title: Differential expression of three CD45 alternative structures on murine T cells: exon 6-dependent epitope as a marker for functional heterogeneity of CD4+ T cells.
abstract: We prepared a novel rat mAb specific for CD45 molecules bearing the epitope coded for by the alternative exon 6 of the murine CD45 gene (CD45RC). Together with available mAbs to alternative exon 4- and 5-dependent epitopes (CD45RA and CD45RB respectively), we found that the three alternative exons show differential expressions on murine lymphocytes. Flow cytometry analysis revealed that although B cells were homogeneously CD45RA+B+C+, the CD4+ T cells clearly included two populations, CD45RA-B+C- and CD45RA-B+C+. The CD8+ T cells were separated into CD45RA-B+C+ and CD45RA+B+C+ populations. Such features of epitope expression on the cell surface correlate well with message levels of corresponding alternative exons. In the CD4+ T cells, messages of alternative exons were associated with either one or two exon forms of the CD45 transcript. In CD8+ T cells, there were transcripts with one, two, or three alternative exons. When stimulated by an immobilized CD3 mAb, the CD45RC+CD4+ T cell subset preferentially secreted IL-2 and CD45RC-CD4+ T cells produced IL-4. Upon stimulation with concanavalin A, CD45RC-CD4+ T cells converted to CD45RC+ cells, and the level of CD45RC expression on the CD45RC+CD4+ T cell subset was up-regulated. These changes were unidirectional and irreversible. Therefore, differential expression of CD45RC probably delineates the functional heterogeneity of murine CD4+ T cells that is associated with the stages of CD4+ T cell maturation or activation.
authors.affiliation: Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nishimura
authors.forename: S
authors.initials: S
authors.lastname: Hattori
authors.forename: M
authors.initials: M
authors.lastname: Abe
authors.forename: G
authors.initials: G
authors.lastname: Ueda
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: H
authors.initials: H
authors.lastname: Tsurui
authors.forename: S
authors.initials: S
authors.lastname: Hirose
authors.forename: T
authors.initials: T
authors.lastname: Shirai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D000939:Epitopes; D005091:Exons; D005434:Flow Cytometry; D015870:Gene Expression; D005796:Genes; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D007376:Interleukin-2; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D015847:Interleukin-4; D017493:Leukocyte Common Antigens