title: CD45 molecule in gammadelta T-cell generation: disruption of CD45 exon 6 does not affect Vgamma3 dendritic epidermal T-cell development.
abstract: There are two distinct lineages of T cells: T-cell receptor (TCR) alphabeta-bearing cells (alphabeta T cells) and TCR gammadelta-bearing cells (gammadelta T cells). All of the alphabeta T cells and most subsets of gammadelta T cells develop in the thymus. It has been demonstrated that the protein tyrosine phosphatase CD45 plays a pivotal role in the intrathymic development of alphabeta T cells. Thymocyte maturation is arrested at the transitional stage from immature CD4+ CD8+ double-positive to mature CD4+ or CD8+ single-positive cells after CD45 exon 6 gene disruption. In this study, we examined whether Vgamma3 dendritic epidermal T cells (DETC), a subset of thymus-dependent gammadelta T cells uniquely residing in the murine epidermis, are altered in the CD45 exon 6-deficient mice. In situ immunolabeling on epidermal sheets demonstrated that the CD45-deficient mice had a normal density and immunophenotype of Vgamma3 DETC compared with the wild-type control mice. Reverse transcriptase polymerase chain reaction revealed that similar levels of Vgamma3 TCR mRNA were present in the epidermis of CD45-deficient mice and wild-type controls. Flow cytometry demonstrated no significant difference in the proportion of Vgamma3 T cells in the epidermis between the genotypes. In addition, Vgamma2 T cells, another subset of gammadelta T cells, were also examined by flow cytometry. The frequency of Vgamma2 T cells in lymph nodes was normal in the CD45-deficient mice. Our results indicate that although CD45 is crucial for the development of alphabeta T cells, this molecule is not necessary for the thymic maturation of gammadelta T cells, including Vgamma3 DETC and Vgamma2 T cells.
authors.affiliation: Division of Dermatology, Sunnybrook Health Science Center, University of Toronto, Ontario, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Fujisawa
authors.forename: S
authors.initials: S
authors.lastname: Kondo
authors.forename: G G
authors.initials: GG
authors.lastname: Shivji
authors.forename: D N
authors.initials: DN
authors.lastname: Sauder
mesh_terms: D000818:Animals; D002452:Cell Count; D002455:Cell Division; D003713:Dendritic Cells / Q000166:cytology*; D000078404:Epidermal Cells; D005091:Exons; D005434:Flow Cytometry; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000502:physiology*; D008198:Lymph Nodes / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology*; D018417:Th1 Cells / Q000502:physiology
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta; D017493:Leukocyte Common Antigens