Rapid increase in mast cell numbers in canine central and peripheral airways

Abstract

In preliminary studies of antigen-induced airway inflammation, we noted an apparent increase in peribronchiolar mast cell number. Experiments were thus undertaken to investigate the nature of this migration of mast cells into the central and peripheral airway epithelium and to determine its time course. The tracheae and small airways of 10 anesthetized mongrel dogs were exposed via a bronchoscope to Ascaris suum antigen (Ag), fMet-Leu-Phe (fMLP), ovalbumin (OVA), and isotonic saline (SAL). In the central airways, all stimuli provoked a significant increase (P less than 0.05) in mast cell numbers at the base of the airway epithelium within 3 h. In the peripheral airways, only Ag aerosol stimulated a significant mast cell increase compared with unexposed tissue. In a second series of experiments, the trachea of seven dogs were exposed to 0.026, 0.26, and 2.6 micrograms of Ag. The tissue was collected at 1, 3, 6, and 10 h after exposure. In these experiments, there was a significant mast cell increase seen within 1 h but it was not dose dependent. By 6-10 h after exposure, mast cell counts were not significantly different from the unexposed condition, which is consistent with the idea that some of the cells either degranulated or migrated into the airway lumen. We conclude that mast cell migration is an acute response that can be demonstrated within 1 h of stimulation with Ag. The observation that nonimmunological stimuli may, in some cases, also stimulate mast cell movement affords the possibility that this process represents a generalized response to airway irritation.

Organic dust exposure increases mast cell tryptase in bronchoalveolar lavage fluid and airway epithelium of heaves horses

“…The majority of mast cells in the healthy equine airway have been reported to reside subepithelially within the lamina propria [35], a pertinent location for recruitment to the epithelium in heaves‐susceptible individuals during HSC. This concurs with a canine allergic airway model in which early epithelial mast cell recruitment was followed by decreased epithelial mast cell counts at 10 h post‐challenge [50]. This decrease was attributed to mast cell degranulation and the inability to visualize these ‘ghost cells’, rather than mast cell movement out of the epithelium as numbers were not increased in the subepithelial area or the airway lumen [50].…”

Mast cell activation and migration to lymph nodes during induction of an immune response in mice.

“…The rapid kinetics and selective expansion in the subcapsular region of the lymph nodes are most readily explained by the arrival of mast cells via afferent lymphatics rather than by local proliferation. Rapid increases in lung mast cell numbers in dogs (33) and human asthmatics (34) after antigen exposure provide support for our data and the notion of mast cell movement within tissues.…”

“…Such increases could occur by recruitment of mast cell precursors from the circulation followed by local maturation, local proliferation of resident mast cells, or migration of mature mast cells from adjacent tissues. The latter possibility is supported by reports that mast cell numbers increase in airway mucosa of dogs within 1 h of local antigenic challenge (33), and that there is a significant increase in submucosal mast cell density in human asthmatic lungs 6 h after antigen exposure (34). The kinetics of cell accumulation observed in these studies support rapid migration of mature mast cells, and recently Friend et al provided evidence of mast cell migration from the jejunum to the spleen during resolution of intestinal parasitic infection in mice (35).…”

The contribution of mast cells to the late-phase of allergic asthma in rats

“…Prior to this study, the data form Giemsa and toludine blue stained sections provided evidence for an increase in the number of mast cells in the dog trachea after allergen challenge [30] and in human bronchial mucosa after the LAR [31]. The activity of chymotrypsin-like serine protease could be detected not only in mucosal mast cells but also in globule leukocytes and basophils [32].…”

“…The digoxigenin-labeled mRNA antisense probe of RMCP-II was hybridized with section overnight in a humidified chamber at 60°C. As posthybridization washes the sections were incubated in 5 ¥ SSC with 50% formamide and 1% SDS for 30 …”