CD47 is a membrane-associated glycoprotein that suppresses the function of immune cells. We previously reported that Langerhans cells (LCs) express Src homology 2 domain-containing protein tyrosine phosphatase substrate 1 (SHPS-1), a ligand for CD47, which plays an important role in the regulation of their motility. In this study, we show that LCs also express CD47, and that ligation of CD47 with SHPS-1-Fc fusion protein in vivo diminishes the development of the contact hypersensitivity response. We further demonstrate that CD47 engagement affects immune functions of LCs. CD47 engagement in vivo significantly inhibits the emigration of LCs from the epidermis into draining lymph nodes following treatment with haptens and tumor necrosis factor-alpha. The emigration of dendritic cells from skin explants into the medium and the chemotaxis of murine XS52 dendritic cells were significantly reduced by treatment with SHPS-1-Fc or an anti-CD47 mAb. Under explant culture system, SHPS-1-Fc treatment suppressed the expression of CD80 and CD86 of LCs. These effects on LCs and contact hypersensitivity response of CD47 ligation were reversed by treatment with pertussis toxin. These results suggest that the ligation of CD47 inhibits the migration of LCs and the expression of B7 costimulatory molecules, which results in inhibition of the contact hypersensitivity response.