|Budget Amount *help
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1997: ¥2,300,000 (Direct Cost: ¥2,300,000)
We recently established an APL cell line (HT93), which has a capacity to differentiate into neutrophils and eosinophils in response to ATRA and human hematopoietic cytokines. When the cells were cultured with ATRA, cells showed nuclear segmentation and developed secondary granules of neutrophils and eosinophils in part. In the presence of ATRA and G-CSF, cells showed polymorphonuclear neutrophil differentiation, accompanied by expression of surface CD11b, positive activity for NAP.In the cultures with ATRA and GM-CSF, IL-3 or IL-5, HT93 showed remarkable eosinophil maturation at day 8 as determined by luxol fast blue staining, and expression of eosinophil peroxidase and major basic protein.
We also investigated the modulation of the expression and phosphatase activity of SHP-1 during granulocytic differentiation of human myeloid leukemia cell lines (HL6O, HT93) in response to ATRA or dimethylsulfoxide (DMSO). ATRA induced differentiation in both cell lines which was associated with mark
ed growth inhibition and S-phase reduction. On the other hand, DMSO induced it only in HL60 without obvious growth inhibition and S-phase reduction. The expression and phosphatase activity of SHIP-1 were upregulated only when the two cell lines were differentiated to granulocytes. Furthermore, the changes were not dependent on the inducers or the growth inhibition, These findings suggest that SHP-1 is involved in common myeloid differentiation, and that upregulation of SHP-1 is not always related to myeloid cell growth.
We have demonstrated the characteristics of peroxidase activity induced in the immatuer basophils cell line KU812-F.Ultrastructually, peroxidase activity was detected in granules as well as in the perinuclear space and endoplasmic reticulum. Immunocytochemistry revealed that KU812-F cells were stained by anti-eosinophil peroxidase antibodies, and eosinophil peroxidase mRNA, not myeloperoxidase, was detected in the cells using Northern hybridization and RT-PCR.Eosinophil peroxidase can be one of the molecules shared with eosinophils and basophils. Less