Human T lymphocyte cell line (Mo) and its subclone (J) produce colony stimulating activity on normal and malignant T cell precursors.

Conditioned medium from a T-lymphoblastic cell line (Mo) is known to produce factors promoting CFU-GM, BFU-E and CFU-MK. In our study we investigated the potential CSA of conditioned media obtained from Mo and its subclone J on normal and malignant lymphoid progenitors of both T and B lineage. Both cell lines release factors inducing a significant increase in number and size of T-lymphoid colonies when compared to standard source of factors (PHA-LCM). On the contrary, they presented a low CSA on B cell precursors confirming the difficulties in identifying a source of growth and differentiation factors for human B cell ontogeny. This study contributes to the knowledege of biological properties of these tumor cell lines, suggesting the possibility to employ Mo- and J-derived supernatants in vitro for improving growth potential of normal and malignant T cell progenitors.