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BioRxiv : the Preprint Server For... Oct 2023Leukocyte infiltration of the CNS can contribute to neuroinflammation and cognitive impairment. Brain endothelial cells regulate adhesion, activation, and diapedesis of...
Leukocyte infiltration of the CNS can contribute to neuroinflammation and cognitive impairment. Brain endothelial cells regulate adhesion, activation, and diapedesis of T cells across the blood-brain barrier (BBB) in inflammatory diseases. The integral membrane protein Caveolin-1 (Cav-1) critically regulates BBB permeability, but its influence on T cell CNS infiltration in respiratory viral infections is unknown. In this study, we sought to determine the role of Cav-1 at the BBB in neuroinflammation in a COVID-19 mouse model. We used mice genetically deficient in Cav-1 to test the role of this protein in T cell infiltration and cognitive impairment. We found that SARS-CoV-2 infection upregulated brain endothelial Cav-1. Moreover, SARS-CoV-2 infection increased brain endothelial cell vascular cell adhesion molecule-1 (VCAM-1) and CD3+ T cell infiltration of the hippocampus, a region important for short term learning and memory. Concordantly, we observed learning and memory deficits. Importantly, genetic deficiency in Cav-1 attenuated brain endothelial VCAM-1 expression and T cell infiltration in the hippocampus of mice with SARS-CoV-2 infection. Moreover, Cav-1 KO mice were protected from the learning and memory deficits caused by SARS-CoV-2 infection. These results indicate the importance of BBB permeability in COVID-19 neuroinflammation and suggest potential therapeutic value of targeting Cav-1 to improve disease outcomes.
PubMed: 37905019
DOI: 10.1101/2023.10.18.563024 -
Biochemical and Biophysical Research... Nov 2023Temsirolimus is a first-generation mTOR inhibitor commonly used in the clinical treatment of cancers that is associated with lung injury. However, the mechanism...
Temsirolimus is a first-generation mTOR inhibitor commonly used in the clinical treatment of cancers that is associated with lung injury. However, the mechanism underlying this adverse effect remains elusive. Endothelial barrier dysfunction plays a pivotal role in the infiltration of neutrophils into the pulmonary alveoli, which eventually induces lung injury. The present study demonstrates that temsirolimus induces the aberrant expression of adhesion molecules in endothelial cells, leading to enhanced neutrophil infiltration and subsequent lung injury. Results of a mouse model revealed that temsirolimus disrupted capillary-alveolar barrier function and facilitated neutrophil transmigration across the endothelium within the alveolar space. Consistent with our in vivo observations, temsirolimus impaired intercellular barrier function within monolayers of human lung endothelial cells, resulting in increased neutrophil infiltration. Furthermore, we demonstrated that temsirolimus-induced neutrophil transendothelial migration was mediated by platelet endothelial cell adhesion molecule-1 (PECAM-1) in both in vitro and in vivo experiments. Collectively, these findings highlight that temsirolimus induces endothelial barrier dysfunction via PECAM-1-dependent pathway both in vitro and in vivo, ultimately leading to neutrophil infiltration and subsequent pulmonary injury.
Topics: Animals; Mice; Humans; Platelet Endothelial Cell Adhesion Molecule-1; Lung Injury; Neutrophils; Endothelial Cells; Transendothelial and Transepithelial Migration; Cell Movement; Endothelium, Vascular
PubMed: 37820453
DOI: 10.1016/j.bbrc.2023.10.019 -
Allergy May 2024Neutrophil migration into the airways is a key process in neutrophilic asthma. Developmental endothelial locus-1 (DEL-1), an extracellular matrix protein, is a...
BACKGROUND
Neutrophil migration into the airways is a key process in neutrophilic asthma. Developmental endothelial locus-1 (DEL-1), an extracellular matrix protein, is a neutrophil adhesion inhibitor that attenuates neutrophilic inflammation.
METHODS
Levels of DEL-1 were measured in exhaled breath condensate (EBC) and serum in asthma patients by ELISA. DEL-1 modulation of neutrophil adhesion and transepithelial migration was examined in a co-culture model in vitro. The effects of DEL-1-adenoviral vector-mediated overexpression on ovalbumin/lipopolysaccharide (OVA/LPS)-induced neutrophilic asthma were studied in mice in vivo.
RESULTS
DEL-1 was primarily expressed in human bronchial epithelial cells and was decreased in asthma patients. Serum DEL-1 concentrations were reduced in patients with severe asthma compared with normal subjects (567.1 ± 75.3 vs. 276.8 ± 29.36 pg/mL, p < .001) and were negatively correlated to blood neutrophils (r = -0.2881, p = .0384) and neutrophil-to-lymphocyte ratio (NLR) (r = -0.5469, p < .0001). DEL-1 concentrations in the EBC of severe asthmatic patients (113.2 ± 8.09 pg/mL) were also lower than normal subjects (193.0 ± 7.61 pg/mL, p < .001) and were positively correlated with the asthma control test (ACT) score (r = 0.3678, p = .0035) and negatively related to EBC IL-17 (r = -0.3756, p = .0131), myeloperoxidase (MPO) (r = -0.5967, p = .0055), and neutrophil elastase (NE) (r = -0.5488, p = .0009) expression in asthma patients. Neutrophil adhesion and transepithelial migration in asthma patients were associated with LFA-1 binding to ICAM-1 and inhibited by DEL-1. DEL-1 mRNA and protein expression in human bronchial epithelial cells were regulated by IL-17. Exogenous DEL-1 inhibited IL-17-enhanced neutrophil adhesion and migration. DEL-1 expression was decreased while neutrophil infiltration was increased in the airway of a murine model of neutrophilic asthma. This was prevented by DEL-1 overexpression.
CONCLUSIONS
DEL-1 down-regulation leads to increased neutrophil migration across bronchial epithelial cells and is associated with neutrophilic airway inflammation in asthma.
Topics: Animals; Female; Humans; Mice; Asthma; Calcium-Binding Proteins; Cell Adhesion; Cell Adhesion Molecules; Disease Models, Animal; Inflammation; Neutrophils; Transendothelial and Transepithelial Migration
PubMed: 37681299
DOI: 10.1111/all.15882 -
Immunity Oct 2023Engagement of platelet endothelial cell adhesion molecule 1 (PECAM, PECAM-1, CD31) on the leukocyte pseudopod with PECAM at the endothelial cell border initiates...
Engagement of platelet endothelial cell adhesion molecule 1 (PECAM, PECAM-1, CD31) on the leukocyte pseudopod with PECAM at the endothelial cell border initiates transendothelial migration (TEM, diapedesis). We show, using fluorescence lifetime imaging microscopy (FLIM), that physical traction on endothelial PECAM during TEM initiated the endothelial signaling pathway. In this role, endothelial PECAM acted as part of a mechanotransduction complex with VE-cadherin and vascular endothelial growth factor receptor 2 (VEGFR2), and this predicted that VEGFR2 was required for efficient TEM. We show that TEM required both VEGFR2 and the ability of its Y1175 to be phosphorylated, but not VEGF or VEGFR2 endogenous kinase activity. Using inducible endothelial-specific VEGFR2-deficient mice, we show in three mouse models of inflammation that the absence of endothelial VEGFR2 significantly (by ≥75%) reduced neutrophil extravasation by selectively blocking diapedesis. These findings provide a more complete understanding of the process of transmigration and identify several potential anti-inflammatory targets.
Topics: Animals; Mice; Cell Adhesion; Cell Movement; Endothelium, Vascular; Mechanotransduction, Cellular; Platelet Endothelial Cell Adhesion Molecule-1; Transendothelial and Transepithelial Migration; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2
PubMed: 37643615
DOI: 10.1016/j.immuni.2023.08.001 -
International Journal of Molecular... Aug 2023Proteomics in respiratory allergic diseases has such a battery of techniques and programs that one would almost think there is nothing impossible to find, invent or... (Review)
Review
Proteomics in respiratory allergic diseases has such a battery of techniques and programs that one would almost think there is nothing impossible to find, invent or mold. All the resources that we document here are involved in solving problems in allergic diseases, both diagnostic and prognostic treatment, and immunotherapy development. The main perspectives, according to this version, are in three strands and/or a lockout immunological system: (1) Blocking the diapedesis of the cells involved, (2) Modifications and blocking of paratopes and epitopes being understood by modifications to antibodies, antagonisms, or blocking them, and (3) Blocking FcεRI high-affinity receptors to prevent specific IgEs from sticking to mast cells and basophils. These tools and targets in the allergic landscape are, in our view, the prospects in the field. However, there are still many allergens to identify, including some homologies between allergens and cross-reactions, through the identification of structures and epitopes. The current vision of using proteomics for this purpose remains a constant; this is also true for the basis of diagnostic and controlled systems for immunotherapy. Ours is an open proposal to use this vision for treatment.
Topics: Humans; Proteomics; Hypersensitivity; Respiration Disorders; Respiratory Tract Diseases; Epitopes; Allergens
PubMed: 37629105
DOI: 10.3390/ijms241612924 -
Vascular Biology (Bristol, England) Jan 2023Intercellular adhesion molecules (ICAMs) are cell surface proteins that play a crucial role in the body's immune response and inflammatory processes. ICAM1 and ICAM2 are...
Intercellular adhesion molecules (ICAMs) are cell surface proteins that play a crucial role in the body's immune response and inflammatory processes. ICAM1 and ICAM2 are two ICAM family members expressed on the surface of various cell types, including endothelial cells. They mediate the interaction between immune cells and endothelial cells, which are critical for the trafficking of leukocytes across the blood vessel wall during inflammation. Although ICAM1 plays a prominent role in the leukocyte extravasation cascade, it is less clear if ICAM2 strengthens ICAM1 function or has a separate function in the cascade. With CRISPR-)Cas9 technology, endothelial cells were depleted for ICAM1,ICAM2, or both, and we found that neutrophils favored ICAM1 over ICAM2 to adhere to. However, the absence of only ICAM2 resulted in neutrophils that were unable to find the transmigration hotspot, i.e. the preferred exit site. Moreover, we found that ICAM2 deficiency prevented neutrophils to migrate against the flow. Due to this deficiency, we concluded that ICAM2 helps neutrophils find the preferred exit sites and thereby contributes to efficient leukocyte extravasation.
PubMed: 37565726
DOI: 10.1530/VB-23-0005 -
Journal of Immunology (Baltimore, Md. :... Sep 2023B cells, like T cells, can infiltrate sites of inflammation, but the processes and B cell subsets involved are poorly understood. Using human cells and in vitro assays,...
B cells, like T cells, can infiltrate sites of inflammation, but the processes and B cell subsets involved are poorly understood. Using human cells and in vitro assays, we find only a very small number of B cells will adhere to TNF-activated (but not to resting) human microvascular endothelial cells (ECs) under conditions of venular flow and do so by binding to ICAM-1 and VCAM-1. CXCL13 and, to a lesser extent, CXCL10 bound to the ECs can increase adhesion and induce transendothelial migration (TEM) of adherent naive and memory B cells in 10-15 min through a process involving cell spreading, translocation of the microtubule organizing center (MTOC) into a trailing uropod, and interacting with EC activated leukocyte cell adhesion molecule. Engagement of the BCR by EC-bound anti-κ L chain Ab also increases adhesion and TEM of κ+ but not λ+ B cells. BCR-induced TEM takes 30-60 min, requires Syk activation, is initiated by B cell rounding up and translocation of the microtubule organizing center to the region of the B cell adjacent to the EC, and also uses EC activated leukocyte cell adhesion molecule for TEM. BCR engagement reduces the number of B cells responding to chemokines and preferentially stimulates TEM of CD27+ B cells that coexpress IgD, with or without IgM, as well as CD43. RNA-sequencing analysis suggests that peripheral blood CD19+CD27+CD43+IgD+ cells have increased expression of genes that support BCR activation as well as innate immune properties in comparison with total peripheral blood CD19+ cells.
Topics: Humans; Transendothelial and Transepithelial Migration; Activated-Leukocyte Cell Adhesion Molecule; Endothelial Cells; Cell Movement; Endothelium, Vascular; Chemokines; Antigens, CD; Cells, Cultured
PubMed: 37530585
DOI: 10.4049/jimmunol.2200887 -
Cells Jul 2023The dynamics of neutrophil transendothelial migration was investigated in a model of experimental septicopyemia. Scanning ion-conductance microscopy allowed us to...
The dynamics of neutrophil transendothelial migration was investigated in a model of experimental septicopyemia. Scanning ion-conductance microscopy allowed us to determine changes in morphometric characteristics of endothelial cells during this process. In the presence of a pyogenic lesion simulated by , such migration was accompanied by both compensatory reactions and alteration of both neutrophils and endothelial cells. Neutrophils demonstrated crawling along the contact sites between endothelial cells, swarming phenomenon, as well as anergy and formation of neutrophil extracellular traps (NETs) as a normergic state. Neutrophil swarming was accompanied by an increase in the intercellular spaces between endothelial cells. Endothelial cells decreased the area of adhesion to the substrate, which was determined by a decrease in the cell projection area, and the cell membrane was smoothed. However, endothelial cell rigidity was paradoxically unchanged compared to the control. Over time, neutrophil migration led to a more significant alteration of endothelial cells: first, shallow perforations in the membrane were formed, which were repaired rather quickly, then stress fibrils were formed, and finally, endothelial cells died and multiple perforations were formed on their membrane.
Topics: Neutrophils; Microscopy; Transendothelial and Transepithelial Migration; Endothelial Cells; Cell Movement
PubMed: 37443839
DOI: 10.3390/cells12131806 -
Immunogenetics Oct 2023Controlling CD4 immune cell infiltration of the brain is a leading aim in designing therapeutic strategies for a range of neuropathological disorders such as multiple... (Review)
Review
Controlling CD4 immune cell infiltration of the brain is a leading aim in designing therapeutic strategies for a range of neuropathological disorders such as multiple sclerosis, Alzheimer's disease, and depression. CD4 T cells are a highly heterogeneous and reprogrammable family, which includes various distinctive cell types such as Th17, Th1, and Treg cells. Interestingly Th17 and Treg cells share a related transcriptomic profile, where the TGFβ-SMADS pathway plays a fundamental role in regulating the differentiation of both of these cell types. However, Th17 could be highly pathogenic and was shown to promote inflammation in various neuropathological disorders. Conversely, Treg is anti-inflammatory and is known to inhibit Th17. It could be noticed that Th17 frequencies of infiltration of the blood-brain barrier in various neurological disorders are significantly upregulated. However, Treg infiltration numbers are significantly low. The reasons behind these contradicting observations are still unknown. In this perspective, we propose that the difference in the T-cell receptor repertoire diversity, diapedesis pathways, chemokine expression, and mechanical properties of these two cell types could be contributing to answering this intriguing question.
Topics: Humans; T-Lymphocytes, Regulatory; Blood-Brain Barrier; Transforming Growth Factor beta; Cell Differentiation; Multiple Sclerosis; Th17 Cells
PubMed: 37430007
DOI: 10.1007/s00251-023-01310-y -
STAR Protocols Sep 2023In vitro modeling of the different steps of immune cell recruitment is essential to decipher the role of endothelial cells in this process. Here, we present a protocol...
In vitro modeling of the different steps of immune cell recruitment is essential to decipher the role of endothelial cells in this process. Here, we present a protocol for the assessment of human monocyte transendothelial migration using a live cell imaging system. We describe steps for culture of fluorescent monocytic THP-1 cells and chemotaxis plate preparation with HUVEC monolayers. We then detail real-time analysis using the IncuCyte® S3 live-cell imaging system, image analysis, and assessment of transendothelial migration rates. For complete details on the use and execution of this protocol, please refer to Ladaigue et al..
Topics: Humans; Monocytes; Transendothelial and Transepithelial Migration; Cell Movement; Endothelial Cells; Chemotaxis
PubMed: 37379221
DOI: 10.1016/j.xpro.2023.102388