title: Formation of contacts between mast cells and sympathetic neurons in vitro.
abstract: Functional interactions between mast cells and peripheral nerves may occur at sites of association seen in vivo. To study the interactions, we developed a tissue culture model of murine sympathetic neurons co-cultured with rat basophilic leukaemia (RBL-2H3) cells (homologues of mucosal mast cells) or rat peritoneal mast cells. In co-cultures of up to 3 days, light microscopy identified neurite contacts with peritoneal mast cells or RBL-2H3 cells, but not with glial cells or fibroblasts. Electron microscopy confirmed membrane-membrane contact between neurites and RBL-2H3 cells. Time-lapse analysis of interactions between neurons and RBL-2H3 cells showed that 60-100% of the cells in a given field acquired neurite contact within 17 h. In matching control studies, there was no increase in the frequency of neurite contact with cells of the rat plasmacytoma line (YB2/0): these were not selected as targets, and contacts were broken if formed. Time-lapse records of the derivation of neurites from their path suggested a neurotropic effect of mast cells, with neurite contact ensuing when the intervening distance was less than 36 +/- 4 microns. Once formed, contacts were invariably maintained throughout the period of examination (up to 72 h), in contrast to YB2/O or fibroblast contacts. We conclude that neurons selectively form and maintain connections with cells representative of rat connective tissue-type and mucosal mast cells in vitro. Similar interactions in vivo could promote nerve/mast cell contacts, which may allow bidirectional communication between the nervous and immune systems.
authors.affiliation: Department of Pathology, McMaster University Health Sciences Center, Hamilton, Ontario, Canada.
authors.forename: M G
authors.initials: MG
authors.lastname: Blennerhassett
authors.forename: M
authors.initials: M
authors.lastname: Tomioka
authors.forename: J
authors.initials: J
authors.lastname: Bienenstock
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D005347:Fibroblasts / Q000473:pathology / Q000648:ultrastructure; D066298:In Vitro Techniques; D007942:Leukemia, Experimental / Q000473:pathology; D008407:Mast Cells / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D051379:Mice; D008808:Mice, Inbred CBA; D008854:Microscopy, Electron; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure*; D010954:Plasmacytoma / Q000473:pathology; D051381:Rats; D013564:Sympathetic Nervous System / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D013997:Time Factors