A novel functional cell surface dimer (kp43) serves as accessory molecule for the activation of a subset of human gamma delta T cells.
Kp43 is a cell surface molecule expressed by NK cells, gamma delta T lymphocytes, and a small subset of CD56+ alpha beta T cells. In the present study the distribution and function of Kp43 on gamma delta T cells is described. The expression of Kp43 on freshly isolated gamma delta T-cell populations derived from fetal and adult tissues was biased toward memory V gamma 2+/V delta 2+ T lymphocytes and appeared to be up-regulated after activation. Several gamma delta T-cell clones were derived from different sources. Adult V gamma 2+/V delta 2+ T-cell clones expressed the highest levels of Kp43, V delta 1 T-cell clones derived from periphery expressed moderate levels, whereas some thymus V delta 1 T cells and fetal gamma delta T-cell clones displayed low or undetectable levels of Kp43 molecule. Based on the effect of a specific mAb, this dimer appears to be fully functional as previously shown for NK cells. The stimulation of Kp43+ gamma delta T-cell clones with a combination of anti-CD3 and anti-Kp43 co-immobilized on a solid substratum enhanced both the expression of cell surface CD25 and the secretion of TNF-alpha. The restricted expression and functional activity of the Kp43 dimer suggests that it may play an important regulatory role in activation, selection, Ag recognition, and responsiveness of a subset of gamma delta T cells.
Rubio
G
G
Sección de Inmunología, Hospital Vírgen de la Arrixaca, El Palmar, Murcia, Spain.
Aramburu
J
J
Ontañón
J
J
López-Botet
M
M
Aparicio
P
P
D000938:Antigen-Presenting Cells / Q000276:immunology; D000954:Antigens, Surface / Q000378:metabolism*; D017252:CD3 Complex / Q000378:metabolism; D002999:Clone Cells; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D008099:Liver / Q000196:embryology; D008213:Lymphocyte Activation; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000954:Antigens, Surface; D017252:CD3 Complex; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015375:Receptors, Interleukin-2