Relationship of histamine-releasing factors and histamine-releasing inhibitory factors to chemokine group of cytokine.

Abstract

The release of mediators from mast cells and basophils represents the central event in the development of immediate hypersensitivity reactions with release of substances such as histamine, Leukotrienes C4/D4, Platelet Activating Factor (PAF), and Prostaglandin D2. Cytokines such as IL-1, TNF alpha, and IL-4 may also be secreted. Histamine Releasing Factors (HRF) are cytokine-like molecules that interact with basophils and/or mast cells to cause cell activation and secretion of mediators. Histamine release is the best characterized of these and has been used as the assay for HRFs, but a wide variety of inflammatory mediators can potentially be secreted. We believe this type of cell to cell communication to be important in tissue inflammation, in which infiltrating cells may produce HRFs in proximity to infiltrating basophils and/or mast cells and cause them to degranulate. Such a reaction appears to be independent of IgE antibody, may no longer require the presence of any inciting antigen, and appears to be pertinent to the allergic late phase reaction as it occurs in the nose, lungs, and skin. It is thought that an ongoing antigenic stimulus, as seen in seasonal or perennial allergic rhinitis and asthma, or in certain types of urticaria, or in atopic dermatitis, leads to a perpetuating inflammatory reaction that persists for many weeks or months. A chronic inflammatory reaction of this sort appears to be required for an allergic reaction (IgE mediated) to manifest as an allergic disease. The relationship of HRF to the chemokine group of cytokine-like molecules and the importance of HRF in the pathogenesis of bronchial hyperreactivity and asthma has been reviewed in this paper.