TRAUMA & SEPSIS INDUCED CHANGES IN IMMUNE CELL MEMBRANE RECEPTOR TRAFFICKING

创伤

• 批准号: 8096537
• 负责人: Joseph Cuschieri
• 金额: $ 23.7万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8096537
• 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; DNA Sequence Rearrangement; Development; Environment; Event; Flow Cytometry; Focal Adhesions; Functional disorder; Future; Generations; Immune; Immunoblotting; Immunofluorescence Microscopy; Immunoprecipitation; In Vitro; Infection; Inflammation Mediators; Injury; Integrins; Invaded; Kinetics; Lead; Life; Link; Lipids; Lipopolysaccharides; Mediating; Membrane; Membrane Microdomains; Molecular; Mononuclear; Morbidity - disease rate; Multiple Organ Failure; Natural Immunity; Organ; Organ failure; Organism; Outcome; 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; 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; oxidant stress; peripheral blood; programs; receptor; release of sequestered calcium ion into cytoplasm; response; therapeutic target; tissue fixing; trafficking

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(申请人提供)：单个核细胞对根除入侵生物至关重要。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(TLRs)。这些受体在特定的质膜微域上的激活是复杂的，而且很少被阐明。根据我们以前的工作，我们假设这些复合体的形成需要质膜鞘脂分解成神经酰胺，从而形成脂筏大结构域和TLR复合体。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。尽管这些反应可能是挽救生命的，但众所周知，严重的创伤会导致重新编程和先天免疫力的改变。这些改变的表型，而不是导致宿主保护，是增加对入侵生物的易感性，导致败血症和器官衰竭的发展。在体外，通过让单个核细胞受到创伤诱导的因素，包括血小板激活因子、氧化应激和补体5a，这种状态已经被重建。尽管负责这种重编程的机制(S)尚不清楚，但先前的工作已经证明，这一过程与质膜内脂质和蛋白质含量的变化有关。这些变化被认为发生在脂筏上。损伤后，我们假设创伤诱导的因素导致神经酰胺的产生，但程度低于激活时的程度。神经酰胺曾经在木筏内产生融合，导致形成类似于激活时发生的大区域的形成。此外，神经酰胺导致钙离子的动员，导致CaMK II的激活。这些细胞信使的激活与局部粘附样复合体的形成有关，这些复合体包含部分但不是全部TLR组分。我们推测，这些复合体的组装和脂筏神经酰胺含量的变化是随后重新编程的原因，这导致了对后续感染的增强激活。因此，这项建议旨在通过探索神经酰胺、钙和CaMK II在体外和严重创伤患者中的作用，更全面地确定创伤后重新编程和激活的分子机制。