Chemicals and reagents used were obtained from Sigma-Aldrich (St. Louis, MO) except as indicated. Direct red 80 was from Santa Cruz Biotechnology (Dallas, TX). Recombinant receptors (hCD40:Fc, CD40:COMP, and TNF-R1:Fc) and tagged ligands (hCD154, hCD154:Fc, MegaCD40L, and TNF-α), were obtained from Enzo Life Sciences (San Diego, CA). Mac-1 (recombinant human integrin αMβ2 protein) and the monoclonal anti-human CD154 (clone 40804) and anti-human TNF-α antibodies (clone 1825) were obtained from R&D Systems (Minneapolis, MN). Inhibitory peptides KGYY1519 (link) were purchased from New England Peptide (Gardner, MA, USA).