TRAUMA & SEPSIS INDUCED CHANGES IN IMMUNE CELL MEMBRANE RECEPTOR TRAFFICKING

创伤

基本信息

批准号：
7294030
负责人：
Joseph Cuschieri
金额：
$ 27.05万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-09-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7294030
关键词：
Alveolar Macrophages Architecture Binding CD14 gene Calcium Calcium/calmodulin-dependent protein kinase Cell Fraction Cell membrane Cells Ceramides Characteristics Cholesterol Clinical Complement 5a Complex Condition DNA Sequence Rearrangement Development Environment Event Flow Cytometry Focal Adhesions Functional disorder Future Generations Hand Immune Immunoblotting Immunofluorescence Microscopy Immunoprecipitation In Vitro Infection Inflammatory Injury Integrins Invaded Kinetics Lead Life Link Lipids Lipopolysaccharides Mediating Mediator of activation protein Membrane Membrane Microdomains Molecular Mononuclear Morbidity - disease rate Multiple Organ Failure Multiple Trauma Natural Immunity Organ Organ failure Organism Outcome Oxidants Patients Pattern recognition receptor Phenotype Phosphotransferases Platelet Activating Factor Predisposition Process Production Protein Isoforms Proteins Proteomics Receptor Activation Recovery Recruitment Activity Research Personnel Risk Sepsis Series Signal Transduction Sphingolipids Stimulus Stress TLR4 gene Techniques Testing Time Toll-like receptors Trauma Work acid sphingomyelinase attenuation base calmodulin-dependent protein kinase IV fluidity improved in vivo injured macrophage monocyte mortality peripheral blood programs receptor release of sequestered calcium ion into cytoplasm response therapeutic target tissue fixing trafficking

项目摘要

DESCRIPTION (provided by applicant): Mononuclear cells are critical to the eradication of invading organisms. The mechanism in which these innate immune cells respond to these invaders is through the activation of a series of pattern recognition receptors or Toll-like receptors (TLRs). Activation of these receptors, on specialized plasma membrane microdomains is complex and poorly elucidated. Based on previous work by us, we hypothesize that formation of these complexes requires breakdown of plasma membrane sphingolipids into ceramide leading to the formation of lipid raft macrodomains and the formation of TLR complexes. As a result, specific infectious factors are presented to these pattern recognition receptors leading to cellular activation. Although these responses may be life saving, severe trauma is know to result in reprogramming and alterations in innate immunity. These altered phenotypes, rather than leading to host protection, are responsible for increased susceptibility to invading organisms leading to the development of sepsis and organ failure. This state has been recreated in vitro by subjecting mononuclear cells to factors induced by trauma, including platelet activating factor, oxidant stress and complement 5a. Although the mechanism(s) responsible for this reprogramming remain unknown, previous work has demonstrated that this process is associated with alterations in the lipid and protein content within the plasma membrane. These alterations are hypothesized to occur on lipid rafts. Following injury, we hypothesize that factors induced by trauma result in the production of ceramide, but to a lesser degree than that seen during activation. Ceramide once produced fuses within rafts leading to the formation of macrodomains similar to that which occurs with activation. Additionally, ceramide leads to the mobilization of calcium leading to the activation of CaMK II. Activation of these cellular messengers is associated with the formation of focal adhesion-like complexes that contain some but not all of the TLR components. We hypothesize that assembly of these complexes and changes in lipid raft ceramide content are responsible for subsequent reprogramming that induces enhanced activation in response to subsequent infection. Thus, this proposal sets out to determine more fully the molecular mechanisms responsible for reprogramming and activation following trauma by exploring the effects of ceramide, calcium and CaMK II in vitro, and in severely injured trauma patients.

描述（由申请人提供）：单核细胞对于根除入侵生物体至关重要。这些先天免疫细胞对这些入侵者做出反应的机制是通过激活一系列模式识别受体或 Toll 样受体 (TLR)。这些受体在特殊的质膜微域上的激活是复杂的并且很少被阐明。基于我们之前的工作，我们假设这些复合物的形成需要质膜鞘脂分解成神经酰胺，从而导致脂筏宏结构域的形成和 TLR 复合物的形成。结果，特定的感染因子被呈现给这些模式识别受体，导致细胞激活。尽管这些反应可能挽救生命，但已知严重的创伤会导致先天免疫的重新编程和改变。这些改变的表型并没有导致宿主保护，而是增加了对入侵微生物的易感性，导致败血症和器官衰竭的发展。通过使单核细胞受到创伤诱导的因素（包括血小板活化因子、氧化应激和补体 5a）的影响，可以在体外重现这种状态。尽管负责这种重编程的机制仍然未知，但先前的工作已证明该过程与质膜内脂质和蛋白质含量的变化有关。假设这些改变发生在脂筏上。受伤后，我们假设创伤诱发的因素会导致神经酰胺的产生，但程度低于激活过程中所见的程度。神经酰胺曾经在筏内产生融合，导致形成类似于激活时发生的大结构域。此外，神经酰胺会导致钙的动员，从而激活 CaMK II。这些细胞信使的激活与粘着斑样复合物的形成相关，该复合物包含一些但不是全部的 TLR 成分。我们假设这些复合物的组装和脂筏神经酰胺含量的变化负责随后的重编程，从而诱导针对随后的感染的增强的激活。因此，该提案旨在通过探索神经酰胺、钙和 CaMK II 在体外以及在严重受伤的创伤患者中的作用，更全面地确定负责创伤后重编程和激活的分子机制。