Isogeneic lymphocyte interaction: recognition of self antigens by cells of the neonatal thymus.

Cells with the ability to recognize self antigens have been demonstrated in the thymus of the neonatal mouse. The detection of these cells is based upon a newly described in vitro phenomenon termed the isogeneic lymphocyte interaction. This interaction is demonstrable by [(14)C]thymidine uptake in cultures containing mixtures of neonatal thymus cells and adult spleen cells from the CBA strain of mice. The response observed in these mixtures has been shown to be almost entirely due to thymic cell proliferation. Other isogeneic lymphoid cells cannot replace adult spleen cells. Thymic isogeneic lymphocyte interaction activity increases sharply after birth, begins to decline within the first week of life and is lost by adulthood. It is suggested that the isogeneic lymphocyte interaction may represent an in vitro model for cognitory and discriminatory cellular events occurring routinely in vivo.