Differential effects of cyclosporin A on diverse B cell activation phenomena triggered by crosslinking of membrane IgM
| Autor: | Tetsunori Seki, Clare A. Blessinger, Jeanne P. Dalton, Patricia K. A. Mongini |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
medicine.medical_treatment
Immunology Receptors Fc Biology Lymphocyte Activation Major histocompatibility complex HLA-DQ Antigens Cyclosporin a Tumor Cells Cultured medicine Humans Child B cell B-Lymphocytes DNA synthesis DNA HLA-DR Antigens Cell cycle Blotting Northern Flow Cytometry Molecular biology Antibodies Anti-Idiotypic Cytokine medicine.anatomical_structure Immunoglobulin M Membrane protein Biochemistry Child Preschool Cyclosporine biology.protein Cytokines RNA Signal transduction |
| Zdroj: | Cellular Immunology. 140:478-494 |
| ISSN: | 0008-8749 |
| Popis: | Cyclosporin A (CsA) was tested for its modulatory effects on the mIgM-mediated signaling of G 0∗ -associated increases in class II MHC expression, G 1 -related RNA synthesis, and S phase-related DNA synthesis in human B cells. While CsA at concentrations as low as 10–100 ng/ml could completely ablate anti-IgM-induced DNA synthesis, earlier G 1 -associated RNA synthesis was only partially inhibited, and signaling of increased membrane class II MHC expression was unaffected by up to 1000 ng/ml of CsA. Similar phenomena were observed in a clonal population of leukemic B lymphocytes susceptible to anti-IgM-mediated activation in the absence of T cells and T cell factors indicating (a) that the inhibitory effects are not due to CsA-mediated suppression of cytokine production by contaminating T cells, and (b) that the varying effects of CsA on the diverse activation phenomena do not reflect B cell subpopulation diversity. Pulsing studies revealed that while maximal suppression of anti-IgM-induced G 1 -associated RNA synthesis required CsA at culture initiation, near maximal suppression of DNA synthesis occurred when CsA, or soluble human IgM, was added up to 30 hr after the initial exposure of resting B cells to the anti-IgM ligand. These latter findings are consistent with the possibility that the CsA-mediated suppression of S phase entry is due to the inhibition of a signaling event proximal to mIgM ligation which must be repeatedly initiated throughout the first 30 hr of activation. |
| Databáze: | OpenAIRE |
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