PATHOLOGY & ONCOLOGY RESEARCHVol. 12 No. 3, 2006

 Article

Differential Regulation of Umbilical Cord Blood and Leukemic B Cells by Interferon-Alpha (IFN-α): Observations in Cultured Cells

István SZEGEDI1, Csongor KISS1, Éva KARÁSZI2, György VÁMOSI3, János SZÖLLÕSI4, Péter KOVÁCS5, Ilona BENKÕ5

1Department of Pediatrics, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
2Department of Clinical Biochemistry and Molecular Pathology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
3Cell Biophysics Research Group, Hungarian Academy of Sciences, Debrecen, Hungary
4Department of Biophysics and Cell Biology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
5Department of Pharmacology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary

 

The exact mechanism of the beneficial therapeutic action of interferon-a (IFN-α) in B-cell-lineage malignancies has not been adequately explained. Here we report on the differential effect of IFN-α2b on non-malignant B cells of umbilical cord blood and leukemic B-cell lines JY, BL-41 and BCBL-1. Leukemic cell proliferation was characterized by colony assay, whereas apoptosis was investigated by flow cytometry of propidium iodide-stained cells. The degree of differentiation was evaluated by measuring the expression level of Fcγ receptor-II (FcγRII) labeled with anti-CD32-FITC monoclonal antibody using flow cytometry. IFN-α protected umbilical cord blood CD19-positive B lymphocytes from apoptotic cell death in vitro. IFN-α significantly decreased colony formation of all three cell lines, and in contrast to normal cells, induced apoptosis in JY and BL-41 and excessive necrosis in HHV-8 infected BCBL-1 cells. FcγRII was upregulated both in normal and in leukemic B cells as indicated by an increase both in the proportion of CD32-positive cells and the mean fluorescence intensity. From our results it seems that antiproliferative, apoptotic and differentiative effects of IFN-α are interrelated but distinct cellular events, which are differentially regulated in normal, leukemic and virus-infected cells of the B-cell lineage. Pathology & Oncology Research, Vol 12, Nr 3, 159-163, 2006

Key words: apoptosis; B cells; colony formation; interferon-alpha; type II Fcy receptor


Received: May 5, 2006; accepted: Aug 15, 2006
Correspondence: Csongor KISS, Department of Pediatrics, Medical and Health Science Center, University of Debrecen, Debrecen H-4012, Hungary; Tel: 36 52 452 747, Fax: 36 52 452 747; E-mail: kisscs@dote.hu

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