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Breznik JA, Rahim A, Zhang A, Ang J, Stacey HD, Bhakta H, Clare R, Liu LM, Kennedy A, Hagerman M, Kajaks T, Miller MS, Nazy I, Bramson JL, Costa AP, Bowdish DM. Early Omicron infection is associated with increased reinfection risk in older adults in long-term care and retirement facilities. EClinicalMedicine 2023; 63:102148. [PMID: 37753447 PMCID: PMC10518514 DOI: 10.1016/j.eclinm.2023.102148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 09/28/2023] Open
Abstract
Background Older adults are at increased risk of SARS-CoV-2 Omicron infection and severe disease, especially those in congregate living settings, despite high SARS-CoV-2 vaccine coverage. It is unclear whether hybrid immunity (combined vaccination and infection) after one Omicron infection provides increased protection against subsequent Omicron reinfection in older adults. Methods Incidence of SARS-CoV-2 Omicron infection was examined in 750 vaccinated residents of long-term care and retirement homes in the observational cohort COVID in Long-Term Care Study in Ontario, Canada, within a 75-day period (July to September 2022). Risk of infection was assessed by Cox proportional hazards regression. Serum anti-spike and anti-RBD SARS-CoV-2 IgG and IgA antibodies, microneutralization titres, and spike-specific T cell memory responses, were examined in a subset of 318 residents within the preceding three months. Findings 133 of 750 participants (17.7%) had a PCR-confirmed Omicron infection during the observation period. Increased infection risk was associated with prior Omicron infection (at 9-29 days: 47.67 [23.73-95.76]), and this was not attributed to days since fourth vaccination (1.00 [1.00-1.01]) or residence outbreaks (>6 compared to ≤6: 0.95 [0.37-2.41]). Instead, reinfected participants had lower serum neutralizing antibodies to ancestral and Omicron BA.1 SARS-CoV-2, and lower anti-RBD IgG and IgA antibodies, after their initial Omicron infection. Interpretation Counterintuitively, SARS-CoV-2 Omicron infection was associated with increased risk of Omicron reinfection in residents of long-term care and retirement homes. Less robust humoral hybrid immune responses in older adults may contribute to risk of Omicron reinfection. Funding COVID-19 Immunity Task Force of the Public Health Agency of Canada.
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Affiliation(s)
- Jessica A. Breznik
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- McMaster Institute for Research on Aging, McMaster University, Hamilton, Ontario, Canada
| | - Ahmad Rahim
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Ali Zhang
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Jann Ang
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Hannah D. Stacey
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Hina Bhakta
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Rumi Clare
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Li-Min Liu
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Allison Kennedy
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Megan Hagerman
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Tara Kajaks
- McMaster Institute for Research on Aging, McMaster University, Hamilton, Ontario, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Matthew S. Miller
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Ishac Nazy
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Jonathan L. Bramson
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Andrew P. Costa
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- McMaster Institute for Research on Aging, McMaster University, Hamilton, Ontario, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
- Centre for Integrated Care, St. Joseph's Health System, Hamilton, Ontario, Canada
| | - Dawn M.E. Bowdish
- McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Department of Medicine, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
- McMaster Institute for Research on Aging, McMaster University, Hamilton, Ontario, Canada
- Firestone Institute of Respiratory Health, St Joseph's Healthcare, Hamilton, Ontario, Canada
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Bowdish DM, Rossi L, Loeb M, Johnstone J, Schenck LP, Fontes M, Surette MG, Whelan FJ. The impact of respiratory infections and probiotic use on the nasal microbiota of frail residents in long-term care homes. ERJ Open Res 2023; 9:00212-2023. [PMID: 37753289 PMCID: PMC10518876 DOI: 10.1183/23120541.00212-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/19/2023] [Indexed: 09/28/2023] Open
Abstract
Background Residents in long-term care homes, who tend to be of advanced age and frail, are at increased risk of respiratory infections. The respiratory microbiota is known to change with age, but whether these changes contribute to the risk of infection is not known. Our goal was to determine how the nasal microbiota of frail older adults changes during symptoms of influenza-like illness (ILI) and how this may be impacted by enrolment in a placebo-controlled trial testing the feasibility of administering a Lactobacillus rhamnosus GG probiotic to prevent respiratory infection (2014-2017). Methods The microbiome of the nasal (mid-turbinate) of 150 residents of long-term care homes was interrogated using 16S rRNA gene sequencing. Results We identified a diverse and individualised microbiota which could be separated into nine distinct clusters based on Bray-Curtis distances. Samples collected during symptoms of ILI differed statistically from those collected pre- and post-cold and influenza season, and we observed decreased temporal stability (as measured by movement between clusters) in individuals who experienced ILI compared to those who did not. Conclusions The use of probiotics decreased ILI-induced changes to the microbiota; however, it is not clear whether this decrease is sufficient to prevent respiratory illness.
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Affiliation(s)
- Dawn M.E. Bowdish
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
- Firestone Institute for Respiratory Health, St Joseph's Healthcare Hamilton, Hamilton, ON, Canada
| | - Laura Rossi
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Mark Loeb
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
- Department of Health Research Methods, Evidence & Impact, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Jennie Johnstone
- Department of Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Louis P. Schenck
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Michelle Fontes
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Michael G. Surette
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Fiona J. Whelan
- School of Life Sciences, University of Nottingham, Nottingham, UK
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Zhang A, Surette MD, Schwartz KL, Brooks JI, Bowdish DM, Mahdavi R, Manuel DG, Talarico R, Daneman N, Shurgold J, MacFadden D. The collapse of infectious disease diagnoses commonly due to communicable respiratory pathogens during the COVID-19 pandemic: A time series and hierarchical clustering analysis. Open Forum Infect Dis 2022; 9:ofac205. [PMID: 35791356 PMCID: PMC9047204 DOI: 10.1093/ofid/ofac205] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 04/16/2022] [Indexed: 11/21/2022] Open
Abstract
Background Nonpharmaceutical interventions such as physical distancing and mandatory masking were adopted in many jurisdictions during the coronavirus disease 2019 pandemic to decrease spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We determined the effects of these interventions on incidence of healthcare utilization for other infectious diseases. Methods Using a healthcare administrative dataset, we employed an interrupted time series analysis to measure changes in healthcare visits for various infectious diseases across the province of Ontario, Canada, from January 2017 to December 2020. We used a hierarchical clustering algorithm to group diagnoses that demonstrated similar patterns of change through the pandemic months. Results We found that visits for infectious diseases commonly caused by communicable respiratory pathogens (eg, acute bronchitis, acute sinusitis) formed distinct clusters from diagnoses that often originate from pathogens derived from the patient’s own flora (eg, urinary tract infection, cellulitis). Moreover, infectious diagnoses commonly arising from communicable respiratory pathogens (hierarchical cluster 1: highly impacted diagnoses) were significantly decreased, with a rate ratio (RR) of 0.35 (95% confidence interval [CI], .30–.40; P < .001) after the introduction of public health interventions in April–December 2020, whereas infections typically arising from the patient’s own flora (hierarchical cluster 3: minimally impacted diagnoses) did not demonstrate a sustained change in incidence (RR, 0.95 [95% CI, .90–1.01]; P = .085). Conclusions Public health measures to curtail the incidence of SARS-CoV-2 were widely effective against other communicable respiratory infectious diseases with similar modes of transmission but had little effect on infectious diseases not strongly dependent on person-to-person transmission.
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Affiliation(s)
- Ali Zhang
- Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Matthew D. Surette
- Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Kevin L. Schwartz
- Public Health Ontario, Toronto, Ontario, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - James I. Brooks
- The Public Health Agency of Canada, Canada
- Division of Infectious Diseases, University of Ottawa, Ottawa, Ontario, Canada
| | - Dawn M.E. Bowdish
- Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- Firestone Institute for Respiratory Health, St. Joseph’s Healthcare, Hamilton, Ontario, Canada
| | | | - Douglas G. Manuel
- IC/ES, Toronto, Ontario, Canada
- Clinical Epidemiology Program, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
| | | | - Nick Daneman
- Public Health Ontario, Toronto, Ontario, Canada
- IC/ES, Toronto, Ontario, Canada
- Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
| | | | - Derek MacFadden
- IC/ES, Toronto, Ontario, Canada
- Clinical Epidemiology Program, The Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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Verschoor CP, McEwen LM, Kobor MS, Loeb MB, Bowdish DM. DNA methylation patterns are related to co-morbidity status and circulating C-reactive protein levels in the nursing home elderly. Exp Gerontol 2018; 105:47-52. [DOI: 10.1016/j.exger.2017.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/14/2017] [Accepted: 10/09/2017] [Indexed: 12/24/2022]
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Thevaranjan N, Puchta A, Schulz C, Naidoo A, Szamosi J, Verschoor CP, Loukov D, Schenck LP, Jury J, Foley KP, Schertzer JD, Larché MJ, Davidson DJ, Verdú EF, Surette MG, Bowdish DM. Age-Associated Microbial Dysbiosis Promotes Intestinal Permeability, Systemic Inflammation, and Macrophage Dysfunction. Cell Host Microbe 2018; 23:570. [PMID: 29649447 PMCID: PMC5899819 DOI: 10.1016/j.chom.2018.03.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Dowhaniuk JK, Chorlton S, Szamosi J, Owens J, Mileski H, Clause R, Pernica J, Bowdish DM, Surette M, Ratcliffe E. A278 ESCHERICHIA ABUNDANCE AND LOW FECAL BUTYRATE IN CHILDREN WITH INTESTINAL FAILURE. J Can Assoc Gastroenterol 2018. [DOI: 10.1093/jcag/gwy009.278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J K Dowhaniuk
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - S Chorlton
- Department of Undergraduate Medicine, McMaster Univeristy, Hamilton, ON, Canada
| | - J Szamosi
- Department of Biochemistry and Biomedical Sciences, McMaster Univeristy, Hamilton, ON, Canada
| | - J Owens
- McMaster Children’s Hospital, Hamilton, ON, Canada
| | - H Mileski
- McMaster Children’s Hospital, Hamilton, ON, Canada
| | - R Clause
- McMaster Children’s Hospital, Hamilton, ON, Canada
| | - J Pernica
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - D M Bowdish
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - M Surette
- Department of Biochemistry and Biomedical Sciences, McMaster Univeristy, Hamilton, ON, Canada
| | - E Ratcliffe
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
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Keith RH, Grana P, Schultz C, Bowdish DM, Xiao Q. Biological evaluation of the MILLIPLEX® map Mouse High Sensitivity T Cell Panel. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.61.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Low levels of inflammation are involved in many clinical and sub-clinical disease states like autoimmune diseases. Measuring picogram levels of cytokines is critical for understanding their pathogenesis. Model organisms, such as mice, offer unique challenges of sample availability and detection of low levels of cytokines. We recently developed a Mouse High Sensitivity T Cell Panel multiplex assay for simultaneous measurement of 18 mouse cytokines using Luminex xMAP® technology. In this study, we analyzed mouse cytokine secretions both in vitro, with PMA-, PHA-, LPS-, Con-A, or calcium ionophore-challenged PBMC samples, and in vivo, using LPS-challenged mice and an aged-mouse model. Typically, the response of mouse PBMCs to in vitro stimulants is difficult to study due to low levels of cytokine secretion. Using the MILLIPLEX® map Mouse High Sensitivity T Cell Panel, distinctly different stimulant-dependent cytokine responses were observed. PMA and LPS induced the secretion of IL-1β, IL-5, IL-10, LIX, MCP-1, MIP-2 and LPS. IL-6 was secreted in response to LPS but not PMA. Th17 cell cytokine IL-17A was secreted in response to PHA and Con A but not LPS. Interestingly, low levels of secretion were seen in response to the combination of all stimulants for GM-CSF, IFNγ, IL-1α and IL-2. The in vivo challenge of LPS significantly increased mouse plasma levels of fourteen cytokines. Small increases were also seen for GM-CSF and IL-2, while IL-5 and IL-12 (p70) trended higher. In a mouse model of aging, sex-specific changes of plasma levels were observed for IL-1, IL-5, IL-10, GM-CSF, IFNγ, KC and MIP-2. Thus, the MILLIPLEX® MAP Mouse High Sensitivity T Cell Panel is a useful tool to study low levels cytokines in mouse models of disease and inflammation.
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Abstract
The human lung produces a variety of peptides and proteins which have intrinsic antimicrobial activity. In general these molecules have broad spectra of antimicrobial activity, kill micro-organisms rapidly, and evade resistance generated by pathogens. In recent years it has become increasingly apparent that the antimicrobial peptides (AMPs) simultaneously possess immunomodulatory functions, suggesting complex roles for these molecules in regulating the clearance of, and immune response to, invading pathogens. These collective properties have stimulated considerable interest in the potential clinical application of endogenous AMPs. This article outlines the biology of AMPs, their pattern of expression in the lung, and their functions, with reference to both antimicrobial and immunomodulatory activity. We then consider the biological importance of AMPs, before concentrating on the potential to use AMPs to therapeutic effect. The principles discussed in the article apply to innate immune defence throughout the body, but particular emphasis is placed on AMPs in the lung and the potential application to pulmonary infection.
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Affiliation(s)
- M A Gibbons
- Rayne Laboratory, MRC Centre for Inflammation Research, Edinburgh University Medical School, Teviot Place, Edinburgh EH8 9AG, Scotland, UK
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Abstract
The innate immune system of mammals contains a series of peptides with overall positive charge and an amphipathic structure which have a variety of important properties in host defences. Although these are often termed cationic antimicrobial peptides, they have numerous roles in innate defences in all complex species of life and thus we prefer to refer to them as host defence peptides. These roles include: (i) an ability to kill micro-organisms directly, ranging from bacteria to viruses, fungi, parasites and helminths; (ii) an adjuvant activity in the adaptive response; and (iii) a multiplicity of roles in modulating innate immunity, including an apparent ability to stimulate protective innate immunity while suppressing harmful inflammatory/septic responses. This latter property may be one of the more important activities of these peptides in vivo. Innate immunity is thought to be triggered by the interaction of conserved bacterial components with particular receptors including Toll-like receptors (TLRs) on host cells. However, the initiation of the innate immune response through this route may trigger a pro-inflammatory cascade that is the principle cause of harmful conditions such as sepsis. Since we are exposed to potentially dangerous pathogens on a daily basis, the host response must contain certain checks and balances. We propose that host defence peptides have a role in feed-back modulation of inflammation under normal (low-pathogen exposure) conditions. This review surveys the available information regarding the antiendotoxic/anti-inflammatory properties of host defence peptides, and will address whether this potential might be exploited for therapeutic benefit in sepsis.
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Affiliation(s)
- Dawn M.E. Bowdish
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert E.W. Hancock
- Centre for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia, Canada,
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Mukhopadhyay S, Plüddemann A, Hoe JC, Williams KJ, Varin A, Makepeace K, Aknin ML, Bowdish DM, Smale ST, Barclay AN, Gordon S. Immune Inhibitory Ligand CD200 Induction by TLRs and NLRs Limits Macrophage Activation to Protect the Host from Meningococcal Septicemia. Cell Host Microbe 2010; 8:236-47. [DOI: 10.1016/j.chom.2010.08.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 03/26/2010] [Accepted: 07/15/2010] [Indexed: 02/02/2023]
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Pistolic J, Cosseau C, Li Y, Yu J(J, Filewod NC, Gellatly S, Rehaume LM, Bowdish DM, Hancock RE. Host defence peptide LL-37 induces IL-6 expression in human bronchial epithelial cells by activation of the NF-kappaB signaling pathway. J Innate Immun 2008; 1:254-67. [PMID: 20375583 PMCID: PMC7312842 DOI: 10.1159/000171533] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 08/21/2008] [Indexed: 12/30/2022] Open
Abstract
LL-37, the only member of the cathelicidin family of cationic host defence peptides in humans, has been shown to mediate multiple immunomodulatory effects and as such is thought to be an important component of innate immune responses. A growing body of evidence indicates that LL-37 affects lung mucosal responses to pathogens through altered regulation of cell migration, proliferation, wound healing and cell apoptosis. These functions are consistent with LL-37 playing a role in regulating lung epithelial inflammatory responses; however, that role has not been clearly defined. In this report we have demonstrated that host defence peptide LL-37 induced cytokine (IL-6) and chemokine (CXCL-1/GRO-alpha and CXCL-8/IL-8) release from human bronchial epithelial cells. It was demonstrated that LL-37-mediated IL-6 release was time and dose dependent and that LL-37 up-regulated this pleiotropic cytokine at the transcriptional level. Using specific inhibitors it was shown that NF-kappaB signaling led to the LL-37-stimulated production of IL-6. LL-37 stimulation of airway epithelial cells activated NF-kappaB signaling, as demonstrated by the phosphorylation and degradation of Ikappa-Balpha, and consequent nuclear translocation of p65 and p50 NF-kappaB subunits. Furthermore this host defence peptide augmented flagellin-mediated cytokine production, indicating that LL-37 likely modulates Toll-like receptor 5-mediated responses.
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Affiliation(s)
- Jelena Pistolic
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Celine Cosseau
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Yuexin Li
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Jie (Jessie) Yu
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Niall C.J. Filewod
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Shaan Gellatly
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Linda M. Rehaume
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
| | - Dawn M.E. Bowdish
- Sir William Dunn School of Pathology, Universityof Oxford, Oxford, UK
| | - Robert E.W. Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, B.C., Canada
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Low AM, Bowdish DM, Prashad TR, Gaspar V. Interactions of chloroethylclonidine with rauwolscine- and prazosin-sensitive adrenoceptors in dog saphenous vein. Br J Pharmacol 1994; 113:1263-8. [PMID: 7889282 PMCID: PMC1510511 DOI: 10.1111/j.1476-5381.1994.tb17134.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
1. alpha 1-Adrenoceptors have been classified pharmacologically into four subtypes (alpha 1A, alpha 1B, alpha 1C and alpha 1D) on the basis of their differential affinity for novel antagonists such as chloroethylclonidine (CEC). While CEC is considered an alpha 1B-adrenoceptor antagonist, our earlier studies revealed that it also acted like an agonist in the dog saphenous vein (DSV). The present study characterized the contraction induced by CEC in endothelium-denuded rings from DSV. 2. Concentration-response curves for CEC were constructed in the absence (EC50 value of 11.13 +/- 3.6 microM, n = 8) and presence of propranolol (beta-adrenoceptor antagonist, 30 nM), rauwolscine (alpha 2-adrenoceptor antagonist, 30 nM), prazosin (alpha 1-adrenoceptor antagonist, 30 nM) or methysergide (5HT2 antagonist, 30 nM) or both prazosin and rauwolscine. Pretreatment with methysergide (9.83 +/- 5.14 microM, n = 4) or propranolol (23.78 +/- 12.32 microM, n = 4) had no consistent effect. In the presence of rauwolscine, the concentration-response curve for CEC was significantly shifted to the right with an EC50 value of 48.82 +/- 13.2 microM (n = 8). In the presence of prazosin, the CEC concentration-response curve had an EC50 value of 29.12 +/- 6.42 microM (n = 8). Pretreatment with both prazosin and rauwolscine shifted the concentration-response curve for CEC to the right with an EC50 value of 72.67 +/- 10.69 microM (n = 8, P < 0.05). Maximum responses were significantly reduced only in tissues that were treated with both prazosin and rauwolscine. 3. CEC (100 microM) pretreatment abolished prazosin binding sites and reduced the Bmax for rauwolscine by 50% without affecting the Kd value or the Hill slope.4. In Ca2+-free Krebs solution containing 50 microM EGTA, CEC produced a small transient contraction,suggesting that it can mobilize internally-stored Ca2+ . Pretreatment with rauwolscine abolished the CEC-induced contraction in Ca2+-free medium; prazosin pretreatment reduced but did not abolish CEC response in Ca2+-free medium.5. Restoring Ca2+ (0.5-2.5 mM) to the extracellular solution increased CEC contraction in a concentration-dependent manner, reaching a plateau at around 1.5mM Ca2 . The contraction was insensitive to nicardipine (1 microM), a voltage-operated Ca2+ channel blocker, but was blocked in a concentration-dependent manner by the putative receptor-operated Ca2+ channel blockers, SK&F 96365(1-1O microM) and genistein, also a tyrosine kinase inhibitor (10-100 microM).6. We conclude that CEC acts on rauwolscine- and, to a less extent, prazosin-sensitive adrenoceptors inDSV to release internally stored Ca2+ and to open receptor-operated Ca2+ channels. The inhibitory effect on CEC-induced contraction that depended on external Ca2+ by genistein suggests a role forty rosine kinase in the regulation of dihydropyridine-insensitive Ca2+ entry.
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Affiliation(s)
- A M Low
- Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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