Biologic and antigenic similarity of virus-induced migration inhibition factor to conventional, lymphocyte-derived migration inhibition factor.

Macrophage migration inhibition factor (MIF) is one of a class of lymphocyte-derived mediator substances (lymphokines) which plays a role in the mechanism of cellular immunity. A variety of other soluble factors produced by non-lymphoid cells have been shown to have effects on macrophage mobility similar to that of MIF. In the present study we demonstrate that one such factor, (MIFV) derived from simian virus 40-infected kidney cells in culture, has several other properties in common with lymphocyte-derived MIF (MIFL), MIFV can be adsorbed on Sepharose bead columns conjugated with an antiserum prepared against MIFL, demonstrating at least some antigenic similarity. Moreover, MIFV can substitute for MIFL in an in vivo system involving the suppression of cutaneous manifestations of cellular immunity by intravenous injection of the lymphokine. These observations, taken in conjunction with the similarity of the in vitro effect of MIFV and MIFL, and their similar chromatographic behavior, suggest that MIFV and MIFL may be identical molecular species.