title: Mast cells present protrusions into blood vessels upon tracheal allergen challenge in mice.
abstract: Mast cells (MC) and myeloid dendritic cells (DC) act proximally in detecting and processing antigens and immune insults. We sought to understand their comparative dynamic behavior with respect to the airway epithelium in the steady state and in response to an allergic stimulus in mouse trachea. We devised methods to label MC in living trachea and to demonstrate that MC and DC occupy distinct layers of the tracheal mucosa, with DC being closer to the lumen. DC numbers doubled after allergen challenge, but MC numbers remained stable. MC and DC migrated minimally in either steady state or allergen-challenge conditions, and their interactions with one another appeared to be stochastic and relatively infrequent. While DC, unlike MC, exhibited probing behaviors involving dendrites, these projections did not cross the epithelium into the airway lumen. MC typically were located too far from the epithelial surface to contact the tracheal lumen. However, MC had protrusions toward and into blood vessels, likely to load with IgE. Thus, DC and MC occupy distinct niches and engage in sessile surveillance in the mouse trachea. Little or no access of these cell types to the airway lumen suggests that trans-epithelial transport of proteins in the steady state would be required for them to access luminal antigens.
authors: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors: Oishee
authors: O
authors: Bose
authors: Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America; Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America.
authors: Peter
authors: P
authors: Baluk
authors: Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, United States of America.
authors: Mark R
authors: MR
authors: Looney
authors: Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America.
authors: Laurence E
authors: LE
authors: Cheng
authors: Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America; Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America.
authors: Donald M
authors: DM
authors: McDonald
authors: Department of Medicine, University of California San Francisco, San Francisco, California, United States of America; Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America.
authors: George H
authors: GH
authors: Caughey
authors: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America; Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America.
authors: Matthew F
authors: MF
authors: Krummel
mesh_terms: D000485:Allergens / Q000276:immunology*; D000818:Animals; D001808:Blood Vessels / Q000276:immunology* / Q000473:pathology*; D002465:Cell Movement; D022081:Cell Surface Extensions / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D021621:Imaging, Three-Dimensional; D007073:Immunoglobulin E / Q000276:immunology; D008407:Mast Cells / Q000166:cytology* / Q000276:immunology*; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D015203:Reproducibility of Results; D013194:Staining and Labeling; D014132:Trachea / Q000276:immunology*
chemical_list: D000485:Allergens; D007073:Immunoglobulin E; D010047:Ovalbumin