Author/Authors :
Gerli، نويسنده , , Roberto and Agea، نويسنده , , Elisabetta and Muscat، نويسنده , , Christopher and Ercolani، نويسنده , , Raffaella and Bistoni، نويسنده , , Onelia and Tognellini، نويسنده , , Rita and Mariggiَ، نويسنده , , Maria A. and Spinozzi، نويسنده , , Fabrizio and Bertotto، نويسنده , , Alberto، نويسنده ,
Abstract :
A role of 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, which is able to modulate the molecule on the cell membrane and synergize with 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 is 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.
