Effect of Organ Culture on the Survival of Thyroid Allografts in Mice

In vivo induction of antigen-specific transplantation tolerance to Qa1a by exposure to alloantigen in the absence of T-cell help.

“…Indeed, we think it is the failure to activate either Th cell population and the subsequent inactivation of antigen-specific Tk cells that is the basis for recent reports of tolerance induction by injection of alloantigen-bearing cells (19). Similarly, it is likely the removal of cells able to activate Th cells that is responsible for the long-term retention of in vitro precultured allografts and for their ability to induce transplantation tolerance (20,21). Future experiments are necessary to examine the applicability ofthese concepts to in vivo rejection responses against other transplantation antigens.…”

Cell migration and chimerism after whole-organ transplantation: The basis of graft acceptance

“…We propose that the crucial variable distinguishing the tolerogenicity of one organ graft from another under effective immunosuppression is its leukocyte (not its parenchymal) component, in a reversal of the immunogenic role described classically for these cells (77)(78)(79)(80)(81)(82)(84)(85)(86)(87)(88)(89)(90)(91). Thus, because of its dense constituency of these migratory leukocytes, the liver is high on the favorable tolerogenic list with the lung and intestine following and the kidney and heart bringing up the rear (Fig.…”

Activation of cytotoxic T cells by nonstimulating tumor cells and spleen cell factor(s).

“…Details of the 4-hr assay and estimation of the number of cytotoxic units (C.U.) have been previously described (7). Cytotoxic activity is usually expressed as loglo (C.U./culture) and replicate assays have a standard deviation of 0.06 loglo units.…”

“…Thus, by using different cell types as stimulators for allogeneic T cells, it is possible to determine the S phenotype (S+ or S-) of the cell under investigation. The available evidence indicates that cells of the lymphocytemacrophage class may express the S+ phenotype (3,5,6), while tissue parenchymal cells appear to lack stimulator activity (5,7), and it is for this reason that passenger leukocytes play a role of over-riding importance in the activation of a specific immune response to tissue allografts.…”