title: T cell activation induced by cross-linking CD3 and CD28 leads to silencing of Epstein-Barr virus/C3d receptor (CR2/CD21) gene and protein expression.
abstract: Complement receptor II (CR2) also known as CD21 is the receptor for C3d on immune complexes. In humans it serves as a receptor for the Epstein-Barr virus (EBV). CR2 is expressed on B cells and in low density in the T cell lineage. EBV can infect T cells and EBV-positive T lymphomas have been described. Although CR2 mRNA is readily detectable in T cells, the function of CR2 in human T lymphocytes remains elusive. Here we have analyzed the expression of CR2 in normal and activated T cells. PCR analyses and immunofluorescence/confocal microscopy of peripheral blood T cells and of activated T cells shows considerable reduction in CR2 mRNA and protein expression upon activation. The downregulation of CR2 expression may modulate life span or immunological reactivity of T cells and the susceptibility of cells to infection by lymphotropic viruses.
authors.affiliation: Immunology, Department of Biology, Faculty of Sciences, University of Konstanz, Konstanz, Germany.
authors.forename: Madhan
authors.initials: M
authors.lastname: Masilamani
authors.forename: Elizabeth
authors.initials: E
authors.lastname: von Seydlitz
authors.forename: Martin
authors.initials: M
authors.lastname: Bastmeyer
authors.forename: Harald
authors.initials: H
authors.lastname: Illges
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D018106:CD28 Antigens / Q000276:immunology / Q000378:metabolism; D017252:CD3 Complex / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000494:pharmacology; D015536:Down-Regulation; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000276:immunology*; D018613:Microscopy, Confocal; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D017464:Receptors, Complement 3d / Q000032:analysis* / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D018106:CD28 Antigens; D017252:CD3 Complex; D003432:Cross-Linking Reagents; D007376:Interleukin-2; D011506:Proteins; D012333:RNA, Messenger; D017464:Receptors, Complement 3d