[Inhibition of PHA-stimulated T cell conditioned medium (PHA-TCM) on the growth of human myeloid progenitor cells (CFU-C)].
Cord blood T cells were enriched by nylon wool colomn, and effects of PHA-stimulated T cell supernatant collected from 18 h to 7 days on the proliferation of CFU-c were studied. The results showed that the supernatant collected at 18 h (PHA-TCM) could significantly inhibit the growth of CFU-c and the inhibition was PHA-TCM dose dependent, suggesting there is a CFU-c inhibitory activity in PHA-TCM. Kinetic studies demonstrated that the activity was decreased in the supernatant collected at 48 h and disappeared at 7 days. On the other hand, unstimulated T cell supernatant and PHA alone had no inhibitory effect on CFU-c growth. Indomethacin did not affect the production of the inhibitory activity and no interferon activity could be detected in PHA-TCM. These suggested that the inhibition was mediated by a non-interferon, non-prostaglandin suppressor. Further studies revealed that the suppressor was a protein stable at 56 degrees C and lost in pH 2 and pH 11 for 3 h, its molecular weight was large than 10,000 dolton.
Feng
Y Q
YQ
Institute of Basic Medical Science, Military Academy of Medical Science, Beijing.
Li
Y
Y
Tang
P S
PS
D000328:Adult; D000368:Aged; D001854:Bone Marrow Cells; D002455:Cell Division; D002478:Cells, Cultured; D003470:Culture Media; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000502:physiology*
D003470:Culture Media; D010835:Phytohemagglutinins