Intrinsic expression of 20 alpha-hydroxysteroid dehydrogenase in murine myelomonocytic cell lines.

The expression of a 20 alpha-hydroxysteroid dehydrogenase (20 alpha SDH) activity was investigated in various murine hematopoietic cells. Large differences appeared between cells belonging to the same hematopoietic lineage. Normal thymocytes were positive when splenocytes, B and T lymphoma cell lines were negative. In two stromal fibroblastic cell lines, the expression of 20 alpha SDH was very high, whereas it was negative in NIH/3T3 normal fibroblasts. Among myelomonocytic cell lines, six expressed high levels and two were negative. Contaminating lymphoid subpopulations were not detectable in these cell lines. The levels of detected enzymatic activity seemed unrelated with the virus infection. The presence of 20 alpha SDH activity in factor-independent myelomonocytic cell lines, and the lack of induction of the enzymatic activity by the IL-3 containing WEHI-3B conditioned medium in negative cell lines, led us to suggest that myelomonocytic cells intrinsically express the 20 alpha SDH enzymatic activity, as well as other hemopoietic and stromal cell lines.