Tags

Type your tag names separated by a space and hit enter

Platelet-activating factor induces an increase in intracellular calcium and expression of regulatory genes in human B lymphoblastoid cells.
J Immunol. 1991 Mar 15; 146(6):1914-20.JI

Abstract

Platelet-activating factor (PAF) has recently been demonstrated to be metabolized by B lymphocytes and to cause enhancement of Ig synthesis by Ig-secreting B lymphoblastoid cell lines. We have now examined some of the early activation events triggered by PAF binding to three Ig-secreting B cell lines, LA350 (IgM secreting), HSCE- (IgG secreting), and U266 (IgE secreting). After addition of 10(-7) to 10(-11) M PAF, but not equimolar concentrations of the inactive metabolite lyso-PAF, all three cell lines demonstrated rapid dose-dependent increases in free cytosolic Ca2+ concentrations ([Ca2+]i). The increases in [Ca2+]i resulted from both the release of Ca2+ from internal stores as well as transmembrane Ca2+ uptake. Addition of PAF triggered the rapid hydrolysis of phosphatidylinositol bisphosphate and accumulation of inositol phosphates. PAF also increased expression of the cell cycle-active genes c-fos and EGR2 in a dose-dependent fashion. The stimulated increases in [Ca2+]i and phosphatidylinositol bisphosphate hydrolysis and the increases in gene expression were all inhibited by the specific PAF receptor antagonist Web 2086. The LA350 cell line (which expresses surface IgM) was also shown to increase [Ca2+]i after addition of anti-IgM antibodies. Sequential addition of PAF or anti-IgM antibody in either order failed to reveal any evidence for heterologous desensitization. Furthermore, the PAF receptor antagonist did not affect anti-IgM induced changes in [Ca2+]i. These data provide evidence for the presence of functional PAF receptors on B lymphoblastoid cells and indicate a potential role for PAF in the regulation of B cell activation.

Authors+Show Affiliations

Department of Pediatrics, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

1848574

Citation

Mazer, B, et al. "Platelet-activating Factor Induces an Increase in Intracellular Calcium and Expression of Regulatory Genes in Human B Lymphoblastoid Cells." Journal of Immunology (Baltimore, Md. : 1950), vol. 146, no. 6, 1991, pp. 1914-20.
Mazer B, Domenico J, Sawami H, et al. Platelet-activating factor induces an increase in intracellular calcium and expression of regulatory genes in human B lymphoblastoid cells. J Immunol. 1991;146(6):1914-20.
Mazer, B., Domenico, J., Sawami, H., & Gelfand, E. W. (1991). Platelet-activating factor induces an increase in intracellular calcium and expression of regulatory genes in human B lymphoblastoid cells. Journal of Immunology (Baltimore, Md. : 1950), 146(6), 1914-20.
Mazer B, et al. Platelet-activating Factor Induces an Increase in Intracellular Calcium and Expression of Regulatory Genes in Human B Lymphoblastoid Cells. J Immunol. 1991 Mar 15;146(6):1914-20. PubMed PMID: 1848574.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Platelet-activating factor induces an increase in intracellular calcium and expression of regulatory genes in human B lymphoblastoid cells. AU - Mazer,B, AU - Domenico,J, AU - Sawami,H, AU - Gelfand,E W, PY - 1991/3/15/pubmed PY - 1991/3/15/medline PY - 1991/3/15/entrez SP - 1914 EP - 20 JF - Journal of immunology (Baltimore, Md. : 1950) JO - J Immunol VL - 146 IS - 6 N2 - Platelet-activating factor (PAF) has recently been demonstrated to be metabolized by B lymphocytes and to cause enhancement of Ig synthesis by Ig-secreting B lymphoblastoid cell lines. We have now examined some of the early activation events triggered by PAF binding to three Ig-secreting B cell lines, LA350 (IgM secreting), HSCE- (IgG secreting), and U266 (IgE secreting). After addition of 10(-7) to 10(-11) M PAF, but not equimolar concentrations of the inactive metabolite lyso-PAF, all three cell lines demonstrated rapid dose-dependent increases in free cytosolic Ca2+ concentrations ([Ca2+]i). The increases in [Ca2+]i resulted from both the release of Ca2+ from internal stores as well as transmembrane Ca2+ uptake. Addition of PAF triggered the rapid hydrolysis of phosphatidylinositol bisphosphate and accumulation of inositol phosphates. PAF also increased expression of the cell cycle-active genes c-fos and EGR2 in a dose-dependent fashion. The stimulated increases in [Ca2+]i and phosphatidylinositol bisphosphate hydrolysis and the increases in gene expression were all inhibited by the specific PAF receptor antagonist Web 2086. The LA350 cell line (which expresses surface IgM) was also shown to increase [Ca2+]i after addition of anti-IgM antibodies. Sequential addition of PAF or anti-IgM antibody in either order failed to reveal any evidence for heterologous desensitization. Furthermore, the PAF receptor antagonist did not affect anti-IgM induced changes in [Ca2+]i. These data provide evidence for the presence of functional PAF receptors on B lymphoblastoid cells and indicate a potential role for PAF in the regulation of B cell activation. SN - 0022-1767 UR - https://www.unboundmedicine.com/medline/citation/1848574/Platelet_activating_factor_induces_an_increase_in_intracellular_calcium_and_expression_of_regulatory_genes_in_human_B_lymphoblastoid_cells_ L2 - https://www.jimmunol.org/lookup/pmidlookup?view=long&pmid=1848574 DB - PRIME DP - Unbound Medicine ER -