An invariant T cell receptor alpha chain defines a novel TAP-independent major histocompatibility complex class Ib-restricted alpha/beta T cell subpopulation in mammals.
We describe here a new subset of T cells, found in humans, mice, and cattle. These cells bear a canonical T cell receptor (TCR) alpha chain containing hAV7S2 and AJ33 in humans and the homologous AV19-AJ33 in mice and cattle with a CDR3 of constant length. These T cells are CD4(-)CD8(-) double-negative (DN) T cells in the three species and also CD8alphaalpha in humans. In humans, their frequency was approximately 1/10 in DN, 1/50 in CD8alpha+, and 1/6,000 in CD4(+) lymphocytes, and they display an activated/memory phenotype (CD45RAloCD45RO+). They preferentially use hBV2S1 and hBV13 segments and have an oligoclonal Vbeta repertoire suggesting peripheral expansions. These cells were present in major histocompatibility complex (MHC) class II- and transporter associated with antigen processing (TAP)-deficient humans and mice and also in classical MHC class I- and CD1-deficient mice but were absent from beta2-microglobulin-deficient mice, indicating their probable selection by a nonclassical MHC class Ib molecule distinct from CD1. The conservation between mammalian species, the abundance, and the unique selection pattern suggest an important role for cells using this novel canonical TCR alpha chain.
Tilloy
F
F
Institut National de la Santé et de la Recherche Médicale (INSERM) U25, Hôpital Necker, 75015 Paris, France.
Treiner
E
E
Park
S H
SH
Garcia
C
C
Lemonnier
F
F
de la Salle
H
H
Bendelac
A
A
Bonneville
M
M
Lantz
O
O
D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology; D016827:CD8 Antigens / Q000276:immunology; D002417:Cattle; D003001:Cloning, Molecular; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*; D017386:Sequence Homology, Amino Acid; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000276:immunology
D015704:CD4 Antigens; D016827:CD8 Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D007135:Immunoglobulin Variable Region; D011948:Receptors, Antigen, T-Cell; D001613:beta 2-Microglobulin