title: Increased expression of complement receptor type 1 (CR1, CD35) on human peripheral blood T lymphocytes after polyclonal activation in vitro.
abstract: The receptor for C3b and C4b--complement receptor type 1 (CR1, CD35)--is present on a variety of cell types including erythrocytes, phagocytic cells, B lymphocytes and a small subpopulation of T lymphocytes. The function of the receptor varies according to the different cell types, but on T lymphocytes the function is as yet not known. The present study concerns the influence of polyclonal stimulation on CR1-expressing T lymphocytes. Incubation with PHA resulted in a dose-dependent increase in the number of CR1-positive T lymphocytes. The CR1-expression T lymphocytes were found in both the CD4- and the CD8-positive subpopulation, but a significant stimulatory increase was only found in the CD4-positive population. A significant increase in the number of CR1-expressing T lymphocytes was found when monocytes were present during stimulation, indicating an importance of monocytes and/or monocyte products. However, the increase was not regulated by arachidonic acid metabolites of the cyclo-oxygenase pathway as indomethacin failed to inhibit the increase. Neither did rIL-1 alpha, rIL-1 beta, rTNF alpha nor rIL-6 alter the number of CR1-expressing T lymphocytes. The results of this study indicate a role for CR1 on T lymphocytes in the regulation of the immune system.
authors.affiliation: Laboratory of Medical Immunology, Rigshospitalet, State University Hospital, Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Rodgaard
authors.forename: B S
authors.initials: BS
authors.lastname: Thomsen
authors.forename: G
authors.initials: G
authors.lastname: Bendixen
authors.forename: K
authors.initials: K
authors.lastname: Bendtzen
mesh_terms: D003208:Concanavalin A / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008213:Lymphocyte Activation; D009000:Monocytes / Q000276:immunology; D010835:Phytohemagglutinins / Q000494:pharmacology; D017463:Receptors, Complement 3b / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D016861:Cyclooxygenase Inhibitors; D007375:Interleukin-1; D015850:Interleukin-6; D010835:Phytohemagglutinins; D017463:Receptors, Complement 3b; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A; D007213:Indomethacin