IL-7 upregulates T cell receptor/CD3 expression by cultured dendritic epidermal T cells.
Dendritic epidermal T Cells (DETC) in adult mice express uniformly the phenotype of Thy-1+, T cell receptor (TCR)-V gamma 3/V delta 1+, CD3+, CD4- and CD8-. In newborn mice, however, the epidermis contains smaller numbers of Thy-1+ cells and they rarely express TCR or CD3, suggesting that a phenotypic maturation and/or a rapid expansion of TCR+/CD3+ cells must occur within the epidermis soon after birth. We have observed previously that keratinocytes produce biologically relevant amounts of IL-7 and that this cytokine promotes the survival and growth of DETC in vitro. Here we report that IL-7 also promotes CD3/TCR expression by DETC. When the long-term cultured DETC line, 7-17, was incubated with IL-7, surface expression was upregulated in time- and dose-dependent fashions, as assessed with antibodies against gamma delta TCR, V gamma 3 TCR or CD3 epsilon. Among 10 other cytokines tested, only IL-2 was effective. IL-7-dependent upregulation also occurred at the levels of mRNA expression (Northern blot) and protein synthesis (immunoprecipitation). We propose that keratinocyte-derived IL-7 promotes not only the growth, but also the phenotypic maturation of DETC, thereby supporting the intraepidermal development of a DETC network during the neonatal period.
Ono
M
M
Department of Dermatology, University of Texas Southwestern Medical Center, Dallas 75235, USA.
Ariizumi
K
K
Bergstresser
P R
PR
Takashima
A
A
D000818:Animals; D017252:CD3 Complex / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D003713:Dendritic Cells / Q000378:metabolism*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D015851:Interleukin-7 / Q000494:pharmacology*; D051379:Mice; D008806:Mice, Inbred AKR; D011948:Receptors, Antigen, T-Cell / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation
D017252:CD3 Complex; D016207:Cytokines; D015851:Interleukin-7; D011948:Receptors, Antigen, T-Cell