Alteration of allospecific t-cell receptors after differentiation from prethymic precursor cells in semiallogeneic environments

Murine bone marrow cells (strain A) have been allowed to differentiate in vivo in syngeneic (A) or semiallogeneic hosts (A × B) to produce mature splenic T lymphocytes. After stimulation of these cells with irradiated allogeneic (C) spleen cells in tissue cultures, the cytotoxic T-cell blasts (CTL) were purified by velocity sedimentation and used to immunize (A × C) F₁ hybrid mice, to produce antisera recognizing the receptor structure (for C) on the relevant A cytotoxic cells (and their precursors). Using these sera we have been able to show that the T-cell receptor for alloantigen C on strain A cytotoxic precursor lymphocytes (CTLp) seems to differ according to the host environment in which those T cells differentiate from immature bone marrow precursors.