1
|
Lopes N, Pereira RB, Correia A, Vilanova M, Cerca N, França A. Deletion of codY impairs Staphylococcus epidermidis biofilm formation, generation of viable but non-culturable cells and stimulates cytokine production in human macrophages. J Med Microbiol 2024; 73. [PMID: 38743043 DOI: 10.1099/jmm.0.001837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024] Open
Abstract
Introduction. Staphylococcus epidermidis biofilms are one of the major causes of bloodstream infections related to the use of medical devices. The diagnosis of these infections is challenging, delaying their treatment and resulting in increased morbidity and mortality rates. As such, it is urgent to characterize the mechanisms employed by this bacterium to endure antibiotic treatments and the response of the host immune system, to develop more effective therapeutic strategies. In several bacterial species, the gene codY was shown to encode a protein that regulates the expression of genes involved in biofilm formation and immune evasion. Additionally, in a previous study, our group generated evidence indicating that codY is involved in the emergence of viable but non-culturable (VBNC) cells in S. epidermidis.Gap statement/Hypothesis. As such, we hypothesized that the gene codY has have an important role in this bacterium virulence.Aim. This study aimed to assess, for the first time, the impact of the deletion of the gene codY in S. epidermidis virulence, namely, in antibiotic susceptibility, biofilm formation, VBNC state emergence and in vitro host immune system response.Methodology. Using an allelic replacement strategy, we constructed and then characterized an S. epidermidis strain lacking codY, in regards to biofilm and VBNC cell formation, susceptibility to antibiotics as well as their role in the interaction with human blood and plasma. Additionally, we investigate whether the codY gene can impact the activation of innate immune cells by evaluating the production of both pro- and anti-inflammatory cytokines by THP-1 macrophages.Results. We demonstrated that the deletion of the gene codY resulted in biofilms with less c.f.u. counts and fewer VBNC cells. Furthermore, we show that although WT and mutant cells were similarly internalized in vitro by human macrophages, a stronger cytokine response was elicited by the mutant in a toll-like receptor 4-dependent manner.Conclusion. Our results indicate that codY contributes to S. epidermidis virulence, which in turn may have an impact on our ability to manage the biofilm-associated infections caused by this bacterium.
Collapse
Affiliation(s)
- Nathalie Lopes
- Laboratório de Investigação em Biofilmes Rosário Oliveira (LIBRO), Centro de Engenharia Biológica (CEB), Universidade do Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Renato B Pereira
- I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Alexandra Correia
- I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
| | - Manuel Vilanova
- I3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Nuno Cerca
- Laboratório de Investigação em Biofilmes Rosário Oliveira (LIBRO), Centro de Engenharia Biológica (CEB), Universidade do Minho, Campus de Gualtar, Braga, 4710-057, Portugal
- LABBELS-Laboratório Associado, Braga, Guimarães, Portugal
| | - Angela França
- Laboratório de Investigação em Biofilmes Rosário Oliveira (LIBRO), Centro de Engenharia Biológica (CEB), Universidade do Minho, Campus de Gualtar, Braga, 4710-057, Portugal
- LABBELS-Laboratório Associado, Braga, Guimarães, Portugal
| |
Collapse
|
2
|
Anderson J, Bender G, Minh Thang C, Quang Thanh L, Thi Trang Dai V, Van Thanh P, Thi Hong Nhu B, Ngoc Xuan Trang D, Thi Phuong Trinh P, Vu Thuong N, Trong Toan N, Mulholland K, Pellicci DG, Anh Ha Do L, Licciardi PV. TLR Responses in Preterm and Term Infant Cord Blood Mononuclear Cells. Pathogens 2023; 12:pathogens12040596. [PMID: 37111482 PMCID: PMC10145848 DOI: 10.3390/pathogens12040596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/12/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Preterm infants are more susceptible to severe bacterial and viral infectious diseases than their full-term counterparts. A major contributor to this increased susceptibility may be due to differences in their ability to respond to pathogens. While studies have demonstrated altered bacterial Toll-like receptor (TLR) responses, there is limited data on viral TLR responses in preterm infants. In this study, cord blood mononuclear cells (CBMCs) from 10 moderately preterm (30.4-34.1 wGA), 10 term (37-39.5 wGA) infants, and 5 adults were stimulated with TLR2 (lipoteichoic acid), TLR3 (poly I:C), TLR4 (lipopolysaccharide), TLR7/8 (R848), and TLR9 (CpG-ODN 2216) agonists. Following stimulation, the cellular response was measured by intracellular flow cytometry to detect cell-specific NF-κB (as a marker of the inflammatory response), and multiplex assays were used to measure the cytokine response. This study found that preterm and term infants exhibit very similar baseline TLR expression. In response to both bacterial and viral TLR agonists comparing cell-specific NF-κB activation, preterm infants exhibited increased monocyte activation following LTA stimulation; however, no other differences were observed. Similarly, no difference in cytokine response was observed following stimulation with TLRs. However, a stronger correlation between NF-κB activation and cytokine responses was observed in term infants following poly I:C and R848 stimulation compared to preterm infants. In contrast, despite similar TLR expression, adults produced higher levels of IFN-α following R848 stimulation compared to preterm and term infants. These findings suggest preterm and term infants have a similar capacity to respond to both bacterial and viral TLR agonists. As preterm infants are more likely to develop severe infections, further research is required to determine the immunological factors that may be driving this and develop better interventions for this highly vulnerable group.
Collapse
Affiliation(s)
- Jeremy Anderson
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Georgia Bender
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Cao Minh Thang
- Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City 72408, Vietnam
| | | | - Vo Thi Trang Dai
- Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City 72408, Vietnam
| | - Phan Van Thanh
- Pasteur Institute of Ho Chi Minh City, Ho Chi Minh City 72408, Vietnam
| | | | | | | | | | | | - Kim Mulholland
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Daniel G Pellicci
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Lien Anh Ha Do
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Paul V Licciardi
- Murdoch Children's Research Institute, Melbourne, VIC 3052, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, VIC 3010, Australia
| |
Collapse
|
3
|
Stepanovich GE, Chapman CA, Meserve KL, Sturza JM, Ellsworth LA, Bailey RC, Bermick JR. Chorioamnionitis-exposure alters serum cytokine trends in premature neonates. J Perinatol 2022:10.1038/s41372-022-01584-2. [PMID: 36539561 DOI: 10.1038/s41372-022-01584-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Determine if chronologic age and/or chorioamnionitis exposure alter normal serum cytokine and chemokine levels in uninfected preterm neonates during their initial NICU stay. STUDY DESIGN A 7-plex immunoassay measured levels of serum IL-1β, IL-6, IL-8, IL-10, TNF-α, CCL2, and CCL3 longitudinally from chorioamnionitis-exposed and unexposed preterm neonates under 33 weeks' gestation. RESULTS Chorioamnionitis-exposed and unexposed preterm neonates demonstrated differences in the trends of IL-1β, IL-6, IL-8, IL-10, TNF-α, and CCL2 over the first month of life. The unexposed neonates demonstrated elevated levels of these inflammatory markers in the first two weeks of life with a decrease by the third week of life, while the chorioamnionitis-exposed neonates demonstrated differences over time without a predictable pattern. Chorioamnionitis-exposed and unexposed neonates demonstrated altered IL-10 and TNF-α trajectories over the first twelve weeks of life. CONCLUSION Chorioamnionitis induces a state of immune dysregulation in preterm neonates that persists beyond the immediate neonatal period.
Collapse
Affiliation(s)
- Gretchen E Stepanovich
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Cole A Chapman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Krista L Meserve
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Julie M Sturza
- Biostatistics and Data Management Unit, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Lindsay A Ellsworth
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Ryan C Bailey
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Jennifer R Bermick
- Division of Neonatal-Perinatal Medicine, Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA. .,Division of Neonatology, Department of Pediatrics, University of Iowa, Iowa City, IA, USA.
| |
Collapse
|
4
|
Abstract
Neonatal late-onset sepsis (LOS) continues to threaten morbidity and mortality in the NICU and poses ongoing diagnostic and therapeutic challenges. Early recognition of clinical signs, rapid evaluation, and prompt initiation of treatment are critical to prevent life-threatening deterioration. Preterm infants-born at ever-decreasing gestational ages-are at particularly high risk for life-long morbidities and death. This changing NICU population necessitates continual reassessments of diagnostic and preventive measures and evidence-based treatment for LOS. The clinical presentation of LOS is varied and nonspecific. Despite ongoing research, reliable, specific laboratory biomarkers facilitating early diagnosis are lacking. These limitations drive an ongoing practice of liberal initiation of empiric antibiotics among infants with suspected LOS. Subsequent promotion of multidrug-resistant microorganisms threatens the future of antimicrobial therapy and puts preterm and chronically ill infants at even higher risk of nosocomial infection. Efforts to identify adjunctive therapies counteracting sepsis-driven hyperinflammation and sepsis-related functional immunosuppression are ongoing. However, most approaches have either failed to improve LOS prognosis or are not yet ready for clinical application. This article provides an overview of the epidemiology, risk factors, diagnostic tools, and treatment options of LOS in the context of increasing numbers of extremely preterm infants. It addresses the question of whether LOS could be identified earlier and more precisely to allow for earlier and more targeted therapy and discusses rational approaches to antibiotic therapy to avoid overuse. Finally, this review elucidates the necessity of long-term follow-up of infants with a history of LOS.
Collapse
Affiliation(s)
- Sarah A. Coggins
- Division of Neonatology, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kirsten Glaser
- Division of Neonatology, Department of Women’s and Children’s Health, University of Leipzig Medical Center, Leipzig, Germany
| |
Collapse
|
5
|
Reiss JD, Peterson LS, Nesamoney SN, Chang AL, Pasca AM, Marić I, Shaw GM, Gaudilliere B, Wong RJ, Sylvester KG, Bonifacio SL, Aghaeepour N, Gibbs RS, Stevenson DK. Perinatal infection, inflammation, preterm birth, and brain injury: A review with proposals for future investigations. Exp Neurol 2022; 351:113988. [DOI: 10.1016/j.expneurol.2022.113988] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/06/2022] [Accepted: 01/13/2022] [Indexed: 11/26/2022]
|
6
|
Sabaté-Brescó M, Berset CM, Zeiter S, Stanic B, Thompson K, Ziegler M, Richards RG, O'Mahony L, Moriarty TF. Fracture biomechanics influence local and systemic immune responses in a murine fracture-related infection model. Biol Open 2021; 10:270855. [PMID: 34240122 PMCID: PMC8496694 DOI: 10.1242/bio.057315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 07/05/2021] [Indexed: 11/26/2022] Open
Abstract
Biomechanical stability plays an important role in fracture healing, with unstable fixation being associated with healing disturbances. A lack of stability is also considered a risk factor for fracture-related infection (FRI), although confirmatory studies and an understanding of the underlying mechanisms are lacking. In the present study, we investigate whether biomechanical (in)stability can lead to altered immune responses in mice under sterile or experimentally inoculated conditions. In non-inoculated C57BL/6 mice, instability resulted in an early increase of inflammatory markers such as granulocyte-colony stimulating factor (G-CSF), keratinocyte chemoattractant (KC) and interleukin (IL)-6 within the bone. When inoculated with Staphylococcus epidermidis, instability resulted in a further significant increase in G-CSF, IL-6 and KC in bone tissue. Staphylococcus aureus infection led to rapid osteolysis and instability in all animals and was not further studied. Gene expression measurements also showed significant upregulation in CCL2 and G-CSF in these mice. IL-17A was found to be upregulated in all S. epidermidis infected mice, with higher systemic IL-17A cell responses in mice that cleared the infection, which was found to be produced by CD4+ and γδ+ T cells in the bone marrow. IL-17A knock-out (KO) mice displayed a trend of delayed clearance of infection (P=0.22, Fisher’s exact test) and an increase in interferon (IFN)-γ production. Biomechanical instability leads to a more pronounced local inflammatory response, which is exaggerated by bacterial infection. This study provides insights into long-held beliefs that biomechanics are crucial not only for fracture healing, but also for control of infection. Summary: Physical movement between bone fragments after a fracture influence healing, and are shown here, for the first time, to influence immune responses and infection.
Collapse
Affiliation(s)
- Marina Sabaté-Brescó
- AO Research Institute Davos, AO Foundation, Davos, Switzerland.,Swiss Institute of Asthma and Allergy Research, University of Zurich, Davos, Switzerland
| | - Corina M Berset
- Swiss Institute of Asthma and Allergy Research, University of Zurich, Davos, Switzerland
| | - Stephan Zeiter
- AO Research Institute Davos, AO Foundation, Davos, Switzerland
| | - Barbara Stanic
- AO Research Institute Davos, AO Foundation, Davos, Switzerland
| | - Keith Thompson
- AO Research Institute Davos, AO Foundation, Davos, Switzerland
| | - Mario Ziegler
- Swiss Institute of Asthma and Allergy Research, University of Zurich, Davos, Switzerland
| | | | - Liam O'Mahony
- Swiss Institute of Asthma and Allergy Research, University of Zurich, Davos, Switzerland
| | | |
Collapse
|
7
|
Strunk T, Hibbert J, Doherty D, Nathan E, Simmer K, Richmond P, Currie A, Burgner D. Impaired Cytokine Responses to Live Staphylococcus epidermidis in Preterm Infants Precede Gram-positive, Late-onset Sepsis. Clin Infect Dis 2021; 72:271-278. [PMID: 31960030 DOI: 10.1093/cid/ciaa063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/17/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Late-onset sepsis (LOS) with Staphylococcus epidermidis is common in preterm infants, but the immunological mechanisms underlying heightened susceptibility are poorly understood. Our aim is to characterize the ontogeny of cytokine responses to live S. epidermidis in preterm infants with and without subsequent Gram-positive LOS. METHODS We conducted a prospective, observational cohort study of preterm infants (<30 weeks gestational age [GA]) with blood sampling on Days 1, 7, 14, 21, and 28 of life. Cytokine responses in peripheral whole blood stimulated with live S. epidermidis were analyzed by 11-plex immunoassay. RESULTS Of 129 infants (mean GA, 26.2 weeks; mean birth weight, 887g), 23 (17.8%) had confirmed LOS with Gram-positive organisms and 15 (11.6%) had clinical sepsis, with median onsets at 13 and 15 days, respectively. Blood cytokine responses to an in vitro S. epidermidis challenge were similar between infected and uninfected infants on Day 1, but diverged thereafter. Infants with subsequent LOS displayed broadly reduced S. epidermidis-induced responses from Day 7 onwards, compared to those who did not develop LOS. This pattern was observed with chemokines (interleukin [IL]-8, monocyte chemotactic protein-1, and macrophage inflammatory protein-1α), pro-inflammatory cytokines (IL-1, IL-6, and tumor necrosis factor-α) and the regulatory cytokine IL-10. CONCLUSIONS Cytokine responses to a live S. epidermidis challenge are impaired in infants with LOS and precede the onset of clinical illness. Quantifying pathogen-specific cytokine responses at Day 7 may identify those high-risk preterm infants at the greatest risk of LOS, and prospective replication is warranted.
Collapse
Affiliation(s)
- Tobias Strunk
- Neonatal Directorate, King Edward Memorial Hospital, Perth, Australia.,Telethon Kids Institute, Perth, Australia.,School of Medicine, University of Western Australia, Perth, Australia
| | - Julie Hibbert
- Neonatal Directorate, King Edward Memorial Hospital, Perth, Australia.,School of Medicine, University of Western Australia, Perth, Australia
| | - Dorota Doherty
- School of Medicine, University of Western Australia, Perth, Australia
| | - Elizabeth Nathan
- School of Medicine, University of Western Australia, Perth, Australia
| | - Karen Simmer
- Neonatal Directorate, King Edward Memorial Hospital, Perth, Australia.,Telethon Kids Institute, Perth, Australia.,School of Medicine, University of Western Australia, Perth, Australia
| | - Peter Richmond
- School of Medicine, University of Western Australia, Perth, Australia.,Department of Immunology, Perth Children's Hospital, Perth, Australia
| | - Andrew Currie
- Medical, Molecular and Forensic Sciences, Murdoch University, Perth, Australia
| | - David Burgner
- Murdoch Children's Research Institute, Royal Children's Hospital, Victoria, Australia.,Department of Paediatrics, University of Melbourne, Victoria, Australia
| |
Collapse
|
8
|
Adams K, Weber KS, Johnson SM. Exposome and Immunity Training: How Pathogen Exposure Order Influences Innate Immune Cell Lineage Commitment and Function. Int J Mol Sci 2020; 21:ijms21228462. [PMID: 33187101 PMCID: PMC7697998 DOI: 10.3390/ijms21228462] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/29/2020] [Accepted: 11/09/2020] [Indexed: 01/02/2023] Open
Abstract
Immune memory is a defining characteristic of adaptive immunity, but recent work has shown that the activation of innate immunity can also improve responsiveness in subsequent exposures. This has been coined “trained immunity” and diverges with the perception that the innate immune system is primitive, non-specific, and reacts to novel and recurrent antigen exposures similarly. The “exposome” is the cumulative exposures (diet, exercise, environmental exposure, vaccination, genetics, etc.) an individual has experienced and provides a mechanism for the establishment of immune training or immunotolerance. It is becoming increasingly clear that trained immunity constitutes a delicate balance between the dose, duration, and order of exposures. Upon innate stimuli, trained immunity or tolerance is shaped by epigenetic and metabolic changes that alter hematopoietic stem cell lineage commitment and responses to infection. Due to the immunomodulatory role of the exposome, understanding innate immune training is critical for understanding why some individuals exhibit protective phenotypes while closely related individuals may experience immunotolerant effects (e.g., the order of exposure can result in completely divergent immune responses). Research on the exposome and trained immunity may be leveraged to identify key factors for improving vaccination development, altering inflammatory disease development, and introducing potential new prophylactic treatments, especially for diseases such as COVID-19, which is currently a major health issue for the world. Furthermore, continued exposome research may prevent many deleterious effects caused by immunotolerance that frequently result in host morbidity or mortality.
Collapse
|
9
|
Cyclic AMP in human preterm infant blood is associated with increased TLR-mediated production of acute-phase and anti-inflammatory cytokines in vitro. Pediatr Res 2020; 88:717-725. [PMID: 31578034 PMCID: PMC7392158 DOI: 10.1038/s41390-019-0586-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/16/2019] [Accepted: 08/21/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND Preterm infants are at high risk of infection and have distinct pathogen recognition responses. Suggested mechanisms include soluble mediators that enhance cellular levels of cAMP. The aim of this study was to assess the relationship between blood cAMP concentrations and TLR-mediated cytokine production in infants during the first month of life. METHODS Cord and serial peripheral blood samples (days of life 1-28) were obtained from a cohort of very preterm (<30 weeks' gestational age) and term human infants. Whole-blood concentrations of cAMP and FSL-1 and LPS in vitro stimulated cytokine concentrations were measured by ELISA and multiplex bead assay. RESULTS cAMP concentrations were higher in cord than in peripheral blood, higher in cord blood of female preterm infants, and lower at Days 1 and 7 in infants exposed to chorioamnionitis, even after adjusting for leukocyte counts. TLR2 and TLR4-mediated TNF-α, IL-1β, IL-6, IL-12p70, and IL-10 production in vitro increased over the first month of life in preterm infants and were positively correlated with leukocyte-adjusted cAMP levels and reduced by exposure to chorioamnionitis. CONCLUSIONS The ontogeny of blood cAMP concentrations and associations with chorioamnionitis and TLR-mediated production of cytokines suggest that this secondary messenger helps shape distinct neonatal pathogen responses in early life.
Collapse
|
10
|
Gravina G, Svedin P, Ardalan M, Levy O, Ek CJ, Mallard C, Lai JCY. Staphylococcus epidermidis Sensitizes Perinatal Hypoxic-Ischemic Brain Injury in Male but Not Female Mice. Front Immunol 2020; 11:516. [PMID: 32373108 PMCID: PMC7186320 DOI: 10.3389/fimmu.2020.00516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/06/2020] [Indexed: 12/21/2022] Open
Abstract
Background: Staphylococcus epidermidis is the most common nosocomial infection and the predominant pathogen in late-onset sepsis in preterm infants. Infection and inflammation are linked to neurological and developmental sequelae and bacterial infections increase the vulnerability of the brain to hypoxia-ischemia (HI). We thus tested the hypothesis that S. epidermidis exacerbates HI neuropathology in neonatal mice. Methods: Male and female C57Bl/6 mice were injected intraperitoneally with sterile saline or 3.5 × 107 colony-forming units of S. epidermidis on postnatal day (PND) 4 and then subjected to HI on PND5 (24 h after injection) or PND9 (5 d after injection) by left carotid artery ligation and exposure to 10% O2. White and gray matter injury was assessed on PND14-16. In an additional group of animals, the plasma, brain, and liver were collected on PND5 or PND9 after infection to evaluate cytokine and chemokine profiles, C5a levels and C5 signaling. Results: HI induced 24 h after injection of S. epidermidis resulted in greater gray and white matter injury compared to saline injected controls in males, but not in females. Specifically, males demonstrated increased gray matter injury in the cortex and striatum, and white matter loss in the subcortical region, hippocampal fimbria and striatum. In contrast, there was no potentiation of brain injury when HI occurred 5 d after infection in either sex. In the plasma, S. epidermidis-injected mice demonstrated increased levels of pro- and anti-inflammatory cytokines and chemokines and a reduction of C5a at 24 h, but not 5 d after infection. Brain CCL2 levels were increased in both sexes 24 h after infection, but increased only in males at 5 d post infection. Conclusion: Ongoing S. epidermidis infection combined with neonatal HI increases the vulnerability of the developing brain in male but not in female mice. These sex-dependent effects were to a large extent independent of expression of systemic cytokines or brain CCL2 expression. Overall, we provide new insights into how systemic S. epidermidis infection affects the developing brain and show that the time interval between infection and HI is a critical sensitizing factor in males.
Collapse
Affiliation(s)
- Giacomo Gravina
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Pernilla Svedin
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Maryam Ardalan
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ofer Levy
- Precision Vaccines Program, Boston Children's Hospital, Boston, MA, United States.,Department of Pediatrics, Harvard Medical School, Boston, MA, United States.,Broad Institute of MIT and Harvard, Cambridge, MA, United States
| | - C Joakim Ek
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Carina Mallard
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jacqueline C Y Lai
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
11
|
Dendritic Cells Internalize Staphylococcus aureus More Efficiently than Staphylococcus epidermidis, but Do Not Differ in Induction of Antigen-Specific T Cell Proliferation. Microorganisms 2019; 8:microorganisms8010019. [PMID: 31861881 PMCID: PMC7022728 DOI: 10.3390/microorganisms8010019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/05/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus and Staphylococcus epidermidis are related species which can cause predominantly acute and subacute infections, respectively. Differences in human adaptive immune responses to these two species are not well understood. Dendritic cells (DCs) have an important role in the control and regulation of anti-staphylococcal T cell responses. Therefore, we aimed to compare the ability of S. aureus and S. epidermidis to influence the essential steps in human DC activation and subsequent antigen-specific CD4+ T cell proliferation, and to investigate the underlying mechanisms. Using multiple strains of both species, we observed that S. aureus was internalized more effectively than S. epidermidis by DCs but that both species were equally potent in activating these host cells, as evidenced by similar induction of DC maturation marker expression and antigen loading onto MHC-II molecules. The DCs stimulated by S. aureus strains not harboring superantigen (SAg) genes or by any of the S. epidermidis strains, induced low, likely physiological levels of T cell proliferation. Only DCs stimulated with S. aureus strains harboring SAg genes induced high levels of T cell proliferation. Taken together, S. aureus and S. epidermidis do not differently affect DC activation and ensuing antigen-specific T cell proliferation, unless a strain has the capacity to produce SAgs.
Collapse
|
12
|
Dietz S, Schwarz J, Vogelmann M, Spring B, Molnár K, Orlikowsky TW, Wiese F, Holzer U, Poets CF, Gille C, Köstlin-Gille N. Cord blood granulocytic myeloid-derived suppressor cells impair monocyte T cell stimulatory capacity and response to bacterial stimulation. Pediatr Res 2019; 86:608-615. [PMID: 31349362 DOI: 10.1038/s41390-019-0504-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 05/20/2019] [Accepted: 07/15/2019] [Indexed: 11/09/2022]
Abstract
BACKGROUND Neonatal sepsis is a leading cause of perinatal morbidity and mortality. In comparison to adults, neonates exhibit a higher susceptibility to infections. Myeloid-derived suppressor cells (MDSCs) are myeloid cells with suppressive activity on other immune cells accumulating during foetal life and controlling inflammation in neonates. Most studies investigating the mechanisms for MDSC-mediated immune suppression have been focused on T-cells. Thus far, little is known about the role of MDSC for monocyte function. METHODS The impact of human cord blood MDSCs (CB-MDSCs) on monocytes was investigated in an in vitro model. CB-MDSCs were co-cultured with peripheral blood mononuclear cells and monocytes were analysed for expression of surface markers, T cell stimulatory and phagocytic capacity, as well as the production of intracellular cytokines by flow cytometry. RESULTS CB-MDSCs increased the expression of co-inhibitory molecules and decreased the expression of major histocompatibility complex class II molecules on monocytes, leading to an impaired T-cell stimulatory capacity. Upon bacterial stimulation, expression of phagocytosis receptors, phagocytosis rates and production of tumor necrosis factor-α by monocytes was diminished by CB-MDSCs. CONCLUSION We show that CB-MDSCs profoundly modulate monocyte functions, thereby indirectly impairing T-cell activation. Further research is needed to figure out if MDSCs could be a therapeutic target for inflammatory diseases in neonates like neonatal sepsis.
Collapse
Affiliation(s)
- Stefanie Dietz
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | - Julian Schwarz
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | - Margit Vogelmann
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | - Bärbel Spring
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | - Kriszta Molnár
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | | | - Franziska Wiese
- Department of Hematology and Oncology, Tübingen University Children's Hospital, Tuebingen, Germany
| | - Ursula Holzer
- Department of Hematology and Oncology, Tübingen University Children's Hospital, Tuebingen, Germany
| | - Christian F Poets
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany
| | - Christian Gille
- Department of Neonatology, Tübingen University Children's Hospital, Tübingen, Germany.
| | | |
Collapse
|
13
|
Taha M, Kyluik‐Price D, Kumaran D, Scott MD, Toyofuku W, Ramirez‐Arcos S. Bacterial survival in whole blood depends on plasma sensitivity and resistance to neutrophil killing. Transfusion 2019; 59:3674-3682. [DOI: 10.1111/trf.15550] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Mariam Taha
- Centre for Innovation, Canadian Blood Services Ottawa Ontario
| | - Dana Kyluik‐Price
- Centre for Blood Research, University of British Columbia Vancouver British Columbia
| | - Dilini Kumaran
- Centre for Innovation, Canadian Blood Services Ottawa Ontario
| | - Mark D. Scott
- Centre for Innovation, Canadian Blood Services Ottawa Ontario
- Centre for Blood Research, University of British Columbia Vancouver British Columbia
| | - Wendy Toyofuku
- Centre for Innovation, Canadian Blood Services Ottawa Ontario
| | - Sandra Ramirez‐Arcos
- Centre for Innovation, Canadian Blood Services Ottawa Ontario
- Department of Biochemistry, Microbiology and ImmunologyUniversity of Ottawa Ottawa Ontario Canada
| |
Collapse
|
14
|
Dong Y, Glaser K, Schlegel N, Claus H, Speer CP. An underestimated pathogen: Staphylococcus epidermidis induces pro-inflammatory responses in human alveolar epithelial cells. Cytokine 2019; 123:154761. [PMID: 31226437 DOI: 10.1016/j.cyto.2019.154761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 06/06/2019] [Accepted: 06/11/2019] [Indexed: 12/27/2022]
Abstract
OBJECTIVES Conventionally regarded as a harmless skin commensal, Staphylococcus epidermidis accounts for the majority of neonatal late-onset sepsis and is shown to be associated with neonatal inflammatory morbidities, especially bronchopulmonary dysplasia. This study addressed the pro-inflammatory capacity of different S. epidermidis strains on human alveolar epithelial cells. METHODS A549 cell monolayers were stimulated by live bacteria of S. epidermidis RP62A strain (biofilm-positive) and ATCC 12228 strain (biofilm-negative) at a multiplicity of infection ratio of 10 for 24 h. LPS (100 ng/ml) and Pam3CSK4 (1 µg/ml) were used for comparisons. Cell viability was measured by MTT method. The mRNA and protein expression of inflammatory mediators and toll-like receptor (TLR)-2 were assessed using RT-PCR, immunoassays and immunofluorescence. RESULTS Both S. epidermidis strains induced expression of tumor necrosis factor (TNF)-α, IL-1β, interleukin (IL)-6, IL-8, monocyte chemoattractant protein (MCP)-1, interferon γ-induced protein 10 (IP-10) and intercellular adhesion molecule (ICAM)-1, but not IL-10. The stimulatory effect of RP62A exceeded that of LPS (p < 0.05). RP62A strain showed a trend towards higher induction of pro-inflammatory mediators than ATCC 12228 strain. The co-stimulation with RP62A strain decreased cell viability compared to control and TLR agonists (p < 0.05). RP62A but not ATCC 12228 stimulated mRNA and protein expression of TLR2. CONCLUSIONS S. epidermidis drives pro-inflammatory responses in lung epithelial cells in vitro. The pro-inflammatory capacity of S. epidermidis may differ between strains. Biofilm-positive S. epidermidis strain seems to induce more potent pulmonary pro-inflammation than biofilm-negative S. epidermidis strain.
Collapse
Affiliation(s)
- Ying Dong
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany.
| | - Kirsten Glaser
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany
| | - Nicolas Schlegel
- Department of Surgery I, University of Wuerzburg, Wuerzburg, Germany
| | - Heike Claus
- Institute for Hygiene and Microbiology, University of Wuerzburg, Wuerzburg, Germany
| | - Christian P Speer
- University Children's Hospital, University of Wuerzburg, Wuerzburg, Germany
| |
Collapse
|
15
|
Bermick J, Gallagher K, denDekker A, Kunkel S, Lukacs N, Schaller M. Chorioamnionitis exposure remodels the unique histone modification landscape of neonatal monocytes and alters the expression of immune pathway genes. FEBS J 2019; 286:82-109. [PMID: 30565411 PMCID: PMC6326865 DOI: 10.1111/febs.14728] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/24/2018] [Accepted: 12/08/2018] [Indexed: 12/13/2022]
Abstract
Chorioamnionitis is an intrauterine infection involving inflammation of the chorion, amnion, and placenta. It leads to a fetal systemic inflammatory response that can alter the transcription of neonatal immune genes. We have previously shown that neonatal monocytes gain the activating histone tail modification H3K4me3 at promoter sites of immunologically important genes as development progresses from preterm neonate to adult. In this study, we applied ChIP-seq and RNA-seq to evaluate the impact of chorioamnionitis on the neonatal monocyte H3K4me3 histone modification landscape over the course of fetal and neonatal immune system development. Chorioamnionitis exposure in neonatal monocytes resulted in a net increase in total monocyte H3K4me3, primarily in introns and intergenic regions. Immune gene expression was decreased in chorioamnionitis-exposed monocytes, with the majority of enriched transcripts falling into pathways that are not linked to the immune system. Over half of all neonatal monocyte H3K4me3 peaks, independent of their location, were associated with active gene transcription. Overall, chorioamnionitis exposure resulted in the global remodeling of the neonatal monocyte H3K4me3 landscape and changes in the expression of known immune genes. These changes resulted in a less robust inflammatory response upon exposure to a secondary challenge, which may explain why chorioamnionitis-exposed neonates have an increased risk of sepsis. DATABASE: ChIP-seq data for U30/O30/Term: GEO GSE81957 ChIP-seq data for U30C/O30C/TermC: GEO GSE111873 RNA-seq data for U/L/CU/CL: GEO GSE111927.
Collapse
Affiliation(s)
- Jennifer Bermick
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Michigan Medicine, Ann Arbor, Michigan
| | | | - Aaron denDekker
- Department of Surgery, Michigan Medicine, Ann Arbor, Michigan
| | - Steve Kunkel
- Department of Pathology, Michigan Medicine, Ann Arbor, Michigan
| | - Nicholas Lukacs
- Department of Pathology, Michigan Medicine, Ann Arbor, Michigan
| | | |
Collapse
|
16
|
Speer EM, Diago-Navarro E, Ozog LS, Dowling DJ, Hou W, Raheel M, Fries BC, Levy O. Pentoxifylline Alone or in Combination with Gentamicin or Vancomycin Inhibits Live Microbe-Induced Proinflammatory Cytokine Production in Human Cord Blood and Cord Blood Monocytes In Vitro. Antimicrob Agents Chemother 2018; 62:e01462-18. [PMID: 30275087 PMCID: PMC6256750 DOI: 10.1128/aac.01462-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 09/22/2018] [Indexed: 01/08/2023] Open
Abstract
Neonatal sepsis and its accompanying inflammatory response contribute to substantial morbidity and mortality. Pentoxifylline (PTX), a phosphodiesterase inhibitor which suppresses transcription and production of proinflammatory cytokines, is a candidate adjunctive therapy for newborn sepsis. We hypothesized that PTX decreases live microbe-induced inflammatory cytokine production in newborn blood. Cord blood was stimulated with live microorganisms commonly encountered in newborn sepsis (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, or Candida albicans) and simultaneously treated with antimicrobial agents (gentamicin, vancomycin, or amphotericin B) and/or clinically relevant concentrations of PTX. Microbial colony counts were enumerated by plating, supernatant cytokines were measured by multiplex assay, intracellular cytokines and signaling molecules were measured by flow cytometry, and mRNA levels were measured by quantitative reverse transcription-PCR. PTX inhibited concentration-dependent E. coli-, S. aureus-, S. epidermidis-, and C. albicans-induced tumor necrosis factor (TNF) and E. coli-induced interleukin-1β (IL-1β) production in whole blood, with greater suppression of proinflammatory cytokines in combination with antimicrobial agents. Likewise, PTX suppressed E. coli-induced monocytic TNF and IL-1β, whereby combined PTX and gentamicin led to significantly greater reduction of TNF and IL-1β. The anti-inflammatory effect of PTX on microbe-induced proinflammatory cytokine production was accompanied by inhibition of TNF mRNA expression and was achieved without suppressing the production of the anti-inflammatory IL-10. Of note, microbial colony counts in newborn blood were not increased by PTX. Our findings demonstrated that PTX inhibited microbe-induced proinflammatory cytokine production, especially when combined with antimicrobial agents, without enhancing microbial proliferation in human cord blood in vitro, thus supporting its utility as candidate adjunctive agent for newborn sepsis.
Collapse
Affiliation(s)
- Esther M Speer
- Department of Pediatrics, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Elizabeth Diago-Navarro
- Division of Infectious Diseases, Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Lukasz S Ozog
- Department of Pediatrics, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - David J Dowling
- Precision Vaccine Program, Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Wei Hou
- Family, Population, and Preventive Medicine Department, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Mahnoor Raheel
- Department of Pediatrics, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Bettina C Fries
- Division of Infectious Diseases, Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Ofer Levy
- Precision Vaccine Program, Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| |
Collapse
|
17
|
Cellular metabolism constrains innate immune responses in early human ontogeny. Nat Commun 2018; 9:4822. [PMID: 30446641 PMCID: PMC6240060 DOI: 10.1038/s41467-018-07215-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 10/16/2018] [Indexed: 02/07/2023] Open
Abstract
Pathogen immune responses are profoundly attenuated in fetuses and premature infants, yet the mechanisms underlying this developmental immaturity remain unclear. Here we show transcriptomic, metabolic and polysome profiling and find that monocytes isolated from infants born early in gestation display perturbations in PPAR-γ-regulated metabolic pathways, limited glycolytic capacity and reduced ribosomal activity. These metabolic changes are linked to a lack of translation of most cytokines and of MALT1 signalosome genes essential to respond to the neonatal pathogen Candida. In contrast, they have little impact on house-keeping phagocytosis functions. Transcriptome analyses further indicate a role for mTOR and its putative negative regulator DNA Damage Inducible Transcript 4-Like in regulating these metabolic constraints. Our results provide a molecular basis for the broad susceptibility to multiple pathogens in these infants, and suggest that the fetal immune system is metabolically programmed to avoid energetically costly, dispensable and potentially harmful immune responses during ontogeny. Little is known about developmental set points of immune responses, especially in humans. Here the authors show that the metabolic state of monocytes isolated from prematurely born infants underlies attenuated responsiveness to fungal infection via selective control of protein translation.
Collapse
|
18
|
Dong Y, Speer CP, Glaser K. Beyond sepsis: Staphylococcus epidermidis is an underestimated but significant contributor to neonatal morbidity. Virulence 2018; 9:621-633. [PMID: 29405832 PMCID: PMC5955464 DOI: 10.1080/21505594.2017.1419117] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus epidermidis accounts for the majority of cases of neonatal sepsis. Moreover, it has been demonstrated to be associated with neonatal morbidities, such as bronchopulmonary dysplasia (BPD), white matter injury (WMI), necrotizing enterocolitis (NEC) and retinopathy of prematurity (ROP), which affect short-term and long-term neonatal outcome. Imbalanced inflammation has been considered to be a major underlying mechanism of each entity. Conventionally regarded as a harmless commensal on human skin, S. epidermidis has received less attention than its more virulent relative Staphylococcus aureus. Particularities of neonatal innate immunity and nosocomial environmental factors, however, may contribute to the emergence of S. epidermidis as a significant nosocomial pathogen. Neonatal host response to S. epidermidis sepsis has not been fully elucidated. Evidence is emerging regarding the implication of S. epidermidis sepsis in the pathogenesis of neonatal inflammatory diseases. This review focuses on the interplay among S. epidermidis, neonatal innate immunity and inflammation-driven organ injury.
Collapse
Affiliation(s)
- Ying Dong
- a University Children's Hospital , University of Wuerzburg , Wuerzburg , Germany.,b Department of Neonatology , Children's Hospital of Fudan University , Shanghai , China
| | - Christian P Speer
- a University Children's Hospital , University of Wuerzburg , Wuerzburg , Germany
| | - Kirsten Glaser
- a University Children's Hospital , University of Wuerzburg , Wuerzburg , Germany
| |
Collapse
|
19
|
de Jong E, Hancock DG, Wells C, Richmond P, Simmer K, Burgner D, Strunk T, Currie AJ. Exposure to chorioamnionitis alters the monocyte transcriptional response to the neonatal pathogen Staphylococcus epidermidis. Immunol Cell Biol 2018. [PMID: 29533486 DOI: 10.1111/imcb.12037] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Preterm infants are uniquely susceptible to late-onset sepsis that is frequently caused by the skin commensal Staphylococcus epidermidis. Innate immune responses, particularly from monocytes, are a key protective mechanism. Impaired cytokine production by preterm infant monocytes is well described, but few studies have comprehensively assessed the corresponding monocyte transcriptional response. Innate immune responses in preterm infants may be modulated by inflammation such as prenatal exposure to histologic chorioamnionitis which complicates 40-70% of preterm pregnancies. Chorioamnionitis alters the risk of late-onset sepsis, but its effect on monocyte function is largely unknown. Here, we aimed to determine the impact of exposure to chorioamnionitis on the proportions and phenotype of cord blood monocytes using flow cytometry, as well as their transcriptional response to live S. epidermidis. RNA-seq was performed on purified cord blood monocytes from very preterm infants (<32 weeks gestation, with and without chorioamnionitis-exposure) and term infants (37-40 weeks), pre- and postchallenge with live S. epidermidis. Preterm monocytes from infants without chorioamnionitis-exposure did not exhibit an intrinsically deficient transcriptional response to S. epidermidis compared to term infants. In contrast, chorioamnionitis-exposure was associated with hypo-responsive transcriptional phenotype regarding a subset of genes involved in antigen presentation and adaptive immunity. Overall, our findings suggest that prenatal exposure to inflammation may alter the risk of sepsis in preterm infants partly by modulation of monocyte responses to pathogens.
Collapse
Affiliation(s)
- Emma de Jong
- Medical & Molecular Sciences, School of Veterinary & Life Sciences, Murdoch University, Perth, Australia
| | - David G Hancock
- School of Medicine, Flinders University, Adelaide, Australia
| | - Christine Wells
- Centre for Stem Cell Systems, Department of Anatomy and Neuroscience, MDHS, University of Melbourne, Melbourne, Australia.,The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Peter Richmond
- Centre for Neonatal Research& Education and Division of Paediatrics, University of Western Australia, Perth, Australia
| | - Karen Simmer
- Centre for Neonatal Research& Education and Division of Paediatrics, University of Western Australia, Perth, Australia
| | - David Burgner
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia.,Department of Paediatrics, University of Melbourne, Melbourne, Australia.,Department of Paediatrics, Monash University, Melbourne, Australia
| | - Tobias Strunk
- Centre for Neonatal Research& Education and Division of Paediatrics, University of Western Australia, Perth, Australia.,Neonatal Directorate, King Edward Memorial and Princess Margaret Hospitals, Perth, Australia
| | - Andrew J Currie
- Medical & Molecular Sciences, School of Veterinary & Life Sciences, Murdoch University, Perth, Australia.,Centre for Neonatal Research& Education and Division of Paediatrics, University of Western Australia, Perth, Australia
| |
Collapse
|
20
|
Infectious Agents as Stimuli of Trained Innate Immunity. Int J Mol Sci 2018; 19:ijms19020456. [PMID: 29401667 PMCID: PMC5855678 DOI: 10.3390/ijms19020456] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/26/2018] [Accepted: 02/02/2018] [Indexed: 12/13/2022] Open
Abstract
The discoveries made over the past few years have modified the current immunological paradigm. It turns out that innate immunity cells can mount some kind of immunological memory, similar to that observed in the acquired immunity and corresponding to the defense mechanisms of lower organisms, which increases their resistance to reinfection. This phenomenon is termed trained innate immunity. It is based on epigenetic changes in innate immune cells (monocytes/macrophages, NK cells) after their stimulation with various infectious or non-infectious agents. Many infectious stimuli, including bacterial or fungal cells and their components (LPS, β-glucan, chitin) as well as viruses or even parasites are considered potent inducers of innate immune memory. Epigenetic cell reprogramming occurring at the heart of the phenomenon may provide a useful basis for designing novel prophylactic and therapeutic strategies to prevent and protect against multiple diseases. In this article, we present the current state of art on trained innate immunity occurring as a result of infectious agent induction. Additionally, we discuss the mechanisms of cell reprogramming and the implications for immune response stimulation/manipulation.
Collapse
|
21
|
Zasada M, Lenart M, Rutkowska-Zapała M, Stec M, Czyz O, Mól N, Siedlar M, Kwinta P. Inflammasome function in monocyte subsets and a risk of late-onset sepsis in preterm very low birth weight neonates. Minerva Pediatr (Torino) 2018; 74:121-131. [PMID: 29381011 DOI: 10.23736/s2724-5276.18.05034-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Immature immune systems predispose very low birth weight (VLBW) neonates to systemic infections in early life. Defective inflammasome function may increase a neonate's susceptibility to late-onset sepsis (LOS). METHODS Blood samples were taken on the 5th day of life (DOL) for all VLBW neonates (non-LOS and before-LOS groups; N.=76), and within 24 hours of sepsis onset (LOS group; N.=39). Monocyte (MO) subsets and intracellular interleukin-1β (IL-1β) expression were analyzed using flow cytometry. Inflammasome function, defined as level of IL-1β and interleukin-18 (IL-18) was measured with enzyme-linked immunosorbent assay. IRA B cells were reported as a fraction of all B cells. RESULTS Stimulation of classical MO in non-LOS cells demonstrated a higher expression of intracellular IL-1β in comparison to MO from before LOS group. Serum from the LOS group revealed a higher level of IL-18. Stimulation of mononuclear cultures from samples taken during LOS resulted in significantly increased supernatant level of IL-1β and IL-18 in comparison to samples taken on 5th DOL. No changes in the levels of IRA B cells were detected with the onset of sepsis. CONCLUSIONS We did not observe a difference in the functioning of the inflammasome within monocytes taken on 5th DOL from premature VLBW neonates. Furthermore, there was no observable change in the IRA B cells of the septic and non-septic groups. The decreased expression of intracellular IL-1β within classical MO of the before-LOS group may be an independent risk factor for LOS development.
Collapse
Affiliation(s)
- Magdalena Zasada
- Department of Pediatrics, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland -
| | - Marzena Lenart
- Department of Clinical Immunology, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| | - Magdalena Rutkowska-Zapała
- Department of Clinical Immunology, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| | - Małgorzata Stec
- Department of Clinical Immunology, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| | - Ola Czyz
- Jagiellonian University, Krakow, Poland
| | - Nina Mól
- Department of Pediatrics, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| | - Maciej Siedlar
- Department of Clinical Immunology, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| | - Przemko Kwinta
- Department of Pediatrics, Institute of Pediatrics, Faculty of Medicine, Jagiellonian University, Krakow, Poland
| |
Collapse
|
22
|
Scheid A, Borriello F, Pietrasanta C, Christou H, Diray-Arce J, Pettengill MA, Joshi S, Li N, Bergelson I, Kollmann T, Dowling DJ, Levy O. Adjuvant Effect of Bacille Calmette-Guérin on Hepatitis B Vaccine Immunogenicity in the Preterm and Term Newborn. Front Immunol 2018; 9:29. [PMID: 29416539 PMCID: PMC5787546 DOI: 10.3389/fimmu.2018.00029] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 01/04/2018] [Indexed: 01/21/2023] Open
Abstract
Immunization is key to protecting term and preterm infants from a heightened risk of infection. However, preterm immunity is distinct from that of the term, limiting its ability to effectively respond to vaccines routinely given at birth, such as hepatitis B vaccine (HBV). As part of the Expanded Program on Immunization, HBV is often given together with the live-attenuated vaccine Bacille Calmette-Guérin (BCG), known to activate multiple pattern-recognition receptors. Of note, some clinical studies suggest BCG can enhance efficacy of other vaccines in term newborns. However, little is known about whether BCG can shape Th-polarizing cytokine responses to HBV nor the age-dependency of such effects, including whether they may extend to the preterm. To characterize the effects of BCG on HBV immunogenicity, we studied individual and combined administration of these vaccines to cord newborn and adult human whole blood and mononuclear cells in vitro and to neonatal and adult mice in vivo. Compared to either BCG or HBV alone, (BCG + HBV) synergistically enhanced in vitro whole blood production of IL-1β, while (BCG + HBV) also promoted production of several cytokines/chemokines in all age groups, age-specific enhancement included IL-12p70 in the preterm and GM-CSF in the preterm and term. In human mononuclear cells, (BCG + HBV) enhanced mRNA expression of several genes including CSF2, which contributed to clustering of genes by vaccine treatment via principle component analysis. To assess the impact of BCG on HBV immunization, mice of three different age groups were immunized subcutaneously with, BCG, HBV, (BCG + HBV) into the same site; or BCG and HBV injected into separate sites. Whether injected into a separate site or at the same site, co-administration of BCG with HBV significantly enhanced anti-HBV IgG titers in mice immunized on day of life-0 or -7, respectively, but not in adult mice. In summary, our data demonstrate that innate and adaptive vaccine responses of preterm and term newborns are immunologically distinct. Furthermore, BCG or "BCG-like" adjuvants should be further studied as a promising adjuvantation approach to enhance immunogenicity of vaccines to protect these vulnerable populations.
Collapse
Affiliation(s)
- Annette Scheid
- Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA, United States
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
| | - Francesco Borriello
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Department of Translational Medical Sciences, Center for Basic and Clinical Immunology Research (CISI), University of Naples Federico II, Naples, Italy
- WAO Center of Excellence, Naples, Italy
| | - Carlo Pietrasanta
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
| | - Helen Christou
- Department of Pediatric Newborn Medicine, Brigham and Women’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA, United States
| | - Joann Diray-Arce
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
| | - Matthew A. Pettengill
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
| | - Sweta Joshi
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Ning Li
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Medical Eli Lilly, Shanghai, China
| | - Ilana Bergelson
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Tobias Kollmann
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Department of Pediatrics, British Columbia Children’s Hospital, Vancouver, BC, Canada
| | - David J. Dowling
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Ofer Levy
- Department of Medicine, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Precision Vaccines Program, Division of Infectious Diseases, Boston Children’s Hospital, Boston, MA, United States
| |
Collapse
|
23
|
Identification of generic and pathogen-specific cord blood monocyte transcriptomes reveals a largely conserved response in preterm and term newborn infants. J Mol Med (Berl) 2017; 96:147-157. [PMID: 29134255 DOI: 10.1007/s00109-017-1609-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 12/20/2022]
Abstract
Escherichia coli and Staphylococcus epidermidis are predominant causes of neonatal sepsis, particularly affecting preterm infants. Susceptibility to infection has been attributed to "immature" innate monocyte defences, but no studies have assessed global transcriptional responses of neonatal monocytes to these pathogens. Here, we aimed to identify and characterise the neonatal monocyte transcriptional responses to E. coli and S. epidermidis and the role of common modifiers such as gestational age (GA) and exposure to chorioamnionitis (a common complication of preterm birth) to better understand early life innate immune responses. RNA-sequencing was performed on purified cord blood monocytes from very preterm (< 32 weeks GA) and term infants (37-40 weeks GA) following standardised challenge with live S. epidermidis or E. coli. The major transcriptional changes induced by either pathogen were highly conserved between infant groups and stimuli, highlighting a common extant neonatal monocyte response to infection, largely mediated by TLR/NF-κB/TREM-1 signalling. In addition, we observed an activated interferon-centred immune response specific to stimulation with E. coli in both preterm and term infants. These data provide novel insights into the functionality of neonatal monocytes at birth and highlight potential pathways that could be targeted to reduce the harmful effects of bacterial-induced inflammation in sepsis. E. coli and S. epidermidis elicit common transcriptional changes in cord monocytes. The common transcriptional response is mediated by TLR/NF-κB/TREM-1 signalling. IFN genes are differentially regulated by E. coli and S. epidermidis in monocytes. These responses are largely unaffected by GA or exposure to chorioamnionitis. KEY MESSAGES E. coli and S. epidermidis elicit common transcriptional changes in cord monocytes. The common transcriptional response is mediated by TLR/NF-κB/TREM-1 signalling. IFN-genes are differentially regulated by E. coli and S. epidermidis in monocytes. These responses are largely unaffected by GA or exposure to chorioamnionitis.
Collapse
|
24
|
Zasada M, Lenart M, Rutkowska-Zapała M, Stec M, Mól N, Czyz O, Siedlar M, Kwinta P. Analysis of selected aspects of inflammasome function in the monocytes from neonates born extremely and very prematurely. Immunobiology 2017; 223:18-24. [PMID: 29042061 DOI: 10.1016/j.imbio.2017.10.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Inflammasomes regulate activation of caspase-1, which cleaves and activates interleukin (IL)-1β and IL-18, the cytokines that trigger pro-inflammatory and antimicrobial responses. There is very little known about inflammasome function in the subsets of monocytes (MO) isolated from preterm neonates born extremely and very prematurely. METHODS A group of 76 very low birth weight patients without early-onset sepsis was divided into extremely preterm (<28 gestational week) or very preterm (28-32 gestational week) neonates. The first blood sample was collected on the 5th day of life (5th DOL) to analyse MO subsets as well as the intracellular IL-1β expression and supernatant concentration of IL-1β and IL-18. Secondary blood samples were collected within 24h of late-onset sepsis (LOS) development and analysed as above. RESULTS On the 5th DOL, the extremely preterm neonates were characterized by a significantly higher absolute count of MO, in particular in the classical and intermediate subsets, as compared to the very preterm group. The counts of the intermediate and non-classical MO subsets increased during LOS in all neonates. We did not observe significant differences in the intracellular IL-1β expression between the analysed groups. Furthermore, the levels of the analysed cytokines in the MO supernatants were comparable between the extremely and very preterm neonates on the 5th DOL. Finally, a higher level of IL-18 was observed in the supernatant of the extremely preterm group during LOS. CONCLUSIONS During LOS, extremely preterm neonates excrete a higher level of IL-18 cytokines compared to very preterm neonates. Further studies are required to determine whether this observation is a result of a higher count of the circulating MO or is a true reflection of increased inflammasome function in this particular group of newborns.
Collapse
Affiliation(s)
- Magdalena Zasada
- Department of Paediatrics, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland.
| | - Marzena Lenart
- Department of Clinical Immunology, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| | - Magdalena Rutkowska-Zapała
- Department of Clinical Immunology, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| | - Małgorzata Stec
- Department of Clinical Immunology, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| | - Nina Mól
- Department of Paediatrics, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| | - Ola Czyz
- Jagiellonian University Medical College, Krakow, Poland
| | - Maciej Siedlar
- Department of Clinical Immunology, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| | - Przemko Kwinta
- Department of Paediatrics, Institute of Paediatrics, Faculty of Medicine, Jagiellonian University Medical College, Wielicka 265, 30-663 Krakow, Poland
| |
Collapse
|
25
|
Sabaté Brescó M, Harris LG, Thompson K, Stanic B, Morgenstern M, O'Mahony L, Richards RG, Moriarty TF. Pathogenic Mechanisms and Host Interactions in Staphylococcus epidermidis Device-Related Infection. Front Microbiol 2017; 8:1401. [PMID: 28824556 PMCID: PMC5539136 DOI: 10.3389/fmicb.2017.01401] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/11/2017] [Indexed: 12/25/2022] Open
Abstract
Staphylococcus epidermidis is a permanent member of the normal human microbiota, commonly found on skin and mucous membranes. By adhering to tissue surface moieties of the host via specific adhesins, S. epidermidis is capable of establishing a lifelong commensal relationship with humans that begins early in life. In its role as a commensal organism, S. epidermidis is thought to provide benefits to human host, including out-competing more virulent pathogens. However, largely due to its capacity to form biofilm on implanted foreign bodies, S. epidermidis has emerged as an important opportunistic pathogen in patients receiving medical devices. S. epidermidis causes approximately 20% of all orthopedic device-related infections (ODRIs), increasing up to 50% in late-developing infections. Despite this prevalence, it remains underrepresented in the scientific literature, in particular lagging behind the study of the S. aureus. This review aims to provide an overview of the interactions of S. epidermidis with the human host, both as a commensal and as a pathogen. The mechanisms retained by S. epidermidis that enable colonization of human skin as well as invasive infection, will be described, with a particular focus upon biofilm formation. The host immune responses to these infections are also described, including how S. epidermidis seems to trigger low levels of pro-inflammatory cytokines and high levels of interleukin-10, which may contribute to the sub-acute and persistent nature often associated with these infections. The adaptive immune response to S. epidermidis remains poorly described, and represents an area which may provide significant new discoveries in the coming years.
Collapse
Affiliation(s)
- Marina Sabaté Brescó
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland.,Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - Llinos G Harris
- Microbiology and Infectious Diseases, Institute of Life Science, Swansea University Medical SchoolSwansea, United Kingdom
| | - Keith Thompson
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Barbara Stanic
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Mario Morgenstern
- Department of Orthopedic and Trauma Surgery, University Hospital BaselBasel, Switzerland
| | - Liam O'Mahony
- Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - R Geoff Richards
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - T Fintan Moriarty
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| |
Collapse
|
26
|
Jong E, Strunk T, Burgner D, Lavoie PM, Currie A. The phenotype and function of preterm infant monocytes: implications for susceptibility to infection. J Leukoc Biol 2017. [DOI: 10.1189/jlb.4ru0317-111r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Emma Jong
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Tobias Strunk
- School of Paediatrics and Child Health, University of Western Australia, Crawley, Australia
- Neonatal Clinical Care Unit, King Edward Memorial and Princess Margaret Hospitals, Subiaco, Australia
| | - David Burgner
- Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Australia
- Department of Paediatrics, Monash University, Clayton, Australia; and
| | - Pascal M. Lavoie
- Department of Paediatrics, University of British Columbia, Vancouver, Canada
| | - Andrew Currie
- School of Paediatrics and Child Health, University of Western Australia, Crawley, Australia
| |
Collapse
|
27
|
de Goede OM, Lavoie PM, Robinson WP. Cord blood hematopoietic cells from preterm infants display altered DNA methylation patterns. Clin Epigenetics 2017; 9:39. [PMID: 28428831 PMCID: PMC5397745 DOI: 10.1186/s13148-017-0339-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 04/08/2017] [Indexed: 12/18/2022] Open
Abstract
Background Premature infants are highly vulnerable to infection. This is partly attributable to the preterm immune system, which differs from that of the term neonate in cell composition and function. Multiple studies have found differential DNA methylation (DNAm) between preterm and term infants’ cord blood; however, interpretation of these studies is limited by the confounding factor of blood cell composition. This study evaluates the epigenetic impact of preterm birth in isolated hematopoietic cell populations, reducing the concern of cell composition differences. Methods Genome-wide DNAm was measured using the Illumina 450K array in T cells, monocytes, granulocytes, and nucleated red blood cells (nRBCs) isolated from cord blood of 5 term and 5 preterm (<31 weeks gestational age) newborns. DNAm of hematopoietic cells was compared globally across the 450K array and through site-specific linear modeling. Results Nucleated red blood cells (nRBCs) showed the most extensive changes in DNAm, with 9258 differentially methylated (DM) sites (FDR < 5%, |Δβ| > 0.10) discovered between preterm and term infants compared to the <1000 prematurity-DM sites identified in white blood cell populations. The direction of DNAm change with gestational age at these prematurity-DM sites followed known patterns of hematopoietic differentiation, suggesting that term hematopoietic cell populations are more epigenetically mature than their preterm counterparts. Consistent shifts in DNAm between preterm and term cells were observed at 25 CpG sites, with many of these sites located in genes involved in growth and proliferation, hematopoietic lineage commitment, and the cytoskeleton. DNAm in preterm and term hematopoietic cells conformed to previously identified DNAm signatures of fetal liver and bone marrow, respectively. Conclusions This study presents the first genome-wide mapping of epigenetic differences in hematopoietic cells across the late gestational period. DNAm differences in hematopoietic cells between term and <31 weeks were consistent with the hematopoietic origin of these cells during ontogeny, reflecting an important role of DNAm in their regulation. Due to the limited sample size and the high coincidence of prematurity and multiple births, the relationship between cause of preterm birth and DNAm could not be evaluated. These findings highlight gene regulatory mechanisms at both cell-specific and systemic levels that may be involved in fetal immune system maturation. Electronic supplementary material The online version of this article (doi:10.1186/s13148-017-0339-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Olivia M de Goede
- BC Children's Hospital Research Institute, Room 2082, 950W 28th Avenue, Vancouver, BC V5Z 4H4 Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| | - Pascal M Lavoie
- BC Children's Hospital Research Institute, Room 2082, 950W 28th Avenue, Vancouver, BC V5Z 4H4 Canada.,Department of Pediatrics, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| | - Wendy P Robinson
- BC Children's Hospital Research Institute, Room 2082, 950W 28th Avenue, Vancouver, BC V5Z 4H4 Canada.,Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| |
Collapse
|
28
|
Michalski C, Kan B, Lavoie PM. Antifungal Immunological Defenses in Newborns. Front Immunol 2017; 8:281. [PMID: 28360910 PMCID: PMC5350100 DOI: 10.3389/fimmu.2017.00281] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/28/2017] [Indexed: 12/28/2022] Open
Abstract
Newborns are prone to fungal infections, largely due to Candida species. The immunological basis for this vulnerability is not yet fully understood. However, useful insights can be gained from the knowledge of the maturation of immune pathways during ontogeny, particularly when placed in context with how rare genetic mutations in humans predispose to fungal diseases. In this article, we review these most current data on immune functions in human newborns, highlighting pathways most relevant to the response to Candida. While discussing these data, we propose a framework of why deficiencies in these pathways make newborns particularly vulnerable to this opportunistic pathogen.
Collapse
Affiliation(s)
- Christina Michalski
- British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Bernard Kan
- British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Pascal M Lavoie
- British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada; Department of Medicine, University of British Columbia, Vancouver, BC, Canada; Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
29
|
Bermick JR, Lambrecht NJ, denDekker AD, Kunkel SL, Lukacs NW, Hogaboam CM, Schaller MA. Neonatal monocytes exhibit a unique histone modification landscape. Clin Epigenetics 2016; 8:99. [PMID: 27660665 PMCID: PMC5028999 DOI: 10.1186/s13148-016-0265-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 09/08/2016] [Indexed: 12/17/2022] Open
Abstract
Background Neonates have dampened expression of pro-inflammatory cytokines and difficulty clearing pathogens. This makes them uniquely susceptible to infections, but the factors regulating neonatal-specific immune responses are poorly understood. Epigenetics, including histone modifications, can activate or silence gene transcription by modulating chromatin structure and stability without affecting the DNA sequence itself and are potentially modifiable. Histone modifications are known to regulate immune cell differentiation and function in adults but have not been well studied in neonates. Results To elucidate the role of histone modifications in neonatal immune function, we performed chromatin immunoprecipitation on mononuclear cells from 45 healthy neonates (gestational ages 23–40 weeks). As gestation approached term, there was increased activating H3K4me3 on the pro-inflammatory IL1B, IL6, IL12B, and TNF cytokine promoters (p < 0.01) with no change in repressive H3K27me3, suggesting that these promoters in preterm neonates are less open and accessible to transcription factors than in term neonates. Chromatin immunoprecipitation with massively parallel DNA sequencing (ChIP-seq) was then performed to establish the H3K4me3, H3K9me3, H3K27me3, H3K4me1, H3K27ac, and H3K36me3 landscapes in neonatal and adult CD14+ monocytes. As development progressed from neonate to adult, monocytes lost the poised enhancer mark H3K4me1 and gained the activating mark H3K4me3, without a change in additional histone modifications. This decreased H3K4me3 abundance at immunologically important neonatal monocyte gene promoters, including CCR2, CD300C, ILF2, IL1B, and TNF was associated with reduced gene expression. Conclusions These results provide evidence that neonatal immune cells exist in an epigenetic state that is distinctly different from adults and that this state contributes to neonatal-specific immune responses that leaves them particularly vulnerable to infections. Electronic supplementary material The online version of this article (doi:10.1186/s13148-016-0265-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jennifer R Bermick
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, University of Michigan Medical Center, 1540 E. Medical Center Drive, C.S. Mott Children's Hospital Room 8-621, Ann Arbor, MI 48109 USA
| | - Nathalie J Lambrecht
- Department of Pediatrics, Division of Neonatal-Perinatal Medicine, University of Michigan Medical Center, 1540 E. Medical Center Drive, C.S. Mott Children's Hospital Room 8-621, Ann Arbor, MI 48109 USA
| | - Aaron D denDekker
- Department of Pathology, University of Michigan Medical Center, Ann Arbor, MI 48109 USA
| | - Steven L Kunkel
- Department of Pathology, University of Michigan Medical Center, Ann Arbor, MI 48109 USA
| | - Nicholas W Lukacs
- Department of Pathology, University of Michigan Medical Center, Ann Arbor, MI 48109 USA
| | - Cory M Hogaboam
- Department of Medicine, Division of Pulmonary & Critical Care Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048 USA
| | - Matthew A Schaller
- Department of Pathology, University of Michigan Medical Center, Ann Arbor, MI 48109 USA
| |
Collapse
|
30
|
Kan B, Razzaghian HR, Lavoie PM. An Immunological Perspective on Neonatal Sepsis. Trends Mol Med 2016; 22:290-302. [PMID: 26993220 PMCID: PMC5104533 DOI: 10.1016/j.molmed.2016.02.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 02/08/2016] [Indexed: 02/07/2023]
Abstract
Despite concerted international efforts, mortality from neonatal infections remains unacceptably high in some areas of the world, particularly for premature infants. Recent developments in flow cytometry and next-generation sequencing technologies have led to major discoveries over the past few years, providing a more integrated understanding of the developing human immune system in the context of its microbial environment. We review these recent findings, focusing on how in human newborns incomplete maturation of the immune system before a full term of gestation impacts on their vulnerability to infection. We also discuss some of the clinical implications of this research in guiding the design of more-accurate age-adapted diagnostic and preventive strategies for neonatal sepsis.
Collapse
Affiliation(s)
- Bernard Kan
- Child and Family Research Institute, Vancouver, British Columbia, Canada; Experimental Medicine Program, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Hamid Reza Razzaghian
- Child and Family Research Institute, Vancouver, British Columbia, Canada; Experimental Medicine Program, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Pascal M Lavoie
- Child and Family Research Institute, Vancouver, British Columbia, Canada; Experimental Medicine Program, Department of Medicine, University of British Columbia, Vancouver, Canada; Department of Pediatrics, University of British Columbia, Vancouver, Canada.
| |
Collapse
|
31
|
Marchant EA, Kan B, Sharma AA, van Zanten A, Kollmann TR, Brant R, Lavoie PM. Attenuated innate immune defenses in very premature neonates during the neonatal period. Pediatr Res 2015; 78:492-7. [PMID: 26186294 PMCID: PMC5059157 DOI: 10.1038/pr.2015.132] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 04/28/2015] [Indexed: 12/15/2022]
Abstract
BACKGROUND Antimicrobial responses have been shown to be profoundly attenuated in very preterm neonates when examined on cord blood. However, we lack data on these responses at the time these neonates are most vulnerable to infections. METHODS Multiple cytokine responses to two prototypic Toll-like receptor (TLR) agonists: lipopolysaccharide (LPS) (TLR4) and R848 (TLR7/8) were prospectively measured in preterm neonates born ≤30 wk of gestation (n = 50) during the first 28 d of age using whole blood and single-cell multiparameter flow cytometry assays. Results were compared to term neonates (n = 30) and adult controls (n = 25). RESULTS In preterm neonates, LPS and R848 responses remained attenuated in both cord blood and in the first 28 d of age. These responses showed significant maturation over time after adjusting for gestational age and were confirmed in monocytes and dendritic cells on a per-cell basis. We detected no major contribution of chorioamnionitis, maternal antenatal corticosteroids or magnesium sulfate treatment, labor, or mode of delivery to the maturation of cytokine responses. CONCLUSION Innate immune antimicrobial defenses are profoundly attenuated developmentally in very preterm neonates during the neonatal period, suggesting that exogenous factors drive the sustained systemic inflammation that has been linked to increased morbidities in these infants.
Collapse
Affiliation(s)
- Elizabeth A. Marchant
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Bernard Kan
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Ashish A. Sharma
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Alice van Zanten
- Department of Pediatrics, University of British Columbia, Vancouver, Canada,Children’s & Women’s Health Centre of British Columbia, University of British Columbia, Vancouver, Canada
| | - Tobias R. Kollmann
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Medicine, University of British Columbia, Vancouver, Canada,Department of Pediatrics, University of British Columbia, Vancouver, Canada,Children’s & Women’s Health Centre of British Columbia, University of British Columbia, Vancouver, Canada
| | - Rollin Brant
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Statistics, University of British Columbia, Vancouver, Canada
| | - Pascal M. Lavoie
- Child & Family Research Institute, University of British Columbia, Vancouver, Canada,Department of Medicine, University of British Columbia, Vancouver, Canada,Department of Pediatrics, University of British Columbia, Vancouver, Canada,Children’s & Women’s Health Centre of British Columbia, University of British Columbia, Vancouver, Canada,Corresponding Author: Dr. Pascal Lavoie, Room A4-147, 4th Floor, Translational Research Building, Child & Family Research Institute, 950 West 28th Avenue, Vancouver, BC, V5Z 4H4; Tel: (604) 875-2135; fax: (604) 875-3106;
| |
Collapse
|
32
|
Abstract
Infection with influenza A virus is responsible for considerable morbidity and mortality in children worldwide. While it is apparent that adequate activation of the innate immune system is essential for pathogen clearance and host survival, an excessive inflammatory response to infection is detrimental to the young host. A review of the literature indicates that innate immune responses change throughout childhood. Whether these changes are genetically programmed or triggered by environmental cues is unknown. The objectives of this review are to summarize the role of innate immunity in influenza A virus infection in the young child and to highlight possible differences between children and adults that may make children more susceptible to severe influenza A infection. A better understanding of age-related differences in innate immune signaling will be essential to improve care for this high-risk population.
Collapse
Affiliation(s)
- Bria M. Coates
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois2Division of Critical Care Medicine, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, Illinois
| | - Kelly L. Staricha
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Kristin M. Wiese
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Karen M. Ridge
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois4Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois
| |
Collapse
|
33
|
Jin C, Londono I, Mallard C, Lodygensky GA. New means to assess neonatal inflammatory brain injury. J Neuroinflammation 2015; 12:180. [PMID: 26407958 PMCID: PMC4583178 DOI: 10.1186/s12974-015-0397-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/10/2015] [Indexed: 01/23/2023] Open
Abstract
Preterm infants are especially vulnerable to infection-induced white matter injury, associated with cerebral palsy, cognitive and psychomotor impairment, and other adverse neurological outcomes. The etiology of such lesions is complex and multifactorial. Furthermore, timing and length of exposure to infection also influence neurodevelopmental outcomes. Different mechanisms have been posited to mediate the observed brain injury including microglial activation followed by subsequent release of pro-inflammatory species, glutamate-induced excitotoxicity, and vulnerability of developing oligodendrocytes to cerebral insults. The prevalence of such neurological impairments requires an urgent need for early detection and effective neuroprotective strategies. Accordingly, noninvasive methods of monitoring disease progression and therapy effectiveness are essential. While diagnostic tools using biomarkers from bodily fluids may provide useful information regarding potential risks of developing neurological diseases, the use of magnetic resonance imaging/spectroscopy has emerged as a promising candidate for such purpose. Various pharmacological agents have demonstrated protective effects in the immature brain in animal models; however, few studies have progressed to clinical trials with promising results.
Collapse
Affiliation(s)
- Chen Jin
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
| | - Irene Londono
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
| | - Carina Mallard
- Perinatal Center, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 405 30, Gothenburg, Sweden.
| | - Gregory A Lodygensky
- Department of Pediatrics, Sainte-Justine Hospital and Research Center, Université de Montréal, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada. .,Montreal Heart Institute, 5000 Rue Bélanger, Montréal, Québec, Canada. .,Department of Neuroscience and Pharmacology, Université de Montréal, Montréal, Québec, Canada.
| |
Collapse
|
34
|
Factors influencing gastrointestinal tract and microbiota immune interaction in preterm infants. Pediatr Res 2015; 77:726-31. [PMID: 25760550 DOI: 10.1038/pr.2015.54] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 12/03/2014] [Indexed: 02/07/2023]
Abstract
The role of microbial colonization is indispensable for keeping a balanced immune response in life. However, the events that regulate the establishment of the microbiota, their timing, and the way in which they interact with the host are not yet fully understood. Factors such as gestational age, mode of delivery, environment, hygienic measures, and diet influence the establishment of microbiota in the perinatal period. Environmental microbes constitute the most important group of exogenous stimuli in this critical time frame. However, the settlement of a stable gut microbiota in preterm infants is delayed compared to term infants. Preterm infants have an immature gastrointestinal tract and immune system which predisposes to infectious morbidity. Neonatal microbial dynamics and alterations in early gut microbiota may precede and/or predispose to diseases such as necrotizing enterocolitis (NEC), late-onset sepsis or others. During this critical period, nutrition is the principal contributor for immunological and metabolic development, and microbiological programming. Breast milk is a known source of molecules that act synergistically to protect the gut barrier and enhance the maturation of the gut-related immune response. Host-microbe interactions in preterm infants and the protective role of diet focused on breast milk impact are beginning to be unveiled.
Collapse
|
35
|
Sharma AA, Jen R, Kan B, Sharma A, Marchant E, Tang A, Gadawski I, Senger C, Skoll A, Turvey SE, Sly LM, Côté HCF, Lavoie PM. Impaired NLRP3 inflammasome activity during fetal development regulates IL-1β production in human monocytes. Eur J Immunol 2014; 45:238-49. [PMID: 25311115 DOI: 10.1002/eji.201444707] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 09/04/2014] [Accepted: 10/08/2014] [Indexed: 02/06/2023]
Abstract
Interleukin-1β (IL-1β) production is impaired in cord blood monocytes. However, the mechanism underlying this developmental attenuation remains unclear. Here, we analyzed the extent of variability within the Toll-like receptor (TLR)/NLRP3 inflammasome pathways in human neonates. We show that immature low CD14 expressing/CD16(pos) monocytes predominate before 33 weeks of gestation, and that these cells lack production of the pro-IL-1β precursor protein upon LPS stimulation. In contrast, high levels of pro-IL-1β are produced within high CD14 expressing monocytes, although these cells are unable to secrete mature IL-1β. The lack of secreted IL-1β in these monocytes parallels a reduction of NLRP3 induction following TLR stimulation resulting in a lack of caspase-1 activity before 29 weeks of gestation, whereas expression of the apoptosis-associated speck-like protein containing a CARD and function of the P2×7 receptor are preserved. Our analyses also reveal a strong inhibitory effect of placental infection on LPS/ATP-induced caspase-1 activity in cord blood monocytes. Lastly, secretion of IL-1β in preterm neonates is restored to adult levels during the neonatal period, indicating rapid maturation of these responses after birth. Collectively, our data highlight important developmental mechanisms regulating IL-1β responses early in gestation, in part due to a downregulation of TLR-mediated NLRP3 expression. Such mechanisms may serve to limit potentially damaging inflammatory responses in a developing fetus.
Collapse
Affiliation(s)
- Ashish A Sharma
- Child & Family Research Institute, Vancouver, BC, Canada; Department of Experimental Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Winterberg T, Vieten G, Meier T, Yu Y, Busse M, Hennig C, Hansen G, Jacobs R, Ure BM, Kuebler JF. Distinct phenotypic features of neonatal murine macrophages. Eur J Immunol 2014; 45:214-24. [DOI: 10.1002/eji.201444468] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 08/29/2014] [Accepted: 10/13/2014] [Indexed: 01/18/2023]
Affiliation(s)
- Thomas Winterberg
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| | - Gertrud Vieten
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| | - Tatiana Meier
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| | - Yi Yu
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| | - Mandy Busse
- Department of Pediatric Pneumology; Hannover Medical School; Hannover Germany
| | - Christian Hennig
- Department of Pediatric Pneumology; Hannover Medical School; Hannover Germany
| | - Gesine Hansen
- Department of Pediatric Pneumology; Hannover Medical School; Hannover Germany
| | - Roland Jacobs
- Department of Clinical Immunology and Rheumatology; Hannover Medical School; Hannover Germany
| | - Benno M. Ure
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| | - Joachim F. Kuebler
- Department of Pediatric Surgery; Hannover Medical School; Hannover Germany
| |
Collapse
|
37
|
Strunk T, Inder T, Wang X, Burgner D, Mallard C, Levy O. Infection-induced inflammation and cerebral injury in preterm infants. THE LANCET. INFECTIOUS DISEASES 2014; 14:751-762. [PMID: 24877996 DOI: 10.1016/s1473-3099(14)70710-8] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Preterm birth and infectious diseases are the most common causes of neonatal and early childhood deaths worldwide. The rates of preterm birth have increased over recent decades and account for 11% of all births worldwide. Preterm infants are at significant risk of severe infection in early life and throughout childhood. Bacteraemia, inflammation, or both during the neonatal period in preterm infants is associated with adverse outcomes, including death, chronic lung disease, and neurodevelopmental impairment. Recent studies suggest that bacteraemia could trigger cerebral injury even without penetration of viable bacteria into the CNS. Here we review available evidence that supports the concept of a strong association between bacteraemia, inflammation, and cerebral injury in preterm infants, with an emphasis on the underlying biological mechanisms, clinical correlates, and translational opportunities.
Collapse
Affiliation(s)
- Tobias Strunk
- Centre for Neonatal Research and Education, School of Paediatrics and Child Health, The University of Western Australia, Perth, WA, Australia; Neonatal Clinical Care Unit, King Edward Memorial Hospital, Perth, WA, Australia.
| | - Terrie Inder
- Department of Pediatrics, Neurology and Radiology, Washington University, St Louis, USA
| | - Xiaoyang Wang
- Perinatal Center, Department of Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; Department of Pediatrics, The Third Affiliated Hospital of Zhengzhou University, Shangjie, Henan, China
| | - David Burgner
- Murdoch Childrens Research Institute, Royal Children's Hospital, Melbourne, VIC, Australia; Department of Paediatrics, University of Melbourne, Melbourne, VIC, Australia
| | - Carina Mallard
- Perinatal Center, Department of Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Ofer Levy
- Department of Medicine, Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| |
Collapse
|
38
|
Dowling DJ, Levy O. Ontogeny of early life immunity. Trends Immunol 2014; 35:299-310. [PMID: 24880460 DOI: 10.1016/j.it.2014.04.007] [Citation(s) in RCA: 257] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/29/2014] [Accepted: 04/30/2014] [Indexed: 12/18/2022]
Abstract
The human immune system comprises cellular and molecular components designed to coordinately prevent infection while avoiding potentially harmful inflammation and autoimmunity. Immunity varies with age, reflecting unique age-dependent challenges including fetal gestation, the neonatal phase, and infancy. Here, we review novel mechanistic insights into early life immunity, with an emphasis on emerging models of human immune ontogeny, which may inform age-specific translational development of novel anti-infectives, immunomodulators, and vaccines.
Collapse
Affiliation(s)
- David J Dowling
- Department of Medicine, Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA
| | - Ofer Levy
- Department of Medicine, Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
39
|
Granland C, Strunk T, Hibbert J, Prosser A, Simmer K, Burgner D, Richmond P, Currie AJ. NOD1 and NOD2 expression and function in very preterm infant mononuclear cells. Acta Paediatr 2014; 103:e212-8. [PMID: 24444388 DOI: 10.1111/apa.12559] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/16/2013] [Accepted: 01/14/2014] [Indexed: 12/29/2022]
Abstract
AIM To evaluate mononuclear cell expression and function of the cytosolic nucleotide-binding oligomerization domain-containing receptors, NOD1 and NOD2, in very preterm and full-term infants. METHODS NOD1 and NOD2 gene and protein expression in very preterm infants, term infants and healthy adult, cord and peripheral blood mononuclear cells (C/PBMC) were quantified using qPCR and flow cytometry. Cytokine responses of purified infant and adult monocytes to NOD1- and NOD2-specific agonists were assessed using a multiplex immunoassay (Bioplex). RESULTS NOD1 and NOD2 were expressed by a range of infant and adult mononuclear cell types, including T- and B cells, with highest expression in classical (CD14(++) CD16(-) ) and intermediate (CD14(++) CD16(+) ) monocytes. NOD1 and NOD2 expression levels by monocytes from very preterm infant were similar to those in term infants or adults. Monocyte production of TNFα, IL-6 and IL-1β induced by activation of NOD1 and NOD2 was similar between very preterm infants, term infants and adults. CONCLUSION Monocyte expression and function of NOD1 and NOD2 in very preterm infants are intact and comparable/equivalent to term infants and adults. Functional deficiencies in monocyte NOD signalling pathways are unlikely to contribute to the increased susceptibility to bacterial sepsis in preterm infants.
Collapse
Affiliation(s)
- Caitlyn Granland
- School of Veterinary and Life Sciences; Murdoch University; Perth WA Australia
| | - Tobias Strunk
- Centre for Neonatal Research and Education; University of Western Australia; Perth WA Australia
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
| | - Julie Hibbert
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
| | - Amy Prosser
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
| | - Karen Simmer
- Centre for Neonatal Research and Education; University of Western Australia; Perth WA Australia
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
| | - David Burgner
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
- Murdoch Childrens Research Institute; Royal Children's Hospital; Parkville Vic. Australia
| | - Peter Richmond
- School of Paediatrics and Child Health; University of Western Australia; Perth WA Australia
| | - Andrew J. Currie
- School of Veterinary and Life Sciences; Murdoch University; Perth WA Australia
- Centre for Neonatal Research and Education; University of Western Australia; Perth WA Australia
| |
Collapse
|
40
|
Sharma AA, Jen R, Brant R, Ladd M, Huang Q, Skoll A, Senger C, Turvey SE, Marr N, Lavoie PM. Hierarchical maturation of innate immune defences in very preterm neonates. Neonatology 2014; 106:1-9. [PMID: 24603545 PMCID: PMC4556450 DOI: 10.1159/000358550] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/13/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Preterm neonates are highly vulnerable to infection. OBJECTIVES To investigate the developmental contribution of prematurity, chorioamnionitis and antenatal corticosteroids (ANS) on the maturation of neonatal microbial pathogen recognition responses. METHODS Using standardized protocols, we assayed multiple inflammatory cytokine responses (IL-1β, IL-6, TNF-α and IL-12/23p40) to three prototypic Toll-like receptor (TLR) agonists, i.e. TLR4 (lipopolysaccharide), TLR5 (flagellin) and TLR7/8 (R848), and to the non-TLR retinoic acid-inducible gene I (RIG-I)-like receptor agonist, in cord blood mononuclear cells from neonates born before 33 weeks of gestation and at term. RESULTS TLR responses develop asynchronously in preterm neonates, whereby responses to TLR7/8 were more mature and were followed by the development of TLR4 responses, which were also heterogeneous. Responses to TLR5 were weakest and most immature. Maturity in TLR responses was not influenced by sex. Overall, we detected no significant contribution of ANS and chorioamnionitis to the developmental attenuation of either TLR or RIG-I responses. CONCLUSIONS The maturation of anti-microbial responses in neonates born early in gestation follows an asynchronous developmental hierarchy independently of an exposure to chorioamnionitis and ANS. Our data provide an immunological basis for the predominance of specific microbial infections in this age group.
Collapse
|
41
|
Innate immune memory: implications for development of pediatric immunomodulatory agents and adjuvanted vaccines. Pediatr Res 2014; 75:184-8. [PMID: 24352476 PMCID: PMC3973534 DOI: 10.1038/pr.2013.214] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 10/25/2013] [Indexed: 11/28/2022]
Abstract
Unique features of immunity early in life include a distinct immune system particularly reliant on innate immunity, with weak T helper (Th)1-polarizing immune responses, and impaired responses to certain vaccines leading to a heightened susceptibility to infection. To these important aspects, we now add an increasingly appreciated concept that the innate immune system displays epigenetic memory of an earlier infection or vaccination, a phenomenon that has been named "trained immunity." Exposure of neonatal leukocytes in vitro or neonatal animals or humans in vivo to specific innate immune stimuli results in an altered innate immune set point. Given the particular importance of innate immunity early in life, trained immunity to early life infection and/or immunization may play an important role in modulating both acute and chronic diseases.
Collapse
|
42
|
Phagocytosis of neonatal pathogens by peripheral blood neutrophils and monocytes from newborn preterm and term infants. Pediatr Res 2013; 74:503-10. [PMID: 23999070 DOI: 10.1038/pr.2013.145] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 03/27/2013] [Indexed: 11/08/2022]
Abstract
BACKGROUND Deficiencies in phagocytosis may contribute to the increased susceptibility of infants to early life infections. Data on phagocytosis of the major neonatal pathogens Staphylococcus epidermidis (SE), Staphylococcus aureus (SA), and Escherichia coli (EC) by preterm infant leukocytes are inconsistent. METHODS Cord and <24-h peripheral blood were collected from very preterm (<30.1 wks gestational age (GA)) and term (37-42 wks GA) infants. Monocyte and neutrophil phagocytosis of pHrodo-labeled SE, SA, and EC were analyzed using a small-volume flow cytometry assay, with simultaneous characterization of surface activation marker expression. RESULTS Preterm infants had lower proportions of monocytes and neutrophils capable of phagocytosis than term infants, but preterm infant phagocytes had higher phagocytic capacity. Phagocytosis was strongly correlated between cord and <24-h peripheral blood. Supplementation with exogenous complement significantly increased phagocytosis of EC but not of SE or SA. Monocyte human leukocyte antigen (HLA)-DR expression was lower in preterm infants but did not correlate with phagocytosis. CONCLUSION There is no defect in phagocytosis by monocytes and neutrophils from preterm compared with term infants, although preterm infants possess fewer phagocytes, possibly contributing to susceptibility to bacterial infection. Further investigation into the development of postnatal phagocytic competence is warranted.
Collapse
|
43
|
Neonatal host defense against Staphylococcal infections. Clin Dev Immunol 2013; 2013:826303. [PMID: 23935651 PMCID: PMC3722842 DOI: 10.1155/2013/826303] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 12/17/2022]
Abstract
Preterm infants are especially susceptible to late-onset sepsis that is often due to Gram-positive bacterial infections resulting in substantial morbidity and mortality. Herein, we will describe neonatal innate immunity to Staphylococcus spp. comparing differences between preterm and full-term newborns with adults. Newborn innate immunity is distinct demonstrating diminished skin integrity, impaired Th1-polarizing responses, low complement levels, and diminished expression of plasma antimicrobial proteins and peptides, especially in preterm newborns. Characterization of distinct aspects of the neonatal immune response is defining novel approaches to enhance host defense to prevent and/or treat staphylococcal infection in this vulnerable population.
Collapse
|
44
|
Neonatal sepsis due to coagulase-negative staphylococci. Clin Dev Immunol 2013; 2013:586076. [PMID: 23762094 PMCID: PMC3674645 DOI: 10.1155/2013/586076] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/27/2013] [Accepted: 04/27/2013] [Indexed: 02/06/2023]
Abstract
Neonates, especially those born prematurely, are at high risk of morbidity and mortality from sepsis. Multiple factors, including prematurity, invasive life-saving medical interventions, and immaturity of the innate immune system, put these infants at greater risk of developing infection. Although advanced neonatal care enables us to save even the most preterm neonates, the very interventions sustaining those who are hospitalized concurrently expose them to serious infections due to common nosocomial pathogens, particularly coagulase-negative staphylococci bacteria (CoNS). Moreover, the health burden from infection in these infants remains unacceptably high despite continuing efforts. In this paper, we review the epidemiology, immunological risk factors, diagnosis, prevention, treatment, and outcomes of neonatal infection due to the predominant neonatal pathogen CoNS.
Collapse
|
45
|
Abstract
Given the "inborn" nature of the innate immune system, it is surprising to find that innate immune function does in fact change with age. Similar patterns of distinct Toll-like-receptor-mediated immune responses come to light when one contrasts innate immune development at the beginning of life with that toward the end of life. Importantly, these developmental patterns of innate cytokine responses correlate with clinical patterns of susceptibility to disease: A heightened risk of suffering from excessive inflammation is often detected in prematurely born infants, disappears over the first few months of life, and reappears toward the end of life. In addition, risk periods for particular infections in early life reemerge in older adults. The near-mirror-image patterns that emerge in contrasts of early versus late innate immune ontogeny emphasize changes in host-environment interactions as the underlying molecular and teleologic drivers.
Collapse
|
46
|
Kronforst KD, Mancuso CJ, Pettengill M, Ninkovic J, Power Coombs MR, Stevens C, Otto M, Mallard C, Wang X, Goldmann D, Levy O. A neonatal model of intravenous Staphylococcus epidermidis infection in mice <24 h old enables characterization of early innate immune responses. PLoS One 2012; 7:e43897. [PMID: 22970147 PMCID: PMC3435332 DOI: 10.1371/journal.pone.0043897] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/30/2012] [Indexed: 11/28/2022] Open
Abstract
Staphylococcus epidermidis (SE) causes late onset sepsis and significant morbidity in catheterized preterm newborns. Animal models of SE infection are useful in characterizing disease mechanisms and are an important approach to developing improved diagnostics and therapeutics. Current murine models of neonatal bacterial infection employ intraperitoneal or subcutaneous routes at several days of age, and may, therefore, not accurately reflect distinct features of innate immune responses to bacteremia. In this study we developed, validated, and characterized a murine model of intravenous (IV) infection in neonatal mice <24 hours (h) old to describe the early innate immune response to SE. C57BL/6 mice <24 h old were injected IV with 106, 107, 108 colony-forming units (CFU) of SE 1457, a clinical isolate from a central catheter infection. A prospective injection scoring system was developed and validated, with only high quality injections analyzed. Newborn mice were euthanized between 2 and 48 h post-injection and spleen, liver, and blood collected to assess bacterial viability, gene expression, and cytokine production. High quality IV injections demonstrated inoculum-dependent infection of spleen, liver and blood. Within 2 h of injection, SE induced selective transcription of TLR2 and MyD88 in the liver, and increased systemic production of plasma IL-6 and TNF-α. Despite clearance of bacteremia and solid organ infection within 48 h, inoculum-dependent impairment in weight gain was noted. We conclude that a model of IV SE infection in neonatal mice <24 h old is feasible, demonstrating inoculum-dependent infection of solid organs and a pattern of bacteremia, rapid and selective innate immune activation, and impairment of weight gain typical of infected human neonates. This novel model can now be used to characterize immune ontogeny, evaluate infection biomarkers, and assess preventative and therapeutic modalities.
Collapse
Affiliation(s)
- Kenny D. Kronforst
- Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Christy J. Mancuso
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Matthew Pettengill
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jana Ninkovic
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | | | - Chad Stevens
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, Maryland, United States of America
| | - Carina Mallard
- Physiology, The University of Gothenburg, Gothenburg, Sweden
| | - Xiaoyang Wang
- Physiology, The University of Gothenburg, Gothenburg, Sweden
| | - Donald Goldmann
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ofer Levy
- Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts, United States of America
- Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
47
|
Sharma AA, Jen R, Butler A, Lavoie PM. The developing human preterm neonatal immune system: a case for more research in this area. Clin Immunol 2012; 145:61-8. [PMID: 22926079 DOI: 10.1016/j.clim.2012.08.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 08/07/2012] [Accepted: 08/08/2012] [Indexed: 12/23/2022]
Abstract
Neonates, particularly those born prematurely, are among the most vulnerable age group for morbidity and mortality due to infections. Immaturity of the innate immune system and a high need for invasive medical procedures in the context of a preterm birth make these infants highly susceptible to common neonatal pathogens. Preterm infants who survive may also suffer permanent disabilities due to organ damage resulting from either the infection itself or from the inflammatory response generated under an oxidative stress. Infections in preterm infants continue to pose important healthcare challenges. Yet, developmental maturation events in the innate immune system that underlie their excessively high vulnerability to infection remain largely understudied. In this review article, we identify pertinent knowledge gaps that must be filled in order to orient future translational research.
Collapse
|