Identification of a novel 110-kilodalton structure expressed on a subset of T cell receptor-gamma delta-bearing cloned lymphocytes.
A small percentage of circulating CD3+ cells express a heterodimeric gamma delta receptor. Most of these cells do not express the surface marker CD4 and only a fraction of them bear CD8 molecules. The specificity and function of TCR-gamma delta are unclear. We obtained a murine mAb produced against an IL-2-dependent human T cell clone defining a novel molecule sTA which is not expressed on resting human peripheral blood CD3+ cells but strongly expressed on a fraction of TCR-gamma delta-bearing clones. Like receptors for growth factors such as IL-2, the sTA Ag is present on clones and cell lines according on the cell cycle. SDS-PAGE analysis of sTA immunoprecipitates from 125I-labeled sTA+ clone lysate demonstrated a single band of molecular mass 110 kDa under reducing conditions. Triggering with anti-sTA mAb did not result in [Ca2+]i mobilization of sTA+ clones. Additionally, the presence of anti-sTA did not alter the cytotoxicity of these sTA+ clones neither against tumor target cells nor against specific PHA blast cells. Interestingly, due to the fact that most sTA+ clones fail to proliferate in response to CD3 triggering, it appears that sTA may serve as a useful marker to study the functional heterogeneity of TCR-gamma delta expressing cells.
David
V
V
Hôpital Saint-Louis, INSERM U93, Paris, France.
Bachelez
H
H
Leca
G
G
Degos
L
L
Boumsell
L
L
Bensussan
A
A
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D017252:CD3 Complex; D002118:Calcium / Q000502:physiology; D002999:Clone Cells; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008970:Molecular Weight; D011948:Receptors, Antigen, T-Cell / Q000032:analysis* / Q000276:immunology*; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D016692:Receptors, Antigen, T-Cell, gamma-delta; D002118:Calcium