Mast-Cell Infiltration of Airway Smooth Muscle in Asthma

Abstract

The infiltration of airway smooth muscle by mast cells is associated with the disordered airway function found in asthma.

Surface CD88 functionally distinguishes the MCTC from the MCT type of human lung mast cell

“…37 However, the current study shows that MC TC cells from lung produce amounts of LTC 4 that are comparable with MC T cells from lung, suggesting the possibility that MC TC cells can acquire the ability to produce this lipid mediator. In fact, mast cells derived from intestinal mucosa 38 and those from cord blood under the influence of both SCF and IL-6, 39 when challenged with antigen to cross-link Fc∊RI, release small quantities of LTC 4 unless first primed with IL-4, in which case LTC synthase is induced and LTC 4 production is substantially amplified. Whether LTC 4 production by activated Sk-MC can be induced was not addressed by the current study.…”

“…Cysteinyl-leukotriene (LT) levels in releasates were measured with an ELISA for LTC 4 /D 4 /E 4 (Amersham Pharmacia Biotech, Piscataway, NJ). For this ELISA, the cross-reactivity between LTC 4 and LTD 4 is 100%; LTC 4 and LTE 4 is 70%; and LTC 4 and LTB 4 is 0.3%. Concentrations were determined according to the manufacturer's instructions, with a lower limit of detection of 10 pg/mL.…”

“…Although Lu-MC TC cells produce LTC 4 in response to these agonists, Sk-MC TC cells do not. Lu-MC T cells only respond to anti-Fc∊RI and substance P by degranulating and secreting LTC 4 . Thus, MC T and MC TC cells appear to be functionally distinct.…”

Regulation of Activin A Expression in Mast Cells and Asthma: Its Effect on the Proliferation of Human Airway Smooth Muscle Cells

“…It was noted that the number of human MC present in asthmatic ASM is increased as compared with that in nonasthmatic ASM (5,45), suggesting that mediators released by MC can modulate ASM function in the asthmatic airway. To determine whether MC promote the proliferation of HASMC by releasing activin A, HASMC were treated with recombinant human activin A. Culturing of HASMC in the presence of activin A for 24 h increased (by 214%) the number of HASMC in a dose-dependent manner as compared with the numbers of HASMC maintained for the same time period under basal, serum-free conditions (Fig.…”

“…The inflammatory process underlying asthma results from a highly complex interaction of various cell types (3)(4)(5). In addition, ECM interacts with inflammatory cells (6), forms a reservoir for cytokines and growth factors (7,8), influences trafficking of cells (9), and activates granulocytes to increase mediator release and enhance their survival (10,11).…”