Products from mast cells influence T lymphocyte proliferation and cytokine production—relevant to allergic asthma?

Bacterial components regulate the expression of Toll-like receptor 4 on human mast cells

“…These fi ndings strongly indicate the sentinel role of mast cells in the self-defense system, and suggest a signifi cant role of TLR4 located in mast cells against bacterial infection [6]. In this study, two distinct human mast cell lines, HMC-1 [16,17] and LAD2 [18] were employed. HMC-1 cells are known to have TLRs [9] and are immature human leukemia mast cells with the fastest growth rate due to the constitutive phosphorylation of c-Kit receptor [19], although with an unknown expression of functional CD14.…”

The biology of Stat4 and Stat6

“…For example, a polarized Th1 response can cause in¯ammatory or autoimmune diseases such as fulminant hepatitis, insulin-dependent diabetes mellitus, ulcerative colitis and graft-versus host diseases. In contrast, an exaggerated Th2 response can lead to allergic diseases such as atopic dermatitis and bronchial asthma (Andre et al, 1996;de Pater-Huijsen et al, 1997;Kapsenberg et al, 1991;Kuchroo et al, 1995;Racke et al, 1994).…”

Involvement of GATA-3-dependent Th2 lymphocyte activation in airway hyperresponsiveness

“…It has been reported that the number of cells producing IL-4, IL-5, and IL-13 is increased in the airways of asthmatics (12,19). Because IgE-cross-linked mast cells also produce Th2 cytokines (6), some investigators believe that mast cells are responsible for production of Th2 cytokines in the initiation of asthmatic responses (5). However, others have shown that T cell transfer can initiate an asthmatic response in the absence of IgE production (4,15).…”