Misoprostol Modulation of Dendritic Cell Function in Immune Responses

Dendritic cells (DC) from blood and other tissues are potent accessory cells for primary immune responses. Because prostaglandins from monocytes and macrophages can suppress DC and T-cell function, we sought to investigate the binding properties of misoprostol (MPL), a prostaglandin E(1) analog, and its regulation of DC function. Results of mouse and human experiments have suggested 1) that MPL could significantly inhibit DC-induced T-cell proliferation in oxidative mitogenesis and allogeneic mixed leukocyte reactions by decreasing interleukin-2 production in DC-T cell cocultures, and 2) that MPL could bind to human peripheral blood mononuclear cells via specific high-affinity MPL binding sites as well as through nonspecific MPL uptake. Taken together, these data suggest that MPL can bind high-affinity and/or nonspecific cell surface receptors and subsequently regulate T-cell growth and cytokine production such as that induced by DC and associated with primary immune responses.