| 1. |
- Mohanty, Tirthankar, et al.
(författare)
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A novel mechanism for NETosis provides antimicrobial defense at the oral mucosa.
- 2015
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 126:18, s. 2128-2137
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils are essential for host defense at the oral mucosa and neutropenia or functional neutrophil defects lead to disordered oral homeostasis. We found that neutrophils from the oral mucosa harvested from morning saliva had undergone NETosis in vivo. The NETosis was mediated through intracellular signals elicited by binding of sialyl lewis(X) present on salival mucins to L-selectin on neutrophils. This led to rapid loss of nuclear membrane and intracellular release of granule proteins with subsequent NET release independent of elastase and NADPH-oxidase activation. The saliva-induced NETs were more DNase-resistant and had higher capacity to bind and kill bacteria than NETs induced by bacteria or by PMA. Furthermore, saliva/sialyl lewis(X) mediated signaling enhanced intracellular killing of bacteria by neutrophils. Saliva from patients with aphthous ulcers and Behçet's disease prone to oral ulcers, failed to induce NETosis, but for different reasons, demonstrating that disordered homeostasis in the oral cavity may result in deficient saliva-mediated NETosis.
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| 2. |
- Sørensen, Ole E, et al.
(författare)
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Papillon-Lefevre syndrome patient reveals species-dependent requirements for neutrophil defenses
- 2014
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 124:10, s. 4539-4548
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Tidskriftsartikel (refereegranskat)abstract
- Papillon-Lefevre syndrome (PLS) results from mutations that inactivate cysteine protease cathepsin C (CTSC), which processes a variety of serine proteases considered essential for antimicrobial defense. Despite serine protease-deficient immune cell populations, PLS patients do not exhibit marked immunodeficiency. Here, we characterized a 24-year-old woman who had suffered from severe juvenile periodontal disease, but was otherwise healthy, and identified a homozygous missense mutation in CTSC indicative of PLS. Proteome analysis of patient neutrophil granules revealed that several proteins that normally localize to azurophil granules, including the major serine proteases, elastase, cathepsin G, and proteinase 3, were absent. Accordingly, neutrophils from this patient were incapable of producing neutrophil extracellular traps (NETs) in response to ROS and were unable to process endogenous cathelicidin hCAP-18. into the antibacterial peptide LL-37 in response to ionomycin. In immature myeloid cells from patient bone marrow, biosynthesis of CTSC and neutrophil serine proteases appeared normal along with initial processing and sorting to cellular storage. In contrast, these proteins were completely absent in mature neutrophils, indicating that CTSC mutation promotes protease degradation in more mature hematopoietic subsets, but does not affect protease production in progenitor cells. Together, these data indicate CTSC protects serine proteases from degradation in mature immune cells and suggest that neutrophil serine proteases are dispensable for human immunoprotection.
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| 3. |
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| 4. |
- Borregaard, Niels, et al.
(författare)
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Neutrophil granules: a library of innate immunity proteins
- 2007
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Ingår i: Trends in Immunology. - : Elsevier BV. - 1471-4981 .- 1471-4906. ; 28:8, s. 340-345
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Forskningsöversikt (refereegranskat)abstract
- Gene expression profiling has revealed that circulating neutrophils rest between two major bursts of transcriptional and protein synthetic activities. The first occurs in the bone marrow. This equips the neutrophil with stocks of innate defense armory that are packaged into different granule subsets. The second burst occurs when the neutrophil exits circulation and migrates into tissues to find, capture and phagocytose microorganisms. This burst results in the synthesis and secretion of cytokines and chemokines that support resolution of inflammation and healing of damaged tissue. Gene expression profiling has revealed that neutrophils express a variety of innate immunity proteins, known previously only to be expressed in other cells. Likewise, it has become clear that some proteins previously thought to be specific to the neutrophil are expressed in epithelial cells during inflammation.
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| 5. |
- Engert, Andreas, et al.
(författare)
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The European Hematology Association Roadmap for European Hematology Research : a consensus document
- 2016
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Ingår i: Haematologica. - Pavia, Italy : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 101:2, s. 115-208
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Tidskriftsartikel (refereegranskat)abstract
- The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at (sic)23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.
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| 6. |
- Ermert, David, et al.
(författare)
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Candida albicans escapes from mouse neutrophils
- 2013
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Ingår i: Journal of Leukocyte Biology. - Bethesda : Federation of American societies for experimental biology. - 0741-5400 .- 1938-3673. ; 94:2, s. 223-236
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Tidskriftsartikel (refereegranskat)abstract
- Candida albicans, the most commonly isolated human fungal pathogen, is able to grow as budding yeasts or filamentous forms, such as hyphae. The ability to switch morphology has been attributed a crucial role for the pathogenesis of C. albicans. To mimic disseminated candidiasis in humans, the mouse is the most widely used model organism. Neutrophils are essential immune cells to prevent opportunistic mycoses. To explore potential differences between the rodent infection model and the human host, we compared the interactions of C. albicans with neutrophil granulocytes from mice and humans. We revealed that murine neutrophils exhibited a significantly lower ability to kill C. albicans than their human counterparts. Strikingly, C. albicans yeast cells formed germ tubes upon internalization by murine neutrophils, eventually rupturing the neutrophil membrane and thereby, killing the phagocyte. On the contrary, growth and subsequent escape of C. albicans are blocked inside human neutrophils. According to our findings, this blockage in human neutrophils might be a result of higher levels of MPO activity and the presence of α-defensins. We therefore outline differences in antifungal immune defense between humans and mouse strains, which facilitates a more accurate interpretation of in vivo results.
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| 7. |
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| 8. |
- Højskov, Ida Elisabeth, et al.
(författare)
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Early physical and psycho-educational rehabilitation in patients with coronary artery bypass grafting: A randomized controlled trial.
- 2019
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Ingår i: Journal of Rehabilitation Medicine. - : Medical Journals Sweden AB. - 1650-1977. ; 51:2, s. 136-143
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Tidskriftsartikel (refereegranskat)abstract
- Rehabilitation of patients following coronary artery bypass grafting (CABG) has been widely studied; however, research into early rehabilitation after CABG is sparse. The aim of this trial was to assess the impact of early rehabilitation, compared with usual care in patients following CABG.Randomized controlled trial.A total of 326 patients treated with CABG.Patients treated with CABG were randomized 1:1 to 4 weeks of comprehensive early rehabilitation or usual care. The primary outcome was the Six Minute Walk Test (6MWT). Secondary outcomes were mental health and physical activity (Medical Outcome Study Short Form; SF-12); anxiety and depression (Hospital Anxiety and Depression Scale; HADS); physical and emotional scores; sleep (Pittsburgh Sleep Quality Index; PSQI); pain (Örebro Musculoskeletal Screening Questionnaire; ÖMSQ) and muscle endurance (Sit-To-Stand test).Sixteen patients dropped out. No significant differences between groups in the primary outcome (6MWT) were found after 4 weeks (p=0.27). For secondary outcomes the odds ratio of HADS-D ≥8 decreased in favour of the experimental intervention (p=0.04). There was non-adherence to parts of the intervention. Per-protocol analysis showed differences between groups for the 6MWT (p=0.02) and the Sit-To-Stand test (p=0.046).In general, the intervention had no effect on the 6MWT, or secondary outcomes, except for depressive symptoms. However, in adherent participants, the intervention had a positive effect for the primary and several secondary outcomes.
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| 9. |
- Jacobsen, Lars C, et al.
(författare)
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The secretory leukocyte protease inhibitor (SLPI) and the secondary granule protein lactoferrin are synthesized in myelocytes, colocalize in subcellular fractions of neutrophils, and are coreleased by activated neutrophils.
- 2008
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Ingår i: Journal of Leukocyte Biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 83, s. 1155-1164
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Tidskriftsartikel (refereegranskat)abstract
- The secretory leukocyte protease inhibitor (SLPI) re-establishes homeostasis at sites of infection by virtue of its ability to exert antimicrobial activity, to suppress LPS-induced cellular immune responses, and to reduce tissue damage through inhibition of serine proteases released by polymorphonuclear neutrophil granulocytes (PMNs). Microarray analysis of bone marrow (BM) populations highly enriched in promyelocytes, myelocytes/metamyelocytes (MYs), and BM neutrophils demonstrates a transient, high mRNA expression of SLPI and genuine secondary granule proteins (GPs) in MYs. Consistent with this finding, immunostaining of BM cells showed SLPI and the secondary GP lactoferrin (LF) to be present in cells from the myelocyte stage and throughout neutrophil differentiation. Subcellular fractionation studies demonstrated the colocalization of SLPI and LF in subcellular fractions highly enriched in secondary granules. Finally, exocytosis studies demonstrated a corelease of SLPI and LF within minutes of activation. Collectively, these findings strongly indicate that SLPI is localized in secondary granules of PMNs. However, the amount of SLPI detected in PMNs is low compared with primary keratinocytes stimulated by growth factors involved in wound healing. This implicates that neutrophil-derived SLPI might not contribute essentially to re-establishment of homeostasis at sites of infection but rather, exert physiologically relevant intracellular activities. These might include the protection of secondary GPs against proteolytic activation and/or degradation by proteases, which might be dislocated to secondary granules at minute amounts as a consequence of spillover.
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| 10. |
- Jena, Prajna, et al.
(författare)
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Azurophil Granule Proteins Constitute the Major Mycobactericidal Proteins in Human Neutrophils and Enhance the Killing of Mycobacteria in Macrophages
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- Pathogenic mycobacteria reside in, and are in turn controlled by, macrophages. However, emerging data suggest that neutrophils also play a critical role in innate immunity to tuberculosis, presumably by their different antibacterial granule proteins. In this study, we purified neutrophil azurophil and specific granules and systematically analyzed the antimycobacterial activity of some purified azurophil and specific granule proteins against M. smegmatis, M. bovis-BCG and M. tuberculosis H37Rv. Using gel overlay and colony forming unit assays we showed that the defensin-depleted azurophil granule proteins (AZP) were more active against mycobacteria compared to other granule proteins and cytosolic proteins. The proteins showing antimycobacterial activity were identified by MALDI-TOF mass spectrometry. Electron microscopic studies demonstrate that the AZP disintegrate bacterial cell membrane resulting in killing of mycobacteria. Exogenous addition of AZP to murine macrophage RAW 264.7, THP-1 and peripheral blood monocyte-derived macrophages significantly reduced the intracellular survival of mycobacteria without exhibiting cytotoxic activity on macrophages. Immunofluorescence studies showed that macrophages actively endocytose neutrophil granular proteins. Treatment with AZP resulted in increase in co-localization of BCG containing phagosomes with lysosomes but not in increase of autophagy. These data demonstrate that neutrophil azurophil proteins may play an important role in controlling intracellular survival of mycobacteria in macrophages. Citation: Jena P, Mohanty S, Mohanty T, Kallert S, Morgelin M, et al. (2012) Azurophil Granule Proteins Constitute the Major Mycobactericidal Proteins in Human Neutrophils and Enhance the Killing of Mycobacteria in Macrophages. PLoS ONE 7(12): e50345. doi:10.1371/journal.pone.0050345
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| 11. |
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Lipocalins
- 2006
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Less than a decade has elapsed since the publication in 2000 of the first anthology devoted to lipocalins (Biochim Biophys Acta 1482, 2000), and only a few years since the first Lipocalin International Symposium in Copenhagen in 2003 (Benzon Symposium no. 50 “The Lipocalin Protein Superfamily,” Copenhagen, 2003) and the introduction of a public lipocalin website (http://www.jenner.ac.uk/lipocalins.htm). In spite of all these recent joint actions from the lipocalin community, the need for another anthology has been expressed. Many new exciting publications have been issued during the past five years, partially outdating the 2000 BBA lipocalin anthology. Likewise, the three events mentioned above have undoubtedly had a positive effect upon lipocalin research and the exchange of research information. As a result the community of lipocalin researchers is highly motivated to continue such pan-lipocalin activities. Several of the chapters in this volume are reviews of groups of lipocalins with a similar phylogenetic or tissue distribution (Chapters 4-6, 12 and 13). Furthermore, two chapters discuss the evolutionary and structural relationships between the lipocalins (Chapters 2 and 3) and the penultimate three chapters are treatises on themes in lipocalin research: receptors, allergy, and clinical diagnosis (Chapters 14-16); the final chapter discusses how lipocalin research might go in future.
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| 12. |
- Malm, Johan, et al.
(författare)
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The human cationic antimicrobial protein (hCAP-18) is expressed in the epithelium of human epididymis, is present in seminal plasma at high concentrations, and is attached to spermatozoa
- 2000
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Ingår i: Infection and Immunity. - 0019-9567. ; 68:7, s. 4297-4302
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Tidskriftsartikel (refereegranskat)abstract
- Innate immunity is important for the integrity of the host against potentially invasive pathogenic microorganisms in the environment. Antibiotic peptides with broad antimicrobial activity are part of the innate immune system. We investigated the presence of the cathelicidin, human cationic antimicrobial protein (hCAP-18), in the male reproductive system. We found strong expression of the hCAP-18 gene by in situ hybridization and hCAP-18 protein, as detected by immunohistochemistry, in the epithelium of the epididymis, but not in the testis. The highest expression in the epididymis was in the caudal part. Western blotting showed a doublet band, the upper part corresponding to the size of hCAP-18 in plasma and neutrophils. Using a specific enzyme-linked immunosorbent assay (ELISA), levels of 86.5 +/- 37.8 microg/ml (mean +/- standard deviation; range, 41.8 to 142.8 microg/ml; n = 10) were detected in seminal plasma from healthy donors, which is 70-fold higher than the level in blood plasma. Flow cytometry and immunocytochemistry revealed the presence of hCAP-18 on spermatozoa. ELISA measurement showed levels of 196 ng/10(6) spermatozoa, corresponding to 6.6 x 10(6) molecules of hCAP-18 per spermatozoon. Our results suggest a key role for hCAP-18 in the antibacterial integrity of the male reproductive system. The attachment of hCAP-18 to spermatozoa may implicate a role for hCAP-18 in conception.
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| 13. |
- Niemann, Carsten U., et al.
(författare)
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Neutrophil elastase depends on serglycin proteoglycan for localization in granules
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 109:10, s. 4478-4486
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Tidskriftsartikel (refereegranskat)abstract
- Granule proteins play a major role in bacterial killing by neutrophils. Serglycin proteoglycan, the major intracellular proteoglycan of hematopoietic cells, has been proposed to play a role in sorting and packing of granule proteins. We examined the content of major neutrophil granule proteins in serglycin knockout mice and found neutrophil elastase absent from mature neutrophils as shown by activity assay, Western blotting, and immunocytochemistry, whereas neutrophil elastase mRNA was present. The localization of other neutrophil granule proteins did not differ between wild-type and serglycin knockout mice. Differential counts and neutrophil ultrastructure were unaffected by the lack of serglycin, indicating that defective localization of neutrophil elastase does not induce neutropenia itself, albeit mutations in the neutrophil elastase gene can cause severe congenital neutropenia or cyclic neutropenia. The virulence of intraperitoneally injected Gram-negative bacteria (Klebsiella pneumoniae)was increased in serglycin knock-out mice compared with wild-type mice, as previously reported for neutrophil elastase knockout mice. Thus, serglycin proteoglycan has an important role in localizing neutrophil elastase in azurophil granules of neutrophils, while localization of other granule proteins must be mediated by other mechanisms.
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| 14. |
- Niemann, Carsten U., et al.
(författare)
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Serglycin proteoglycan is not implicated in localizing exocrine pancreas enzymes to zymogen granules
- 2009
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Ingår i: European Journal of Cell Biology. - : Elsevier BV. - 0171-9335 .- 1618-1298. ; 88:8, s. 473-479
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Tidskriftsartikel (refereegranskat)abstract
- Storage and release of proteins from granules forms the basis of cellular functions as diverse as cell mediated cytotoxicity, neuronal communication, activation of muscle fibres, and release of hormones or digestive enzymes from endocrine and exocrine glands, such as the pancreas. Serglycin is the major intracellular proteoglycan of haematopoietic cells. Serglycin is important for localization of proteins in granules of different haematopoietic cell types. Previous reports have indicated a role for serglycin in granule formation and localization of zymogens in granules of the exocrine pancreas in rat. We here present data showing that serglycin is not present at the protein level in human or murine pancreas. Furthermore, the amount and localization of three exocrine pancreas zymogens (amylase, trypsinogen, and carboxypeptidase A) is not affected by the absence of serglycin in a serglycin knock-out mouse model.
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| 15. |
- Rapin, Nicolas, et al.
(författare)
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Comparing cancer vs normal gene expression profiles identifies new disease entities and common transcriptional programs in AML patients
- 2014
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 123:6, s. 894-904
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Tidskriftsartikel (refereegranskat)abstract
- Gene expression profiling has been used extensively to characterize cancer, identify novel subtypes, and improve patient stratification. However, it has largely failed to identify transcriptional programs that differ between cancer and corresponding normal cells and has not been efficient in identifying expression changes fundamental to disease etiology. Here we present a method that facilitates the comparison of any cancer sample to its nearest normal cellular counterpart, using acute myeloid leukemia (AML) as a model. We first generated a gene expression-based landscape of the normal hematopoietic hierarchy, using expression profiles from normal stem/progenitor cells, and next mapped the AML patient samples to this landscape. This allowed us to identify the closest normal counterpart of individual AML samples and determine gene expression changes between cancer and normal. We find the cancer vs normal method (CvN method) to be superior to conventional methods in stratifying AML patients with aberrant karyotype and in identifying common aberrant transcriptional programs with potential importance for AML etiology. Moreover, the CvN method uncovered a novel poor-outcome subtype of normal-karyotype AML, which allowed for the generation of a highly prognostic survival signature. Collectively, our CvN method holds great potential as a tool for the analysis of gene expression profiles of cancer patients.
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| 16. |
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| 17. |
- Sørensen, Ole E, et al.
(författare)
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Antimicrobial peptides in innate immune responses.
- 2008
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Ingår i: Contributions to Microbiology. - Basel : KARGER. - 1420-9519. ; 15, s. 61-77
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Forskningsöversikt (refereegranskat)abstract
- Antimicrobial peptides (AMPs) are ancient effector molecules in the innate immune response of eukaryotes. These peptides are important for the antimicrobial efficacy of phagocytes and for the innate immune response mounted by epithelia of humans and other mammals. AMPs are generated either by de novo synthesis or by proteolytic cleavage from antimicrobially inactive proproteins. Studies of human diseases and animal studies have given important clues to the in vivo role of AMPs. It is now evident that dysregulation of the generation of AMPs in innate immune responses plays a role in certain diseases like Crohn's disease and atopic dermatitis. AMPs are attractive candidates for development of novel antibiotics due to their in vivo activity profile and some peptides may serve as templates for further drug development.
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| 18. |
- Sørensen, Ole E., et al.
(författare)
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Neutrophil extracellular traps - The dark side of neutrophils
- 2016
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Ingår i: Journal of Clinical Investigation. - 0021-9738. ; 126:5, s. 1612-1620
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Forskningsöversikt (refereegranskat)abstract
- Neutrophil extracellular traps (NETs) were discovered as extracellular strands of decondensed DNA in complex with histones and granule proteins, which were expelled from dying neutrophils to ensnare and kill microbes. NETs are formed during infection in vivo by mechanisms different from those originally described in vitro. Citrullination of histones by peptidyl arginine deiminase 4 (PAD4) is central for NET formation in vivo. NETs may spur formation of autoantibodies and may also serve as scaffolds for thrombosis, thereby providing a link among infection, autoimmunity, and thrombosis. In this review, we present the mechanisms by which NETs are formed and discuss the physiological and pathophysiological consequences of NET formation. We conclude that NETs may be of more importance in autoimmunity and thrombosis than in innate immune defense.
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| 19. |
- Sørensen, Ole E, et al.
(författare)
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Wound healing and expression of antimicrobial peptides/polypeptides in human keratinocytes, a consequence of common growth factors
- 2003
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Ingår i: Journal of Immunology. - 1550-6606. ; 170:11, s. 5583-5589
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Tidskriftsartikel (refereegranskat)abstract
- In addition to acting as a physical barrier against microorganisms, the skin produces antimicrobial peptides and proteins. After wounding, growth factors are produced to stimulate the regeneration of tissue. The growth factor response ceases after regeneration of the tissue, when the physical barrier protecting against microbial infections is re-established. We found that the growth factors important in wound healing, insulin-like growth factor I and TGF-alpha, induce the expression of the antimicrobial peptides/polypeptides human cationic antimicrobial protein hCAP-18/LL-37, human beta-defensin 3, neutrophil gelatinase-associated lipocalin, and secretory leukocyte protease inhibitor in human keratinocytes. Both an individual and a synergistic effect of these growth factors were observed. These findings offer an explanation for the expression of these peptides/polypeptides in the skin disease psoriasis and in wound healing and define a host defense role for growth factors in wound healing.
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| 20. |
- Theilgaard-Mönch, Kim, et al.
(författare)
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The transcriptional activation program of human neutrophils in skin lesions supports their important role in wound healing
- 2004
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Ingår i: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 172:12, s. 7684-7693
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the cellular fate and function of polymorphonuclear neutrophilic granulocytes (PMNs) attracted to skin wounds, we used a human skin-wounding model and microarray technology to define differentially expressed genes in PMNs from peripheral blood, and PMNs that had transmigrated to skin lesions. After migration to skin lesions, PMNs demonstrated a significant transcriptional response including genes from several different functional categories. The up-regulation of anti-apoptotic genes concomitant with the down-regulation of proapoptotic genes suggested a transient anti-apoptotic priming of PMNs. Among the up-regulated genes were cytokines and chemokines critical for chemotaxis of macrophages, T cells, and PMNs, and for the modulation of their inflammatory responses. PMNs in skin lesions down-regulated receptors mediating chemotaxis and anti-microbial activity, but up-regulated other receptors involved in inflammatory responses. These findings indicate a change of responsiveness to chemotactic and immunoregulatory mediators once PMNs have migrated to skin lesions and have been activated. Other effects of the up-regulated cytokines/chemokines/enzymes were critical for wound healing. These included the breakdown of fibrin clots and degradation of extracellular matrix, the promotion of angiogenesis, the migration and proliferation of keratinocytes and fibroblasts, the adhesion of keratinocytes to the dermal layer, and finally, the induction of anti-microbial gene expression in keratinocytes. Notably, the up-regulation of genes, which activate lysosomal proteases, indicate a priming of skin lesion-PMNs for degradation of phagocytosed material. These findings demonstrate that migration of PMNs to skin lesions induces a transcriptional activation program, which regulates cellular fate and function, and promotes wound healing.
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| 21. |
- Tjabringa, G Sandra, et al.
(författare)
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The antimicrobial peptide LL-37 activates innate immunity at the airway epithelial surface by transactivation of the epidermal growth factor receptor
- 2003
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Ingår i: Journal of Immunology. - 1550-6606. ; 171:12, s. 6690-6696
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Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial peptides produced by epithelial cells and neutrophils represent essential elements of innate immunity, and include the defensin and cathelicidin family of antimicrobial polypeptides. The human cathelicidin cationic antimicrobial protein-18 is an antimicrobial peptide precursor predominantly expressed in neutrophils, and its active peptide LL-37 is released from the precursor through the action of neutrophil serine proteinases. LL-37 has been shown to display antimicrobial activity against a broad spectrum of microorganisms, to neutralize LPS bioactivity, and to chemoattract neutrophils, monocytes, mast cells, and T cells. In this study we show that LL-37 activates airway epithelial cells as demonstrated by activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and increased release of IL-8. Epithelial cell activation was inhibited by the MAPK/ERK kinase (MEK) inhibitors PD98059 and U0126, by the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor AG1478, by blocking anti-EGFR and anti-EGFR-ligand Abs, and by the metalloproteinase inhibitor GM6001. These data suggest that LL-37 transactivates the EGFR via metalloproteinase-mediated cleavage of membrane-anchored EGFR-ligands. LL-37 may thus constitute one of the mediators by which neutrophils regulate epithelial cell activity in the lung.
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