Publication Date:
2018-11-09
Description:
Anaphylactic reactions are triggered when allergens enter the blood circulation and activate immunoglobulin E (IgE)–sensitized mast cells (MCs), causing systemic discharge of prestored proinflammatory mediators. As MCs are extravascular, how they perceive circulating allergens remains a conundrum. Here, we describe the existence of a CD301b + perivascular dendritic cell (DC) subset that continuously samples blood and relays antigens to neighboring MCs, which vigorously degranulate and trigger anaphylaxis. DC antigen transfer involves the active discharge of surface-associated antigens on 0.5- to 1.0-micrometer microvesicles (MVs) generated by vacuolar protein sorting 4 (VPS4). Antigen sharing by DCs is not limited to MCs, as neighboring DCs also acquire antigen-bearing MVs. This capacity of DCs to distribute antigen-bearing MVs to various immune cells in the perivascular space potentiates inflammatory and immune responses to blood-borne antigens.
Keywords:
Immunology, Online Only
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Geosciences
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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