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Evaluate three v-SNAREs in regulated and constitutive TNF release from mast cells

评估肥大细胞调节和组成型 TNF 释放中的三种 v-SNARE

基本信息

批准号：
10557868
负责人：
Hao Xu
金额：
$ 7.4万
依托单位：
UNIVERSITY OF SOUTHERN MISSISSIPPI
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10557868
关键词：
Acute Allergens Allergic inflammation Animals Asthma Binding Biological Assay Bone Marrow Breeding Cell Line Cell membrane Cell surface Cells Complex Confocal Microscopy Cues Cytoplasmic Granules Development Disease Double-Stranded RNA Endosomes Endotoxins Enzyme-Linked Immunosorbent Assay Exocytosis Fluorescence Golgi Apparatus Harvest Heterozygote IgE Immune Immune response Inflammatory Innate Immune Response Investigation Knock-out Knockout Mice Length Measures Mediating Membrane Membrane Fusion Methods Molecular Multivesicular Body Mus Natural Immunity Nature Pathway interactions Pattern Peritoneal Play Poly I-C Proteolysis Recycling Regulation Rheumatoid Arthritis Role SNAP receptor SNAP23 gene Signal Transduction Stimulus TNF gene Testing The Jackson Laboratory Time Tumor Promotion Vesicle Viral Work adaptive immunity cellubrevin combat exosome granule cell insight late endosome mast cell novel therapeutic intervention pathogen release factor response syntaxin syntaxin A target SNARE proteins transcription factor

项目摘要

PROJECT SUMMARY Mast cell-derived TNF (tumor necrosis factor) plays important roles in immune responses, but when in excess, causes inflammatory disorders including asthma and rheumatoid arthritis. Unlike other TNF producing cells, mast cells pre-store TNF in cytoplasmic granules, which can undergo rapid exocytosis/degranulation under specific conditions. Mast cells can also be activated to promote TNF transcription, and newly synthesized TNF is released over time via constitutive secretory carriers such as Golgi-derived vesicles. Both regulated and constitutive TNF secretion require specific interactions between vesicle/granule-anchored SNAREs (v-SNAREs) and SNAREs anchored to the plasma membrane (the target membrane; hence t-SNAREs), resulting in the formation of trans-SNARE complexes and concomitant membrane fusion. Exocytic trans-SNARE complexes in immune cells are typically composed of a VAMP (v-SNARE), a SNAP23 (t-SNARE) and a syntaxin (t-SNARE). However, the identities of the SNAREs that underscore TNF release from activated mast cells are largely unknown, which has hindered the understanding of the stimulus-specific regulation of TNF exocytosis in these cells. The overall objective of this proposal is to uncover the missing v-SNAREs required in regulated and constitutive TNF secretion from primary mast cells. New evidence from our lab has suggested that TNF is associated with exosomes within MVBs (multivesicular bodies; a type of late endosomes), which rely on VAMP7 or Ykt6 (a unique, multi-purpose v-SNARE) to fuse with the plasma membrane. Meanwhile, VAMP2 has recently emerged as the v-SNARE that mediates the exocytosis of Golgi-derived vesicles. Based on these fresh insights, we hypothesize that mast cells employ VAMP7/Ykt6 and VAMP2 to release prestored and newly synthesized TNF respectively in response to different environmental cues. To test this hypothesis, we will exploit primary mast cells derived from KO mice and their wildtype littermates to pursue two specific aims. Aim1 will assess the requirement of VAMP7 and Ykt6 in acute/regulated TNF exocytosis. Aim2 will assess the requirement of VAMP2 in constitutive TNF exocytosis. The completion of this study will delineate the catalytic machineries that drive TNF exocytosis under different environmental conditions, setting a stage for revealing stimulus-specific regulation of TNF release unique to mast cells.

项目总结