The Immunochemistry of Mouse Tissue Components

In a previous paper, a survey of the relationships among antigens which were obtained from various normal mouse tissues and which had comparable solubility properties was presented. This communication is concerned with an analysis of the immunological relationships of components similarly obtained, but derived from a variety of transplantable mouse tumors. Several of these tumors possessed the capacity to survive not only homologous but also heterologous transplantation, if, in the latter case, the anterior chamber of the eye was utilized as the transplantation site. Greene3, 14 15 16 has emphasized the fact that this peculiar growth property is characteristic of embryonic and of malignant tissues, and that it is not shared by normal adult tissues. Watson36 investigated the immunological properties of such surviving heterologously grown tumor transplants and found that their species-specificity was that of the new host. It would appear, then, that malignant and embryonic cells possess the ability to initiate, or carry on, an organized series of synthetic processes upon transplantation into an alien host, but that the chemical structure of the cellular products synthesized in their new environment is dependent on that host and differs from the products synthesized in the original, parent species. Previously, in the few cases where the species-specificity of a heterotransplant was studied, a distinction between the parenchymal elements of the tumor transplant and the stromal elements was not always drawn.2' 33 The stromal elements are necessarily supplied by the new host and therefore are characteristic of that species. However, alterations in the intracellular components of the parenchymal elements of the heterologous tumor transplants are of utmost significance. For this reason the immunological relationships of the desoxyribosenucleoprotein