IL-4-dependent regulation of TGF-α and TGF-β1 expression in human eosinophils
The Journal of Immunology, 1998•journals.aai.org
TGFs play important roles in wound healing and carcinogenesis. We have previously
demonstrated that eosinophils infiltrating into different pathologic processes elaborate TGF-
α and TGF-β1. Eosinophils infiltrating hamster cutaneous wounds were found to express
TGFs sequentially. In this study, we examined the biologic mediators that may regulate the
expression of TGF-α and-β1 by eosinophils. Eosinophils were isolated from the peripheral
blood of healthy donors and cultured in the absence or presence of IL-3, IL-4, and IL-5. Cells …
demonstrated that eosinophils infiltrating into different pathologic processes elaborate TGF-
α and TGF-β1. Eosinophils infiltrating hamster cutaneous wounds were found to express
TGFs sequentially. In this study, we examined the biologic mediators that may regulate the
expression of TGF-α and-β1 by eosinophils. Eosinophils were isolated from the peripheral
blood of healthy donors and cultured in the absence or presence of IL-3, IL-4, and IL-5. Cells …
Abstract
TGFs play important roles in wound healing and carcinogenesis. We have previously demonstrated that eosinophils infiltrating into different pathologic processes elaborate TGF-α and TGF-β1. Eosinophils infiltrating hamster cutaneous wounds were found to express TGFs sequentially. In this study, we examined the biologic mediators that may regulate the expression of TGF-α and-β1 by eosinophils. Eosinophils were isolated from the peripheral blood of healthy donors and cultured in the absence or presence of IL-3, IL-4, and IL-5. Cells were analyzed by in situ hybridization and immunohistochemistry. Supernatants from these cultures were assayed for secreted TGF-α and TGF-β1 using TGF-specific ELISAs. IL-3, IL-4, and IL-5 independently up-regulated TGF-β1 mRNA and product expression by eosinophils in all donors. Interestingly, TGF-α production by eosinophils was up-regulated by IL-3 and IL-5 but was down-regulated by IL-4. Consistent with the ability of IL-4 to regulate eosinophil responses, IL-4 signaling molecules are present in human eosinophils. The observation that IL-4 can differentially regulate the expression of TGF-α and TGF-β1 suggests that IL-4 may serve as a physiologic molecular switch of TGF expression by the infiltrating eosinophils in wound healing and carcinogenesis.
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