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Evolutionary Conservation, Variability, and Adaptation of Type III Secretion Systems. J Membr Biol 2022; 255:599-612. [PMID: 35695900 DOI: 10.1007/s00232-022-00247-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 05/20/2022] [Indexed: 10/18/2022]
Abstract
Type III secretion (T3S) systems are complex bacterial structures used by many pathogens to inject proteins directly into the cytosol of the host cell. These secretion machines evolved from the bacterial flagella and they have been grouped into families by phylogenetic analysis. The T3S system is composed of more than 20 proteins grouped into five complexes: the cytosolic platform, the export apparatus, the basal body, the needle, and the translocon complex. While the proteins located inside the bacterium are conserved, those exposed to the external media present high variability among families. This suggests that the T3S systems have adapted to interact with different cells or tissues in the host, and/or have been subjected to the evolutionary pressure of the host immune defenses. Such adaptation led to changes in the sequence of the T3S needle tip and translocon suggesting differences in the mechanism of assembly and structure of this complex.
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2
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Kinoshita M, Shimizu M, Akiyama K, Kato H, Moriyama K, Sawa T. Epidemiological survey of serum titers from adults against various Gram-negative bacterial V-antigens. PLoS One 2020; 15:e0220924. [PMID: 32155175 PMCID: PMC7064248 DOI: 10.1371/journal.pone.0220924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 02/24/2020] [Indexed: 11/18/2022] Open
Abstract
The V-antigen, a virulence-associated protein, was first identified in Yersinia pestis more than half a century ago. Since then, other V-antigen homologs and orthologs have been discovered and are now considered as critical molecules for the toxic effects mediated by the type III secretion system during infections caused by various pathogenic Gram-negative bacteria. After purifying recombinant V-antigen proteins, including PcrV from Pseudomonas aeruginosa, LcrV from Yersinia, LssV from Photorhabdus luminescens, AcrV from Aeromonas salmonicida, and VcrV from Vibrio parahaemolyticus, we developed an enzyme-linked immunoabsorbent assay to measure titers against each V-antigen in sera collected from 186 adult volunteers. Different titer-specific correlation levels were determined for the five V-antigens. The anti-LcrV and anti-AcrV titers shared the highest correlation with each other with a correlation coefficient of 0.84. The next highest correlation coefficient was between anti-AcrV and anti-VcrV titers at 0.79, while the lowest correlation was found between anti-LcrV and anti-VcrV titers, which were still higher than 0.7. Sera from mice immunized with one of the five recombinant V-antigens displayed cross-antigenicity with some of the other four V-antigens, supporting the results from the human sera. Thus, the serum anti-V-antigen titer measurement system may be used for epidemiological investigations of various pathogenic Gram-negative bacteria.
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Affiliation(s)
- Mao Kinoshita
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Masaru Shimizu
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Koichi Akiyama
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hideya Kato
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kiyoshi Moriyama
- Department of Anesthesiology, School of Medicine, Kyorin University, Tokyo, Japan
| | - Teiji Sawa
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
- * E-mail:
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3
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Sawa T, Kinoshita M, Inoue K, Ohara J, Moriyama K. Immunoglobulin for Treating Bacterial Infections: One More Mechanism of Action. Antibodies (Basel) 2019; 8:antib8040052. [PMID: 31684203 PMCID: PMC6963986 DOI: 10.3390/antib8040052] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/17/2019] [Accepted: 10/28/2019] [Indexed: 02/08/2023] Open
Abstract
The mechanisms underlying the effects of immunoglobulins on bacterial infections are thought to involve bacterial cell lysis via complement activation, phagocytosis via bacterial opsonization, toxin neutralization, and antibody-dependent cell-mediated cytotoxicity. Nevertheless, recent advances in the study of the pathogenicity of Gram-negative bacteria have raised the possibility of an association between immunoglobulin and bacterial toxin secretion. Over time, new toxin secretion systems like the type III secretion system have been discovered in many pathogenic Gram-negative bacteria. With this system, the bacterial toxins are directly injected into the cytoplasm of the target cell through a special secretory apparatus without any exposure to the extracellular environment, and therefore with no opportunity for antibodies to neutralize the toxin. However, antibodies against the V-antigen, which is located on the needle-shaped tip of the bacterial secretion apparatus, can inhibit toxin translocation, thus raising the hope that the toxin may be susceptible to antibody targeting. Because multi-drug resistant bacteria are now prevalent, inhibiting this secretion mechanism is an attractive alternative or adjunctive therapy against lethal bacterial infections. Thus, it is not unreasonable to define the blocking effect of anti-V-antigen antibodies as the fifth mechanism for immunoglobulin action against bacterial infections.
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Affiliation(s)
- Teiji Sawa
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
| | - Mao Kinoshita
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
| | - Keita Inoue
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
| | - Junya Ohara
- Department of Anesthesiology, School of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
| | - Kiyoshi Moriyama
- Department of Anesthesiology, Kyorin University School of Medicine, Tokyo 181-8611, Japan.
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4
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Zhang L, Chen L, Dong H. Plant Aquaporins in Infection by and Immunity Against Pathogens - A Critical Review. FRONTIERS IN PLANT SCIENCE 2019; 10:632. [PMID: 31191567 PMCID: PMC6546722 DOI: 10.3389/fpls.2019.00632] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/26/2019] [Indexed: 05/18/2023]
Abstract
Plant aquaporins (AQPs) of the plasma membrane intrinsic protein (PIP) family face constant risk of hijack by pathogens aiming to infect plants. PIPs can also be involved in plant immunity against infection. This review will utilize two case studies to discuss biochemical and structural mechanisms that govern the functions of PIPs in the regulation of plant infection and immunity. The first example concerns the interaction between rice Oryza sativa and the bacterial blight pathogen Xanthomonas oryzae pv. oryzae (Xoo). To infect rice, Xoo uses the type III (T3) secretion system to secrete the proteic translocator Hpa1, and Hpa1 subsequently mediates the translocation of T3 effectors secreted by this system. Once shifted from bacteria into rice cells, effectors exert virulent or avirulent effects depending on the susceptibility of the rice varieties. The translocator function of Hpa1 requires cooperation with OsPIP1;3, the rice interactor of Hpa1. This role of OsPIP1;3 is related to regulatory models of effector translocation. The regulatory models have been proposed as, translocon-dependent delivery, translocon-independent pore formation, and effector endocytosis with membrane protein/lipid trafficking. The second case study includes the interaction of Hpa1 with the H2O2 transport channel AtPIP1;4, and the associated consequence for H2O2 signal transduction of immunity pathways in Arabidopsis thaliana, a non-host of Xoo. H2O2 is generated in the apoplast upon induction by a pathogen or microbial pattern. H2O2 from this source translocates quickly into Arabidopsis cells, where it interacts with pathways of intracellular immunity to confer plant resistance against diseases. To expedite H2O2 transport, AtPIP1;4 must adopt a specific conformation in a number of ways, including channel width extension through amino acid interactions and selectivity for H2O2 through amino acid protonation and tautomeric reactions. Both topics will reference relevant studies, conducted on other organisms and AQPs, to highlight possible mechanisms of T3 effector translocation currently under debate, and highlight the structural basis of AtPIP1;4 in H2O2 transport facilitated by gating and trafficking regulation.
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Affiliation(s)
- Liyuan Zhang
- Plant Immunity Research Group, National Key Laboratory of Crop Science, Department of Plant Pathology, Shandong Agricultural University, Tai’an, China
| | - Lei Chen
- Plant Immunity Research Group, National Key Laboratory of Crop Science, Department of Plant Pathology, Shandong Agricultural University, Tai’an, China
| | - Hansong Dong
- Plant Immunity Research Group, National Key Laboratory of Crop Science, Department of Plant Pathology, Shandong Agricultural University, Tai’an, China
- Plant Immunity Laboratory, Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
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Carvalho AL, Miquel-Clopés A, Wegmann U, Jones E, Stentz R, Telatin A, Walker NJ, Butcher WA, Brown PJ, Holmes S, Dennis MJ, Williamson ED, Funnell SGP, Stock M, Carding SR. Use of bioengineered human commensal gut bacteria-derived microvesicles for mucosal plague vaccine delivery and immunization. Clin Exp Immunol 2019; 196:287-304. [PMID: 30985006 PMCID: PMC6514708 DOI: 10.1111/cei.13301] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2019] [Indexed: 12/19/2022] Open
Abstract
Plague caused by the Gram‐negative bacterium, Yersinia pestis, is still endemic in parts of the world today. Protection against pneumonic plague is essential to prevent the development and spread of epidemics. Despite this, there are currently no licensed plague vaccines in the western world. Here we describe the means of delivering biologically active plague vaccine antigens directly to mucosal sites of plague infection using highly stable microvesicles (outer membrane vesicles; OMVs) that are naturally produced by the abundant and harmless human commensal gut bacterium Bacteroides thetaiotaomicron (Bt). Bt was engineered to express major plague protective antigens in its OMVs, specifically Fraction 1 (F1) in the outer membrane and LcrV (V antigen) in the lumen, for targeted delivery to the gastrointestinal (GI) and respiratory tracts in a non‐human primate (NHP) host. Our key findings were that Bt OMVs stably expresses F1 and V plague antigens, particularly the V antigen, in the correct, immunogenic form. When delivered intranasally V‐OMVs elicited substantive and specific immune and antibody responses, both in the serum [immunoglobulin (Ig)G] and in the upper and lower respiratory tract (IgA); this included the generation of serum antibodies able to kill plague bacteria. Our results also showed that Bt OMV‐based vaccines had many desirable characteristics, including: biosafety and an absence of any adverse effects, pathology or gross alteration of resident microbial communities (microbiotas); high stability and thermo‐tolerance; needle‐free delivery; intrinsic adjuvanticity; the ability to stimulate both humoral and cell‐mediated immune responses; and targeting of primary sites of plague infection.
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Affiliation(s)
- A L Carvalho
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - A Miquel-Clopés
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - U Wegmann
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - E Jones
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - R Stentz
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - A Telatin
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK
| | - N J Walker
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - W A Butcher
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - P J Brown
- Public Health England, Porton, Porton, Salisbury, UK
| | - S Holmes
- Public Health England, Porton, Porton, Salisbury, UK
| | - M J Dennis
- Public Health England, Porton, Porton, Salisbury, UK
| | - E D Williamson
- Defence Science and Technology Laboratory, Porton, Salisbury, UK
| | - S G P Funnell
- Public Health England, Porton, Porton, Salisbury, UK
| | - M Stock
- Plant Biotechnology Ltd, Norwich, UK
| | - S R Carding
- Gut Microbes and Health Research Programme, Quadram Institute Bioscience, Norwich, UK.,Norwich Medical School, University East Anglia, Norwich, UK
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Barta ML, Shearer JP, Arizmendi O, Tremblay JM, Mehzabeen N, Zheng Q, Battaile KP, Lovell S, Tzipori S, Picking WD, Shoemaker CB, Picking WL. Single-domain antibodies pinpoint potential targets within Shigella invasion plasmid antigen D of the needle tip complex for inhibition of type III secretion. J Biol Chem 2017; 292:16677-16687. [PMID: 28842484 DOI: 10.1074/jbc.m117.802231] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 08/14/2017] [Indexed: 12/18/2022] Open
Abstract
Numerous Gram-negative pathogens infect eukaryotes and use the type III secretion system (T3SS) to deliver effector proteins into host cells. One important T3SS feature is an extracellular needle with an associated tip complex responsible for assembly of a pore-forming translocon in the host cell membrane. Shigella spp. cause shigellosis, also called bacillary dysentery, and invade colonic epithelial cells via the T3SS. The tip complex of Shigella flexneri contains invasion plasmid antigen D (IpaD), which initially regulates secretion and provides a physical platform for the translocon pore. The tip complex represents a promising therapeutic target for many important T3SS-containing pathogens. Here, in an effort to further elucidate its function, we created a panel of single-VH domain antibodies (VHHs) that recognize distinct epitopes within IpaD. These VHHs recognized the in situ tip complex and modulated the infectious properties of Shigella Moreover, structural elucidation of several IpaD-VHH complexes provided critical insights into tip complex formation and function. Of note, one VHH heterodimer could reduce Shigella hemolytic activity by >80%. Our observations along with previous findings support the hypothesis that the hydrophobic translocator (IpaB in Shigella) likely binds to a region within the tip protein that is structurally conserved across all T3SS-possessing pathogens, suggesting potential therapeutic avenues for managing infections by these pathogens.
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Affiliation(s)
- Michael L Barta
- From the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Jonathan P Shearer
- Department of Infectious Diseases and Global Health, Tufts Clinical and Translational Science Institute, North Grafton, Massachusetts 02111
| | - Olivia Arizmendi
- From the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Jacqueline M Tremblay
- Department of Infectious Diseases and Global Health, Tufts Clinical and Translational Science Institute, North Grafton, Massachusetts 02111
| | - Nurjahan Mehzabeen
- Protein Structure Laboratory, Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047, and
| | - Qi Zheng
- From the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Kevin P Battaile
- IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne, Illinois 60439
| | - Scott Lovell
- Protein Structure Laboratory, Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047, and
| | - Saul Tzipori
- Department of Infectious Diseases and Global Health, Tufts Clinical and Translational Science Institute, North Grafton, Massachusetts 02111
| | - William D Picking
- From the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Tufts Clinical and Translational Science Institute, North Grafton, Massachusetts 02111
| | - Wendy L Picking
- From the Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, Kansas 66047,
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7
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Hamaoka S, Naito Y, Katoh H, Shimizu M, Kinoshita M, Akiyama K, Kainuma A, Moriyama K, Ishii KJ, Sawa T. Efficacy comparison of adjuvants in PcrV vaccine against Pseudomonas aeruginosa pneumonia. Microbiol Immunol 2017; 61:64-74. [PMID: 28370521 DOI: 10.1111/1348-0421.12467] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/16/2017] [Accepted: 01/19/2017] [Indexed: 11/27/2022]
Abstract
Vaccination against the type III secretion system of P. aeruginosa is a potential prophylactic strategy for reducing the incidence and improving the poor prognosis of P. aeruginosa pneumonia. In this study, the efficacies of three different adjuvants, Freund's adjuvant (FA), aluminum hydroxide (alum) and CpG oligodeoxynucleotide (ODN), were examined from the viewpoint of inducing PcrV-specific immunity against virulent P. aeruginosa. Mice that had been immunized intraperitoneally with recombinant PcrV formulated with one of the above adjuvants were challenged intratracheally with a lethal dose of P. aeruginosa. The PcrV-FA immunized group attained a survival rate of 91%, whereas the survival rates of the PcrV-alum and PcrV-CpG groups were 73% and 64%, respectively. In terms of hypothermia recovery after bacterial instillation, PcrV-alum was the most protective, followed by PcrV-FA and PcrV-CpG. The lung edema index was lower in the PcrV-CpG vaccination group than in the other groups. PcrV-alum immunization was associated with the greatest decrease in myeloperoxidase in infected lungs, and also decreased the number of lung bacteria to a similar number as in the PcrV-FA group. There was less neutrophil recruitment in the lungs of mice vaccinated with PcrV-alum or PcrV-CpG than in those of mice vaccinated with PcrV-FA or PcrV alone. Overall, in terms of mouse survival the PcrV-CpG vaccine, which could be a relatively safe next-generation vaccine, showed a comparable effect to the PcrV-alum vaccine.
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Affiliation(s)
- Saeko Hamaoka
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Yoshifumi Naito
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Hideya Katoh
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Masaru Shimizu
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Mao Kinoshita
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Koichi Akiyama
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Atsushi Kainuma
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
| | - Kiyoshi Moriyama
- Department of Anesthesiology, School of Medicine, Kyorin University, Mitaka 181-8611, Japan
| | - Ken J Ishii
- Laboratory of Adjuvant Innovation, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka 567-0085, Japan.,Laboratory of Vaccine Science, Immunology Frontier Research Center, World Premier International Research Center, Osaka University, Suita, Osaka 565-0871, Japan
| | - Teiji Sawa
- Department of Anesthesiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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Grabowski B, Schmidt MA, Rüter C. Immunomodulatory Yersinia outer proteins (Yops)-useful tools for bacteria and humans alike. Virulence 2017; 8:1124-1147. [PMID: 28296562 DOI: 10.1080/21505594.2017.1303588] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Human-pathogenic Yersinia produce plasmid-encoded Yersinia outer proteins (Yops), which are necessary to down-regulate anti-bacterial responses that constrict bacterial survival in the host. These Yops are effectively translocated directly from the bacterial into the target cell cytosol by the type III secretion system (T3SS). Cell-penetrating peptides (CPPs) in contrast are characterized by their ability to autonomously cross cell membranes and to transport cargo - independent of additional translocation systems. The recent discovery of bacterial cell-penetrating effector proteins (CPEs) - with the prototype being the T3SS effector protein YopM - established a new class of autonomously translocating immunomodulatory proteins. CPEs represent a vast source of potential self-delivering, anti-inflammatory therapeutics. In this review, we give an update on the characteristic features of the plasmid-encoded Yops and, based on recent findings, propose the further development of these proteins for potential therapeutic applications as natural or artificial cell-penetrating forms of Yops might be of value as bacteria-derived biologics.
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Affiliation(s)
- Benjamin Grabowski
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
| | - M Alexander Schmidt
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
| | - Christian Rüter
- a Institute of Infectiology - Centre for Molecular Biology of Inflammation (ZMBE), University of Münster , Münster , Germany
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Kinoshita M, Kato H, Yasumoto H, Shimizu M, Hamaoka S, Naito Y, Akiyama K, Moriyama K, Sawa T. The prophylactic effects of human IgG derived from sera containing high anti-PcrV titers against pneumonia-causing Pseudomonas aeruginosa. Hum Vaccin Immunother 2016; 12:2833-2846. [PMID: 27454613 DOI: 10.1080/21645515.2016.1209280] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The PcrV cap structure of the type III secretory apparatus of Pseudomonas aeruginosa is a vaccine target. Human immunoglobulin G (IgG) molecules extracted from sera containing high or low anti-PcrV titers were tested for their effects against P. aeruginosa pneumonia in a mouse model. Among 198 volunteers, we selected the top 10 high anti-PcrV titer sera and the bottom 10 low anti-PcrV titer sera and extracted the IgG fraction from each serum sample. First, we examined the effects of the IgG against virulent P. aeruginosa. A lethal dose of P. aeruginosa premixed with saline, low titer human IgG, high titer human IgG, or rabbit-derived polyclonal anti-PcrV IgG was intratracheally administered into the lungs of mice, and their survival and lung inflammation were evaluated for 24 h. The high anti-PcrV titer human IgG had a prophylactic effect. Next, the prophylactic effects of intravenous administration of extracted and pooled high or low anti-PcrV titer human IgG were examined. Here, prophylactic intravenous administration of pooled high anti-PcrV titer human IgG, which showed binding capacity to P. aeruginosa PcrV, was more effective than the administration of its low titer pooled equivalent, and the measured physiological and inflammatory parameters correlated with the anti-PcrV titer levels. This result indirectly implies that high anti-PcrV titers in blood can help to protect against virulent P. aeruginosa infections. In addition, the IgG fractions from such high titer sera have potential to be a source of specific intravenous immunoglobulin products for passive vaccination against virulent P. aeruginosa infections.
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Affiliation(s)
- Mao Kinoshita
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Hideya Kato
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Hiroaki Yasumoto
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Masaru Shimizu
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Saeko Hamaoka
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Yoshifumi Naito
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Koichi Akiyama
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
| | - Kiyoshi Moriyama
- b Department of Anesthesiology , School of Medicine, Kyorin University , Mitaka , Japan
| | - Teiji Sawa
- a Department of Anesthesiology , Kyoto Prefectural University of Medicine , Kyoto , Japan
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10
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De Tavernier E, Detalle L, Morizzo E, Roobrouck A, De Taeye S, Rieger M, Verhaeghe T, Correia A, Van Hegelsom R, Figueirido R, Noens J, Steffensen S, Stöhr T, Van de Velde W, Depla E, Dombrecht B. High Throughput Combinatorial Formatting of PcrV Nanobodies for Efficient Potency Improvement. J Biol Chem 2016; 291:15243-55. [PMID: 27226529 DOI: 10.1074/jbc.m115.684241] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Indexed: 11/06/2022] Open
Abstract
Improving potencies through concomitant blockage of multiple epitopes and avid binding by fusing multiple (different) monovalent Nanobody building blocks via linker sequences into one multivalent polypeptide chain is an elegant alternative to affinity maturation. We explored a large and random formatting library of bivalent (combinations of two identical) and biparatopic (combinations of two different) Nanobodies for functional blockade of Pseudomonas aeruginosa PcrV. PcrV is an essential part of the P. aeruginosa type III secretion system (T3SS), and its oligomeric nature allows for multiple complex binding and blocking options. The library screening yielded a large number of promising biparatopic lead candidates, revealing significant (and non-trivial) preferences in terms of Nanobody building block and epitope bin combinations and orientations. Excellent potencies were confirmed upon further characterization in two different P. aeruginosa T3SS-mediated cytotoxicity assays. Three biparatopic Nanobodies were evaluated in a lethal mouse P. aeruginosa challenge pneumonia model, conferring 100% survival upon prophylactic administration and reducing lung P. aeruginosa burden by up to 2 logs. At very low doses, they protected the mice from P. aeruginosa infection-related changes in lung histology, myeloperoxidase production, and lung weight. Importantly, the most potent Nanobody still conferred protection after therapeutic administration up to 24 h post-infection. The concept of screening such formatting libraries for potency improvement is applicable to other targets and biological therapeutic platforms.
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Affiliation(s)
| | | | - Erika Morizzo
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
| | | | | | - Melanie Rieger
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
| | - Tom Verhaeghe
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
| | | | | | | | - Jeroen Noens
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
| | | | - Thomas Stöhr
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
| | | | - Erik Depla
- From Ablynx N.V., Technologiepark 21, 9052 Ghent, Belgium
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11
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Sawa T, Ito E, Nguyen VH, Haight M. Anti-PcrV antibody strategies against virulent Pseudomonas aeruginosa. Hum Vaccin Immunother 2015; 10:2843-52. [PMID: 25483637 DOI: 10.4161/21645515.2014.971641] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic bacterial pathogen that causes fatal acute lung infections in critically ill individuals. Its pathogenesis is associated with bacterial virulence conferred by the type III secretion system (TTSS), through which P. aeruginosa causes necrosis of the lung epithelium and disseminates into the circulation, resulting in bacteremia, sepsis, and mortality. TTSS allows P. aeruginosa to directly translocate cytotoxins into eukaryotic cells, inducing cell death. The P. aeruginosa V-antigen PcrV, a homolog of the Yersinia V-antigen LcrV, is an indispensable contributor to TTS toxin translocation. Vaccination against PcrV ensures the survival of challenged mice and decreases lung inflammation and injury. Both the rabbit polyclonal anti-PcrV antibody and the murine monoclonal anti-PcrV antibody, mAb166, inhibit TTS toxin translocation. mAb166 IgG was cloned, and a molecular engineered humanized anti-PcrV IgG antigen-binding fragment, KB001, was developed for clinical use. KB001 is currently undergoing Phase-II clinical trials for ventilator-associated pneumonia in France and chronic pneumonia in cystic fibrosis in USA. In these studies, KB001 has demonstrated its safety, a favorable pharmacokinetic profile, and promising potential as a nonantibiotic strategy to reduce airway inflammation and damage in P. aeruginosa pneumonia.
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Key Words
- CF, cystic fibrosis
- Fab, fragment antigen binding
- Fc, fragment crystallizable region
- MDR, multidrug resistant
- MDRP, multidrug resistant Pseudomonas aeruginosa
- P. aeruginosa, Pseudomonas aeruginosa
- PcrV
- Pseudomonas aeruginosa
- TTS, type III secretory
- TTSS, type III secretion system
- V-antigen
- VAP, ventilator-associated pneumonia
- antibody
- immunoglobulin G, IgG
- mAb, monoclonal antibody
- type III secretion system
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Affiliation(s)
- Teiji Sawa
- a Department of Anesthesiology ; Kyoto Prefectural University of Medicine ; Kyoto , Japan
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Sawa T, Shimizu M, Moriyama K, Wiener-Kronish JP. Association between Pseudomonas aeruginosa type III secretion, antibiotic resistance, and clinical outcome: a review. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:668. [PMID: 25672496 PMCID: PMC4331484 DOI: 10.1186/s13054-014-0668-9] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Pseudomonas aeruginosa uses a complex type III secretion system to inject the toxins ExoS, ExoT, ExoU, and ExoY into the cytosol of target eukaryotic cells. This system is regulated by the exoenzyme S regulon and includes the transcriptional activator ExsA. Of the four toxins, ExoU is characterized as the major virulence factor responsible for alveolar epithelial injury in patients with P. aeruginosa pneumonia. Virulent strains of P. aeruginosa possess the exoU gene, whereas non-virulent strains lack this particular gene. The mechanism of virulence for the exoU+ genotype relies on the presence of a pathogenic gene cluster (PAPI-2) encoding exoU and its chaperone, spcU. The ExoU toxin has a patatin-like phospholipase domain in its N-terminal, exhibits phospholipase A2 activity, and requires a eukaryotic cell factor for activation. The C-terminal of ExoU has a ubiquitinylation mechanism of activation. This probably induces a structural change in enzymatic active sites required for phospholipase A2 activity. In P. aeruginosa clinical isolates, the exoU+ genotype correlates with a fluoroquinolone resistance phenotype. Additionally, poor clinical outcomes have been observed in patients with pneumonia caused by exoU+-fluoroquinolone-resistant isolates. Therefore, the potential exists to improve clinical outcomes in patients with P. aeruginosa pneumonia by identifying virulent and antimicrobial drug-resistant strains through exoU genotyping or ExoU protein phenotyping or both.
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