Induction of leucocyte migration inhibitory factor (LIF) by stimulation with free hapten and water-insoluble epoxy resin.

The indirect leucocyte migration inhibition test was applied to the contact sensitivity to a hapten (dinitrofluorobenzene, DNFB) and a water-insoluble epoxy resin (Araldite). Sensitized guinea-pig leucocytes were pulsed with DNFB, which was not conjugated to a carrier protein, or with Araldite which was made particulate by ultrasonication. When these pulsed leucocytes were incubated for 24 hr, they released significant amounts of leucocyte migration inhibitory factor (LIF). The optimal dose for pulse-stimulation was 10 microgram/ml. A correlation was observed between the degree of contact sensitivity and the production of LIF.