Efficacy of an experimental gonococcal lipooligosaccharide mimitope vaccine requires terminal complement

Abstract A safe and effective vaccine against multidrug-resistant gonorrhea is urgently needed. An experimental peptide vaccine called TMCP2 that mimics an oligosaccharide epitope in gonococcal lipooligosaccharide, when adjuvanted with glucopyranosyl lipid adjuvant-stable emulsion (GLA-SE), elicits bactericidal IgG and hastens clearance of gonococci in the mouse vaginal colonization model. Here, we show that efficacy of TMCP2 requires an intact terminal complement pathway, evidenced by loss of activity in C9 -/- mice or when C7 function was blocked. In conclusion, TMCP2 vaccine efficacy in the mouse vagina requires membrane attack complex. Serum bactericidal activity may serve as a correlate of protection for TMCP2.

Download Full-text

Inhibition of the Membrane Attack Complex by Dengue Virus NS1 through Interaction with Vitronectin and Terminal Complement Proteins

Journal of Virology ◽

10.1128/jvi.00912-16 ◽

2016 ◽

Vol 90 (21) ◽

pp. 9570-9581 ◽

Cited By ~ 29

Author(s):

Jonas Nascimento Conde ◽

Emiliana Mandarano da Silva ◽

Diego Allonso ◽

Diego Rodrigues Coelho ◽

Iamara da Silva Andrade ◽

...

Keyword(s):

Dengue Virus ◽

Complement System ◽

Membrane Attack Complex ◽

Denv Infection ◽

Enzyme Linked Immunosorbent Assay ◽

Complement Pathway ◽

Binding Partner ◽

Complement Regulator ◽

The Complement System ◽

Terminal Complement

ABSTRACTDengue virus (DENV) infects millions of people worldwide and is a major public health problem. DENV nonstructural protein 1 (NS1) is a conserved glycoprotein that associates with membranes and is also secreted into the plasma in DENV-infected patients. The present study describes a novel mechanism by which NS1 inhibits the terminal complement pathway. We first identified the terminal complement regulator vitronectin (VN) as a novel DENV2 NS1 binding partner by using a yeast two-hybrid system. This interaction was further assessed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay. The NS1-VN complex was also detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the DENV2 NS1 protein, either by itself or by interacting with VN, hinders the formation of the membrane attack complex (MAC) and C9 polymerization. Finally, we showed that DENV2, West Nile virus (WNV), and Zika virus (ZIKV) NS1 proteins produced in mammalian cells inhibited C9 polymerization. Taken together, our results points to a role for NS1 as a terminal pathway inhibitor of the complement system.IMPORTANCEDengue is the most important arthropod-borne viral disease nowadays and is caused by dengue virus (DENV). The flavivirus NS1 glycoprotein has been characterized functionally as a complement evasion protein that can attenuate the activation of the classical, lectin, and alternative pathways. The present study describes a novel mechanism by which DENV NS1 inhibits the terminal complement pathway. We identified the terminal complement regulator vitronectin (VN) as a novel DENV NS1 binding partner, and the NS1-VN complex was detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the NS1-VN complex inhibited membrane attack complex (MAC) formation, thus interfering with the complement terminal pathway. Interestingly, NS1 itself also inhibited MAC activity, suggesting a direct role of this protein in the inhibition process. Our findings imply a role for NS1 as a terminal pathway inhibitor of the complement system.

Download Full-text

Skeletal muscle reperfusion injury is mediated by neutrophils and the complement membrane attack complex

AJP Cell Physiology ◽

10.1152/ajpcell.1999.277.6.c1263 ◽

1999 ◽

Vol 277 (6) ◽

pp. C1263-C1268 ◽

Cited By ~ 60

Author(s):

Constantinos Kyriakides ◽

William Austen ◽

Yong Wang ◽

Joanne Favuzza ◽

Lester Kobzik ◽

...

Keyword(s):

Skeletal Muscle ◽

Reperfusion Injury ◽

Membrane Attack Complex ◽

Wild Type ◽

Complement Components ◽

Neutrophil Activity ◽

Deficient Mice ◽

Terminal Complement

The relative inflammatory roles of neutrophils, selectins, and terminal complement components are investigated in this study of skeletal muscle reperfusion injury. Mice underwent 2 h of hindlimb ischemia followed by 3 h of reperfusion. The role of neutrophils was defined by immunodepletion, which reduced injury by 38%, as did anti-selectin therapy with recombinant soluble P-selectin glycoprotein ligand-immunoglobulin (Ig) fusion protein. Injury in C5-deficient and soluble complement receptor type 1-treated wild-type mice was 48% less than that of untreated wild-type animals. Injury was restored in C5-deficient mice reconstituted with wild-type serum, indicating the effector role of C5–9. Neutropenic C5-deficient animals showed additive reduction in injuries (71%), which was lower than C5-deficient neutrophil-replete mice, indicating neutrophil activity without C5a. Hindlimb histological injury was worse in ischemic wild-type and C5-deficient animals reconstituted with wild-type serum. In conclusion, the membrane attack complex and neutrophils act additively to mediate skeletal muscle reperfusion injury. Neutrophil activity is independent of C5a but is dependent on selectin-mediated adhesion.

Download Full-text

Immunoinformatics and Structural Analysis for Identification of Immunodominant Epitopes in SARS-CoV-2 as Potential Vaccine Targets

Vaccines ◽

10.3390/vaccines8020290 ◽

2020 ◽

Vol 8 (2) ◽

pp. 290 ◽

Cited By ~ 13

Author(s):

Sumit Mukherjee ◽

Dmitry Tworowski ◽

Rajesh Detroja ◽

Sunanda Biswas Mukherjee ◽

Milana Frenkel-Morgenstern

Keyword(s):

Peptide Vaccine ◽

Vaccine Design ◽

Computational Prediction ◽

Effective Vaccine ◽

Cell Mediated Immunity ◽

T Cell Epitopes ◽

Protective Antigens ◽

Global Pandemic ◽

Time Required ◽

Immunodominant Epitopes

A new coronavirus infection, COVID-19, has recently emerged, and has caused a global pandemic along with an international public health emergency. Currently, no licensed vaccines are available for COVID-19. The identification of immunodominant epitopes for both B- and T-cells that induce protective responses in the host is crucial for effective vaccine design. Computational prediction of potential epitopes might significantly reduce the time required to screen peptide libraries as part of emergent vaccine design. In our present study, we used an extensive immunoinformatics-based approach to predict conserved immunodominant epitopes from the proteome of SARS-CoV-2. Regions from SARS-CoV-2 protein sequences were defined as immunodominant, based on the following three criteria regarding B- and T-cell epitopes: (i) they were both mapped, (ii) they predicted protective antigens, and (iii) they were completely identical to experimentally validated epitopes of SARS-CoV. Further, structural and molecular docking analyses were performed in order to understand the binding interactions of the identified immunodominant epitopes with human major histocompatibility complexes (MHC). Our study provides a set of potential immunodominant epitopes that could enable the generation of both antibody- and cell-mediated immunity. This could contribute to developing peptide vaccine-based adaptive immunotherapy against SARS-CoV-2 infections and prevent future pandemic outbreaks.

Download Full-text

Pilot Ex Vivo and In Vitro Evaluation of a Novel Foley Catheter with Antimicrobial Periurethral Irrigation for Prevention of Extraluminal Biofilm Colonization Leading to Catheter-Associated Urinary Tract Infections (CAUTIs)

BioMed Research International ◽

10.1155/2019/2869039 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Nylev Vargas-Cruz ◽

Joel Rosenblatt ◽

Ruth A Reitzel ◽

Anne-Marie Chaftari ◽

Ray Hachem ◽

...

Keyword(s):

Ex Vivo ◽

Foley Catheter ◽

Irrigation Treatment ◽

Multidrug Resistant ◽

Indwelling Catheter ◽

Carbapenem Resistant ◽

Colonization Model ◽

Tract Infections

CAUTI remains a serious healthcare issue for incontinent patients whose urine drainage is managed by catheters. A novel double-balloon Foley catheter was developed which was capable of irrigating the extraluminal catheter surfaces within the periurethral space between the urethral-bladder junction and meatus. The catheter has a retention cuff that is inflated to secure the catheter in the bladder and a novel irrigation cuff proximal to the urethral-bladder junction capable of providing periurethral irrigation from the urethral-bladder junction to the meatus. Uniform periurethral irrigation was demonstrated in an ex vivo porcine model by adding a dye to the antimicrobial urethral irrigation solution. An in vitro biofilm colonization model was adapted to study the ability of periurethral irrigation with a newly developed antimicrobial combination consisting of polygalacturonic acid + caprylic acid (PG + CAP) to prevent axial colonization of the extraluminal urethral indwelling catheter shaft by common uropathogens. The extraluminal surface of control catheters that were not irrigated formed biofilms along the entire axial urethral tract after 24 hours. Significant (p<0.001) inhibition of colonization was seen against multidrug-resistant Pseudomonas aeruginosa (PA), carbapenem-resistant Escherichia coli (EC), and carbapenem-resistant Klebsiella pneumoniae (KB). For other common uropathogens including Candida albicans (CA), Proteus mirabilis (PR), and Enterococcus faecalis (EF), a first irrigation treatment completely inhibited colonization of half of the indwelling catheter closest to the bladder and a second treatment largely disinfected the remaining intraurethral portion of the catheter towards the meatus. The novel Foley catheter and PG + CAP antimicrobial irrigant prevented biofilm colonization in an in vitro CAUTI model and merits further testing in an in vivo CAUTI prevention model.

Download Full-text

Immunogenicity and Safety of a Chemically Synthesized Divalent Group A Streptococcal Vaccine

Canadian Journal of Infectious Diseases and Medical Microbiology ◽

10.1155/2018/4702152 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Yongxiang Wu ◽

Suhua Li ◽

Yanting Luo ◽

Yunyue Zhao ◽

Jiarui Wang ◽

...

Keyword(s):

Clinical Trial ◽

Amino Acids ◽

Survival Rate ◽

Protective Effect ◽

Health Problem ◽

Group A Streptococcus ◽

Peptide Vaccine ◽

Effective Vaccine ◽

Histopathological Analysis ◽

Group A

Background. Group A streptococcus (GAS) infections and poststreptococcal sequelae remain a health problem worldwide, which necessitates searching for an effective vaccine, while no licensed GAS vaccine is available. We have developed a divalent peptide vaccine composed of 84 amino acids to cover the main GAS serotypes (M1 and M12 streptococci) in China, and herein, we aimed to evaluate immunogenicity and safety of this vaccine.Methods. Mice were immunized with the vaccine. ELISA, indirect bactericidal test, and immunofluorescent assay were used to study immunogenicity. GAS challenge assay was used to test the protective effect. Safety was tested by histopathological analysis.Results. Immunized group mice (n=16) developed higher titer antibody after immunization than nonimmunized group mice (n=16) did. This antibody can deposit on the surface of GAS and promote killing of GAS, resulting in 93.1% decrease of M1 GAS and 89.5% of M12 GAS. When challenged with M1 and M12 streptococci, immunized group mice had a higher survival rate (87.5% and 75%) than nonimmunized group mice (37.5% and 25%). No autoimmune reactions were detected on organs of mice.Conclusion. The results suggest that this vaccine shows fair immunogenicity and safety, which will lead our research on GAS vaccine into clinical trial.

Download Full-text

Immunohistochemistry of Complement Response on Human Renal Cell Carcinoma Biopsies

Tumori Journal ◽

10.1177/030089169608200513 ◽

1996 ◽

Vol 82 (5) ◽

pp. 473-479 ◽

Cited By ~ 13

Author(s):

Tamás Magyarlaki ◽

Szilvia Mosolits ◽

Ferenc Baranyay ◽

István Buzogány

Keyword(s):

Renal Cell Carcinoma ◽

Cell Carcinoma ◽

Complement Activation ◽

Renal Cell ◽

Membrane Attack Complex ◽

Tumor Infiltrating Lymphocytes ◽

Complement Pathway ◽

Histocompatibility Complex ◽

Pathway Activation ◽

Infiltrating Lymphocytes

The goal of the study was to characterize the complement humoral and cellular antitumor responses on primary renal cell carcinoma biopsies. As an original observation, complement activation was found on 11/22 cases. Classical complement pathway activation was characterized by tumor C1q complement protein and IgG deposition (5/22 cases). Alternative or nonimmune complement pathway activation was seen as tissue deposition of C3 (6/22 cases). The membrane attack complex was present in cases with alternative complement pathway activation at the sites of tumor necrosis. Renal cell carcinomas with complement activation overexpressed at least one of the complement regulatory factors (membrane cofactor protein, decay accelerating factor, membrane attack complex inhibitor) and major histocompatibility complex class II molecules. Tumor infiltrating lymphocytes were present in most of the renal cell carcinomas with complement activation (8/11). However, the number of tumor-infiltrating lymphocytes was correlated with the intensity of major histocompatibility complex-ll expression in 18/22 cases. Detection of complement activation and immune cell infiltrates on renal cell carcinoma primary biopsies may serve as a new predictive factor for immunotherapy.

Download Full-text

Design of Epitope-Based Peptide Vaccine against Pseudomonas aeruginosa Fructose Bisphosphate Aldolase Protein Using Immunoinformatics

Journal of Immunology Research ◽

10.1155/2020/9475058 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11

Author(s):

Mustafa Elhag ◽

Ruaa Mohamed Alaagib ◽

Nagla Mohamed Ahmed ◽

Mustafa Abubaker ◽

Esraa Musa Haroun ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Peptide Vaccine ◽

Multidrug Resistant ◽

Fructose Bisphosphate ◽

Mhc I ◽

Mhc Ii ◽

Fructose Bisphosphate Aldolase ◽

Hospital Acquired

Pseudomonas aeruginosa is a common pathogen that is responsible for serious hospital-acquired infections, ventilator-associated pneumonia, and various sepsis syndromes. Also, it is a multidrug-resistant pathogen recognized for its ubiquity and its intrinsically advanced antibiotic-resistant mechanisms. It usually affects immunocompromised individuals but can also infect immunocompetent individuals. There is no vaccine against it available till now. This study predicts an effective epitope-based vaccine against fructose bisphosphate aldolase (FBA) of Pseudomonas aeruginosa using immunoinformatics tools. The protein sequences were obtained from NCBI, and prediction tests were undertaken to analyze possible epitopes for B and T cells. Three B cell epitopes passed the antigenicity, accessibility, and hydrophilicity tests. Six MHC I epitopes were found to be promising, while four MHC II epitopes were found promising from the result set. Nineteen epitopes were shared between MHC I and II results. For the population coverage, the epitopes covered 95.62% worldwide excluding certain MHC II alleles. We recommend in vivo and in vitro studies to prove its effectiveness.

Download Full-text

Development of Immunity to Serogroup B Meningococci during Carriage of Neisseria meningitidis in a Cohort of University Students

Infection and Immunity ◽

10.1128/iai.72.11.6503-6510.2004 ◽

2004 ◽

Vol 72 (11) ◽

pp. 6503-6510 ◽

Cited By ~ 30

Author(s):

J. Zoe Jordens ◽

Jeannette N. Williams ◽

Graeme R. Jones ◽

Myron Christodoulides ◽

John E. Heckels

Keyword(s):

University Students ◽

Neisseria Meningitidis ◽

Protective Immunity ◽

Capsular Polysaccharide ◽

Effective Vaccine ◽

First Year ◽

Major Step ◽

Serum Bactericidal Activity ◽

First Year University ◽

Heterologous Protection

ABSTRACT Understanding the basis of protective immunity is a key requirement for the development of an effective vaccine against infection with Neisseria meningitidis of serogroup B. We have conducted a longitudinal study into the dynamics of meningococcal acquisition and carriage in first-year university students. The detection of carriage of serogroup B meningococci correlated with an increase in detection of serum bactericidal activity (SBA) against both colonizing and heterologous serogroup B strains. Once induced, SBA remained high throughout the study. Although students showed increases in antibodies reactive with capsular polysaccharide and lipopolysaccharide (LPS), these antibody responses were transitory, and their decline was not accompanied by a corresponding decline in SBA. In contrast, there was a significant correlation between the presence of antibodies to the PorA outer membrane protein and SBA against both homologous and heterologous strains. SBA induced by a PorA-negative mutant confirmed the contribution of PorA to heterologous activity. Increases in SBA against a range of serogroup B strains were also observed in students in whom no meningococcal carriage was detected. This heterologous protection could not be associated with the presence of antibodies reacting with capsule, LPS, PorA, PorB, Rmp, Opa, Opc, or pilin, demonstrating that other, as yet unidentified, antigens contribute to the development of immunity to serogroup B meningococci. Identification of such antigens with the ability to induce an effective cross-reactive bactericidal response to a range of strains would be a major step in the production of a universally effective vaccine against infections caused by serogroup B meningococci.

Download Full-text