Activation of cord T lymphocytes. IV. Analysis of surface expression and functional role of 1F7 (CD26) molecule.
A role for CD26 surface antigen (Ag) in both CD3- and CD2-mediated T cell activation has been previously demonstrated. To analyze the functional role of CD26 in the CD3- and CD2-induced activation pathways of cord T cells, which represent the most reliable source of Ag-unprimed T cells, we employed a newly developed anti-CD26 monoclonal antibody, termed anti-1F7, anti-CD3 and anti-CD2 in activating T lymphocytes. The results showed that CD26 Ag is expressed on the surface of almost all resting cord T cells and that its fluorescence intensity is enhanced by activation. The binding of anti-1F7 induced a decrease in CD26 membrane expression, with no detectable effect on the surface expression of other cord T cell-related molecules. Moreover, the modulation of CD26 resulted in an increase in anti-CD3-mediated cord T cell activation through an enhancement in intracellular calcium levels, IL-2 receptor expression, and IL-2 synthesis, whereas it had no effect on cord T cell activation induced by anti-CD2 or anti-CD2 plus exogenous IL-2. The fact that the selective involvement of CD26 in the activation pathway triggered by anti-CD3, but not anti-CD2, could be reversed by prior stimulation of cord T cells with anti-CD3 suggests that this functional feature, which resembles that of mature thymocytes, may be linked to the Ag-unprimed cell phenotype of cord T lymphocytes.
Gerli
R
R
Institute of Internal Medicine and Oncologic Sciences, University of Perugia, Italy.
Agea
E
E
Muscat
C
C
Ercolani
R
R
Bistoni
O
O
Tognellini
R
R
Mariggió
M A
MA
Spinozzi
F
F
Bertotto
A
A
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000276:immunology; D018801:CD2 Antigens; D017252:CD3 Complex / Q000032:analysis; D002118:Calcium / Q000032:analysis; D018819:Dipeptidyl Peptidase 4; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D011971:Receptors, Immunologic / Q000032:analysis; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D007376:Interleukin-2; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D018819:Dipeptidyl Peptidase 4; D002118:Calcium