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Lokken-Toyli KL, Aggarwal SD, Bee GCW, de Steenhuijsen Piters WAA, Wu C, Chen KZM, Loomis C, Bogaert D, Weiser JN. Impaired upper respiratory tract barrier function during postnatal development predisposes to invasive pneumococcal disease. PLoS Pathog 2024; 20:e1012111. [PMID: 38718049 PMCID: PMC11078396 DOI: 10.1371/journal.ppat.1012111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/10/2024] [Indexed: 05/12/2024] Open
Abstract
Infants are highly susceptible to invasive respiratory and gastrointestinal infections. To elucidate the age-dependent mechanism(s) that drive bacterial spread from the mucosa, we developed an infant mouse model using the prevalent pediatric respiratory pathogen, Streptococcus pneumoniae (Spn). Despite similar upper respiratory tract (URT) colonization levels, the survival rate of Spn-infected infant mice was significantly decreased compared to adults and corresponded with Spn dissemination to the bloodstream. An increased rate of pneumococcal bacteremia in early life beyond the newborn period was attributed to increased bacterial translocation across the URT barrier. Bacterial dissemination in infant mice was independent of URT monocyte or neutrophil infiltration, phagocyte-derived ROS or RNS, inflammation mediated by toll-like receptor 2 or interleukin 1 receptor signaling, or the pore-forming toxin pneumolysin. Using molecular barcoding of Spn, we found that only a minority of bacterial clones in the nasopharynx disseminated to the blood in infant mice, indicating the absence of robust URT barrier breakdown. Rather, transcriptional profiling of the URT epithelium revealed a failure of infant mice to upregulate genes involved in the tight junction pathway. Expression of many such genes was also decreased in early life in humans. Infant mice also showed increased URT barrier permeability and delayed mucociliary clearance during the first two weeks of life, which corresponded with tighter attachment of bacteria to the respiratory epithelium. Together, these results demonstrate a window of vulnerability during postnatal development when altered mucosal barrier function facilitates bacterial dissemination.
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Affiliation(s)
- Kristen L. Lokken-Toyli
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Surya D. Aggarwal
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Gavyn Chern Wei Bee
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Wouter A. A. de Steenhuijsen Piters
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital/University Medical Center Utrecht, Utrecht, the Netherlands
- National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Cindy Wu
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Kenny Zhi Ming Chen
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
| | - Cynthia Loomis
- Department of Pathology, New York University School of Medicine, New York, New York, United States of America
| | - Debby Bogaert
- Department of Paediatric Immunology and Infectious Diseases, Wilhelmina Children’s Hospital/University Medical Center Utrecht, Utrecht, the Netherlands
- Centre for Inflammation Research, Institute for Regeneration and Repair, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Jeffrey N. Weiser
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
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Leung S, Collett CF, Allen L, Lim S, Maniatis P, Bolcen SJ, Alston B, Patel PY, Kwatra G, Hall T, Thomas S, Taylor S, Le Doare K, Gorringe A. Development of A Standardized Opsonophagocytosis Killing Assay for Group B Streptococcus and Assessment in an Interlaboratory Study. Vaccines (Basel) 2023; 11:1703. [PMID: 38006035 PMCID: PMC10675794 DOI: 10.3390/vaccines11111703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
The placental transfer of antibodies that mediate bacterial clearance via phagocytes is likely important for protection against invasive group B Streptococcus (GBS) disease. A robust functional assay is essential to determine the immune correlates of protection and assist vaccine development. Using standard reagents, we developed and optimized an opsonophagocytic killing assay (OPKA) where dilutions of test sera were incubated with bacteria, baby rabbit complement (BRC) and differentiated HL60 cells (dHL60) for 30 min. Following overnight incubation, the surviving bacteria were enumerated and the % bacterial survival was calculated relative to serum-negative controls. A reciprocal 50% killing titer was then assigned. The minimal concentrations of anti-capsular polysaccharide (CPS) IgG required for 50% killing were 1.65-3.70 ng/mL (depending on serotype). Inhibition of killing was observed using sera absorbed with homologous CPS but not heterologous CPS, indicating specificity for anti-CPS IgG. The assay performance was examined in an interlaboratory study using residual sera from CPS-conjugate vaccine trials with international partners in the Group B Streptococcus Assay STandardisatiON (GASTON) Consortium. Strong correlations of reported titers between laboratories were observed: ST-Ia r = 0.88, ST-Ib r = 0.91, ST-II r = 0.91, ST-III r = 0.90 and ST-V r = 0.94. The OPKA is an easily transferable assay with accessible standard reagents and will be a valuable tool to assess GBS-specific antibodies in natural immunity and vaccine studies.
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Affiliation(s)
- Stephanie Leung
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
| | - Clare F. Collett
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
| | - Lauren Allen
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
| | - Suzanna Lim
- Maternal and Neonatal Vaccine Immunology Research Group, Centre for Neonatal and Paediatric Infection, St George’s, University of London, London SW17 0RE, UK; (S.L.); (T.H.)
| | - Pete Maniatis
- Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (P.M.)
| | - Shanna J. Bolcen
- Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (P.M.)
| | | | - Palak Y. Patel
- Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (P.M.)
| | - Gaurav Kwatra
- South African Medical Research Council, Vaccines and Infectious Diseases Analytics Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2050, South Africa;
- Division of Infectious Diseases, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229, USA
| | - Tom Hall
- Maternal and Neonatal Vaccine Immunology Research Group, Centre for Neonatal and Paediatric Infection, St George’s, University of London, London SW17 0RE, UK; (S.L.); (T.H.)
| | - Stephen Thomas
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
| | - Stephen Taylor
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
| | - Kirsty Le Doare
- Maternal and Neonatal Vaccine Immunology Research Group, Centre for Neonatal and Paediatric Infection, St George’s, University of London, London SW17 0RE, UK; (S.L.); (T.H.)
| | - Andrew Gorringe
- UK Health Security Agency, Porton Down, Salisbury SP4 0JG, UK (A.G.)
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Efficient antigen delivery by dendritic cell-targeting peptide via nucleolin confers superior vaccine effects in mice. iScience 2022; 25:105324. [PMID: 36304121 PMCID: PMC9593262 DOI: 10.1016/j.isci.2022.105324] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/28/2022] [Accepted: 10/06/2022] [Indexed: 11/22/2022] Open
Abstract
Efficient delivery of subunit vaccines to dendritic cells (DCs) is necessary to improve vaccine efficacy, because the vaccine antigen alone cannot induce sufficient protective immunity. Here, we identified DC-targeting peptides using a phage display system and demonstrated the potential of these peptides as antigen-delivery carriers to improve subunit vaccine effectiveness in mice. The fusion of antigen proteins and peptides with DC-targeting peptides induced strong antigen-specific IgG responses, even in the absence of adjuvants. In addition, the DC-targeting peptide improved the distribution of antigens to DCs and antigen presentation by DCs. The combined use of an adjuvant with a DC-targeting peptide improved the effectiveness of the vaccine. Furthermore, nucleolin, located on the DC surface, was identified as the receptor for DC-targeting peptide, and nucleolin was indispensable for the vaccine effect of the DC-targeting peptide. Overall, the findings of this study could be useful for developing subunit vaccines against infectious diseases. We successfully identified an efficient DC-targeting peptide using a phage display system Fusion of the peptide improves the efficacy of vaccine even in the absence of adjuvants The peptide improves the distribution of antigens to DCs and antigen presentation by DCs Nucleolin is indispensable for the vaccine effect of the DC-targeting peptide
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Nie M, Dong Y, Cao Q, Zhao D, Ji S, Huang H, Jiang M, Liu G, Liu Y. CRISPR Contributes to Adhesion, Invasion, and Biofilm Formation in Streptococcus agalactiae by Repressing Capsular Polysaccharide Production. Microbiol Spectr 2022; 10:e0211321. [PMID: 35861526 PMCID: PMC9430516 DOI: 10.1128/spectrum.02113-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 07/03/2022] [Indexed: 12/03/2022] Open
Abstract
The clustered regularly interspaced palindromic repeat (CRISPR)-associated (Cas) system functions classically as a prokaryotic defense system against invading mobile genetic elements, such as phages, plasmids, and viruses. Our previous study revealed that CRISPR deletion caused increased transcription of capsular polysaccharide (CPS) synthesis-related genes and severely attenuated virulence in the hypervirulent piscine Streptococcus agalactiae strain GD201008-001. Here, we found that CRISPR deficiency resulted in reduced adhesion, invasion, and biofilm formation abilities in this strain by upregulating the production of CPS. However, enhanced CPS production was not responsible for the attenuated phenotype of the ΔCRISPR mutant. RNA degradation assays indicated that inhibited transcription of the cps operon by CRISPR RNA (crRNA) was not due to the base pairing of the crRNA with the cps mRNA but to the repression of the promoter activity of cpsA, which is a putative transcriptional regulator of the capsule locus. IMPORTANCE Beyond protection from invading nucleic acids, CRISPR-Cas systems have been shown to have an important role in regulating bacterial endogenous genes. In this study, we demonstrate that crRNA inhibits the transcription of the cps operon by repressing the activity of promoter PcpsA, leading to increases in the abilities of adhesion, invasion, and biofilm formation in S. agalactiae. This study highlights the regulatory role of crRNA in bacterial physiology and provides a new explanation for the mechanism of crRNA-mediated endogenous gene regulation in S. agalactiae.
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Affiliation(s)
- Meng Nie
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yuhao Dong
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qing Cao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Dan Zhao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Shuting Ji
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Hao Huang
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Mingguo Jiang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, China
| | - Guangjin Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yongjie Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
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Tao C, Du J, Tang Y, Wang J, Dong K, Yang M, Hu B, Zhang Z. A Deep-Learning Based System for Rapid Genus Identification of Pathogens under Hyperspectral Microscopic Images. Cells 2022; 11:cells11142237. [PMID: 35883680 PMCID: PMC9315805 DOI: 10.3390/cells11142237] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/06/2022] [Accepted: 07/15/2022] [Indexed: 11/21/2022] Open
Abstract
Infectious diseases have always been a major threat to the survival of humanity. Additionally, they bring an enormous economic burden to society. The conventional methods for bacteria identification are expensive, time-consuming and laborious. Therefore, it is of great importance to automatically rapidly identify pathogenic bacteria in a short time. Here, we constructed an AI-assisted system for automating rapid bacteria genus identification, combining the hyperspectral microscopic technology and a deep-learning-based algorithm Buffer Net. After being trained and validated in the self-built dataset, which consists of 11 genera with over 130,000 hyperspectral images, the accuracy of the algorithm could achieve 94.9%, which outperformed 1D-CNN, 2D-CNN and 3D-ResNet. The AI-assisted system we developed has great potential in assisting clinicians in identifying pathogenic bacteria at the single-cell level with high accuracy in a cheap, rapid and automatic way. Since the AI-assisted system can identify the pathogenic genus rapidly (about 30 s per hyperspectral microscopic image) at the single-cell level, it can shorten the time or even eliminate the demand for cultivating. Additionally, the system is user-friendly for novices.
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Affiliation(s)
- Chenglong Tao
- Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China; (C.T.); (J.D.); (J.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Biomedical Spectroscopy of Xi’an, Xi’an 710119, China
| | - Jian Du
- Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China; (C.T.); (J.D.); (J.W.)
- Key Laboratory of Biomedical Spectroscopy of Xi’an, Xi’an 710119, China
| | | | - Junjie Wang
- Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China; (C.T.); (J.D.); (J.W.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ke Dong
- The Second Affiliated Hospital of Air Force Military Medical University, Xi’an 710119, China; (K.D.); (M.Y.)
| | - Ming Yang
- The Second Affiliated Hospital of Air Force Military Medical University, Xi’an 710119, China; (K.D.); (M.Y.)
| | - Bingliang Hu
- Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China; (C.T.); (J.D.); (J.W.)
- Key Laboratory of Biomedical Spectroscopy of Xi’an, Xi’an 710119, China
- Correspondence: (B.H.); (Z.Z.)
| | - Zhoufeng Zhang
- Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China; (C.T.); (J.D.); (J.W.)
- Key Laboratory of Biomedical Spectroscopy of Xi’an, Xi’an 710119, China
- Correspondence: (B.H.); (Z.Z.)
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6
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Wang H, Chen D, Lu H. Anti-bacterial monoclonal antibodies: next generation therapy against superbugs. Appl Microbiol Biotechnol 2022; 106:3957-3972. [PMID: 35648146 DOI: 10.1007/s00253-022-11989-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 12/19/2022]
Abstract
Prior to the nineteenth century, infectious disease was one of the leading causes of death. Human life expectancy has roughly doubled over the past century as a result of the development of antibiotics and vaccines. However, the emergence of antibiotic-resistant superbugs brings new challenges. The side effects of broad-spectrum antibiotics, such as causing antimicrobial resistance and destroying the normal flora, often limit their applications. Furthermore, the development of new antibiotics has lagged far behind the emergence and spread of antibiotic resistance. On the other hand, the genome complexity of bacteria makes it difficult to create effective vaccines. Therefore, novel therapeutic agents in supplement to antibiotics and vaccines are urgently needed to improve the treatment of infections. In recent years, monoclonal antibodies (mAbs) have achieved remarkable clinical success in a variety of fields. In the treatment of infectious diseases, mAbs can play functions through multiple mechanisms, including toxins neutralization, virulence factors inhibition, complement-mediated killing activity, and opsonic phagocytosis. Toxins and bacterial surface components are good targets to generate antibodies against. The U.S. FDA has approved three monoclonal antibody drugs, and there are numerous candidates in the preclinical or clinical trial stages. This article reviews recent advances in the research and development of anti-bacterial monoclonal antibody drugs in order to provide a valuable reference for future studies in this area. KEY POINTS: • Novel drugs against antibiotic-resistant superbugs are urgently required • Monoclonal antibodies can treat bacterial infections through multiple mechanisms • There are many anti-bacterial monoclonal antibodies developed in recent years and some candidates have entered the preclinical or clinical stages of development.
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Affiliation(s)
- Hui Wang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Daijie Chen
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Huili Lu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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Abstract
Capsular polysaccharides (CPSs) are important antigenic targets against bacterial infections. As T-independent antigens, however, CPSs elicit short-lived immune responses in adults and are poorly immunogenic in young children. Coupling CPS with protein carriers enhances anti-CPS responses and generates long-lasting immune memory. However, the mechanisms whereby carrier proteins accomplish this are not fully understood. Here, we dissect different mechanisms whereby carrier proteins enhance anti-CPS immunity. We show how coupling CPS with protein carriers modifies the interaction of CPS with antigen-presenting cells, enables a dual-activation mechanism for CPS-specific B cells via interaction with CPS- or carrier-specific T helper cells, and potentiates the recall of anti-CPS responses by engaging memory T helper cells during subsequent vaccination or bacterial exposure. Our findings provide new insights into the immunological basis of carrier-mediated anti-CPS immunity and may help in the design of more effective CPS-based vaccines.
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Abstract
Nephrotic syndrome (NS) encompasses a variety of disease processes leading to heavy proteinuria and edema. Minimal change disease (MCD) remains the most common primary cause of NS, as well as the most responsive to pharmacologic treatment with often minimal to no chronic kidney disease. Other causes of NS include focal segmental glomerulosclerosis, which follows MCD, and secondary causes, including extrarenal or systemic diseases, infections, and drugs. Although initial diagnosis relies on clinical findings as well as urine and blood chemistries, renal biopsy and genetic testing are important diagnostic tools, especially when considering non-MCD NS. Moreover, biomarkers in urine and serum have become important areas for research in this disease. NS progression and prognosis are variable and depend on etiology, with corticosteroids being the mainstay of treatment. Other alternative therapies found to be successful in inducing and maintaining remission include calcineurin inhibitors and rituximab. Disease course can range from recurrent disease relapse with or without acute kidney injury to end-stage renal disease in some cases. Given the complex pathogenesis of NS, which remains incompletely understood, complications are numerous and diverse and include infections, electrolyte abnormalities, acute kidney injury, and thrombosis. Pediatricians must be aware of the presentation, complications, and overall long-term implications of NS and its treatment.
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Tsubata T. Role of inhibitory B cell co-receptors in B cell self-tolerance to non-protein antigens. Immunol Rev 2022; 307:53-65. [PMID: 34989000 DOI: 10.1111/imr.13059] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 12/14/2022]
Abstract
Antibodies to non-protein antigens such as nucleic acids, polysaccharides, and glycolipids play important roles in both host defense against microbes and development of autoimmune diseases. Although non-protein antigens are not recognized by T cells, antibody production to non-protein antigens involve T cell-independent mechanisms such as signaling through TLR7 and TLR9 in antibody production to nucleic acids. Although self-reactive B cells are tolerized by various mechanisms including deletion, anergy, and receptor editing, T cell tolerance is also crucial in self-tolerance of B cells to protein self-antigen because self-reactive T cells induce autoantibody production to these self-antigens. However, presence of T cell-independent mechanism suggests that T cell tolerance is not able to maintain B cell tolerance to non-protein self-antigens. Lines of evidence suggest that B cell response to non-protein self-antigens such as nucleic acids and gangliosides, sialic acid-containing glycolipids, are suppressed by inhibitory B cell co-receptors CD72 and Siglec-G, respectively. These inhibitory co-receptors recognize non-protein self-antigens and suppress BCR signaling induced by these antigens, thereby inhibiting B cell response to these self-antigens. Inhibitory B cell co-receptors appear to be involved in B cell self-tolerance to non-protein self-antigens that can activate B cells by T cell-independent mechanisms.
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Affiliation(s)
- Takeshi Tsubata
- Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
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Immunobiology of the Classical Lancefield Group A Streptococcal Carbohydrate Antigen. Infect Immun 2021; 89:e0029221. [PMID: 34543125 DOI: 10.1128/iai.00292-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Group A Streptococcus (GAS) is a preeminent human bacterial pathogen causing hundreds of millions of infections each year worldwide. In the clinical setting, the bacterium is easily identified by a rapid antigen test against the group A carbohydrate (GAC), a polysaccharide that comprises 30 to 50% of the GAS cell wall by weight. Originally described by Rebecca Lancefield in the 1930s, GAC consists of a polyrhamnose backbone and a N-acetylglucosamine (GlcNAc) side chain. This side chain, the species-defining immunodominant antigen, is potentially implicated in autoreactive immune responses against human heart or brain tissue in poststreptococcal rheumatic fever or rheumatic heart disease. The recent discovery of the genetic locus encoding GAC biosynthesis and new insights into its chemical structure have provided novel insights into the assembly of the polysaccharide, its contribution to immune evasion and virulence, and ideas for safely harnessing its natural immunogenicity in vaccine design. This minireview serves to summarize the emerging new literature on GAC, the eponymous cell well antigen that provides structural integrity to GAS and directly interfaces with host innate and adaptive immune responses.
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Toh ZQ, Higgins RA, Mazarakis N, Abbott E, Nathanielsz J, Balloch A, Mulholland K, Licciardi PV. Evaluating Functional Immunity Following Encapsulated Bacterial Infection and Vaccination. Vaccines (Basel) 2021; 9:677. [PMID: 34203030 PMCID: PMC8234458 DOI: 10.3390/vaccines9060677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/16/2021] [Accepted: 06/16/2021] [Indexed: 11/19/2022] Open
Abstract
Encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis cause significant morbidity and mortality in young children despite the availability of vaccines. Highly specific antibodies are the primary mechanism of protection against invasive disease. Robust and standardised assays that measure functional antibodies are also necessary for vaccine evaluation and allow for the accurate comparison of data between clinical studies. This mini review describes the current state of functional antibody assays and their importance in measuring protective immunity.
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Affiliation(s)
- Zheng Quan Toh
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
- Department of Paediatrics, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Rachel A. Higgins
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
| | - Nadia Mazarakis
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
| | - Elysia Abbott
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
| | - Jordan Nathanielsz
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
| | - Anne Balloch
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
| | - Kim Mulholland
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
- Department of Paediatrics, The University of Melbourne, Parkville, VIC 3052, Australia
- London School of Hygiene and Tropical Medicine, University of London, London WC1E 7HT, UK
| | - Paul V. Licciardi
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia; (Z.Q.T.); (R.A.H.); (N.M.); (E.A.); (J.N.); (A.B.); (K.M.)
- Department of Paediatrics, The University of Melbourne, Parkville, VIC 3052, Australia
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Alderson MR, Welsch JA, Regan K, Newhouse L, Bhat N, Marfin AA. Vaccines to Prevent Meningitis: Historical Perspectives and Future Directions. Microorganisms 2021; 9:microorganisms9040771. [PMID: 33917003 PMCID: PMC8067733 DOI: 10.3390/microorganisms9040771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/02/2021] [Accepted: 04/02/2021] [Indexed: 12/20/2022] Open
Abstract
Despite advances in the development and introduction of vaccines against the major bacterial causes of meningitis, the disease and its long-term after-effects remain a problem globally. The Global Roadmap to Defeat Meningitis by 2030 aims to accelerate progress through visionary and strategic goals that place a major emphasis on preventing meningitis via vaccination. Global vaccination against Haemophilus influenzae type B (Hib) is the most advanced, such that successful and low-cost combination vaccines incorporating Hib are broadly available. More affordable pneumococcal conjugate vaccines are becoming increasingly available, although countries ineligible for donor support still face access challenges and global serotype coverage is incomplete with existing licensed vaccines. Meningococcal disease control in Africa has progressed with the successful deployment of a low-cost serogroup A conjugate vaccine, but other serogroups still cause outbreaks in regions of the world where broadly protective and affordable vaccines have not been introduced into routine immunization programs. Progress has lagged for prevention of neonatal meningitis and although maternal vaccination against the leading cause, group B streptococcus (GBS), has progressed into clinical trials, no GBS vaccine has thus far reached Phase 3 evaluation. This article examines current and future efforts to control meningitis through vaccination.
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Sinha A, Bagga A, Banerjee S, Mishra K, Mehta A, Agarwal I, Uthup S, Saha A, Mishra OP. Steroid Sensitive Nephrotic Syndrome: Revised Guidelines. Indian Pediatr 2021. [PMID: 33742610 PMCID: PMC8139225 DOI: 10.1007/s13312-021-2217-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Justification Steroid sensitive nephrotic syndrome (SSNS) is one of the most common chronic kidney diseases in children. These guidelines update the existing Indian Society of Pediatric Nephrology recommendations on its management. Objective To frame revised guidelines on diagnosis, evaluation, management and supportive care of patients with the illness. Process The guidelines combine evidence-based recommendations and expert opinion. Formulation of key questions was followed by review of literature and evaluation of evidence by experts in two face-to-face meetings. Recommendations The initial statements provide advice for evaluation at onset and follow up and indications for kidney biopsy. Subsequent statements provide recommendations for management of the first episode of illness and of disease relapses. Recommendations on the use of immunosuppressive strategies in patients with frequent relapses and steroid dependence are accompanied by suggestions for step-wise approach and plan of monitoring. Guidance is also provided regarding the management of common complications including edema, hypovolemia and serious infections. Advice on immunization and transition of care is given. The revised guideline is intended to improve the management and outcomes of patients with SSNS, and provide directions for future research.
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Affiliation(s)
- Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India. Correspondence to: Dr. Arvind Bagga, Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
| | | | - Kirtisudha Mishra
- Department of Pediatrics, Chacha Nehru Bal Chikitsalaya, Delhi, India
| | - Amarjeet Mehta
- Department of Pediatrics, Sawai Man Singh Medical College, Jaipur, India
| | - Indira Agarwal
- Department of Pediatrics, Christian Medical College, Vellore, India
| | - Susan Uthup
- Department of Pediatrics, Trivandrum Medical College, Thiruvananthapuram, India
| | - Abhijeet Saha
- Department of Pediatrics, Lady Hardinge Medical College, New Delhi, India
| | - Om Prakash Mishra
- Department of Pediatrics, Institute of Medical Sciences, Benaras Hindu University, Varanasi, India
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Mitsuyama Y, Shimizu K, Hirayama A, Komukai S, Kitamura T, Ogura H, Shimazu T. Splenic volume on computed tomography scans is associated with mortality in patients with sepsis. Int J Infect Dis 2021; 104:624-630. [PMID: 33444753 DOI: 10.1016/j.ijid.2021.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES The spleen is a key organ of the immune system. Asplenia has been reported to increase the risk of sepsis from overwhelming post-splenectomy infection. However, there are few reports on the association between splenic volume and mortality in patients with no history of splenectomy. This study focused on splenic volume of patients with sepsis and evaluated the association between splenic volume and mortality. METHODS We retrospectively investigated 232 patients with sepsis. The splenic volume was calculated by using computed tomography scans obtained on admission. The patients were categorized into tertiles based on their splenic volume, and the relationship between splenic volume and mortality was evaluated. Odds ratio curves based on splenic volume were created to assess the continuous associations between splenic volume and outcome with a logistic regression model. RESULTS The patients with sepsis were divided into three groups according to the first (73.6cm3) and second (128.7cm3) tertile values of splenic volume. Kaplan-Meier estimation of the probability of the patients' survival followed up to 28 days showed significant differences between the groups (p=0.03). The hazard ratio for 28-day mortality in the first tertile group was 3.46 (95% CI 1.3-10.2; p=0.01) as compared with patients in the third tertile group. Patients with smaller spleens had increased odds ratios for mortality in the logistic regression model. CONCLUSIONS Splenic volume appeared to be an independent predictor of poor prognosis.
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Affiliation(s)
- Yumi Mitsuyama
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka, Japan; Division of Trauma and Surgical Critical Care, Osaka General Medical Center, Osaka, Japan.
| | - Kentaro Shimizu
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Atsushi Hirayama
- Public Health, Department of Social Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Sho Komukai
- Division of Biomedical Statistics, Department of Integrated Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tetsuhisa Kitamura
- Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Hiroshi Ogura
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Takeshi Shimazu
- Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
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The Pneumococcal Polysaccharide-Tetanus Toxin Native C-Fragment Conjugate Vaccine: The Carrier Effect and Immunogenicity. Mediators Inflamm 2020; 2020:9596129. [PMID: 32714092 PMCID: PMC7355367 DOI: 10.1155/2020/9596129] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 06/15/2020] [Indexed: 11/18/2022] Open
Abstract
The encapsulated bacteria, as Streptococcus pneumonia, Haemophilus influenzae type b, and Neisseria meningitidis, cause serious morbidity and mortality worldwide. The capsular polysaccharide (PS), which could elicit a weak T cell-independent immune response, is a vital virulence determinant. One of the strategies to improve the PS-specific immunogenicity is to conjugate PS with a nontoxic carrier protein. Tetanus toxoid (TT) and CRM197 are the typical carrier proteins for the PS conjugate vaccines. TT is the inactivated tetanus toxin manipulated with formaldehyde, which suffers from the pollution from residual formaldehyde and the incomplete detoxification. CRM197 has the disadvantage of low-yield purification with the requirement of sophisticated culture conditions. Thus, a novel carrier protein without these disadvantages is highly required. The tetanus toxin native C-fragment (Hc) is safe, low-cost, and highly immunogenic with easy purification, which can act as a promising carrier protein. Pneumococcal serogroups 14 and 23F were major epidemic causes of pneumococcal infections. In the present study, the capsular PSs (PS14 and PS23F) were conjugated with Hc, TT, and CRM197, respectively. TT- and CRM197-based conjugates acted as controls for Hc-based conjugates (PS14-Hc and PS23F-Hc). The structural properties of Hc were not fundamentally changed after conjugated with PS. PS14-Hc and PS23F-Hc could potentiate sound PS-specific antibody levels comparable to the controls. Thus, Hc exhibited a practical carrier effect to help the pneumococcal conjugate vaccines perform good immunogenicities.
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Riesbeck K. Complement evasion by the human respiratory tract pathogens Haemophilus influenzae and Moraxella catarrhalis. FEBS Lett 2020; 594:2586-2597. [PMID: 32053211 DOI: 10.1002/1873-3468.13758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 01/26/2020] [Accepted: 02/09/2020] [Indexed: 12/14/2022]
Abstract
All infective bacterial species need to conquer the innate immune system in order to colonize and survive in their hosts. The human respiratory pathogens Haemophilus influenzae and Moraxella catarrhalis are no exceptions and have developed sophisticated mechanisms to evade complement-mediated killing. Both bacterial species carry lipooligosaccharides preventing complement attacks and attract and utilize host complement regulators C4b binding protein and factor H to inhibit the classical and alternative pathways of complement activation, respectively. In addition, the regulator of the terminal pathway of complement activation, vitronectin, is hijacked by both bacteria. An array of different outer membrane proteins (OMP) in H. influenzae and M. catarrhalis simultaneously binds complement regulators, but also plasminogen. Several of the bacterial complement-binding proteins are important adhesins and contain highly conserved regions for interactions with the host. Thus, some of the OMP are viable targets for new therapeutics, including vaccines aimed at preventing respiratory tract diseases such as otitis media in children and exacerbations in patients suffering from chronic obstructive pulmonary disease.
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Affiliation(s)
- Kristian Riesbeck
- Clinical Microbiology, Department of Translational Medicine, Faculty of Medicine, Lund University, Malmö, Sweden
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