A heterophile system in human renal transplantation. VIII. The morphological distribution of the antigen in rat tissues.

The morphological distribution of heterophile transplant antigen (HTA) was determined in rat tissues using an indirect immunofluorescence technique. Human anti-HTA sera were used to localize HTA in rat kidney, liver, heart, skeletal muscle, spleen, and stomach. HTA was found in basement membrane and supporting stromal elements of all tissues studied. In the kidney, HTA was demonstrated in tubular basement membrane but not glomerular basement membrane. No evidence for cell surface antigen distribution could be ascertained except for erythrocyte membranes. HTA was not found on endothelium of rat blood vessels. We know of no antigens previously implicated in histocompatibility that are stromal in location.