scholarly journals Modulation of Neutrophil Apoptosis by Antimicrobial Peptides

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Isao Nagaoka ◽  
Kaori Suzuki ◽  
François Niyonsaba ◽  
Hiroshi Tamura ◽  
Michimasa Hirata

Peptide antibiotics possess the potent antimicrobial activities against invading microorganisms and contribute to the innate host defense. Human antimicrobial peptides, α-defensins (human neutrophil peptides, HNPs), human β-defensins (hBDs), and cathelicidin (LL-37) not only exhibit potent bactericidal activities against Gram-negative and Gram-positive bacteria, but also function as immunomodulatory molecules by inducing cytokine and chemokine production, and inflammatory and immune cell activation. Neutrophil is a critical effector cell in host defense against microbial infection, and its lifespan is regulated by various pathogen- and host-derived substances. Here, we provided the evidence that HNP-1, hBD-3, and LL-37 cannot only destroy bacteria but also potently modulate (suppress) neutrophil apoptosis, accompanied with the phosphorylation of ERK-1/-2, the downregulation of tBid (an proapoptotic protein) and upregulation of Bcl-xL (an antiapoptotic protein), and the inhibition of mitochondrial membrane potential change and caspase 3 activity, possibly via the actions on the distinct receptors, the P2Y6 nucleotide receptor, the chemokine receptor CCR6, and the low-affinity formyl-peptide receptor FPRL1/the nucleotide receptor P2X7, respectively. Suppression of neutrophil apoptosis results in the prolongation of their lifespan and may be advantageous for the host defense against bacterial invasion.

1998 ◽  
Vol 9 (4) ◽  
pp. 399-414 ◽  
Author(s):  
A. Weinberg ◽  
S. Krisanaprakornkit ◽  
B.A. Dale

Epithelial tissues provide the first line of defense between an organism and the environment. Disruption of this barrier leads to bacterial invasion and subsequent inflammation. This is precisely the situation existing in the human oral cavity, where tissues are constantly exposed to a variety of microbial challenges that can lead to bacterially induced periodontal diseases, and to infections of the oral mucosa by bacteria, fungi, and viruses. With the recent discoveries of host-derived peptide antibiotics in mammalian mucosal epithelium, a new line of investigation is emerging to test the hypothesis that one class of these peptides, called " β-defensins", functions to protect the host against microbial pathogenesis at these critical, confrontational sites. In that light, impairment of β-defensin activity has recently been implicated in chronic bacterial infections in cystic fibrosis patients. The first direct evidence of expression of defensin peptides in the oral mucosa was the identification of a novel epithelial β-defensin in mammalian tongue. It was shown to be upregulated in inflammation, suggesting that it participates in host defense. It is theorized that epithelial cell-derived antimicrobial peptides function to keep the natural flora of micro-organisms in a steady state in different niches such as the skin, the intestines, the airway, the endocervix, and the mouth. There is now evidence indicating that normal gingival epithelial cells and tissues express two β-defensins, hBD- I and the newly described hBD-2. In addition, a cathelin-class antimicrobial peptide, designated LL-37 and found in human neutrophils, is also expressed in skin and gingiva. It is highly likely that these and/or other epithelial antimicrobial peptides play an important role in determining the outcome of the host-pathogen interaction at the oral mucosal barrier, and that they may have important future applications in antibiotic treatment.


2013 ◽  
Vol 20 (37) ◽  
pp. 4806-4814 ◽  
Author(s):  
Brigitta Buttari ◽  
Elisabetta Profumo ◽  
Rita Businaro ◽  
Luciano Saso ◽  
Raffaele Capoano ◽  
...  

2021 ◽  
Vol 116 (1) ◽  
Author(s):  
Marius Keller ◽  
Valbona Mirakaj ◽  
Michael Koeppen ◽  
Peter Rosenberger

AbstractCardiovascular pathologies are often induced by inflammation. The associated changes in the inflammatory response influence vascular endothelial biology; they complicate the extent of ischaemia and reperfusion injury, direct the migration of immune competent cells and activate platelets. The initiation and progression of inflammation is regulated by the classical paradigm through the system of cytokines and chemokines. Therapeutic approaches have previously used this knowledge to control the extent of cardiovascular changes with varying degrees of success. Neuronal guidance proteins (NGPs) have emerged in recent years and have been shown to be significantly involved in the control of tissue inflammation and the mechanisms of immune cell activation. Therefore, proteins of this class might be used in the future as targets to control the extent of inflammation in the cardiovascular system. In this review, we describe the role of NGPs during cardiovascular inflammation and highlight potential therapeutic options that could be explored in the future.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 178-179
Author(s):  
S. Alehashemi ◽  
M. Garg ◽  
B. Sellers ◽  
A. De Jesus ◽  
A. Biancotto ◽  
...  

Background:Systemic Autoinflammatory diseases present with sterile inflammation. NOMID (Neonatal-Onset Multisystem Inflammatory Disease) is caused by gain-of-function mutations inNLRP3and excess IL-1 production, presents with fever, neutrophilic dermatosis, aseptic meningitis, hearing loss and eye inflammation; CANDLE (Chronic Atypical Neutrophilic Dermatosis, Lipodystrophy and Elevated Temperature) is caused by loss-of-function mutations in proteasome genes that lead to type-1 interferon signaling, characterized by fever, panniculitis, lipodystrophy, cytopenia, systemic and pulmonary hypertension and basal ganglia calcification. IL-1 blockers are approved for NOMID and JAK-inhibitors show efficacy in CANDLE treatment.Objectives:We used proteomic analysis to compare differentially expressed proteins in active NOMID and CANDLE compared to healthy controls before and after treatment, and whole blood bulk RNA seq to identify the immune cell signatures.Methods:Serum samples from active NOMID (n=12) and CANDLE (n=7) before and after treatment (table 1) and age matched healthy controls (HC) (n=7) were profiled using the SomaLogic platform (n=1125 proteins). Differentially expressed proteins in NOMID and CANDLE were ranked after non-parametric tests for unpaired (NOMIDp<0.05, CANDLE,p<0.1) and paired (p<0.05) analysis and assessed by enriched Gene Ontology pathways and network visualization. Whole blood RNA seq was performed (NOMID=7, CANDLE=7, Controls =5) and RPKM values were used to assess immune cells signatures.Table 1.Patient’s characteristicsNOMIDN=12, Male =6CANDLEN=7, Male =6AgeMedian (range)12 (2, 28)16 (3, 20)Ethnicity%White (Hispanic)80 (20)100 (30)GeneticsNLRP3mutation(2 Somatic, 10 Germline)mutations in proteasome component genes(1 digenic, 6 Homozygous/compound Heterozygous)Before treatmentAfter treatmentBefore treatmentAfter treatmentCRPMedian (range) mg/L52 (16-110)5 (0-23)5 (0-101)1 (0-4)IFN scoremedian (range)0NA328 (211-1135)3 (0-548)Results:Compared to control, 205 proteins (127 upregulated, 78 downregulated) were significantly different at baseline in NOMID, compared to 163 proteins (101 upregulated, and 62 downregulated) in CANDLE. 134 dysregulated proteins (85 upregulated, 49 downregulated) overlapped in NOMID and CANDLE (Figure 1). Pathway analysis identified neutrophil and monocyte chemotaxis signature in both NOMID and CANDLE. NOMID patients had neutrophilia and active neutrophils. CANDLE patients exhibited active neutrophils in whole blood RNA. Endothelial cell activation was the most prominent non-hematopoietic signature and suggest distinct endothelial cell dysregulation in NOMID and CANDLE. In NOMID, the signature included neutrophil transmigration (SELE) endothelial cell motility in response to angiogenesis (HGF, VEGF), while in CANDLE the endothelial signatures included extracellular matrix protein deposition (COL8A) suggesting increased vascular stiffness. CANDLE patients had higher expression of Renin, 4 out of 7 had hypertension, NOMID patients did not have hypertension. Treatment with anakinra and baricitinib normalized 143 and 142 of dysregulated proteins in NOMID and CANDLE respectively.Conclusion:Differentially expressed proteins in NOMID and CANDLE are consistent with innate immune cell activation. Distinct endothelial cell signatures in NOMID and CANDLE may provide mechanistic insight into differences in vascular phenotypes. Treatment with anakinra and Baricitinib in NOMID and CANDLE leaves 30% and 13% of the dysregulated proteins unchanged.Acknowledgments:This work was supported by Intramural Research atNational Institute of Allergy Immunology and Infectious Diseases of National Institutes of Health, Bethesda, Maryland, the Center of Human Immunology and was approved by the IRB.Disclosure of Interests:None declared


Pteridines ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 68-82
Author(s):  
Gregory Baxter-Parker ◽  
Ravinder Reddy Gaddam ◽  
Elena Moltchanova ◽  
Anitra Carr ◽  
Geoff Shaw ◽  
...  

AbstractIntroduction: Neopterin and 7,8-dihydroneopterin are used as biomarkers of oxidative stress and inflammation, but the effect of kidney function on these measurements has not been extensively explored. We examine the levels of oxidative stress, inflammation and kidney function in intensive patients and compare them to equivalent patients without sepsis.Methods: 34 Intensive care patients were selected for the study, 14 without sepsis and 20 with. Both groups had equivalent levels of trauma, assessed by SAPS II, SOFA, and APACHE II and III scores. Plasma and urinary neopterin and total neopterin (neopterin + 7,8-dihydroneopterin) values were measured.Results: Neopterin and total neopterin were significantly elevated in urine and plasma for multiple days in sepsis versus non-sepsis patients. Plasma neopterin and total neopterin have decreasing relationships with increased eGFR (p<0.008 and p<0.001, respectively). Plasma/urinary neopterin and total neopterin ratios demonstrate that total neopterin flux is more influenced by eGFR than neopterin, with significantce of p<0.02 and p<0.0002 respectively.Conclusion: Sepsis patients present with greater levels of oxidative stress and immune system activation than non-sepsis patients of equal levels of trauma, as measured by neopterin and total neopterin. eGFR may need to be taken into account when accessing the level of inflammation from urinary neopterin measurements.


Lupus ◽  
2021 ◽  
pp. 096120332199010
Author(s):  
Vineeta Shobha ◽  
Anu Mohan ◽  
AV Malini ◽  
Puneet Chopra ◽  
Preethi Karunanithi ◽  
...  

Objective Despite the significant advancement in the understanding of the pathophysiology of systemic lupus erythematosus (SLE) variable clinical response to newer therapies remain a major concern, especially for patients with lupus nephritis and neuropsychiatric systemic lupus erythematosus (NPSLE). We performed this study with an objective to comprehensively characterize Indian SLE patients with renal and neuropsychiatric manifestation with respect to their gene signature, cytokine profile and immune cell phenotypes. Methods We characterized 68 Indian SLE subjects with diverse clinical profiles and disease activity and tried to identify differentially expressed genes and enriched pathways. To understand the temporal profile, same patients were followed at 6 and 12-months intervals. Additionally, auto-antibody profile, levels of various chemokines, cytokines and the proportion of different immune cells and their activation status were captured in these subjects. Results Multiple IFN-related pathways were enriched with significant increase in IFN-I gene signature in SLE patients as compared to normal healthy volunteers (NHV). We identified two transcriptionally distinct clusters within the same cohort of SLE patients with differential immune cell activation status, auto-antibody as well as plasma chemokines and cytokines profile. Conclusions Identification of two distinct clusters of patients based on IFN-I signature provided new insights into the heterogeneity of underlying disease pathogenesis of Indian SLE cohort. Importantly, patient within those clusters retain their distinct expression dynamics of IFN-I signature over the time course of one year despite change in disease activity. This study will guide clinicians and researchers while designing future clinical trials on Indian SLE cohort.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1681
Author(s):  
Lucia Sophie Kilian ◽  
Derk Frank ◽  
Ashraf Yusuf Rangrez

Chronic inflammation, the activation of immune cells and their cross-talk with cardiomyocytes in the pathogenesis and progression of heart diseases has long been overlooked. However, with the latest research developments, it is increasingly accepted that a vicious cycle exists where cardiomyocytes release cardiocrine signaling molecules that spiral down to immune cell activation and chronic state of low-level inflammation. For example, cardiocrine molecules released from injured or stressed cardiomyocytes can stimulate macrophages, dendritic cells, neutrophils and even T-cells, which then subsequently increase cardiac inflammation by co-stimulation and positive feedback loops. One of the key proteins involved in stress-mediated cardiomyocyte signal transduction is a small GTPase RhoA. Importantly, the regulation of RhoA activation is critical for effective immune cell response and is being considered as one of the potential therapeutic targets in many immune-cell-mediated inflammatory diseases. In this review we provide an update on the role of RhoA at the juncture of immune cell activation, inflammation and cardiac disease.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1413
Author(s):  
Sofia Ojasalo ◽  
Petteri Piskunen ◽  
Boxuan Shen ◽  
Mauri A. Kostiainen ◽  
Veikko Linko

Viruses are among the most intriguing nanostructures found in nature. Their atomically precise shapes and unique biological properties, especially in protecting and transferring genetic information, have enabled a plethora of biomedical applications. On the other hand, structural DNA nanotechnology has recently emerged as a highly useful tool to create programmable nanoscale structures. They can be extended to user defined devices to exhibit a wide range of static, as well as dynamic functions. In this review, we feature the recent development of virus-DNA hybrid materials. Such structures exhibit the best features of both worlds by combining the biological properties of viruses with the highly controlled assembly properties of DNA. We present how the DNA shapes can act as “structured” genomic material and direct the formation of virus capsid proteins or be encapsulated inside symmetrical capsids. Tobacco mosaic virus-DNA hybrids are discussed as the examples of dynamic systems and directed formation of conjugates. Finally, we highlight virus-mimicking approaches based on lipid- and protein-coated DNA structures that may elicit enhanced stability, immunocompatibility and delivery properties. This development also paves the way for DNA-based vaccines as the programmable nano-objects can be used for controlling immune cell activation.


Author(s):  
Lorena P. Suarez-Kelly ◽  
Steven H. Sun ◽  
Casey Ren ◽  
Isaac V. Rampersaud ◽  
David Albertson ◽  
...  

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