Comparative analysis of CD43-and T-cell costimulation-induced signaling pathways in human peripheral T lymphocytes. Cells were stimulated for the indicated periods with agonistic αCD43 or αCD3/CD28 antibodies and lysed. Equal amounts of protein contained in total cell extracts were analyzed by immunoblotting. The occurrence of p65 and c-Jun was revealed with specific antibodies; phosphorylation of endogenous proteins was revealed by phosphospecific antibodies detecting phosphorylated forms of p65, IκBα, c-Jun, and Jun N-terminal kinase 1 and 2 (JNK1/2).