Steroid metabolism was investigated in cultured human B-lymphoblastoid cells (B-LCL), and peripheral blood T and B cells. Gene expression was examined by reverse-transcription polymerase chain reaction amplification (RT-PCR). Appropriate sized transcripts were detected in both cultured and fresh peripheral lymphocytes for CYP11A, CYP17, HSD11L (11β-hydroxysteroid dehydrogenase I), HSD17B1 (17β-hydroxysteroid dehydrogenase type I) and SRD5A1 (5α-reductase I). B-LCL, but not T and B cells, expressed CYP11B. There was minimal expression of HSD3B1 and HSD3B2 (3β-hydroxysteroid dehydrogenase I and II) in B-LCL and T cells. Transcripts for CYP19 and HSD11K were not detected. Corresponding enzymatic activity was detectable only for 17-hydroxysteroid dehydrogenase and 5α-reductase, respectively producing testosterone and 5α-dihydrotestosterone. Steroid identities were confirmed by gas chromatography/mass spectrometry (GC/MS). One metabolite thought to be deoxycorticosterone was identified by GC/MS as 6α-hydroxypregnanolone. It was concluded that sex hormone metabolism, including androgen synthesis, occurs in lymphocytes, and may modulate immune response.
- Steroid 17 hydroxysteroid dehydrogenase
- Steroid 5 alpha reductase
ASJC Scopus subject areas
- Molecular Biology