Regulated expression and function of CD11c/CD18 integrin on human B lymphocytes. Relation between attachment to fibrinogen and triggering of proliferation through CD11c/CD18.
CD11c/CD18 (p150,95) is a beta 2 integrin expressed by myeloid, natural killer and certain lymphoid cells such as some cytotoxic T cell clones and B cell malignancies. We have studied the expression and function of CD11c on resting and activated B lymphocytes. Flow cytometry, immunoprecipitation, and mRNA analyses showed that cell activation with phorbol esters or with a variety of stimuli such as Staphylococcus aureus or anti-mu antibodies in combination with cytokines induced de novo CD11c/CD18 cell surface expression on most B cells while CD11b expression was not affected. Functional analysis of CD11c/CD18 on B cells revealed that it plays a dual role. First, CD11c/CD18 is implicated in B cell proliferation, as demonstrated by the ability of several anti-CD11c monoclonal antibodies to trigger comitogenic signals; and second, the newly expressed CD11c/CD18 mediates B cell binding to fibrinogen. Our data conclusively demonstrate the role of CD11c/CD18 on both B cell activation and adhesion processes.
Servicio de Immunología, Hospital de la Princesa, Universidad Autónoma de Madrid, Spain.
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Postigo
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Corbí
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Sánchez-Madrid
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de Landázuri
D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000032:analysis* / Q000502:physiology; D001402:B-Lymphocytes / Q000276:immunology*; D018821:CD18 Antigens; D002448:Cell Adhesion; D002648:Child; D002675:Child, Preschool; D005340:Fibrinogen / Q000502:physiology*; D006801:Humans; D016167:Integrin alphaXbeta2 / Q000032:analysis* / Q000502:physiology; D008213:Lymphocyte Activation; D016028:Receptors, Leukocyte-Adhesion / Q000032:analysis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018821:CD18 Antigens; D016167:Integrin alphaXbeta2; D016028:Receptors, Leukocyte-Adhesion; D005340:Fibrinogen; D013755:Tetradecanoylphorbol Acetate