Injection with interleukin-4-secreting fibroblasts efficiently induces T helper type 2 cell-dominated immune response.

To determine whether the paracrine secretion of interleukin-4 (IL-4) can efficiently induce T helper type 2 (Th2) cell-dominated immune response, BLK fibroblasts were stably transfected to secrete IL-4 (750 units/10(6) cells/48 h). Their effects on T helper cell-mediated immune response were investigated in ovalbumin (OVA)-primed C57BL/6 mice, and were compared with those of free recombinant IL-4. Injection with IL-4-secreting fibroblasts (BLK/IL-4) significantly increased anti-OVA IgG1 production in OVA-primed mice. In addition, the BLK/IL-4 cells were more effective than free recombinant IL-4 in decreasing OVA-specific IFN-gamma production and in increasing OVA-specific IL-4 production by splenic CD4(+) T cells. This work suggests that IL-4-secreting fibroblasts can efficiently induce Th2 cell-dominated immune response and may be beneficial in the treatment of diseases caused by undesired Th1 cell-dominated responses.