Interleukin 4 is localized to and released by human mast cells
journal contributionposted on 24.10.2012, 09:12 by P. Bradding, I. H. Feather, P. H. Howarth, R. Mueller, J. A. Roberts, K. Britten, J. P. A. Bews, T. C. Hunt, Y. Okayama, C. H. Heusser, G. R. Bullock, M. K. Church, S. T. Holgate
Recent attention has focused on the T helper type 2 (Th2) lymphocyte as a source of interleukin 4 (IL-4) in allergic disease. However, Th2 cells themselves require a pulse of IL-4 to initiate this synthesis. Here we provide immunohistochemical evidence of IL-4 localization to human mast cells of the skin and respiratory tract, and demonstrate that immunoglobulin E-dependent stimulation of purified human lung mast cells leads to the rapid release of IL-4 into the extracellular environment. We propose that mast cell activation in an allergic response provides a rapid and local pulse of IL-4 into the local environment essential for the triggering of T lymphocytes into sustained IL-4 production and to initiate inflammatory cell accumulation and activation.