Correlation between specific cytolysis and expression of idiotypic receptors of allograft-infiltrating cells

REJECTION of an allograft is normally accompanied by infiltration of the graft by host cells. The origin, type and receptor specificity of these cells as well as their precise functions are largely unknown, primarily because of the extreme difficulties of quantitative recovery of the infiltrating cells. A promising experimental technique1 has recently been developed: a spongey matrix tissue is infiltrated by strain A fibroblasts, transplanted into B animals and removed at various times thereafter. Mere physical compression of the ‘sponge’ releases virtually all of the infiltrating B cells whereas virtually none of the A fibroblasts will be released. The released B-strain cells are functionally intact.