Bone marrow-derived dendritic epidermal T cells express T cell receptor-alpha beta/CD3 and CD8. Evidence for their extrathymic maturation.
The majority of murine Thy-1+ dendritic epidermal T cells (DETC) express virtually identical TCR encoded by V gamma 5 and V delta 1 genes and are derived from early fetal thymic precursors. However, not consistent with this notion is an early finding that DETC arise continuously from bone marrow (BM) precursors by a thymus-independent mechanism. To address this issue, donor-type DETC were characterized in lethally irradiated mice that were reconstituted by Thy-1-disparate BM cells with or without a thymus. The BM-derived DETC, unlike their normal TCR-gamma delta counterparts, were found to express the TCR-alpha beta/CD3 complex and CD8, and their migration to the epidermis dermis occurred independently of the thymus. The numbers of the BM-derived DETC increased with time and reached a plateau 6 mo after BM transfer, at which time the TCR-alpha beta/CD3 complex was expressed on a small fraction of the DETC in athymic BM chimeras. Although no further increase in the number was observed at later times, at 1 yr after transfer most of the BM-derived DETC came to express the TCR-alpha beta/CD3 complex in the absence of thymic influence. By contrast, most of BM-derived T cells in other lymphoid organs from athymic BM chimeras still failed to express the TCR-alpha beta/CD3 complex even at 1 yr after transfer. These results suggest that extrathymic differentiation of BM-derived DETC could occur with the epidermal microenvironment.
Shiohara
T
T
Department of Dermatology, Kyorin University School of Medicine, Tokyo, Japan.
Moriya
N
N
Hayakawa
J
J
Arahari
K
K
Yagita
H
H
Nagashima
M
M
Ishikawa
H
H
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001854:Bone Marrow Cells; D017252:CD3 Complex / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D016827:CD8 Antigens / Q000378:metabolism*; D002465:Cell Movement; D003713:Dendritic Cells / Q000378:metabolism*; D000078404:Epidermal Cells; D005455:Fluorescent Antibody Technique; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008815:Mice, Inbred Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism*; D018800:Thy-1 Antigens
D000954:Antigens, Surface; D017252:CD3 Complex; D016827:CD8 Antigens; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018800:Thy-1 Antigens