[Type IV allergic reaction (delayed type)].

In guinea pig system, we have shown that a T cell-derived eosinophil chemotactic factor (ECF) plays a role especially in delayed-in-time tissue eosinophilia. In Kimura's disease characterized by blood and tissue eosinophilia, OKT4-positive T cells from the patients spontaneously produce an ECF (LDECF-HES; pI 6) without any additional stimulation. A monocyte-derived factor with mw of greater than 100,000 induce LDECF-HES production from T cells. On the other hand, OKT4-positive T cells from patients with parasite infection produce another ECF (LDECF-PD; pI 7-8) during mitogenic or antigenic stimulation. LDECF-PD production is selectively potentiated by ECF-potentiating factor derived from monocytes. Furthermore we have shown that the two ECF differ in their effects on eosinophil chemotaxis, eosinophil cationic protein release and Fc receptor expression. Recently we have established a T cell line, STO-2, constitutively producing 5 ECF with different pI (5, 6, 7, 8 and 9). These 5 ECF have different biological activities in eosinophil survival, Fc receptor expression and induction of specific eosinophilic granules. Comparison of chemotactic response of eosinophils from various patients with eosinophilia to respective ECF has revealed that eosinophils are heterogeneous in their chemotactic activity.