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Sanford TC, Tweten RK, Abrahamsen HL. Bacterial cholesterol-dependent cytolysins and their interaction with the human immune response. Curr Opin Infect Dis 2024; 37:164-169. [PMID: 38527455 PMCID: PMC11042984 DOI: 10.1097/qco.0000000000001010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
PURPOSE OF REVIEW Many cholesterol-dependent cytolysin (CDC)-producing pathogens pose a significant threat to human health. Herein, we review the pore-dependent and -independent properties CDCs possess to assist pathogens in evading the host immune response. RECENT FINDINGS Within the last 5 years, exciting new research suggests CDCs can act to inhibit important immune functions, disrupt critical cell signaling pathways, and have tissue-specific effects. Additionally, recent studies have identified a key region of CDCs that generates robust immunity, providing resources for the development of CDC-based vaccines. SUMMARY This review provides new information on how CDCs alter host immune responses to aid bacteria in pathogenesis. These studies can assist in the design of more efficient vaccines and therapeutics against CDCs that will enhance the immune response to CDC-producing pathogens while mitigating the dampening effects CDCs have on the host immune response.
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Affiliation(s)
- Tristan C. Sanford
- University of Oklahoma Health Sciences Center, Department of Microbiology and Immunology, Oklahoma City, OK 73104
| | - Rodney K. Tweten
- University of Oklahoma Health Sciences Center, Department of Microbiology and Immunology, Oklahoma City, OK 73104
| | - Hunter L. Abrahamsen
- University of Oklahoma Health Sciences Center, Department of Microbiology and Immunology, Oklahoma City, OK 73104
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2
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Dai CC, Huang W, Yang J, Hussein WM, Wang J, Khalil ZG, Capon RJ, Toth I, Stephenson RJ. Polyethylenimine quantity and molecular weight influence its adjuvanting properties in liposomal peptide vaccines. Bioorg Med Chem Lett 2021; 40:127920. [PMID: 33705898 DOI: 10.1016/j.bmcl.2021.127920] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/08/2021] [Accepted: 02/26/2021] [Indexed: 01/23/2023]
Abstract
We recently reported that polyethylenimine (PEI; molecular weight of 600 Da) acted as a vaccine adjuvant for liposomal group A Streptococcus (GAS) vaccines, eliciting immune responses in vivo with IgG antibodies giving opsonic activity against five Australian GAS clinical isolates. However, to date, no investigation comparing the structure-activity relationship between the molecular weight of PEI and its adjuvanting activity in vaccine development has been performed. We hypothesized that the molecular weight and quantity of PEI in a liposomal vaccine will impact its adjuvanting properties. In this study, we successfully formulated liposomes containing different molecular weights of PEI (600, 1800, 10k and 25k Da) and equivalents of PEI (0.5, 1 and 2) of branched PEI. Outbred mice were administrated the vaccine formulations intranasally, and the mice that received a high ratio of PEI 600 reported a stronger immune response than the mice that received a lower ratio of PEI 600. Interestingly, mice that received the same quantity of PEI 600, PEI 10k and PEI 25k showed similar immune responses in vivo and in vitro. This comparative study highlights the ratio of PEI present in the liposome vaccines impacts adjuvanting activity, however, PEI molecular weight did not significantly enhance its adjuvanting properties. We also report that the stability of PEI liposomes is critical for vaccines to elicit the desired immune response.
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Affiliation(s)
- Charles C Dai
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Wenbin Huang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jieru Yang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Waleed M Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Jingwen Wang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Zeinab G Khalil
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Robert J Capon
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Rachel J Stephenson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
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3
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Dooley LM, Ahmad TB, Pandey M, Good MF, Kotiw M. Rheumatic heart disease: A review of the current status of global research activity. Autoimmun Rev 2020; 20:102740. [PMID: 33333234 DOI: 10.1016/j.autrev.2020.102740] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 09/04/2020] [Indexed: 01/17/2023]
Abstract
Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.
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Affiliation(s)
- Leanne M Dooley
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Tarek B Ahmad
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
| | - Manisha Pandey
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael F Good
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia.
| | - Michael Kotiw
- School of Health and Wellbeing, University of Southern Queensland, Toowoomba, Queensland, Australia; Institute for Life Sciences and the Environment, University of Southern Queensland, Toowoomba, Queensland, Australia.
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4
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Dai CC, Yang J, Hussein WM, Zhao L, Wang X, Khalil ZG, Capon RJ, Toth I, Stephenson RJ. Polyethylenimine: An Intranasal Adjuvant for Liposomal Peptide-Based Subunit Vaccine against Group A Streptococcus. ACS Infect Dis 2020; 6:2502-2512. [PMID: 32786276 DOI: 10.1021/acsinfecdis.0c00452] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Group A Streptococcus (GAS) and GAS-related infections are a worldwide challenge, with no commercial GAS vaccine available. Polyethylenimine (PEI) attaches to the cells' surface and delivers cargo into endosomal and cytosolic compartments. We hypothesized that this will confer mucosal adjuvant properties for peptide antigens against group A Streptococcus (GAS). In this study, we successfully demonstrated the development of PEI incorporated liposomes for the delivery of a lipopeptide-based vaccine (LCP-1) against GAS. Outbred mice were administrated with the vaccine formulations intranasally, and immunological investigation showed that the PEI liposomes elicited significant mucosal and systemic immunity with the production of IgA and IgG antibodies. Antibodies were shown to effectively opsonize multiple isolates of clinically isolated GAS. This proof-of-concept study showed the capability for PEI liposomes to act as a safe vehicle for the delivery of GAS peptide antigens to elicit immune responses against GAS infection, making PEI a promising addition to liposomal mucosal vaccines.
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Affiliation(s)
- Charles C. Dai
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Jieru Yang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan 11795, Egypt
| | - Lili Zhao
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Xiumin Wang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Zeinab G. Khalil
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Robert J. Capon
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
- School of Pharmacy, The University of Queensland, Woolloongabba, Queensland 4102, Australia
| | - Rachel J. Stephenson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
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5
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Dai C, Khalil ZG, Hussein WM, Yang J, Wang X, Zhao L, Capon RJ, Toth I, Stephenson RJ. Opsonic Activity of Conservative Versus Variable Regions of the Group A Streptococcus M Protein. Vaccines (Basel) 2020; 8:vaccines8020210. [PMID: 32392777 PMCID: PMC7349123 DOI: 10.3390/vaccines8020210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/23/2020] [Accepted: 05/05/2020] [Indexed: 12/13/2022] Open
Abstract
Group A Streptococcus (GAS) and GAS-associated infections are a global challenge, with no licensed GAS vaccine on the market. The GAS M protein is a critical virulence factor in the fight against GAS infection, and it has been a primary target for GAS vaccine development. Measuring functional opsonic antibodies against GAS is an important component in the clinical development path for effective vaccines. In this study, we compared the opsonic activity of two synthetic, self-adjuvanting subunit vaccines containing either the J8- or 88/30-epitope in Swiss outbred mice using intranasal administration. Following primary immunization and three boosts, sera were assessed for IgG activity using ELISA, and opsonization activity against seven randomly selected clinical isolates of GAS was measured. Vaccine constructs containing the conservative J8-epitope showed significant opsonic activity against six out of the seven GAS clinical isolates, while the vaccine containing the variable 88/30-epitope did not show any significant opsonic activity.
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Affiliation(s)
- Chuankai Dai
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
| | - Zeinab G. Khalil
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; (Z.G.K.); (R.J.C.)
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
- Pharmaceutical Organic Chemistry Department, Faculty of Pharmacy, Helwan University, Helwan 11795, Egypt
| | - Jieru Yang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
| | - Xiumin Wang
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
- Gene Engineering Laboratory, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing 100081, China
| | - Lili Zhao
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
| | - Robert J. Capon
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; (Z.G.K.); (R.J.C.)
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; (Z.G.K.); (R.J.C.)
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Rachel J. Stephenson
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia; (C.D.); (W.M.H.); (J.Y.); (X.W.); (L.Z.); (I.T.)
- Correspondence:
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Abstract
The clinico-epidemiological features of diseases caused by group A streptococci (GAS) is presented through the lens of the ecology, population genetics, and evolution of the organism. The serological targets of three typing schemes (M, T, SOF) are themselves GAS cell surface proteins that have a myriad of virulence functions and a diverse array of structural forms. Horizontal gene transfer expands the GAS antigenic cell surface repertoire by generating numerous combinations of M, T, and SOF antigens. However, horizontal gene transfer of the serotype determinant genes is not unconstrained, and therein lies a genetic organization that may signify adaptations to a narrow ecological niche, such as the primary tissue reservoirs of the human host. Adaptations may be further shaped by selection pressures such as herd immunity. Understanding the molecular evolution of GAS on multiple levels-short, intermediate, and long term-sheds insight on mechanisms of host-pathogen interactions, the emergence and spread of new clones, rational vaccine design, and public health interventions.
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7
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Yi J, Tang R, Yang J, Chen Y, Fei J. Streptolysin O derived from Streptococcus pyogenes inhibits RANKL‑induced osteoclastogenesis through the NF‑κB signaling pathway. Mol Med Rep 2018; 19:414-422. [PMID: 30431141 PMCID: PMC6297742 DOI: 10.3892/mmr.2018.9662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/17/2018] [Indexed: 01/03/2023] Open
Abstract
Streptococcus pyogenes (GAS) is a clinically significant bacterial strain that causes bacterial arthritis, osteomyelitis and implant infections. Infection complications can lead to serious bone destruction. Osteoclasts, the only type of cell with bone resorption function, participate in this process. Streptolysin O (SLO) is produced by almost all clinical Streptococcus pyogenes isolates. However, the role of SLO in bone infection caused by GAS had not been previously examined. The current study was performed to define the effects of SLO on receptor activator of NF-κB ligand-stimulated osteoclast differentiation in vitro. Results demonstrated that SLO decreased the phosphorylation of p65 and NF-κB inhibitor α, suppressed c-FOS and nuclear factor of activated T-cells cytoplasmic 1, and downregulated the expression of osteoclast marker genes. SLO also induced apoptosis of mature osteoclasts. The results suggested that SLO blocked osteoclast activation during GAS infection. These findings may prove useful in the development of novel strategies for treating GAS-associated bone infectious diseases.
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Affiliation(s)
- Jin Yi
- Centre of Trauma of PLA, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Ruohui Tang
- Centre of Trauma of PLA, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Jing Yang
- Centre of Trauma of PLA, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
| | - Yueqi Chen
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing 400038, P.R. China
| | - Jun Fei
- Centre of Trauma of PLA, Daping Hospital, Third Military Medical University, Chongqing 400042, P.R. China
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8
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Laabei M, Ermert D. Catch Me if You Can: Streptococcus pyogenes Complement Evasion Strategies. J Innate Immun 2018; 11:3-12. [PMID: 30269134 DOI: 10.1159/000492944] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/16/2018] [Indexed: 12/27/2022] Open
Abstract
The human host has evolved elaborate protection mechanisms to prevent infection from the billions of microorganisms to which it host is exposed and is home. One of these systems, complement, is an evolutionary ancient arm of innate immunity essential for combatting bacterial infection. Complement permits the efficient labelling of bacteria with opsonins, supports phagocytosis, and facilitates phagocyte recruitment to the site of infection through the production of chemoattractants. However, it is by no means perfect, and certain organisms engage in an evolutionary arms race with the host where complement has become a major target to promote immune evasion. Streptococcus pyogenes is a major human pathogen that causes significant morbidity and mortality globally. S. pyogenes is also a member of an elite group of bacterial pathogens possessing a sophisticated arsenal of virulence determinants capable of interfering with complement. In this review, we focus on these complement evasins, their mechanism of action, and their importance in disease progression. Finally, we highlight new therapeutic options for fighting S. pyogenes, by interfering with one of its main mechanisms of complement evasion.
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9
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Schmitz M, Roux X, Huttner B, Pugin J. Streptococcal toxic shock syndrome in the intensive care unit. Ann Intensive Care 2018; 8:88. [PMID: 30225523 PMCID: PMC6141408 DOI: 10.1186/s13613-018-0438-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/11/2018] [Indexed: 11/10/2022] Open
Abstract
The streptococcal toxic shock syndrome is a severe complication associated with invasive infections by group A streptococci. In spite of medical progresses in the care of patients with septic shock during the last decades, this condition has remained associated with a high mortality. Early recognition and multidisciplinary management are key to the care of patients with streptococcal toxic shock syndrome, with intensive and appropriate intensive support of failing organs, rapid diagnosis of infectious source(s), and surgical management. The epidemiology and risk factors for streptococcal toxic shock syndrome remain to be better studied, including the possible causal role of exposure to nonsteroidal anti-inflammatory drugs. In this review article, the authors review the current knowledge of streptococcal toxic shock syndrome and discuss the pathophysiology as well as its supportive and specific treatment.
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Affiliation(s)
- Marylin Schmitz
- Division of Intensive Care, Faculty of Medicine Geneva, University Hospitals of Geneva, University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland
| | - Xavier Roux
- Division of Intensive Care, Faculty of Medicine Geneva, University Hospitals of Geneva, University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland
| | - Benedikt Huttner
- Division of Infectious Diseases, Faculty of Medicine Geneva, University Hospitals of Geneva, University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland
| | - Jérôme Pugin
- Division of Intensive Care, Faculty of Medicine Geneva, University Hospitals of Geneva, University of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14, Switzerland
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10
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Sekuloski S, Batzloff MR, Griffin P, Parsonage W, Elliott S, Hartas J, O’Rourke P, Marquart L, Pandey M, Rubin FA, Carapetis J, McCarthy J, Good MF. Evaluation of safety and immunogenicity of a group A streptococcus vaccine candidate (MJ8VAX) in a randomized clinical trial. PLoS One 2018; 13:e0198658. [PMID: 29965967 PMCID: PMC6028081 DOI: 10.1371/journal.pone.0198658] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 05/06/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Group A streptococcus (GAS) is a serious human pathogen that affects people of different ages and socio-economic levels. Although vaccination is potentially one of the most effective methods to control GAS infection and its sequelae, few prototype vaccines have been investigated in humans. In this study, we report the safety and immunogenicity of a novel acetylated peptide-protein conjugate vaccine candidate MJ8VAX (J8-DT), when delivered intramuscularly to healthy adults. METHODS A randomized, double-blinded, controlled Phase I clinical trial was conducted in 10 healthy adult participants. Participants were randomized 4:1 to receive the vaccine candidate (N = 8) or placebo (N = 2). A single dose of the vaccine candidate (MJ8VAX), contained 50 μg of peptide conjugate (J8-DT) adsorbed onto aluminium hydroxide and re-suspended in PBS in a total volume of 0.5 mL. Safety of the vaccine candidate was assessed by monitoring local and systemic adverse reactions following intramuscular administration. The immunogenicity of the vaccine was assessed by measuring the levels of peptide (anti-J8) and toxoid carrier (anti-DT)-specific antibodies in serum samples. RESULTS No serious adverse events were reported over 12 months of study. A total of 13 adverse events (AEs) were recorded, two of which were assessed to be associated with the vaccine. Both were mild in severity. No local reactogenicity was recorded in any of the participants. MJ8VAX was shown to be immunogenic, with increase in vaccine-specific antibodies in the participants who received the vaccine. The maximum level of vaccine-specific antibodies was detected at 28 days post immunization. The level of these antibodies decreased with time during follow-up. Participants who received the vaccine also had a corresponding increase in anti-DT serum antibodies. CONCLUSIONS Intramuscular administration of MJ8VAX was demonstrated to be safe and immunogenic. The presence of DT in the vaccine formulation resulted in a boost in the level of anti-DT antibodies. TRIAL REGISTRATION ACTRN12613000030774.
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Affiliation(s)
- Silvana Sekuloski
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Michael R. Batzloff
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Paul Griffin
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- Q-Pharm Pty Ltd, Brisbane, Australia
- Department of Medicine and Infectious Diseases, Mater Hospital and Mater Medical Research Institute, Brisbane, Australia
- The University of Queensland, Brisbane, Australia
| | - William Parsonage
- Australian Centre for Health Service Innovation, Queensland University of Technology, Brisbane, Australia
| | | | - Jon Hartas
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Peter O’Rourke
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Louise Marquart
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Manisha Pandey
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
| | - Fran A. Rubin
- Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jonathan Carapetis
- Telethon Kids Institute, University of Western Australia and Perth Children’s Hospital, Perth, Australia
| | - James McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Australia
- The University of Queensland, Brisbane, Australia
| | - Michael F. Good
- The Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
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11
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Katzenellenbogen JM, Ralph AP, Wyber R, Carapetis JR. Rheumatic heart disease: infectious disease origin, chronic care approach. BMC Health Serv Res 2017; 17:793. [PMID: 29187184 PMCID: PMC5708129 DOI: 10.1186/s12913-017-2747-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 11/20/2017] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Rheumatic heart disease (RHD) is a chronic cardiac condition with an infectious aetiology, causing high disease burden in low-income settings. Affected individuals are young and associated morbidity is high. However, RHD is relatively neglected due to the populations involved and its lower incidence relative to other heart diseases. METHODS AND RESULTS In this narrative review, we describe how RHD care can be informed by and integrated with models of care developed for priority non-communicable diseases (coronary heart disease), and high-burden communicable diseases (tuberculosis). Examining the four-level prevention model (primordial through tertiary prevention) suggests primordial and primary prevention of RHD can leverage off existing tuberculosis control efforts, given shared risk factors. Successes in coronary heart disease control provide inspiration for similarly bold initiatives for RHD. Further, we illustrate how the Chronic Care Model (CCM), developed for use in non-communicable diseases, offers a relevant framework to approach RHD care. Systems strengthening through greater integration of services can improve RHD programs. CONCLUSION Strengthening of systems through integration/linkages with other well-performing and resourced services in conjunction with policies to adopt the CCM framework for the secondary and tertiary prevention of RHD in settings with limited resources, has the potential to significantly reduce the burden of RHD globally. More research is required to provide evidence-based recommendations for policy and service design.
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Affiliation(s)
- Judith M Katzenellenbogen
- Telethon Kids Institute, The University of Western Australia, Perth, Western, Australia.
- School of Population and Global Health, The University of Western Australia, Perth, Western, Australia.
| | - Anna P Ralph
- Global and Tropical Health, Menzies School of Health Research, Darwin, Northern Territory, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, NT, Australia
| | - Rosemary Wyber
- Telethon Kids Institute, The University of Western Australia, Perth, Western, Australia
| | - Jonathan R Carapetis
- Telethon Kids Institute, The University of Western Australia, Perth, Western, Australia
- Princess Margaret Hospital for Children, Perth, Western, Australia
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12
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Affiliation(s)
- Eloi Marijon
- From Paris Descartes University and the Department of Cardiology and Global Health Unit (INSERM Unité 970), European Georges Pompidou Hospital, Paris (E.M., X.J.); and Sydney Medical School, Sydney (D.S.C.)
| | - David S Celermajer
- From Paris Descartes University and the Department of Cardiology and Global Health Unit (INSERM Unité 970), European Georges Pompidou Hospital, Paris (E.M., X.J.); and Sydney Medical School, Sydney (D.S.C.)
| | - Xavier Jouven
- From Paris Descartes University and the Department of Cardiology and Global Health Unit (INSERM Unité 970), European Georges Pompidou Hospital, Paris (E.M., X.J.); and Sydney Medical School, Sydney (D.S.C.)
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13
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Masters IB, Isles AF, Grimwood K. Necrotizing pneumonia: an emerging problem in children? Pneumonia (Nathan) 2017; 9:11. [PMID: 28770121 PMCID: PMC5525269 DOI: 10.1186/s41479-017-0035-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 06/22/2017] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND In children, necrotizing pneumonia (NP) is an uncommon, severe complication of pneumonia. It is characterized by destruction of the underlying lung parenchyma resulting in multiple small, thin-walled cavities and is often accompanied by empyema and bronchopleural fistulae. REVIEW NP in children was first reported in children in 1994, and since then there has been a gradual increase in cases, which is partially explained by greater physician awareness and use of contrast computed tomography (CT) scans, and by temporal changes in circulating respiratory pathogens and antibiotic prescribing. The most common pathogens detected in children with NP are pneumococci and Staphylococcus aureus. The underlying disease mechanisms are poorly understood, but likely relate to multiple host susceptibility and bacterial virulence factors, with viral-bacterial interactions also possibly having a role. Most cases are in previously healthy young children who, despite adequate antibiotic therapy for bacterial pneumonia, remain febrile and unwell. Many also have evidence of pleural effusion, empyema, or pyopneumothorax, which has undergone drainage or surgical intervention without clinical improvement. The diagnosis is generally made by chest imaging, with CT scans being the most sensitive, showing loss of normal pulmonary architecture, decreased parenchymal enhancement and multiple thin-walled cavities. Blood culture and culture and molecular testing of pleural fluid provide a microbiologic diagnosis in as many as 50% of cases. Prolonged antibiotics, draining pleural fluid and gas that causes mass effects, and maintaining ventilation, circulation, nutrition, fluid, and electrolyte balance are critical components of therapy. Despite its serious nature, death is uncommon, with good clinical, radiographic and functional recovery achieved in the 5-6 months following diagnosis. Increased knowledge of NP's pathogenesis will assist more rapid diagnosis and improve treatment and, ultimately, prevention. CONCLUSION It is important to consider that our understanding of NP is limited to individual case reports or small case series, and treatment data from randomized-controlled trials are lacking. Furthermore, case series are retrospective and usually confined to single centers. Consequently, these studies may not be representative of patients in other locations, especially when allowing for temporal changes in pathogen behaviour and differences in immunization schedules and antibiotic prescribing practices.
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Affiliation(s)
- I. Brent Masters
- Department of Respiratory and Sleep Medicine, Lady Cilento Children’s Hospital, South Brisbane, QLD Australia
| | - Alan F. Isles
- Department of Respiratory and Sleep Medicine, Lady Cilento Children’s Hospital, South Brisbane, QLD Australia
| | - Keith Grimwood
- School of Medicine and Menzies Health Institute Queensland, Gold Coast campus, Griffith University, Building G40, Southport Gold Coast, QLD Australia
- Departments of Infectious Diseases and Paediatrics, Gold Coast Health, Southport Gold Coast, QLD Australia
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Fagan V, Hussein WM, Su M, Giddam AK, Batzloff MR, Good MF, Toth I, Simerska P. Synthesis, Characterization and Immunological Evaluation of Self‐Adjuvanting Group A Streptococcal Vaccine Candidates Bearing Various Lipidic Adjuvanting Moieties. Chembiochem 2017; 18:545-553. [DOI: 10.1002/cbic.201600639] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Vincent Fagan
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
| | - Waleed M. Hussein
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
| | - Mei Su
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
| | - Ashwini K. Giddam
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
| | | | - Michael F. Good
- Institute for Glycomics Griffith University Gold Coast 4215 Australia
| | - Istvan Toth
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
- School of Pharmacy Pharmacy Australia Centre of Excellence The University of Queensland Cornwall Street Woolloongabba QLD 4072 Australia
- Institute for Molecular Bioscience The University of Queensland St. Lucia QLD 4072 Australia
| | - Pavla Simerska
- School of Chemistry and Molecular Biosciences The University of Queensland Cooper Road St. Lucia QLD 4072 Australia
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15
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Lipid core peptide/poly(lactic-co-glycolic acid) as a highly potent intranasal vaccine delivery system against Group A streptococcus. Int J Pharm 2016; 513:410-420. [PMID: 27659862 DOI: 10.1016/j.ijpharm.2016.09.057] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/15/2016] [Accepted: 09/19/2016] [Indexed: 12/16/2022]
Abstract
Rheumatic heart disease represents a leading cause of mortality caused by Group A Streptococcus (GAS) infections transmitted through the respiratory route. Although GAS infections can be treated with antibiotics these are often inadequate. An efficacious GAS vaccine holds more promise, with intranasal vaccination especially attractive, as it mimics the natural route of infections and should be able to induce mucosal IgA and systemic IgG immunity. Nanoparticles were prepared by either encapsulating or coating lipopeptide-based vaccine candidate (LCP-1) on the surface of poly(lactic-co-glycolic acid) (PLGA). In vitro study showed that encapsulation of LCP-1 vaccine into nanoparticles improved uptake and maturations of antigen-presenting cells. The immunogenicity of lipopeptide incorporated PLGA-based nanoparticles was compared with peptides co-administered with mucosal adjuvant cholera toxin B in mice upon intranasal administration. Higher levels of J14-specific salivary mucosal IgA and systemic antibody IgG titres were observed for groups immunized with encapsulated LCP-1 compared to LCP-1 coated nanoparticles or free LCP-1. Systemic antibodies obtained from LCP-1 encapsulated PLGA NPs inhibited the growth of bacteria in six different GAS strains. Our results show that PLGA-based lipopeptide delivery is a promising approach for rational design of a simple, effective and patient friendly intranasal GAS vaccine resulting in mucosal IgA response.
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16
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McNeilly C, Cosh S, Vu T, Nichols J, Henningham A, Hofmann A, Fane A, Smeesters PR, Rush CM, Hafner LM, Ketheesan N, Sriprakash KS, McMillan DJ. Predicted Coverage and Immuno-Safety of a Recombinant C-Repeat Region Based Streptococcus pyogenes Vaccine Candidate. PLoS One 2016; 11:e0156639. [PMID: 27310707 PMCID: PMC4911098 DOI: 10.1371/journal.pone.0156639] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/17/2016] [Indexed: 12/14/2022] Open
Abstract
The C-terminal region of the M-protein of Streptococcus pyogenes is a major target for vaccine development. The major feature is the C-repeat region, consisting of 35–42 amino acid repeat units that display high but not perfect identity. SV1 is a S. pyogenes vaccine candidate that incorporates five 14mer amino acid sequences (called J14i variants) from differing C-repeat units in a single recombinant construct. Here we show that the J14i variants chosen for inclusion in SV1 are the most common variants in a dataset of 176 unique M-proteins. Murine antibodies raised against SV1 were shown to bind to each of the J14i variants present in SV1, as well as variants not present in the vaccine. Antibodies raised to the individual J14i variants were also shown to bind to multiple but different combinations of J14i variants, supporting the underlying rationale for the design of SV1. A Lewis Rat Model of valvulitis was then used to assess the capacity of SV1 to induce deleterious immune response associated with rheumatic heart disease. In this model, both SV1 and the M5 positive control protein were immunogenic. Neither of these antibodies were cross-reactive with cardiac myosin or collagen. Splenic T cells from SV1/CFA and SV1/alum immunized rats did not proliferate in response to cardiac myosin or collagen. Subsequent histological examination of heart tissue showed that 4 of 5 mice from the M5/CFA group had valvulitis and inflammatory cell infiltration into valvular tissue, whereas mice immunised with SV1/CFA, SV1/alum showed no sign of valvulitis. These results suggest that SV1 is a safe vaccine candidate that will elicit antibodies that recognise the vast majority of circulating GAS M-types.
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Affiliation(s)
- Celia McNeilly
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, QLD, 4006, Australia
| | - Samantha Cosh
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, QLD, 4006, Australia
| | - Therese Vu
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, QLD, 4006, Australia
| | - Jemma Nichols
- Inflammation and Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia
| | - Anna Henningham
- Australian Infectious Disease Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute for Cell and Molecular Therapies, Griffith University, Nathan, and Queensland Tropical Health Alliance, Smithfield, QLD, Australia
| | - Anne Fane
- Australian Institute of Tropical Medicine, James Cook University, Townsville, QLD, 4811, Australia
| | - Pierre R Smeesters
- Laboratoire de Génétique et Physiologie Bactérienne, Institut de Biologie et de Médecine Moléculaires, Faculté des Sciences, Université Libre de Bruxelles, Gosselies, Belgium, and Murdoch Children Research Institute, Melbourne, VIC, 3052, Australia
| | - Catherine M Rush
- Australian Institute of Tropical Medicine, James Cook University, Townsville, QLD, 4811, Australia
| | - Louise M Hafner
- School of Biomedical Sciences, Faculty of Health & Institute of Health and Biomedical Innovation (IHBI), Queensland University of Technology, Brisbane, QLD, 4001, Australia
| | - Natkuman Ketheesan
- Australian Institute of Tropical Medicine, James Cook University, Townsville, QLD, 4811, Australia
| | - Kadaba S Sriprakash
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, QLD, 4006, Australia
| | - David J McMillan
- Bacterial Pathogenesis Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Herston, QLD, 4006, Australia.,Inflammation and Healing Research Cluster, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia
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17
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Pandey M, Mortensen R, Calcutt A, Powell J, Batzloff MR, Dietrich J, Good MF. Combinatorial Synthetic Peptide Vaccine Strategy Protects against Hypervirulent CovR/S Mutant Streptococci. THE JOURNAL OF IMMUNOLOGY 2016; 196:3364-74. [PMID: 26969753 DOI: 10.4049/jimmunol.1501994] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/16/2016] [Indexed: 11/19/2022]
Abstract
Cluster of virulence responder/sensor (CovR/S) mutant group A streptococci (GAS) are serious human pathogens of multiple M protein strains that upregulate expression of virulence factors, including the IL-8 proteaseStreptococcus pyogenescell envelope proteinase (SpyCEP), thus blunting neutrophil-mediated killing and enabling ingress of bacteria from a superficial wound to deep tissue. We previously showed that a combination vaccine incorporating J8-DT (conserved peptide vaccine from the M protein) and a recombinant SpyCEP fragment protects against CovR/S mutants. To enhance the vaccine's safety profile, we identified a minimal epitope (S2) that was the target for anti-SpyCEP Abs that could protect IL-8 from SpyCEP-mediated proteolysis. Abs from healthy humans and from mice experimentally infected with GAS also recognized S2, albeit at low titers. Native SpyCEP may be poorly immunogenic (cryptic or subdominant), and it would be to the organism's advantage if the host did not induce a strong Ab response against it. However, S2 conjugated to diphtheria toxoid is highly immunogenic and induces Abs that recognize and neutralize SpyCEP. Hence, we describe a two-component peptide vaccine that induces Abs (anti-S2) that protect IL-8 from proteolysis and other Abs (anti-J8) that cause strain-independent killing in the presence of neutrophils. We show that either component alone is ineffectual in preventing skin infection and bacteremia due to CovR/S mutants but that the combination induces complete protection. This protection correlated with a significant influx of neutrophils to the infection site. The data strongly suggest that the lack of natural immunity to hypervirulent GAS strains in humans could be rectified by this combination vaccine.
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Affiliation(s)
- Manisha Pandey
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland 4222, Australia;
| | - Rasmus Mortensen
- Department of Infectious Disease Immunology, Statens Serum Institut, 2300 Copenhagen, Denmark; and Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Ainslie Calcutt
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland 4222, Australia
| | - Jessica Powell
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland 4222, Australia
| | - Michael R Batzloff
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland 4222, Australia
| | - Jes Dietrich
- Department of Infectious Disease Immunology, Statens Serum Institut, 2300 Copenhagen, Denmark; and
| | - Michael F Good
- Institute for Glycomics, Griffith University, Gold Coast Campus, Southport, Queensland 4222, Australia;
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18
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Uchiyama S, Döhrmann S, Timmer AM, Dixit N, Ghochani M, Bhandari T, Timmer JC, Sprague K, Bubeck-Wardenburg J, Simon SI, Nizet V. Streptolysin O Rapidly Impairs Neutrophil Oxidative Burst and Antibacterial Responses to Group A Streptococcus. Front Immunol 2015; 6:581. [PMID: 26635795 PMCID: PMC4644796 DOI: 10.3389/fimmu.2015.00581] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/30/2015] [Indexed: 12/11/2022] Open
Abstract
Group A Streptococcus (GAS) causes a wide range of human infections, ranging from simple pharyngitis to life-threatening necrotizing fasciitis and toxic shock syndrome. A globally disseminated clone of M1T1 GAS has been associated with an increase in severe, invasive GAS infections in recent decades. The secreted GAS pore-forming toxin streptolysin O (SLO), which induces eukaryotic cell lysis in a cholesterol-dependent manner, is highly upregulated in the GAS M1T1 clone during bloodstream dissemination. SLO is known to promote GAS resistance to phagocytic clearance by neutrophils, a critical first element of host defense against invasive bacterial infection. Here, we examine the role of SLO in modulating specific neutrophil functions during their early interaction with GAS. We find that SLO at subcytotoxic concentrations and early time points is necessary and sufficient to suppress neutrophil oxidative burst, in a manner reversed by free cholesterol and anti-SLO blocking antibodies. In addition, SLO at subcytotoxic concentrations blocked neutrophil degranulation, interleukin-8 secretion and responsiveness, and elaboration of DNA-based neutrophil extracellular traps, cumulatively supporting a key role for SLO in GAS resistance to immediate neutrophil killing. A non-toxic SLO derivate elicits protective immunity against lethal GAS challenge in a murine infection model. We conclude that SLO exerts a novel cytotoxic-independent function at early stages of invasive infections (<30 min), contributing to GAS escape from neutrophil clearance.
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Affiliation(s)
- Satoshi Uchiyama
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA
| | - Simon Döhrmann
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA
| | - Anjuli M Timmer
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA
| | - Neha Dixit
- Department of Biomedical Engineering, University of California Davis , Davis, CA , USA
| | - Mariam Ghochani
- Department of Biological Sciences, San Diego State University , San Diego, CA , USA
| | - Tamara Bhandari
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA
| | - John C Timmer
- Department of Pharmacology, University of California San Diego , La Jolla, CA , USA
| | - Kimberly Sprague
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA
| | | | - Scott I Simon
- Department of Biomedical Engineering, University of California Davis , Davis, CA , USA
| | - Victor Nizet
- Department of Pediatrics, University of California San Diego , La Jolla, CA , USA ; Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego , La Jolla, CA , USA
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19
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Epidemiology Analysis of Streptococcus pyogenes in a Hospital in Southern Taiwan by Use of the Updated emm Cluster Typing System. J Clin Microbiol 2015; 54:157-62. [PMID: 26560544 DOI: 10.1128/jcm.02089-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/05/2015] [Indexed: 12/14/2022] Open
Abstract
emm typing is the most widely used molecular typing method for the human pathogen Streptococcus pyogenes (group A streptococcus [GAS]). emm typing is based on a small variable region of the emm gene; however, the emm cluster typing system defines GAS types according to the nearly complete sequence of the emm gene. Therefore, emm cluster typing is considered to provide more information regarding the functional and structural properties of M proteins in different emm types of GAS. In the present study, 677 isolates collected between 1994 and 2008 in a hospital in southern Taiwan were analyzed by the emm cluster typing system. emm clusters A-C4, E1, E6, and A-C3 were the most prevalent emm cluster types and accounted for 67.4% of total isolates. emm clusters A-C4 and E1 were associated with noninvasive diseases, whereas E6 was significantly associated with both invasive and noninvasive manifestations. In addition, emm clusters D4, E2, and E3 were significantly associated with invasive manifestations. Furthermore, we found that the functional properties of M protein, including low fibrinogen-binding and high IgG-binding activities, were correlated significantly with invasive manifestations. In summary, the present study provides updated epidemiological information on GAS emm cluster types in southern Taiwan.
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