Release of migration inhibitory factor from mouse T and B cells activated by insoluble phytomitogens.

The production of macrophage migration inhibitory factor (MIF) was studied with mouse B spleen cells and with the low density subpopulation of thymus cells (T cells) stimulated by phytomitogens. MIF was released from mouse B cells when stimulated by Sepharose-PWM but was not released by Sepharose-Con A. MIF was produced by the low density subpopulation of thymus cells stimulated by Sepharose-Con A. MIF from B cells could not be distinguished from that of the low density subpopulation of thymus cells by gel filtration on Sephadex G-100 column. The molecular size of both MIF was calculated to be 45,000-55,000 dalton.