Partial characterization of immunosuppressive factors from short-term cultures of murine decidual tissue

Summary Previous in vitro experiments provided evidence for the immunosuppressive properties of supernatants from short-term cultures of decidual tissue obtained from the uterus of the pregnant mouse. The inhibitory activity of supernatants, previously detected in a mixed lymphocyte reaction (MLR), has now been demonstrated in an in vitro thymocyte proliferation assay. Fractionation of these supernatants on Sephadex G-15 and Sephacryl S-300 revealed that inhibition of the thymocyte proliferation assay was associated only with a low molecular weight fraction (