytes that can kill strain A‐derived YAC‐1 and some other in vitro‐grown Moloney lymphoma lines in a ⁵¹Cr‐release cytotoxic test. We have previously shown that mouse strains can be classified as high or low reactors in this test. F₁ hybrids between low‐ and high‐reactive strains are high‐reactive. In the present study, strain‐A mice and eight different A F₁ hybrids were tested in parallel for their spleen‐cell‐mediated killing effect in vitro and their ability to reject graded numbers of YAC ascites or in vitro cultivated cells in vivo. There was a clear correlation between in vitro cytotoxicity and in vivo rejection in all tested genotypes. In segregating (A × C57Bl) × A backcross mice, in vivo rejection of YAC cells was H‐2 linked. This is in line with the earlier backcross analysis of the in vitro cytotoxicity, suggesting a polygenic control with at least one H‐2 linked factor.