Collagen I-induced inhibition of AICD in Jurkat cells is mediated by the 2β1 integrin.

(A) Jurkat cells were stimulated with or without anti-CD3 and collagen I in the presence or absence of inhibitory antibodies against α1 and α2 integrin subunits or control antibodies (IgG). The anti-integrin antibodies were used at 25 μg/mL and were added 30 minutes before plating the cells on anti-CD3–coated wells. The cells were then cultured for 24 hours and cell death was determined by DNA fragmentation assay. (B) Adhesion assay of Jurkat cells on immobilized collagen I. Cells were activated or not with PMA/ionomycin and plated on wells that had been coated with collagen I and were allowed to attach for 1 hour at 37°C. 25 μg/mL of inhibitory anti-α1 and anti-α2 integrin antibodies were added to the wells as indicated in the figure. Adhesion was quantified as described in “Materials and methods.” The results are representative of 3 different experiments performed in triplicates.