Histamine influences the expression of IFN-γ in atopic and nonatopic human Th1 cell cultures

Lack of Th1 lymphocyte derived interferon-g (IFN-g) is one of the main indicators for the development of allergic diseases. Furthermore allergic reactions, infections, and tumors are associated with excessive histamine production and shift toward Th2 responses. Histamine inhibits IFN-g production via H2 receptors [1]. In most studies, histamine was found to suppress the secretion of the IFN-g-antagonistic interleukin-4 (IL-4). However this point is controversial and the question remains open in how far this results because of a shift of the Th1/Th2 balance toward the Th2 phenotype [for review 2, 3]. This paper aims to demonstrate influence of histamine on human T-cell development and expression of IFN-g mRNA ex vivo.