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Dual inhibition of complement C5 and CD14 attenuates inflammation in a cord blood model. Pediatr Res 2023:10.1038/s41390-023-02489-2. [PMID: 36725909 DOI: 10.1038/s41390-023-02489-2] [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: 02/08/2022] [Revised: 12/20/2022] [Accepted: 01/13/2023] [Indexed: 02/03/2023]
Abstract
BACKGROUND Escherichia coli and Group B streptococci (GBS) are the main causes of neonatal early-onset sepsis (EOS). Despite antibiotic therapy, EOS is associated with high morbidity and mortality. Dual inhibition of complement C5 and the Toll-like receptor co-factor CD14 has in animal studies been a promising novel therapy for sepsis. METHODS Whole blood was collected from the umbilical cord after caesarean section (n = 30). Blood was anti-coagulated with lepirudin. C5 inhibitor (eculizumab) and anti-CD14 was added 8 min prior to, or 15 and 30 min after adding E. coli or GBS. Total bacterial incubation time was 120 min (n = 16) and 240 min (n = 14). Cytokines and the terminal complement complex (TCC) were measured using multiplex technology and ELISA. RESULTS Dual inhibition significantly attenuated TCC formation by 25-79% when adding inhibitors with up to 30 min delay in both E. coli- and GBS-induced inflammation. TNF, IL-6 and IL-8 plasma concentration were significantly reduced by 28-87% in E. coli-induced inflammation when adding inhibitors with up to 30 min delay. The dual inhibition did not significantly reduce TNF, IL-6 and IL-8 plasma concentration in GBS-induced inflammation. CONCLUSION Dual inhibition of C5 and CD14 holds promise as a potential future treatment for severe neonatal EOS. IMPACT Neonatal sepsis can cause severe host inflammation with high morbidity and mortality, but there are still no effective adjunctive immunologic interventions available. Adding CD14 and complement C5 inhibitors up to 30 min after incubation of E. coli or Group B streptococci in a human umbilical cord blood model significantly reduced complement activation and cytokine release. Dual inhibition of C5 and CD14 is a potential future therapy to modulate systemic inflammation in severe cases of neonatal sepsis.
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Szylberg Ł, Bodnar M, Lebioda A, Krepska P, Kowalewski A, Bręborowicz G, Marszałek A. Differences in the Expression of TLR-2, NOD2, and NF-κB in Placenta Between Twins. Arch Immunol Ther Exp (Warsz) 2018; 66:463-470. [PMID: 29796818 PMCID: PMC6245244 DOI: 10.1007/s00005-018-0514-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 05/08/2018] [Indexed: 12/12/2022]
Abstract
Dizygotic twins share the same type of genetic relationship as non-twin siblings. Whereas monozygotic (MZ) twins are considered to have identical genetic material, they still differ. There is a number of reasons for early MZ twin discordance, including differences in the in utero environment, stochasticity, genetic mosaicism, and epigenetic factors. During gestation, the efficient innate immune system is of utmost importance. Our study was based on immunohistochemical evaluation of the differences in innate immune protein expression (TLR-2, NOD2, and NF-κB) in the 95 placentas between twins. Our study revealed statistical significant differences between diamniotic–dichorionic and monoamniotic–dichorionic twins. Monoamniotic–monochorionic twins exhibited no significant differences in protein expressions. To identify epigenetic factors causing the differences between twins, we made a series of comparisons with clinical data. The study revealed more cases with infections, miscarriages, in vitro fertilization, and premature rupture of membranes within the group with higher differences level of NF-κB, NOD2 and TLR-2 between twins. In case of twin-to-twin transfusion syndrome, there were no significant differences in innate immune protein expressions between twins. These results show that dissimilar genetic material and separate in utero environment promote discordance in innate immune protein expressions between twins. Moreover, additional blood flow between twins may be favorable in life-threatening conditions ensuring similar microenvironment.
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Affiliation(s)
- Łukasz Szylberg
- Chair and Department of Clinical Pathomorphology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland. .,Chair and Department of Oncologic Pathology and Prophylactics, Greater Poland Cancer Center, Poznań University of Medical Sciences and Department of Oncologic Pathology, Poznan, Poland. .,Department of Pathomorphology, Military Clinical Hospital, Bydgoszcz, Poland.
| | - Magdalena Bodnar
- Chair and Department of Clinical Pathomorphology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Anna Lebioda
- Department and Clinic of Perinatology and Gynecology, Poznań University of Medical Sciences, Poznan, Poland
| | - Patrycja Krepska
- Department of Obstetrics and Gynecology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Adam Kowalewski
- Chair and Department of Clinical Pathomorphology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Bydgoszcz, Poland
| | - Grzegorz Bręborowicz
- Department and Clinic of Perinatology and Gynecology, Poznań University of Medical Sciences, Poznan, Poland
| | - Andrzej Marszałek
- Chair and Department of Oncologic Pathology and Prophylactics, Greater Poland Cancer Center, Poznań University of Medical Sciences and Department of Oncologic Pathology, Poznan, Poland
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3
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Upadhyay K, Park JE, Yoon TW, Halder P, Kim YI, Metcalfe V, Talati AJ, English BK, Yi AK. Group B Streptococci Induce Proinflammatory Responses via a Protein Kinase D1-Dependent Pathway. THE JOURNAL OF IMMUNOLOGY 2017; 198:4448-4457. [PMID: 28461572 DOI: 10.4049/jimmunol.1601089] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 04/02/2017] [Indexed: 12/31/2022]
Abstract
Group B streptococci (GBS) are one of the leading causes of life-threatening illness in neonates. Proinflammatory responses to GBS mediated through host innate immune receptors play a critical role in the disease manifestation. However, the mechanisms involved in proinflammatory responses against GBS, as well as the contribution of signaling modulators involved in host immune defense, have not been fully elucidated. In the present study, we investigated the role of protein kinase D (PKD)1 in the proinflammatory responses to GBS. We found that both live and antibiotic-killed GBS induce activation of PKD1 through a pathway that is dependent on the TLR signaling adaptor MyD88 and its downstream kinase IL-1R-associated kinase 1, but independent of TNFR-associated factor 6. Our studies using pharmacological PKD inhibitors and PKD1-knockdown macrophages revealed that PKD1 is indispensable for GBS-mediated activation of MAPKs and NF-κB and subsequent expression of proinflammatory mediators. Furthermore, systemic administration of a PKD inhibitor protects d-galactosamine-sensitized mice from shock-mediated death caused by antibiotic-killed GBS. These findings imply that PKD1 plays a critical regulatory role in GBS-induced proinflammatory reactions and sepsis, and inhibition of PKD1 activation together with antibiotic treatment in GBS-infected neonates could be an effective way to control GBS diseases.
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Affiliation(s)
- Kirtikumar Upadhyay
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Department of Obstetrics and Gynecology, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Jeoung-Eun Park
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163
| | - Tae Won Yoon
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Priyanka Halder
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Young-In Kim
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - Victoria Metcalfe
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
| | - Ajay J Talati
- Department of Pediatrics, The University of Tennessee Health Science Center, Memphis, TN 38163.,Department of Obstetrics and Gynecology, The University of Tennessee Health Science Center, Memphis, TN 38163.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, TN 38103
| | - B Keith English
- Department of Pediatrics and Human Development, Michigan State University, Lansing, MI 48912
| | - Ae-Kyung Yi
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163; and
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4
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Borghesi A, Stronati M, Fellay J. Neonatal Group B Streptococcal Disease in Otherwise Healthy Infants: Failure of Specific Neonatal Immune Responses. Front Immunol 2017; 8:215. [PMID: 28326082 PMCID: PMC5339282 DOI: 10.3389/fimmu.2017.00215] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/15/2017] [Indexed: 12/26/2022] Open
Abstract
Only a small proportion of newborn infants exposed to a pathogenic microorganism develop overt infection. Susceptibility to infection in preterm infants and infants with known comorbidities has a likely multifactorial origin and can be often attributed to the concurrence of iatrogenic factors, environmental determinants, underlying pathogenic processes, and probably genetic predisposition. Conversely, infection occurring in otherwise healthy full-term newborn infants is unexplained in most cases. Microbial virulence factors and the unique characteristics of the neonatal immune system only partially account for the interindividual variability in the neonatal immune responses to pathogens. We here suggest that neonatal infection occurring in otherwise healthy infants is caused by a failure of the specific protective immunity to the microorganism. To explain infection in term and preterm infants, we propose an extension of the previously proposed model of the genetic architecture of infectious diseases in humans. We then focus on group B streptococcus (GBS) disease, the best characterized neonatal infection, and outline the potential molecular mechanisms underlying the selective failure of the immune responses against GBS. In light of the recent discoveries of pathogen-specific primary immunodeficiencies and of the role of anticytokine autoantibodies in increasing susceptibility to specific infections, we hypothesize that GBS disease occurring in otherwise healthy infants could reflect an immunodeficiency caused either by rare genetic defects in the infant or by transmitted maternal neutralizing antibodies. These hypotheses are consistent with available epidemiological data, with clinical and epidemiological observations, and with the state of the art of neonatal physiology and disease. Studies should now be designed to comprehensively search for genetic or immunological factors involved in susceptibility to severe neonatal infections.
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Affiliation(s)
- Alessandro Borghesi
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Neonatal Intensive Care Unit, San Matteo Hospital, Pavia, Italy
| | - Mauro Stronati
- Neonatal Intensive Care Unit, San Matteo Hospital, Pavia, Italy
| | - Jacques Fellay
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
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5
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Santos-Sierra S, Golenbock DT, Henneke P. Toll-like receptor-dependent discrimination of streptococci. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519060120050601] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Streptococcus pneumoniae and Streptococcus agalactiae cause distinct infectious diseases in small children. Similarly, these bacteria elicit very different host-cell responses in vitro. Inactivated S. agalactiae by far exceeds S. pneumoniae in the activation of inflammatory cytokines and upstream signaling intermediates such as the MAP kinase JNK. The inflammatory response to both Streptococcus spp. is mediated by MyD88, an essential adapter protein of Toll-like receptors (TLRs), although the specific TLRs that are involved have not been fully resolved. Furthermore, during logarithmic growth, S. pneumoniae releases pneumolysin that interacts with TLR4 whereas S. agalactiae releases diacylated molecules that interact with TLR2/6. Interaction of these soluble bacterial products with their cognate TLRs is critical for limiting bacterial dissemination and and systemic inflammation in mice. This might be due, in part, to TLR-mediated apoptosis induced by these factors. In conclusion related streptococcal species induce specific events in TLR-mediated signal transduction. Comparative analysis of the host-cell response to these bacteria reveals molecules such as JNK as valuable targets for adjunctive sepsis therapy.
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Affiliation(s)
| | - Douglas T. Golenbock
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Philipp Henneke
- Division of Infectious Diseases, Children's Hospital, Freiburg, Germany, philipp.henneke@ uniklinik-freiburg.de
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6
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Tokarz SA, DeValk J, Luo W, Pattnaik BR, Schrodi SJ, Pillers DAM. Cell line donor genotype and its influence on experimental phenotype: Toll-like receptor SNPs and potential variability in innate immunity. Mol Genet Metab 2016; 118:147-152. [PMID: 27324283 DOI: 10.1016/j.ymgme.2016.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 04/21/2016] [Accepted: 04/21/2016] [Indexed: 11/28/2022]
Abstract
Cell lines are used to model a disease and provide valuable information regarding phenotype, mechanism, and response to novel therapies. Derived from individuals of diverse genetic backgrounds, the cell's genetic complement predicts the phenotype, and although some lines have been sequenced, little emphasis has been placed on genotyping. Toll-like receptors (TLRs) are essential in initiating the inflammatory cascade in response to infection. TLR single nucleotide polymorphism (SNP) alleles may predict an altered innate immune response: a SNP can affect TLR-dependent pathways and may alter experimental results. Thus, genotype variation may have far-reaching implications when using cell lines to model phenotypes. We recommend that cell lines be genotyped and cataloged in a fashion similar to that used for bacteria, with cumulative information being archived in an accessible central database to facilitate the understanding of SNP cell phenotypes reported in the literature.
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Affiliation(s)
- Sara A Tokarz
- Division of Neonatology & Newborn Nursery, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jessica DeValk
- Division of Neonatology & Newborn Nursery, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Wenxiang Luo
- Division of Neonatology & Newborn Nursery, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Bikash R Pattnaik
- Division of Neonatology & Newborn Nursery, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Steven J Schrodi
- Computation and Informatics in Biology and Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA; Center for Human Genetics, Marshfield Clinic Research Foundation, Marshfield, WI 54449, USA
| | - De-Ann M Pillers
- Division of Neonatology & Newborn Nursery, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA; J.F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI 53706, USA.
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7
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Yanai S, Tokuhara D, Tachibana D, Saito M, Sakashita Y, Shintaku H, Koyama M. Diabetic pregnancy activates the innate immune response through TLR5 or TLR1/2 on neonatal monocyte. J Reprod Immunol 2016; 117:17-23. [PMID: 27351455 DOI: 10.1016/j.jri.2016.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 05/09/2016] [Accepted: 06/20/2016] [Indexed: 11/28/2022]
Abstract
Diabetes mellitus (DM) during pregnancy causes congenital malformation, macrosomia, respiratory distress syndrome, and other abnormalities in neonates, but whether maternal DM affects the neonatal innate immune system is unknown. Therefore we aimed to reveal the influence of DM in pregnancy on the toll-like receptor (TLR)-mediated innate immune response in neonates. Cord blood was collected after full-term vaginal or cesarean delivery and classified into a DM group (n=8) and non-DM (control) group (n=7). Mononuclear cells were harvested from cord blood by using density gradient centrifugation, after which anti-CD14 magnetic beads were used to isolate monocytes from the mononuclear population. After monocytes were cultured with lipopolysaccharide (TLR4 ligand), flagellin (TLR5 ligand), Pam3CSK4 (TLR1/TLR2 ligand), zymosan (TLR2/TLR6 ligand), or macrophage-activating lipopeptide (TLR2/TLR6 ligand) for 12h, the cytokine levels (interleukin [IL]-8, IL-6, IL-1β, IL-10, tumor necrosis factor alpha and IL-12) in the culture supernatants were measured. Compared with the control group, the DM group had higher concentrations of IL-8 (P=0.01) and tumor necrosis factor alpha (P=0.02) after monocyte cultures were stimulated with Pam3CSK4 and higher concentrations of IL-8 (P=0.01) after flagellin treatment. In contrast, stimulation with lipopolysaccharide, zymosan, or macrophage-activating lipopeptide did not lead to any difference in cytokine profiles between the two groups. These data indicate that maternal DM induces excessive inflammatory activation in neonates via a TLR5- or TLR1/2-mediated innate immune response.
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Affiliation(s)
- Sakika Yanai
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
| | - Daisuke Tokuhara
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan.
| | - Daisuke Tachibana
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
| | - Mika Saito
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
| | - Yuko Sakashita
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
| | - Haruo Shintaku
- Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
| | - Masayasu Koyama
- Department of Obstetrics and Gynecology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abenoku, Osaka 545-8585, Japan
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Scholl J, Nasioudis D, Boester A, Speleotes M, Grunebaum A, Witkin SS. Group B streptococcus alters properties of vaginal epithelial cells in pregnant women. Am J Obstet Gynecol 2016; 214:383.e1-5. [PMID: 26928153 DOI: 10.1016/j.ajog.2015.12.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/18/2015] [Accepted: 12/29/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Group B streptococcus (GBS) infection in pregnancy is a major cause of maternal and neonatal morbidity. An understanding of the mechanisms responsible for GBS persistence in the genital tract, as well as recognition of host defenses employed to combat its presence, are crucial to our efforts to reduce maternal GBS colonization and prevent the acquisition of neonatal infections. However, alterations in vaginal immunity in response to GBS colonization in pregnant women remain incompletely defined. Whether GBS modulates autophagy, a major host defense mechanism and contributor to the control of intracellular microbial infections, also remains unclear. OBJECTIVE We sought to identify differences in the extent of autophagy as well as in the concentration of biomarkers previously shown to be involved in vaginal innate immunity between GBS-positive and GBS-negative pregnant women. STUDY DESIGN We performed a prospective cohort study of healthy pregnant women, who had vaginal secretions obtained at 35-37 weeks of gestation, just prior to the standard GBS rectovaginal sample collection. The contents of the swabs were released into tubes containing 1 mL of sterile phosphate-buffered saline. Samples were centrifuged, and supernatant and cell pellet fractions were collected and stored separately at -80°C until used for analysis. Epithelial cells were then lysed, and the extent of autophagy was determined by measuring the residual level of p62 remaining in the cytoplasm. p62 is a protein that is consumed during autophagy, and so its concentration detectable in the cytoplasm is inversely related to the extent of autophagy induction. The intracellular level of the inducible 70-kDa heat shock protein (hsp70), an inhibitor of autophagy, was also measured. The cell-free fraction was assayed for D- and L-lactic acid, neutrophil gelatinase-associated lipocalin, extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinase (MMP)-8, alpha amylase, hyaluronan, and total protein. Laboratory personnel were blinded to all clinical data. RESULTS There were 145 women included in the study, of which 45 (31%) were culture-positive for GBS. Vaginal cells from GBS-positive women had elevated intracellular levels of p62 (2.1 vs 0.7 pg/mL, P < .01) and hsp70 (16.9 vs 9.6 ng/mL, P = .03) as compared to GBS-negative women. The p62 and hsp70 levels were highly correlated in both groups of subjects (P < .01). In vaginal fluid, concentrations of neutrophil gelatinase-associated lipocalin (1.1 vs 0.7 ng/μg total protein, P = .01), MMP-8 (21.9 vs 11.1 pg/μg total protein, P = .01), and extracellular MMP inducer (8.8 vs 7.2 pg/μg total protein, P = .03) were highest in GBS-positive women. There were no differences in the concentrations of D- and L-lactic acid, alpha amylase, or hyaluronan between the 2 groups of women. CONCLUSION The inhibition of autophagy in vaginal epithelial cells by GBS-induced hsp70 production is associated with its persistence. Concurrently, alterations in components known to influence vaginal bacterial colonization or facilitate microbial passage to the upper genital tract also occur in relation to GBS carriage.
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9
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Group B Streptococcus Induces a Robust IFN-γ Response by CD4(+) T Cells in an In Vitro and In Vivo Model. J Immunol Res 2016; 2016:5290604. [PMID: 26989699 PMCID: PMC4771917 DOI: 10.1155/2016/5290604] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/06/2016] [Indexed: 11/17/2022] Open
Abstract
Group B Streptococcus (GBS) serotype III causes life-threatening infections. Cytokines have emerged as important players for the control of disease, particularly IFN-γ. Although potential sources of this cytokine have been proposed, no specific cell line has ever been described as a leading contributor. In this study, CD4+ T cell activation profiles in response to GBS were evaluated through in vivo, ex vivo, and in vitro approaches. Total splenocytes readily produce a type 1 proinflammatory response by releasing IFN-γ, TNF-α, and IL-6 and actively recruit T cells via chemokines like CXCL9, CXCL10, and CCL3. Responding CD4+ T cells differentiate into Th1 cells producing large amounts of IFN-γ, TNF-α, and IL-2. In vitro studies using dendritic cell and CD4+ T cell cocultures infected with wild-type GBS or a nonencapsulated mutant suggested that GBS capsular polysaccharide, one of the major bacterial virulence factors, differentially modulates surface expression of CD69 and IFN-γ production. Overall, CD4+ T cells are important producers of IFN-γ and might thus influence the course of GBS infection through the expression balance of this cytokine.
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10
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Li Y, Zhang S, Xu W, Guo X, Xu Q, Chen Y. A normal polymorphism site of TLR2 3′ untranslated region is related to rheumatic heart disease by up-regulating TLR2 expression. Ann Clin Biochem 2014; 52:470-5. [PMID: 25487598 DOI: 10.1177/0004563214564581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 11/17/2022]
Abstract
Background The worldwide incidence of rheumatic heart disease is at least 15.6 million cases and is responsible for around 233,000 deaths per year. The pathogenesis of rheumatic heart disease is complex and involves genetic factors that predispose a person to the development of autoimmune reactions. Although Arg753Gln polymorphism of the TLR2 gene was considered to be related to acute rheumatic fever susceptibility in child, two groups have identified that there were no relations between this Arg753Gln polymorphism and rheumatic heart disease susceptibility. Methods In this study, we scanned the full length 826 bp of 3′ untranslated region of TLR2 in a Chinese-Han population and found that the rare allele G of rs35514500 was highly related to rheumatic heart disease. Results Results of dual-luciferase assay indicated that this T->G variation weakens the interaction between miR-340 and TLR2 3′ untranslated region and up-regulated firefly luciferase expression. Further results about the patients’ serum cytokines concentration detection constructed a relationship between G allele of rs35514550 and up-regulated serum IL-6 and TNFα. Conclusions These findings may give insight into understanding of rheumatic heart disease development and create an opportunity to approach the diagnosis and treatment of rheumatic heart disease.
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Affiliation(s)
- Yanhua Li
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Shu Zhang
- Department of Respiration, Chinese PLA General Hospital, Beijing, China
| | - Wenhuan Xu
- Scientific Research Department, Medical Administrative Division, Chinese PLA General Hospital, Beijing, China
| | - Xinhong Guo
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Qiang Xu
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
| | - Yundai Chen
- Department of Cardiology, Chinese PLA General Hospital, Beijing, China
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11
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Lemire P, Roy D, Fittipaldi N, Okura M, Takamatsu D, Bergman E, Segura M. Implication of TLR- but not of NOD2-signaling pathways in dendritic cell activation by group B Streptococcus serotypes III and V. PLoS One 2014; 9:e113940. [PMID: 25436906 PMCID: PMC4250082 DOI: 10.1371/journal.pone.0113940] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/31/2014] [Indexed: 12/31/2022] Open
Abstract
Group B Streptococcus (GBS) is an important agent of life-threatening invasive infection. It has been previously shown that encapsulated type III GBS is easily internalized by dendritic cells (DCs), and that this internalization had an impact on cytokine production. The receptors underlying these processes are poorly characterized. Knowledge on the mechanisms used by type V GBS to activate DCs is minimal. In this work, we investigated the role of Toll-like receptor (TLR)/MyD88 signaling pathway, the particular involvement of TLR2, and that of the intracellular sensing receptor NOD2 in the activation of DCs by types III and V GBS. The role of capsular polysaccharide (CPS, one of the most important GBS virulence factors) in bacterial-DC interactions was evaluated using non-encapsulated mutants. Despite differences in the role of CPS between types III and V GBS in bacterial internalization and intracellular survival, no major differences were observed in their capacity to modulate release of cytokines by DC. For both serotypes, CPS had a minor role in this response. Production of cytokines by DCs was shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize GBS and become activated mostly through TLR signaling. Yet, GBS-infected TLR2-/- DCs only showed a partial reduction in the production of IL-6 and CXCL1 compared to control DCs. Surprisingly, CXCL10 release by type III or type V GBS-infected DCs was MyD88-independent. No differences in DC activation were observed between NOD2-/- and control DCs. These results demonstrate the involvement of various receptors and the complexity of the cytokine production pathways activated by GBS upon DC infection.
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Affiliation(s)
- Paul Lemire
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - David Roy
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - Nahuel Fittipaldi
- Public Health Ontario, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Masatoshi Okura
- Bacterial and Parasitic Diseases Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Daisuke Takamatsu
- Bacterial and Parasitic Diseases Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Eugenia Bergman
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
| | - Mariela Segura
- Laboratory of Immunology, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, Quebec, Canada
- * E-mail:
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The bacteriostatic protein lipocalin 2 is induced in the central nervous system of mice with west Nile virus encephalitis. J Virol 2013; 88:679-89. [PMID: 24173226 DOI: 10.1128/jvi.02094-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Lipocalin 2 (Lcn2) is a bacteriostatic factor produced during the innate immune response to bacterial infection. Whether Lcn2 has a function in viral infection is unknown. We investigated the regulation and function of Lcn2 in the central nervous system (CNS) of mice during West Nile virus (WNV) encephalitis. Lcn2 mRNA and protein were induced in the brain by day 5, and this induction increased further by day 7 postinfection but was delayed compared with the induction of the toll-like receptor 3 (TLR3) gene, retinoic acid-inducible gene 1 (RIG-I), and melanoma differentiation-associated protein 5 (MDA5) gene. The Lcn2 mRNA and protein were both found at high levels in the choroid plexus, vascular endothelium, macrophage/microglia, and astrocytes. However, some neuronal subsets contained Lcn2 protein but no detectable mRNA. In Lcn2 knockout (KO) mice, with the exception of CXC motif chemokine 5 (CXCL5), which was significantly more downregulated than in wild-type (WT) mice, expression levels of a number of other host response genes were similar in the two genotypes. The brain from Lcn2 and WT mice with WNV encephalitis contained similar numbers of infiltrating macrophages, granulocytes, and T cells. Lcn2 KO and WT mice had no significant difference in tissue viral loads or survival after infection with different doses of WNV. We conclude that Lcn2 gene expression is induced to high levels in a time-dependent fashion in a variety of cells and regions of the CNS of mice with WNV encephalitis. The function of Lcn2 in the host response to WNV infection remains largely unknown, but our data indicate that it is dispensable as an antiviral or immunoregulatory factor in WNV encephalitis.
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Eller K, Schroll A, Banas M, Kirsch AH, Huber JM, Nairz M, Skvortsov S, Weiss G, Rosenkranz AR, Theurl I. Lipocalin-2 expressed in innate immune cells is an endogenous inhibitor of inflammation in murine nephrotoxic serum nephritis. PLoS One 2013; 8:e67693. [PMID: 23861783 PMCID: PMC3701542 DOI: 10.1371/journal.pone.0067693] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/19/2013] [Indexed: 12/12/2022] Open
Abstract
Lipocalin-2 (Lcn-2) is involved in divergent processes such as acute kidney injury or bacterial host defence. Our study was designed to evaluate the functional role of Lcn-2 in nephrotoxic serum nephritis (NTS). Since Lcn-2 is expressed in tubular epithelial cells as well as in cells of innate immunity such as macrophages and polymorphonuclear neutrophils (PMN), we induced NTS in wild-type (WT), Lcn-2 knock-out (KO) mice and WT/Lcn-2 KO chimeras. Mice lacking Lcn-2 exhibited more glomerular damage with increased proteinuria and interstitial leukocyte accumulation compared to WT mice. Chimeras able to express Lcn-2 in macrophages and PMN but not in epithelial cells were found to develop NTS comparable to wild-type controls. In contrast, chimeras expressing Lcn-2 in tubular epithelial cells with no expression in innate immune cells developed increased NTS due to decreased concerted apoptosis but increased necrosis and formation of damage-associated molecular patterns (DAMPs) such as high-mobility group box 1 (HMGB-1) in the kidney. In vivo blockade of HMGB-1, a toll-like receptor (TLR)-2 agonist, significantly reduced inflammation and NTS in Lcn-2 knock-out mice. In parallel, TLR-2 signalling was found to drive Lcn-2 transcription in vitro. Taken together, Lcn-2 expressed in innate immune cells is protective in NTS by inducing concerted apoptosis and inhibiting the formation of HMGB-1 thereby limiting cytokine production via TLR-2 signalling. In parallel, TLR-2 dependent transcription of Lcn-2 is an endogenous inhibitor of inflammation in NTS.
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Affiliation(s)
- Kathrin Eller
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
- * E-mail: (KE); (IT)
| | - Andrea Schroll
- Clinical Immunology and Infectious Diseases, Department of Internal Medicine VI, Innsbruck Medical University, Innsbruck, Austria
| | - Miriam Banas
- Department of Nephrology, Internal Medicine II, University Hospital Regensburg, Regensburg, Germany
| | - Alexander H. Kirsch
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Julia M. Huber
- Laboratory for Molecular Cell Biology, Internal Medicine I, Innsbruck Medical University, Innsbruck, Austria
| | - Manfred Nairz
- Clinical Immunology and Infectious Diseases, Department of Internal Medicine VI, Innsbruck Medical University, Innsbruck, Austria
| | - Sergej Skvortsov
- Department of Therapeutic Radiology and Oncology, Innsbruck Medical University, Innsbruck, Austria
| | - Günter Weiss
- Clinical Immunology and Infectious Diseases, Department of Internal Medicine VI, Innsbruck Medical University, Innsbruck, Austria
| | - Alexander R. Rosenkranz
- Clinical Division of Nephrology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Igor Theurl
- Clinical Immunology and Infectious Diseases, Department of Internal Medicine VI, Innsbruck Medical University, Innsbruck, Austria
- * E-mail: (KE); (IT)
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Group B Streptococcus and Streptococcus suis capsular polysaccharides induce chemokine production by dendritic cells via Toll-like receptor 2- and MyD88-dependent and -independent pathways. Infect Immun 2013; 81:3106-18. [PMID: 23774593 DOI: 10.1128/iai.00113-13] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Streptococcus agalactiae (also known as group B Streptococcus [GBS]) and Streptococcus suis are encapsulated streptococci causing severe septicemia and meningitis. Bacterial capsular polysaccharides (CPSs) are poorly immunogenic, but anti-CPS antibodies are essential to the host defense against encapsulated bacteria. The mechanisms underlying anti-CPS antibody responses are not fully elucidated, but the biochemistry of CPSs, particularly the presence of sialic acid, may have an immunosuppressive effect. We investigated the ability of highly purified S. suis and GBS native (sialylated) CPSs to activate dendritic cells (DCs), which are crucial actors in the initiation of humoral immunity. The influence of CPS biochemistry was studied using CPSs extracted from different serotypes within these two streptococcal species, as well as desialylated CPSs. No interleukin-1β (IL-1β), IL-6, IL-12p70, tumor necrosis factor alpha (TNF-α), or IL-10 production was observed in S. suis or GBS CPS-stimulated DCs. Moreover, these CPSs exerted immunosuppressive effects on DC activation, as a diminution of gamma interferon (IFN-γ)-induced B cell-activating factor of the tumor necrosis factor family (BAFF) expression was observed in CPS-pretreated cells. However, S. suis and GBS CPSs induced significant production of CCL3, via partially Toll-like receptor 2 (TLR2)- and myeloid differentiation factor 88 (MyD88)-dependent pathways, and CCL2, via TLR-independent mechanisms. No major influence of CPS biochemistry was observed on the capacity to induce chemokine production by DCs, indicating that DCs respond to these CPSs in a patterned way rather than a structure-dedicated manner.
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Kumar GSS, Venugopal AK, Kashyap MK, Raju R, Marimuthu A, Palapetta SM, Subbanayya Y, Goel R, Chawla A, Dikshit JB, Tata P, Harsha HC, Maharudraiah J, Ramachandra YL, Satishchandra P, Prasad TSK, Pandey A, Mahadevan A, Shankar SK. Gene Expression Profiling of Tuberculous Meningitis Co-infected with HIV. JOURNAL OF PROTEOMICS & BIOINFORMATICS 2012; 5:235-244. [PMID: 27053842 PMCID: PMC4820295 DOI: 10.4172/jpb.1000243] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tuberculous meningitis (TBM) is a fatal form of Mycobacterium tuberculosis infection of the central nervous system (CNS). The similarities in the clinical and radiological findings in TBM cases with or without HIV make the diagnosis very challenging. Identification of genes, which are differentially expressed in brain tissues of HIV positive and HIV negative TBM patients, would enable better understanding of the molecular aspects of the infection and would also serve as an initial platform to evaluate potential biomarkers. Here, we report the identification of 796 differentially regulated genes in brain tissues of TBM patients co-infected with HIV using oligonucleotide DNA microarrays. We also performed immunohistochemical validation and confirmed the abundance of four gene products-glial fibrillary acidic protein (GFAP), serpin peptidase inhibitor, clade A member 3 (SERPINA3), thymidine phosphorylase (TYMP/ECGF1) and heat shock 70 kDa protein 8 (HSPA8). Our study paves the way for understanding the mechanism of TBM in HIV positive patients and for further validation of potential disease biomarkers.
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Affiliation(s)
- Ghantasala S. Sameer Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | - Abhilash K. Venugopal
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
- McKusick-Nathans Institute of Genetic Medicine; Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Manoj Kumar Kashyap
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Rajesh Raju
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Arivusudar Marimuthu
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Shyam Mohan Palapetta
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Centre of Excellence in Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
| | - Yashwanth Subbanayya
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Rajiv Gandhi University of Health Sciences, Bangalore 560041, India
| | - Renu Goel
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | - Ankit Chawla
- Armed Forces Medical College, Pune-411040, India
| | | | - Pramila Tata
- Strand Life Sciences, Bangalore 560024, Karnataka, India
| | - H. C. Harsha
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Jagadeesha Maharudraiah
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Y. L. Ramachandra
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | | | - T. S. Keshava Prasad
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Centre of Excellence in Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
- Manipal University, Madhav Nagar, Manipal 576104, India
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine; Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pathology and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Corresponding authors: Akhilesh Pandey, McKusick-Nathans Institute of Genetic Medicine, 733 N. Broadway, BRB 527, Johns Hopkins University, Baltimore, USA, Tel: 410-502-6662; Fax: 410-502-7544; , S. K. Shankar, Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India, Tel: 91-080-26995001/5002; Fax: 91-080-26564830;
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - S. K. Shankar
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Corresponding authors: Akhilesh Pandey, McKusick-Nathans Institute of Genetic Medicine, 733 N. Broadway, BRB 527, Johns Hopkins University, Baltimore, USA, Tel: 410-502-6662; Fax: 410-502-7544; , S. K. Shankar, Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India, Tel: 91-080-26995001/5002; Fax: 91-080-26564830;
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Genome-wide mapping of cystitis due to Streptococcus agalactiae and Escherichia coli in mice identifies a unique bladder transcriptome that signifies pathogen-specific antimicrobial defense against urinary tract infection. Infect Immun 2012; 80:3145-60. [PMID: 22733575 DOI: 10.1128/iai.00023-12] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The most common causes of urinary tract infections (UTIs) are Gram-negative pathogens such as Escherichia coli; however, Gram-positive organisms, including Streptococcus agalactiae, or group B streptococcus (GBS), also cause UTI. In GBS infection, UTI progresses to cystitis once the bacteria colonize the bladder, but the host responses triggered in the bladder immediately following infection are largely unknown. Here, we used genome-wide expression profiling to map the bladder transcriptome of GBS UTI in mice infected transurethrally with uropathogenic GBS that was cultured from a 35-year-old women with cystitis. RNA from bladders was applied to Affymetrix Gene-1.0ST microarrays; quantitative reverse transcriptase PCR (qRT-PCR) was used to analyze selected gene responses identified in array data sets. A surprisingly small significant-gene list of 172 genes was identified at 24 h; this compared to 2,507 genes identified in a side-by-side comparison with uropathogenic E. coli (UPEC). No genes exhibited significantly altered expression at 2 h in GBS-infected mice according to arrays despite high bladder bacterial loads at this early time point. The absence of a marked early host response to GBS juxtaposed with broad-based bladder responses activated by UPEC at 2 h. Bioinformatics analyses, including integrative system-level network mapping, revealed multiple activated biological pathways in the GBS bladder transcriptome that regulate leukocyte activation, inflammation, apoptosis, and cytokine-chemokine biosynthesis. These findings define a novel, minimalistic type of bladder host response triggered by GBS UTI, which comprises collective antimicrobial pathways that differ dramatically from those activated by UPEC. Overall, this study emphasizes the unique nature of bladder immune activation mechanisms triggered by distinct uropathogens.
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Lemire P, Houde M, Lecours MP, Fittipaldi N, Segura M. Role of capsular polysaccharide in Group B Streptococccus interactions with dendritic cells. Microbes Infect 2012; 14:1064-76. [PMID: 22683668 DOI: 10.1016/j.micinf.2012.05.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 05/19/2012] [Accepted: 05/29/2012] [Indexed: 12/19/2022]
Abstract
Group B Streptococcus (GBS) type III is an important agent of life-threatening invasive infections. Albeit the immune system plays a dual role in development and protection against disease, mechanisms leading to an efficient immune response against GBS remain obscure. Mouse bone marrow-derived dendritic cells (DCs) and primary spleen DCs were used to evaluate GBS capacity to modulate the functions of these important antigen-presenting cells. The role of capsular polysaccharide (CPS), one of the most important GBS virulence factors, in bacterial-DC interactions was evaluated by using a non-encapsulated mutant. Phagocytosis assays, confocal and electron microscopy showed that DCs efficiently internalize encapsulated GBS, but the latter possesses strong intracellular survival capacity. GBS devoid of CPS was internalized and killed at higher and faster rates than encapsulated GBS early after infection. Among several cytokines tested, GBS internalization was required for modulation of IL-12, IL-10 and CXCL10 pathways. In contrast, GBS induced DC expression of co-stimulatory molecules in a phagocytosis-independent manner. Finally, the production of pro-inflammatory and Th1 cytokines by GBS-stimulated DCs was differentially modulated by CPS expression, depending on DC origin. Our data suggest multiple mechanisms involved in GBS modulation of DC functions, which were selectively regulated by the presence of CPS.
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Affiliation(s)
- Paul Lemire
- Laboratory of Immunology, Université de Montréal, St-Hyacinthe, J2S 2M2 Québec, Canada
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18
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Segura M. Fisher scientific award lecture - the capsular polysaccharides of Group B Streptococcus and Streptococcus suis differently modulate bacterial interactions with dendritic cells. Can J Microbiol 2012; 58:249-60. [PMID: 22356626 DOI: 10.1139/w2012-003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Infections with encapsulated bacteria cause serious clinical problems. Besides being poorly immunogenic, the bacterial capsular polysaccharide (CPS) cloaks antigenic proteins, allowing bacterial evasion of the host immune system. Despite the clinical significance of bacterial CPS and its suggested role in the pathogenesis of the infection, the mechanisms underlying innate and, critically, adaptive immune responses to encapsulated bacteria have not been fully elucidated. As such, we became interested in studying the CPS of two similar, but unique, streptococcal species: Group B Streptococcus (GBS) and Streptococcus suis . Both streptococci are well encapsulated, some capsular types are more virulent than others, and they can cause severe meningitis and septicemia. For both pathogens, the CPS is considered the major virulence factor. Finally, these two streptococci are the sole Gram-positive bacteria possessing sialic acid in their capsules. GBS type III is a leading cause of neonatal invasive infections. Streptococcus suis type 2 is an important swine and emerging zoonotic pathogen in humans. We recently characterized the S. suis type 2 CPS. It shares common structural elements with GBS, but sialic acid is α2,6-linked to galactose rather than α2,3-linked. Differential sialic acid expression by pathogens might result in modulation of immune cell activation and, consequently, may affect the immuno-pathogenesis of these bacterial infections. Here, we review and compare the interactions of these two sialylated encapsulated bacteria with dendritic cells, known as the most potent antigen-presenting cells linking innate and adaptive immunity. We further address differences between dendritic cells and professional phagocytes, such as macrophages and neutrophils, in their interplay with these encapsulated pathogens. Elucidation of the molecular and cellular basis of the impact of CPS composition on bacterial interactions with immune cells is critical for mechanistic understanding of anti-CPS responses. Knowledge generated will help to advance the development of novel, more effective anti-CPS vaccines and improved immunotherapies.
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Affiliation(s)
- Mariela Segura
- Laboratory of Immunology, Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, 3200 rue Sicotte, St-Hyacinthe, QC J2S 2M2, Canada.
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Magnusson NE, Hornum M, Jørgensen KA, Hansen JM, Bistrup C, Feldt-Rasmussen B, Flyvbjerg A. Plasma neutrophil gelatinase associated lipocalin (NGAL) is associated with kidney function in uraemic patients before and after kidney transplantation. BMC Nephrol 2012; 13:8. [PMID: 22325322 PMCID: PMC3296621 DOI: 10.1186/1471-2369-13-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 02/10/2012] [Indexed: 12/11/2022] Open
Abstract
Background Neutrophil gelatinase associated lipocalin (NGAL) is a biomarker of kidney injury. We examined plasma levels of NGAL in a cohort of 57 kidney allograft recipients (Tx group, 39 ± 13 years), a uraemic group of 40 patients remaining on the waiting list (47 ± 11 years) and a control group of 14 healthy subjects matched for age, sex and body mass index (BMI). The kidney graft recipients were studied at baseline before transplantation and 3 and 12 months after transplantation and the uraemic group at baseline and after 12 months. Methods NGAL was measured using a validated in-house Time-Resolved Immuno-flourometric assay (TRIFMA). Repeated measurements differed by < 10% and mean values were used for statistical analyses. Spearman rank order correlation analysis and the Kruskal-Wallis non-parametric test were used to evaluate the association of NGAL concentrations with clinical parameters. Results Plasma NGAL levels before transplantation in the Tx and uraemic groups were significantly higher than in the healthy controls (1,251 μg/L, 1,478 μg/L vs. 163 μg/L, p < 0.0001). In the Tx group NGAL concentrations were associated with serum creatinine (R = 0.51, p < 0.0001), duration of end-stage renal failure (R = 0.41, p = 0.002) and leukocyte count (R = 0.29, p < 0.026). At 3 and 12 months plasma NGAL concentrations declined to 223 μg/L and 243 μg/L, respectively and were associated with homocysteine (R = 0.39, p = 0.0051 and R = 0.47, p = 0.0007). Conclusions Plasma NGAL is a novel marker of kidney function, which correlates to duration of end-stage renal failure (ESRD) and serum creatinine in uraemic patients awaiting kidney transplantation. Plasma NGAL is associated with homocysteine in transplanted patients. The prognostic value of these findings requires further studies.
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Affiliation(s)
- Nils E Magnusson
- The Medical Research Laboratories, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark.
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Wang Y. Small lipid-binding proteins in regulating endothelial and vascular functions: focusing on adipocyte fatty acid binding protein and lipocalin-2. Br J Pharmacol 2012; 165:603-21. [PMID: 21658023 PMCID: PMC3315034 DOI: 10.1111/j.1476-5381.2011.01528.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 05/26/2011] [Accepted: 05/31/2011] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Dysregulated production of adipokines from adipose tissue plays a critical role in the development of obesity-associated cardiovascular abnormalities. A group of adipokines, including adipocyte fatty acid binding protein (A-FABP) and lipocalin-2, possess specific lipid-binding activity and are up-regulated in obese human subjects and animal models. They act as lipid chaperones to promote lipotoxicity in endothelial cells and cause endothelial dysfunction under obese conditions. However, different small lipid-binding proteins modulate the development of vascular complications in distinctive manners, which are partly attributed to their specialized structural features and functionalities. By focusing on A-FABP and lipocalin-2, this review summarizes recent advances demonstrating the causative roles of these newly identified adipose tissue-derived lipid chaperones in obesity-related endothelial dysfunction and cardiovascular complications. The specific lipid-signalling mechanisms mediated by these two proteins are highlighted to support their specialized functions. In summary, A-FABP and lipocalin-2 represent potential therapeutic targets to design drugs for preventing vascular diseases associated with obesity. LINKED ARTICLES This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.
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Affiliation(s)
- Yu Wang
- Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong.
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21
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LIU YAN, NICULESCU-MIZIL ALEXANDRU, LOZANO AURÉLIE, LU YONG. TEMPORAL GRAPHICAL MODELS FOR CROSS-SPECIES GENE REGULATORY NETWORK DISCOVERY. J Bioinform Comput Biol 2011; 9:231-50. [DOI: 10.1142/s0219720011005525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 11/18/2022]
Abstract
Many genes and biological processes function in similar ways across different species. Cross-species gene expression analysis, as a powerful tool to characterize the dynamical properties of the cell, has found a number of applications, such as identifying a conserved core set of cell cycle genes. However, to the best of our knowledge, there is limited effort on developing appropriate techniques to capture the causality relations between genes from time-series microarray data across species. In this paper, we present hidden Markov random field regression with L1penalty to uncover the regulatory network structure for different species. The algorithm provides a framework for sharing information across species via hidden component graphs and is able to incorporate domain knowledge across species easily. We demonstrate our method on two synthetic datasets and apply it to discover causal graphs from innate immune response data.
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Affiliation(s)
- YAN LIU
- Computer Science Department, University of Southern California, 941 Bloom Walk SAL 300, Los Angeles, CA 90089, USA
| | | | - AURÉLIE LOZANO
- IBM T. J. Watson Research Center, Yorktown Heights, NY 10598, USA
| | - YONG LU
- Harvard Medical School, Harvard University, Boston, MA 02115, USA
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22
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Lumsden KR, Nelson AM, Dispenza MC, Gilliland KL, Cong Z, Zaenglein AL, Thiboutot DM. Isotretinoin increases skin-surface levels of neutrophil gelatinase-associated lipocalin in patients treated for severe acne. Br J Dermatol 2011; 165:302-10. [PMID: 21466536 DOI: 10.1111/j.1365-2133.2011.10362.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND A clear-cut need exists for safe and effective alternatives to the use of isotretinoin in severe acne. Lack of data regarding the specifics of isotretinoin's mechanism of action has hampered progress in this area. Recently, the protein neutrophil gelatinase-associated lipocalin (NGAL) has been identified as a mediator of the apoptotic effect of isotretinoin on sebocytes. OBJECTIVES To establish further the clinical relevance of NGAL and to elucidate the factors that induce NGAL expression in sebocytes. METHODS Methods were developed to isolate and quantify skin-surface levels of NGAL from normal subjects and patients with acne undergoing treatment with isotretinoin. RESULTS Patients with acne were found to have higher skin levels of NGAL compared with normal subjects. Studies in SEB-1 sebocytes indicate that NGAL expression is increased in response to Propionibacterium acnes and interleukin (IL)-1β. In patients, isotretinoin increases NGAL levels by 2·4-fold on the skin surface and this increase precedes decreases in sebum and P. acnes counts. CONCLUSIONS These data support the hypothesis that NGAL is an important mediator of the early effects of isotretinoin on the sebaceous glands and provide insights into the mechanisms that regulate NGAL expression in the skin.
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Affiliation(s)
- K R Lumsden
- The Jake Gittlen Cancer Research Foundation, Department of Dermatology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
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Lipocalin 2 regulation and its complex role in inflammation and cancer. Cytokine 2011; 56:435-41. [PMID: 21855366 DOI: 10.1016/j.cyto.2011.07.021] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 07/15/2011] [Accepted: 07/25/2011] [Indexed: 11/22/2022]
Abstract
Lipocalin 2 is a protein that has garnered a great deal of interest in multidisciplinary fields over the last two decades since its discovery. However, its exact function in metabolic processes remains to be completely characterized. More recently, it has come to light as a highly upregulated protein in the setting of injury and infection. This review focuses on lipocalin 2 regulation and its relationship to cytokine and endocrine signaling pathways.
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Gram-positive pathogenic bacteria induce a common early response in human monocytes. BMC Microbiol 2010; 10:275. [PMID: 21044323 PMCID: PMC2988769 DOI: 10.1186/1471-2180-10-275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 11/02/2010] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND We infected freshly isolated human peripheral monocytes with live bacteria of three clinically important gram-positive bacterial species, Staphylococcus aureus, Streptococcus pneumoniae and Listeria monocytogenes and studied the ensuing early transcriptional response using expression microarrays. Thus the observed response was unbiased by signals originating from other helper and effector cells of the host and was not limited to induction by solitary bacterial constituents. RESULTS Activation of monocytes was demonstrated by the upregulation of chemokine rather than interleukin genes except for the prominent expression of interleukin 23, marking it as the early lead cytokine. This activation was accompanied by cytoskeleton rearrangement signals and a general anti-oxidative stress and anti-apoptotic reaction. Remarkably, the expression profiles also provide evidence that monocytes participate in the regulation of angiogenesis and endothelial function in response to these pathogens. CONCLUSION Regardless of the invasion properties and survival mechanisms of the pathogens used, we found that the early response comprised of a consistent and common response. The common response was hallmarked by the upregulation of interleukin 23, a rather unexpected finding regarding Listeria infection, as this cytokine has been linked primarily to the control of extracellular bacterial dissemination.
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Lu Y, Rosenfeld R, Nau GJ, Bar-Joseph Z. Cross species expression analysis of innate immune response. J Comput Biol 2010; 17:253-68. [PMID: 20377444 DOI: 10.1089/cmb.2009.0147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The innate immune response is the first line of host defense against infections. This system employs a number of different types of cells, which in turn activate different sets of genes. Microarray studies of human and mouse cells infected with various pathogens identified hundreds of differentially expressed genes. However, combining these datasets to identify common and unique response patterns remained a challenge. We developed methods based on probabilistic graphical models to combine expression experiments across species, cells, and pathogens. Our method analyzes homologous genes in different species concurrently overcoming problems related to noise and orthology assignments. Using our method, we identified both core immune response genes and genes that are activated in macrophages in both human and mouse but not in dendritic cells, and vice versa. Our results shed light on immune response mechanisms and on the differences between various types of cells that are used to fight infecting bacteria. For supporting website, see www.cs.cmu.edu/-lyongu/pub/immune/.
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Affiliation(s)
- Yong Lu
- School of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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26
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No association of the TLR2 gene Arg753Gln polymorphism with rheumatic heart disease and Behçet’s disease. Clin Rheumatol 2009; 28:1385-8. [DOI: 10.1007/s10067-009-1252-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 07/19/2009] [Accepted: 08/05/2009] [Indexed: 01/07/2023]
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Wennekamp J, Henneke P. Induction and termination of inflammatory signaling in group B streptococcal sepsis. Immunol Rev 2009; 225:114-27. [PMID: 18837779 DOI: 10.1111/j.1600-065x.2008.00673.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
SUMMARY Group B streptococcus (GBS) is part of the normal genital and gastrointestinal flora in healthy humans. However, GBS is a major cause of sepsis and meningitis in newborn infants in the Western world and an important pathogen in many developing countries. The dissection of the host response to GBS may increase the general understanding of innate immunity in sepsis, because newborn infants lack a sufficient adaptive response. Inflammatory signal induction in macrophages by GBS seems largely preserved in newborn infants, as shown both in vitro and in vivo. The engagement of Toll-like receptor 2 (TLR2) by lipoproteins and a myeloid differentiation factor 88 (MyD88)--dependent pathway induced by GBS cell wall are both important in this context. TLR2 activation of microglia by GBS induces neuronal damage, which might account for the high morbidity of GBS meningitis. At the same time, TLR2 mediates activation-induced cell death (AICD), a process involved in the containment of inflammation. In newborn infants, AICD and anti-bacterial polymorphonuclear leukocyte activity appears to be compromised. Accordingly, neonatal aberrations in the pathogen-specific negative control of inflammatory signaling are likely to contribute to excessive inflammation and neurological sequelae in GBS sepsis and meningitis.
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Affiliation(s)
- Julia Wennekamp
- Centre for Pediatrics and Adolescent Medicine, University Medical Centre, Freiburg, Germany
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MyD88 expression by CNS-resident cells is pivotal for eliciting protective immunity in brain abscesses. ASN Neuro 2009; 1:AN20090004. [PMID: 19570030 PMCID: PMC2695586 DOI: 10.1042/an20090004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
MyD88 KO (knockout) mice are exquisitely sensitive to CNS (central nervous system) infection with Staphylococcus aureus, a common aetiological agent of brain abscess, exhibiting global defects in innate immunity and exacerbated tissue damage. However, since brain abscesses are typified by the involvement of both activated CNS-resident and infiltrating immune cells, in our previous studies it has been impossible to determine the relative contribution of MyD88-dependent signalling in the CNS compared with the peripheral immune cell compartments. In the present study we addressed this by examining the course of S. aureus infection in MyD88 bone marrow chimaera mice. Interestingly, chimaeras where MyD88 was present in the CNS, but not bone marrow-derived cells, mounted pro-inflammatory mediator expression profiles and neutrophil recruitment equivalent to or exceeding that detected in WT (wild-type) mice. These results implicate CNS MyD88 as essential in eliciting the initial wave of inflammation during the acute response to parenchymal infection. Microarray analysis of infected MyD88 KO compared with WT mice revealed a preponderance of differentially regulated genes involved in apoptotic pathways, suggesting that the extensive tissue damage characteristic of brain abscesses from MyD88 KO mice could result from dysregulated apoptosis. Collectively, the findings of the present study highlight a novel mechanism for CNS-resident cells in initiating a protective innate immune response in the infected brain and, in the absence of MyD88 in this compartment, immunity is compromised.
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Wang L, Cherayil BJ. Ironing out the wrinkles in host defense: interactions between iron homeostasis and innate immunity. J Innate Immun 2009; 1:455-64. [PMID: 20375603 DOI: 10.1159/000210016] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 01/16/2009] [Indexed: 12/15/2022] Open
Abstract
Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Recent advances in our understanding of the molecular regulation of iron metabolism have shed new light on how alterations in iron homeostasis both contribute to and influence innate immunity. In this article, we review what is currently known about the role of iron in the response to infection.
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Affiliation(s)
- Lijian Wang
- Mucosal Immunology Laboratory, Massachusetts General Hospital, Charlestown, MA, USA
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Abstract
Bacterial meningitis is still an important infectious disease with a high morbidity and mortality rate. Bacterial infection of the cerebrospinal fluid (CSF) space causes a powerful inflammatory reaction that is largely responsibly for meningitis-induced tissue damage and adverse outcome of the disease. In a landmark series of experiments in the mid-1980s, cell wall components including lipooligosaccharides and lipoteichoic acid were indicated to be the key bacterial elements that can trigger the host inflammatory response in the CSF. Ten years ago, the discovery of Toll-like receptor proteins (TLRs) that allow the detection of microbial components and initiate the host immune response opened up new horizons in research on the pathophysiology of meningitis. Cell culture approaches provided the first evidence for a crucial role of TLRs in sensing meningeal pathogens including Streptococcus pneumoniae, Neisseria meningitidis, Streptococcus agalactiae, and Listeria monocytogenes. Subsequently, studies in mice with single or combined deficiencies in TLRs demonstrated that TLR activation is a key event in meningeal inflammation and, even more interestingly, a pivotal factor for meningitis-associated tissue damage. A detailed understanding of the mechanisms of host-pathogen interactions in the CSF space may generate new opportunities for specific treatment strategies for bacterial meningitis.
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Nelson AM, Zhao W, Gilliland KL, Zaenglein AL, Liu W, Thiboutot DM. Neutrophil gelatinase-associated lipocalin mediates 13-cis retinoic acid-induced apoptosis of human sebaceous gland cells. J Clin Invest 2008; 118:1468-78. [PMID: 18317594 DOI: 10.1172/jci33869] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 01/16/2008] [Indexed: 01/13/2023] Open
Abstract
13-cis retinoic acid (13-cis RA; also known as isotretinoin) is the most potent agent available for treatment of acne. It is known that the drug induces apoptosis in cells cultured from human sebaceous glands, but its mechanism of action has not been determined. In this study, skin biopsies were taken from 7 patients with acne prior to and at 1 week of treatment with 13-cis RA. TUNEL staining confirmed that 13-cis RA induced apoptosis in sebaceous glands. Transcriptional profiling of patient skin and cultured human sebaceous gland cells (SEB-1 sebocytes) indicated that lipocalin 2 was among the genes most highly upregulated by 13-cis RA. Lipocalin 2 encodes neutrophil gelatinase-associated lipocalin (NGAL), which functions in innate immune defense and induces apoptosis of murine B lymphocytes. Increased immunolocalization of NGAL was noted in patients' sebaceous glands following treatment with 13-cis RA, and recombinant NGAL induced apoptosis in SEB-1 sebocytes. Furthermore, apoptosis in response to 13-cis RA was inhibited in the presence of siRNA to lipocalin 2. These data indicate that NGAL mediates the apoptotic effect of 13-cis RA and suggest that agents that selectively induce NGAL expression in sebaceous glands might represent therapeutic alternatives to the use of 13-cis RA to treat individuals with acne.
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Landrø L, Damås JK, Flo TH, Heggelund L, Ueland T, Tjønnfjord GE, Espevik T, Aukrust P, Frøland SS. Decreased serum lipocalin-2 levels in human immunodeficiency virus-infected patients: increase during highly active anti-retroviral therapy. Clin Exp Immunol 2008; 152:57-63. [PMID: 18241231 DOI: 10.1111/j.1365-2249.2008.03592.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Although neutrophil gelatinase-associated lipocalin (NGAL) may play a pivotal role in the innate immune response, there are currently no data on NGAL levels in human immunodeficiency virus (HIV)-infected patients. In this study we aimed to examine the regulation of NGAL in HIV infection. The regulation of NGAL in HIV infection was examined by different experimental approaches, including studies in peripheral blood and mononuclear cells (MNC) from bone marrow aspirates before and during highly active anti-retroviral therapy (HAART). We found that: before initiating HAART, HIV-infected patients (n = 37) had significantly decreased serum NGAL levels compared with healthy controls (n = 26); (ii) during HAART, there was a gradual and significant increase in NGAL concentrations reaching levels comparable to those in healthy controls after 12 months; (iii) this increase was seen primarily in virological responders to HAART (HIV RNA level <200 copies/ml after 24 months); (iv) phytohaemagglutinin-stimulated NGAL release in MNC cells from bone marrow aspirates was decreased in untreated HIV-infected patients compared with healthy controls, but increased after 26 weeks on HAART; and (v) there was a significant positive correlation between neutrophil counts and NGAL levels at all time-points during HAART. We have shown decreased NGAL levels in HIV-infected patients, potentially reflecting decreased number and function of neutrophils as well as impaired bone marrow myelopoiesis. These abnormalities were reversed by successful HAART. Our findings underscore further the involvement of neutrophils and innate immunity in HIV-related immunodeficiency.
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Affiliation(s)
- L Landrø
- Research Institute for Internal Medicine, Rikshospitalet-Radiumhospitalet Medical Center, Unviersity of Oslo, Oslo, Norway.
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Hoo RL, Yeung DC, Lam KS, Xu A. Inflammatory biomarkers associated with obesity and insulin resistance: a focus on lipocalin-2 and adipocyte fatty acid-binding protein. Expert Rev Endocrinol Metab 2008; 3:29-41. [PMID: 30743783 DOI: 10.1586/17446651.3.1.29] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Obesity is an important risk factor for a cluster of metabolic and cardiovascular diseases, including insulin resistance, Type 2 diabetes, nonalcoholic fatty liver disease and atherosclerosis. Systemic low-grade inflammation, characterized by elevated circulating concentrations of proinflammatory factors, has recently been proposed to be a key mediator that links obesity with its medical complications. Adipose tissue is now recognized as the major contributor to systemic inflammation associated with obesity. As obesity develops, adipose tissue is infiltrated with activated macrophages. The 'inflamed' adipose tissue secretes a large number of proinflammatory adipokines and/or cytokines, which can act either in an autocrine manner to perpetuate local inflammation or in an endocrine manner to induce insulin resistance and endothelial dysfunction. In this review, we summarize recent advances in several newly identified adipose tissue-derived inflammatory factors, with the focus on lipocalin-2 and adipocyte fatty acid-binding protein (A-FABP). Both lipocalin-2 and A-FABP possess lipid-binding properties and are important integrators of metabolic and inflammatory pathways. A growing body of evidence from experimental, epidemiological and genetic studies suggests that both lipocalin-2 and A-FABP represent a novel class of serum biomarkers for risk prediction and therapeutic intervention of obesity-related medical complications.
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Affiliation(s)
- Ruby Lc Hoo
- a University of Hong Kong, Department of Medicine and Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, L8-40, 21 Sassoon Road, Hong Kong, China.
| | - Dennis Cy Yeung
- b University of Hong Kong, Department of Medicine and Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, L8-40, 21 Sassoon Road, Hong Kong, China.
| | - Karen Sl Lam
- c University of Hong Kong, Department of Medicine and Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, L8-40, 21 Sassoon Road, Hong Kong, China.
| | - Aimin Xu
- d University of Hong Kong, Department of Medicine and Research Centre of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, L8-40, 21 Sassoon Road, Hong Kong, China.
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Aravalli RN, Peterson PK, Lokensgard JR. Toll-like Receptors in Defense and Damage of the Central Nervous System. J Neuroimmune Pharmacol 2007; 2:297-312. [DOI: 10.1007/s11481-007-9071-5] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Accepted: 03/01/2007] [Indexed: 12/13/2022]
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Rodríguez N, Mages J, Dietrich H, Wantia N, Wagner H, Lang R, Miethke T. MyD88-dependent changes in the pulmonary transcriptome after infection with Chlamydia pneumoniae. Physiol Genomics 2007; 30:134-45. [PMID: 17374847 DOI: 10.1152/physiolgenomics.00011.2007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chlamydia pneumoniae, an intracellular bacterium, causes pneumonia in humans and mice. Toll-like receptors and the key adaptor molecule myeloid differentiation factor-88 (MyD88) play a critical role in inducing immunity against this microorganism and are crucial for survival. To explore the influence of MyD88 on induction of immune responses in vivo on a genome-wide level, wildtype (WT) or MyD88(-/-) mice were infected with C. pneumoniae on anesthesia, and the pulmonary transcriptome was analyzed 3 days later by microarrays. We found that the infection caused pulmonary cellular infiltration in WT but not MyD88(-/-) mice. Furthermore, it induced the transcription of 360 genes and repressed 18 genes in WT mice. Of these, 221 genes were not or weakly induced in lungs of MyD88(-/-) mice. This cluster contains primarily genes encoding for chemokines and cytokines like MIP-1alpha, MIP-2, MIP-1gamma, MCP-1, TNF, and KC and other immune effector molecules like immunoresponsive gene-1 and TLR2. Arginase was highly induced after C. pneumoniae infection and was MyD88 dependent. Genes induced by interferons were abundant in a cluster of 102 genes that were only partially MyD88 dependent. Also, lcn2 (lipocalin-2) and timp1 were represented within this cluster. Interestingly, a set of 37 genes including sprr1a was induced more strongly in MyD88(-/-) mice, and most of them are involved in the regulation of cellular replication. In summary, ex vivo analysis of the pulmonary transcriptome on infection with C. pneumoniae demonstrated a major impact of MyD88 on inflammatory responses but not on interferon-type responses and identified MyD88-independent genes involved in cellular replication.
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Affiliation(s)
- Nuria Rodríguez
- Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Munich, Germany
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Hossain H, Tchatalbachev S, Chakraborty T. Host gene expression profiling in pathogen–host interactions. Curr Opin Immunol 2006; 18:422-9. [PMID: 16782318 DOI: 10.1016/j.coi.2006.05.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 05/31/2006] [Indexed: 01/16/2023]
Abstract
Microarray technology is a powerful high-throughput tool for the analysis of host-pathogen interactions that permits simultaneous interrogation of the transcriptional status of thousands of genes. Emerging topics from microarray-based studies employing diverse pathogens and cell types suggest an initial common host response largely characterised by features of the innate immune response. However, specific host gene expression patterns that reflect differences between bacteria of related genera, different species of a particular genus, as well as strains within a single species can also be discerned. These differences are indicative of virulence determinant functions and suggest adaptive survival strategies. These studies have led to a more comprehensive understanding of the host response and identified new avenues of research for potential control strategies against pathogens.
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Affiliation(s)
- Hamid Hossain
- Institute for Medical Microbiology, Giessen, Germany
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37
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Ong ST, Ho JZS, Ho B, Ding JL. Iron-withholding strategy in innate immunity. Immunobiology 2006; 211:295-314. [PMID: 16697921 DOI: 10.1016/j.imbio.2006.02.004] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Accepted: 02/14/2006] [Indexed: 10/24/2022]
Abstract
The knowledge of how organisms fight infections has largely been built upon the ability of host innate immune molecules to recognize microbial determinants. Although of overwhelming importance, pathogen recognition is but only one of the facets of innate immunity. A primitive yet effective antimicrobial mechanism which operates by depriving microbial organisms of their nutrients has been brought into the forefront of innate immunity once again. Such a tactic is commonly referred to as the iron-withholding strategy of innate immunity. In this review, we introduce various vertebrate iron-binding proteins and their invertebrate homologues, so as to impress upon readers an obscured arm of innate immune defense. An excellent comprehension of the mechanics of innate immunity paves the way for the possibility that novel antimicrobial therapeutics may emerge one day to overcome the prevalent antibiotic resistance in bacteria.
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Affiliation(s)
- Sek Tong Ong
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
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