Expression of an EL4 tumour-associated determinant on subpopulations of murine T cells in normal and lympho-proliferative autoimmune mice.

It has been demonstrated that the single autosomal recessive lpr and gld genes are responsible for the accumulation of unusual T-cell subsets. Although these subsets have been assigned to the T-cell lineage, they share certain antigenic cell surface markers with mature B lymphocytes. Consequently the maturational pathway(s) of these cells has been difficult to fit in the currently accepted models of T-cell differentiation. Previous work has determined that the YE1/19.1 monoclonal antibody (mAb), developed against the EL4 tumour line, reacts with the accumulating T cells in lpr-expressing mice. In this study we report that YE1/19.1 could also be used as a marker for the accumulating T cells in gld-expressing mice and that the hyporesponsiveness seen in gld mice correlated with these accumulating cells. We then demonstrated that the YE1/19.1 antibody also reacts with a subpopulation of neonatal thymocytes as well as a mitogen non-responsive subpopulation of 'double negative' T cells from the spleens and thymuses of non-autoimmune mice. Our findings indicate that the YE1/19.1 mAb will be a useful probe for helping in the eludication of the intra-thymic maturational pathways of T lymphocytes.