1
|
Barber MF, Fitzgerald JR. Mechanisms of host adaptation by bacterial pathogens. FEMS Microbiol Rev 2024; 48:fuae019. [PMID: 39003250 PMCID: PMC11308195 DOI: 10.1093/femsre/fuae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 07/02/2024] [Accepted: 07/24/2024] [Indexed: 07/15/2024] Open
Abstract
The emergence of new infectious diseases poses a major threat to humans, animals, and broader ecosystems. Defining factors that govern the ability of pathogens to adapt to new host species is therefore a crucial research imperative. Pathogenic bacteria are of particular concern, given dwindling treatment options amid the continued expansion of antimicrobial resistance. In this review, we summarize recent advancements in the understanding of bacterial host species adaptation, with an emphasis on pathogens of humans and related mammals. We focus particularly on molecular mechanisms underlying key steps of bacterial host adaptation including colonization, nutrient acquisition, and immune evasion, as well as suggest key areas for future investigation. By developing a greater understanding of the mechanisms of host adaptation in pathogenic bacteria, we may uncover new strategies to target these microbes for the treatment and prevention of infectious diseases in humans, animals, and the broader environment.
Collapse
Affiliation(s)
- Matthew F Barber
- Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, United States
- Department of Biology, University of Oregon, Eugene, OR 97403, United States
| | - J Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Midlothian, EH25 9RG, United Kingdom
| |
Collapse
|
2
|
Patel SM, Sahoo M, Thakor JC, Murali D, Kumar P, Singh R, Singh KP, Saikumar G, Jana C, Patel SK, Mote AB, Karthikeyan R, Vandre RK, Biswal JK, Sahoo NR. Pathomolecular epidemiology, antimicrobial resistance, and virulence genes of Streptococcus dysgalactiae subsp. equisimilis isolates from slaughtered pigs in India. J Appl Microbiol 2024; 135:lxae002. [PMID: 38178631 DOI: 10.1093/jambio/lxae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/27/2023] [Accepted: 01/03/2024] [Indexed: 01/06/2024]
Abstract
AIMS We aimed to investigate the prevalence, pathology, and characterization of Streptococcus dysgalactiae subsp. equisimilis (SDSE) in slaughtered pigs of India. METHODS AND RESULTS We collected 1254 morbid tissues (lungs-627 and spleen-627) and 627 heart-blood from 627 slaughtered pigs. The bacterial isolation, antibiogram, virulence gene profiling, and mouse pathogenicity testing were performed for the detection and characterization of SDSE. A total of 177 isolates (heart-blood-160 and tissues-17) were recovered from 627 slaughtered pigs with higher isolation rate in heart-blood (25.51%). The prevalence of SDSE was 11% in morbid tissues by polymerase chain reaction. Majority of isolates showed higher detection of streptolysin O, followed by streptokinase and extracellular phospholipase A virulence genes with higher degree of resistance to azithromycin, clindamycin, erythromycin, and penicillin antibiotics. Mouse pathogenicity testing confirmed virulence based on histopathological lesions and re-isolation of SDSE. CONCLUSIONS Our findings highlight the high prevalence of SDSE in slaughtered pigs. The presence of virulence genes and mouse pathogenicity testing confirm their pathogenic potential.
Collapse
Affiliation(s)
- Sagar M Patel
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Monalisa Sahoo
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
- ICAR-National Institute on Foot and Mouth Disease (NIFMD), Arugul, Jatni, Bhubaneswar 752050, India
| | - Jigarji Chaturji Thakor
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Dinesh Murali
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Pradeep Kumar
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Rajendra Singh
- Veterinary Pathology, Institute of Veterinary Science and Animal Husbandry, Siksha "O" Anusandhan, Ghatikia, Bhubaneswar 751030, India
| | - Karam Pal Singh
- CADRAD, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - G Saikumar
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Chandrakanta Jana
- Division of Pathology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Shailesh Kumar Patel
- Department of Veterinary Pathology, College of Veterinary Science & Animal Husbandry, Rewa 486001, India
| | - Akash B Mote
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Ravichandran Karthikeyan
- Division of Epidemiology, ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar 243122, India
| | - Rajesh Kumar Vandre
- Department of Animal Genetics and Breeding, College of Veterinary Science & Animal Husbandry, Rewa, India
| | - Jitendra Kumar Biswal
- ICAR-National Institute on Foot and Mouth Disease (NIFMD), Arugul, Jatni, Bhubaneswar 752050, India
| | - Nihar Ranjan Sahoo
- ICAR-National Institute on Foot and Mouth Disease (NIFMD), Arugul, Jatni, Bhubaneswar 752050, India
| |
Collapse
|
3
|
Yoshida H, Takahashi T, Matsui H. A naturally occurring point mutation in the rocA gene of Streptococcus pyogenes confers the highly virulent phenotype. J Infect Chemother 2020; 27:578-584. [PMID: 33309630 DOI: 10.1016/j.jiac.2020.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Mucoid (MTB313) and nonmucoid (MTB314) strains of group A streptococcus (GAS) emm (antiphagocytic M protein) type 1 were simultaneously isolated from a single patient suffering from streptococcal meningitis. In a CD46-expressing transgenic (CD46 Tg) mouse model of subcutaneous infection into both hind footpads with MTB313 or MTB314, MTB313 showed considerably higher virulence than MTB314. METHODS The comparative genomic analysis based on the whole-genome sequencing revealed that MTB313 possessed an amber codon within rocA (sensory transduction protein kinase), but MTB314 did not carry this stop codon. Thereafter, MAT101 was generated from MTB313 by introducing pRocA, which contained the full-length rocA from MTB314, into the cloning plasmid pLZ12-Km2. MAT100 was also generated by introducing pLZ12-Km2 into MTB313. RESULTS Although MTB313 and MAT100 showed large quantities of cell-associated hyaluronic acid (HA) in the culture pellets, MTB314 and MAT101 showed small quantities of HA production. Finally, higher mortalities were observed in the MTB313- or MAT100-infected CD46 Tg mice than the MTB314- or MAT101-infected CD46 Tg mice. CONCLUSIONS These data indicate the possibility that a spontaneous point mutation in the rocA gene led to the highly virulent phenotype of M1 GAS.
Collapse
Affiliation(s)
- Haruno Yoshida
- Department of Infection Control and Immunology, Omura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takashi Takahashi
- Department of Infection Control and Immunology, Omura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hidenori Matsui
- Department of Infection Control and Immunology, Omura Satoshi Memorial Institute and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
| |
Collapse
|
4
|
Pickering AC, Fitzgerald JR. The Role of Gram-Positive Surface Proteins in Bacterial Niche- and Host-Specialization. Front Microbiol 2020; 11:594737. [PMID: 33193271 PMCID: PMC7658395 DOI: 10.3389/fmicb.2020.594737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/05/2020] [Indexed: 11/25/2022] Open
Abstract
Gram-positive bacterial pathogens have an array of proteins on their cell surface that mediate interactions with the host environment. In particular, bacterial cell wall-associated (CWA) proteins play key roles in both colonization and pathogenesis. Furthermore, some CWA proteins promote specialization for host-species or mediate colonization of specific anatomical niches within a host. In this mini review, we provide examples of the many ways by which major pathogens, such as Staphylococci, Streptococci and Listeria monocytogenes, utilize CWA proteins for both host- and niche-specialization. We describe different biological mechanisms mediated by CWA proteins including: the acquisition of iron from hemoglobin in the bloodstream, adherence to and invasion of host cells, and innate immune evasion through binding to the plasma proteins fibrinogen, immunoglobulin G, and complement. We also discuss the limitations of using animal models for understanding the role of specific CWA proteins in host-specialization and how transformative technologies, such as CRISPR-Cas, offer tremendous potential for developing transgenic models that simulate the host environment of interest. Improved understanding of the role of CWA proteins in niche- or host-specificity will allow the design of new therapeutic approaches which target key host–pathogen interactions underpinning Gram-positive bacterial infections.
Collapse
Affiliation(s)
- Amy C Pickering
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, United Kingdom
| | - J Ross Fitzgerald
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, United Kingdom
| |
Collapse
|
5
|
Volzke J, Schultz D, Kordt M, Müller M, Bergmann W, Methling K, Kreikemeyer B, Müller-Hilke B. Inflammatory Joint Disease Is a Risk Factor for Streptococcal Sepsis and Septic Arthritis in Mice. Front Immunol 2020; 11:579475. [PMID: 33117382 PMCID: PMC7576673 DOI: 10.3389/fimmu.2020.579475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Septic arthritis is a medical emergency associated with high morbidity and mortality, yet hardly any novel advances exist for its clinical management. Despite septic arthritis being a global health burden, experimental data uncovering its etiopathogenesis remain scarce. In particular, any interplay between septic arthritis and preceding joint diseases are unknown as is the contribution of the synovial membrane to the onset of inflammation. Using C57BL/6 mice as a model to study sepsis, we discovered that Group A Streptococcus (GAS) – an important pathogen causing septic arthritis - was able to invade the articular microenvironment. Bacterial invasion resulted in the infiltration of immune cells and detrimental inflammation. In vitro infected fibroblast-like synoviocytes induced the expression of chemokines (Ccl2, Cxcl2), inflammatory cytokines (Tnf, Il6), and integrin ligands (ICAM-1, VCAM-1). Apart from orchestrating immune cell attraction and retention, synoviocytes also upregulated mediators impacting on bone remodeling (Rankl) and cartilage integrity (Mmp13). Using collagen-induced arthritis in DBA/1 × B10.Q F1 mice, we could show that an inflammatory joint disease exacerbated subsequent septic arthritis which was associated with an excessive release of cytokines and eicosanoids. Importantly, the severity of joint inflammation controlled the extent of bone erosions during septic arthritis. In order to ameliorate septic arthritis, our results suggest that targeting synoviocytes might be a promising approach when treating patients with inflammatory joint disease for sepsis.
Collapse
Affiliation(s)
- Johann Volzke
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | - Daniel Schultz
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Marcel Kordt
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | - Michael Müller
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | - Wendy Bergmann
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | - Karen Methling
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Rostock, Rostock, Germany
| | - Brigitte Müller-Hilke
- Core Facility for Cell Sorting and Cell Analysis, University Medical Center Rostock, Rostock, Germany
| | | |
Collapse
|
6
|
Gandhi GD, Krishnamoorthy N, Motal UMA, Yacoub M. Towards developing a vaccine for rheumatic heart disease. Glob Cardiol Sci Pract 2017; 2017:e201704. [PMID: 28971103 PMCID: PMC5621712 DOI: 10.21542/gcsp.2017.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Rheumatic heart disease (RHD) is the most serious manifestations of rheumatic fever, which is caused by group A Streptococcus (GAS or Streptococcus pyogenes) infection. RHD is an auto immune sequelae of GAS pharyngitis, rather than the direct bacterial infection of the heart, which leads to chronic heart valve damage. Although antibiotics like penicillin are effective against GAS infection, improper medical care such as poor patient compliance, overcrowding, poverty, and repeated exposure to GAS, leads to acute rheumatic fever and RHD. Thus, efforts have been put forth towards developing a vaccine. However, a potential global vaccine is yet to be identified due to the widespread diversity of S. pyogenes strains and cross reactivity of streptococcal proteins with host tissues. In this review, we discuss the available vaccine targets of S. pyogenes and the significance of in silico approaches in designing a vaccine for RHD.
Collapse
Affiliation(s)
- Geethanjali Devadoss Gandhi
- Division of Cardiovascular Research, Sidra Medical and Research Center, Qatar Foundation, Doha, Qatar.,Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar
| | - Navaneethakrishnan Krishnamoorthy
- Division of Cardiovascular Research, Sidra Medical and Research Center, Qatar Foundation, Doha, Qatar.,Division of Experimental Genetics, Sidra Medical and Research Center, Doha, Qatar.,Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Ussama M Abdel Motal
- Division of Cardiovascular Research, Sidra Medical and Research Center, Qatar Foundation, Doha, Qatar
| | - Magdi Yacoub
- Division of Cardiovascular Research, Sidra Medical and Research Center, Qatar Foundation, Doha, Qatar.,Heart Science Centre, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| |
Collapse
|
7
|
Matsui H, Nakatani Y, Yoshida H, Takizawa A, Takeuchi O, Øverby A, Takahashi T, Murayama SY, Matsuo K. Flesh-eatingStreptococcus pyogenestriggers the expression of receptor activator of nuclear factor-κB ligand. Cell Microbiol 2016; 18:1390-404. [DOI: 10.1111/cmi.12581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 02/11/2016] [Accepted: 02/12/2016] [Indexed: 02/06/2023]
Affiliation(s)
- Hidenori Matsui
- Department of Infection Control and Immunology, Kitasato Institute for Life Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
| | - Yuriko Nakatani
- Department of Infection Control and Immunology, Kitasato Institute for Life Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
- National Center for Child Health and Development; 2-10-1 Okura Setagaya-ku Tokyo 157-8535 Japan
| | - Haruno Yoshida
- Department of Infection Control and Immunology, Kitasato Institute for Life Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
| | - Asako Takizawa
- Biomedical Laboratory, Biochemical Research Center, Kitasato Institute Hospital; Kitasato University; Minato-ku Tokyo 108-8642 Japan
| | - Osamu Takeuchi
- Biomedical Laboratory, Biochemical Research Center, Kitasato Institute Hospital; Kitasato University; Minato-ku Tokyo 108-8642 Japan
| | - Anders Øverby
- Research and Education Center for Clinical Pharmacy, School of Pharmaceutical Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
| | - Takashi Takahashi
- Department of Infection Control and Immunology, Kitasato Institute for Life Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
| | - Somay Y. Murayama
- Department of Infection Control and Immunology, Kitasato Institute for Life Sciences; Kitasato University; Minato-ku Tokyo 108-8641 Japan
- Laboratory of Molecular Cell Biology; Nihon University School of Pharmacy; 7-7-1 Narashinodai Funabashi-shi Chiba 274-8555 Japan
| | - Koichi Matsuo
- Laboratory of Cell and Tissue Biology; Keio University School of Medicine; Shinjuku-ku Tokyo 160-8582 Japan
| |
Collapse
|
8
|
Yoshida H, Takahashi T, Nakamura M, Øverby A, Takahashi T, Ubukata K, Matsui H. A highly susceptible CD46 transgenic mouse model of subcutaneous infection with Streptococcus dysgalactiae subspecies equisimilis. J Infect Chemother 2016; 22:229-34. [PMID: 26908231 DOI: 10.1016/j.jiac.2016.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/21/2015] [Accepted: 01/04/2016] [Indexed: 11/29/2022]
Abstract
The Streptococcus dysgalactiae subspecies equisimilis (SDSE) possesses clinical similarities to group A streptococcus (GAS) and has recently been recognized as a causative pathogen of life-threatening streptococcal infections. Human membrane cofactor protein (CD46), a complement regulatory protein ubiquitously expressed on every cell type except for erythrocytes, has been implicated as a receptor for human-specific pathogens including GAS. In the present report, SDSE strain GGS_124 was isolated from a patient suffering from streptococcal toxic shock syndrome. When CD46-expressing transgenic (Tg) and non-Tg mice were infected subcutaneously into a hind footpad with 1 × 10(7) colony-forming units of GGS_124, both CD46 Tg and non-Tg mice showed similar levels of colonization in the popliteal lymph nodes at day 3 after infection. However, the following differences were found between CD46 Tg and non-Tg mice after infection. First, there was a statistically significant difference in mortality rates between CD46 Tg (33%) and non-Tg (0%) mice within 35 days after infection. Second, all surviving CD46 Tg mice developed ankle arthritis at day 35 after infection, whereas non-Tg mice did not develop ankle arthritis on the infected hind paws. Finally, CD46 Tg mice developed a pus-filled abscess accompanied by renal failure at day 6 or later after infection. These observations suggest that CD46, the host cell-surface pathogen receptor, functioned to attract GGS_124 into deep tissues, so that the subcutaneous infection with GGS_124 induced invasive streptococcal diseases in CD46 Tg mice.
Collapse
Affiliation(s)
- Haruno Yoshida
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Tetsufumi Takahashi
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Masahiko Nakamura
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Anders Øverby
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takashi Takahashi
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kimiko Ubukata
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hidenori Matsui
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan.
| |
Collapse
|
9
|
Douam F, Gaska JM, Winer BY, Ding Q, von Schaewen M, Ploss A. Genetic Dissection of the Host Tropism of Human-Tropic Pathogens. Annu Rev Genet 2015; 49:21-45. [PMID: 26407032 DOI: 10.1146/annurev-genet-112414-054823] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Infectious diseases are the second leading cause of death worldwide. Although the host multitropism of some pathogens has rendered their manipulation possible in animal models, the human-restricted tropism of numerous viruses, bacteria, fungi, and parasites has seriously hampered our understanding of these pathogens. Hence, uncovering the genetic basis underlying the narrow tropism of such pathogens is critical for understanding their mechanisms of infection and pathogenesis. Moreover, such genetic dissection is essential for the generation of permissive animal models that can serve as critical tools for the development of therapeutics or vaccines against challenging human pathogens. In this review, we describe different experimental approaches utilized to uncover the genetic foundation regulating pathogen host tropism as well as their relevance for studying the tropism of several important human pathogens. Finally, we discuss the current and future uses of this knowledge for generating genetically modified animal models permissive for these pathogens.
Collapse
Affiliation(s)
- Florian Douam
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| | - Jenna M Gaska
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| | - Benjamin Y Winer
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| | - Qiang Ding
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| | - Markus von Schaewen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; , , , , ,
| |
Collapse
|
10
|
Matsui H, Takahashi T, Murayama SY, Uchiyama I, Yamaguchi K, Shigenobu S, Matsumoto T, Kawakubo M, Horiuchi K, Ota H, Osaki T, Kamiya S, Smet A, Flahou B, Ducatelle R, Haesebrouck F, Takahashi S, Nakamura S, Nakamura M. Development of new PCR primers by comparative genomics for the detection of Helicobacter suis in gastric biopsy specimens. Helicobacter 2014; 19:260-71. [PMID: 24673878 DOI: 10.1111/hel.12127] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Although the infection rate of Helicobacter suis is significantly lower than that of Helicobacter pylori, the H. suis infection is associated with a high rate of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In addition, in vitro cultivation of H. suis remains difficult, and some H. suis-infected patients show negative results on the urea breath test (UBT). MATERIALS AND METHODS Female C57BL/6J mice were orally inoculated with mouse gastric mucosal homogenates containing H. suis strains TKY or SNTW101 isolated from a cynomolgus monkey or a patient suffering from nodular gastritis, respectively. The high-purity chromosomal DNA samples of H. suis strains TKY and SNTW101 were prepared from the infected mouse gastric mucosa. The SOLiD sequencing of two H. suis genomes enabled comparative genomics of 20 Helicobacter and 11 Campylobacter strains for the identification of the H. suis-specific nucleotide sequences. RESULTS Oral inoculation with mouse gastric mucosal homogenates containing H. suis strains TKY and SNTW101 induced gastric MALT lymphoma and the formation of gastric lymphoid follicles, respectively, in C57BL/6J mice. Two conserved nucleotide sequences among six H. suis strains were identified and were used to design diagnostic PCR primers for the detection of H. suis. CONCLUSIONS There was a strong association between the H. suis infection and gastric diseases in the C57BL/6 mouse model. PCR diagnosis using an H. suis-specific primer pair is a valuable method for detecting H. suis in gastric biopsy specimens.
Collapse
Affiliation(s)
- Hidenori Matsui
- Kitasato Institute for Life Sciences and Graduate School of Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Kasper KJ, Zeppa JJ, Wakabayashi AT, Xu SX, Mazzuca DM, Welch I, Baroja ML, Kotb M, Cairns E, Cleary PP, Haeryfar SMM, McCormick JK. Bacterial superantigens promote acute nasopharyngeal infection by Streptococcus pyogenes in a human MHC Class II-dependent manner. PLoS Pathog 2014; 10:e1004155. [PMID: 24875883 PMCID: PMC4038607 DOI: 10.1371/journal.ppat.1004155] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/17/2014] [Indexed: 11/19/2022] Open
Abstract
Establishing the genetic determinants of niche adaptation by microbial pathogens to specific hosts is important for the management and control of infectious disease. Streptococcus pyogenes is a globally prominent human-specific bacterial pathogen that secretes superantigens (SAgs) as 'trademark' virulence factors. SAgs function to force the activation of T lymphocytes through direct binding to lateral surfaces of T cell receptors and class II major histocompatibility complex (MHC-II) molecules. S. pyogenes invariably encodes multiple SAgs, often within putative mobile genetic elements, and although SAgs are documented virulence factors for diseases such as scarlet fever and the streptococcal toxic shock syndrome (STSS), how these exotoxins contribute to the fitness and evolution of S. pyogenes is unknown. Here we show that acute infection in the nasopharynx is dependent upon both bacterial SAgs and host MHC-II molecules. S. pyogenes was rapidly cleared from the nasal cavity of wild-type C57BL/6 (B6) mice, whereas infection was enhanced up to ∼10,000-fold in B6 mice that express human MHC-II. This phenotype required the SpeA superantigen, and vaccination with an MHC -II binding mutant toxoid of SpeA dramatically inhibited infection. Our findings indicate that streptococcal SAgs are critical for the establishment of nasopharyngeal infection, thus providing an explanation as to why S. pyogenes produces these potent toxins. This work also highlights that SAg redundancy exists to avoid host anti-SAg humoral immune responses and to potentially overcome host MHC-II polymorphisms.
Collapse
Affiliation(s)
- Katherine J. Kasper
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Joseph J. Zeppa
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Adrienne T. Wakabayashi
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Stacey X. Xu
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Delfina M. Mazzuca
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Ian Welch
- Department of Animal Care and Veterinary Services, Western University, London, Ontario, Canada
| | - Miren L. Baroja
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - Malak Kotb
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, United States of America
| | - Ewa Cairns
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - P. Patrick Cleary
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - S. M. Mansour Haeryfar
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
| | - John K. McCormick
- Department of Microbiology and Immunology and the Centre for Human Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- * E-mail:
| |
Collapse
|
12
|
Functional genomic characterization of virulence factors from necrotizing fasciitis-causing strains of Aeromonas hydrophila. Appl Environ Microbiol 2014; 80:4162-83. [PMID: 24795370 DOI: 10.1128/aem.00486-14] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The genomes of 10 Aeromonas isolates identified and designated Aeromonas hydrophila WI, Riv3, and NF1 to NF4; A. dhakensis SSU; A. jandaei Riv2; and A. caviae NM22 and NM33 were sequenced and annotated. Isolates NF1 to NF4 were from a patient with necrotizing fasciitis (NF). Two environmental isolates (Riv2 and -3) were from the river water from which the NF patient acquired the infection. While isolates NF2 to NF4 were clonal, NF1 was genetically distinct. Outside the conserved core genomes of these 10 isolates, several unique genomic features were identified. The most virulent strains possessed one of the following four virulence factors or a combination of them: cytotoxic enterotoxin, exotoxin A, and type 3 and 6 secretion system effectors AexU and Hcp. In a septicemic-mouse model, SSU, NF1, and Riv2 were the most virulent, while NF2 was moderately virulent. These data correlated with high motility and biofilm formation by the former three isolates. Conversely, in a mouse model of intramuscular infection, NF2 was much more virulent than NF1. Isolates NF2, SSU, and Riv2 disseminated in high numbers from the muscular tissue to the visceral organs of mice, while NF1 reached the liver and spleen in relatively lower numbers on the basis of colony counting and tracking of bioluminescent strains in real time by in vivo imaging. Histopathologically, degeneration of myofibers with significant infiltration of polymorphonuclear cells due to the highly virulent strains was noted. Functional genomic analysis provided data that allowed us to correlate the highly infectious nature of Aeromonas pathotypes belonging to several different species with virulence signatures and their potential ability to cause NF.
Collapse
|
13
|
Pan X, Yang Y, Zhang JR. Molecular basis of host specificity in human pathogenic bacteria. Emerg Microbes Infect 2014; 3:e23. [PMID: 26038515 PMCID: PMC3974339 DOI: 10.1038/emi.2014.23] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 01/08/2023]
Abstract
Pathogenic bacteria display various levels of host specificity or tropism. While many bacteria can infect a wide range of hosts, certain bacteria have strict host selectivity for humans as obligate human pathogens. Understanding the genetic and molecular basis of host specificity in pathogenic bacteria is important for understanding pathogenic mechanisms, developing better animal models and designing new strategies and therapeutics for the control of microbial diseases. The molecular mechanisms of bacterial host specificity are much less understood than those of viral pathogens, in part due to the complexity of the molecular composition and cellular structure of bacterial cells. However, important progress has been made in identifying and characterizing molecular determinants of bacterial host specificity in the last two decades. It is now clear that the host specificity of bacterial pathogens is determined by multiple molecular interactions between the pathogens and their hosts. Furthermore, certain basic principles regarding the host specificity of bacterial pathogens have emerged from the existing literature. This review focuses on selected human pathogenic bacteria and our current understanding of their host specificity.
Collapse
Affiliation(s)
- Xiaolei Pan
- Center for Infectious Disease Research, School of Medicine, Tsinghua University , Beijing 10084, China
| | - Yang Yang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University , Beijing 10084, China
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, School of Medicine, Tsinghua University , Beijing 10084, China
| |
Collapse
|
14
|
Henningham A, Gillen CM, Walker MJ. Group a streptococcal vaccine candidates: potential for the development of a human vaccine. Curr Top Microbiol Immunol 2012; 368:207-42. [PMID: 23250780 DOI: 10.1007/82_2012_284] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Currently there is no commercial Group A Streptococcus (GAS; S. pyogenes) vaccine available. The development of safe GAS vaccines is challenging, researchers are confronted with obstacles such as the occurrence of many unique serotypes (there are greater than 150 M types), antigenic variation within the same serotype, large variations in the geographical distribution of serotypes, and the production of antibodies cross-reactive with human tissue which can lead to host auto-immune disease. Cell wall anchored, cell membrane associated, secreted and anchorless proteins have all been targeted as GAS vaccine candidates. As GAS is an exclusively human pathogen, the quest for an efficacious vaccine is further complicated by the lack of an animal model which mimics human disease and can be consistently and reproducibly colonized by multiple GAS strains.
Collapse
Affiliation(s)
- Anna Henningham
- School of Chemistry and Molecular Biosciences and Australian Infectious Disease Research Centre, University of Queensland, St Lucia, QLD 4072, Australia
| | | | | |
Collapse
|
15
|
Yoshida H, Matsui H, Murayama SY, Takada Y, Matsuo K, Takahashi T, Nakamura M, Ubukata K, Takahashi T. A CD46 transgenic mouse model for studying the histopathology of arthritis caused by subcutaneous infection with Streptococcus dysgalactiae subspecies equisimilis. J Med Microbiol 2011; 60:1860-1868. [DOI: 10.1099/jmm.0.034108-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Haruno Yoshida
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Hidenori Matsui
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Somay Yamagata Murayama
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yasunari Takada
- Laboratory of Cell and Tissue Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Koichi Matsuo
- Laboratory of Cell and Tissue Biology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Tetsufumi Takahashi
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minatoku, Tokyo 108-8641, Japan
| | - Masahiko Nakamura
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minatoku, Tokyo 108-8641, Japan
| | - Kimiko Ubukata
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takashi Takahashi
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| |
Collapse
|
16
|
Abstract
Necrotizing fasciitis belongs to a group of complicated soft tissue infections that can be even life threatening. Despite growing knowledge about its etiology, predictors, and the clinical progression, the mortality remains at a high level with 20%. A relevant reduction can be achieved only by an early diagnosis followed by consistent therapy. The clinical findings in about 75% of the cases are pain out of proportion, edema and tenderness, blisters, and erythema. It is elementary to differentiate a necrotizing or a non-necrotizing soft tissue infection early. In uncertain cases it can be necessary to perform a surgical exploration to confirm the diagnosis. The histopathologic characteristics are the fascial necrosis, vasculitis, thrombosis of perforating veins, the presence of the disease-causing bacteria as well as inflammatory cells like macrophages and polymorphonuclear granulocytes. Secondly, both the cutis and the muscle can be affected. In many cases there is a disproportion of the degree of local and systemic symptoms. Depending on the infectious agents there are two main types: type I is a polymicrobial infection and type II is a more invasive, serious, and fulminant monomicrobial infection mostly caused by group A Streptococcus pyogenes.Invasive, severe forms of streptococcal infections seem to occur more often in recent years. Multimodal and interdisciplinary therapy should be based on radical surgical débridement, systemic antibiotic therapy as well as enhanced intensive care therapy, which is sometimes combined with immunoglobulins (in streptococcal or staphylococcal infections) or hyperbaric oxygen therapy (HBOT, in clostridial infections). For wound care of extensive soft tissue defects vacuum-assisted closure has shown its benefit.
Collapse
|
17
|
Lactobacilli reduce cell cytotoxicity caused by Streptococcus pyogenes by producing lactic acid that degrades the toxic component lipoteichoic acid. Antimicrob Agents Chemother 2011; 55:1622-8. [PMID: 21245448 DOI: 10.1128/aac.00770-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactobacilli are known to prevent colonization by many pathogens; nevertheless, the mechanisms of their protective effect are largely unknown. In this work, we investigated the role of lactobacilli during infection of epithelial cells with group A streptococci (GAS). GAS cause a variety of illnesses ranging from noninvasive disease to more severe invasive infections, such as necrotizing fasciitis and toxic shock-like syndrome. Invasion of deeper tissues is facilitated by GAS-induced apoptosis and cell death. We found that lactobacilli inhibit GAS-induced host cell cytotoxicity and shedding of the complement regulator CD46. Further, survival assays demonstrated that lactic acid secreted by lactobacilli is highly bactericidal toward GAS. In addition, lactic acid treatment of GAS, but not heat killing, prior to infection abolishes the cytotoxic effects against human cells. Since lipoteichoic acid (LTA) of GAS is heat resistant and cytotoxic, we explored the effects of lactic acid on LTA. By applying such an approach, we demonstrate that lactic acid reduces epithelial cell damage caused by GAS by degrading both secreted and cell-bound LTA. Taken together, our experiments reveal a mechanism by which lactobacilli prevent pathogen-induced host cell damage.
Collapse
|
18
|
Matsui H, Sekiya Y, Takahashi T, Nakamura M, Imanishi K, Yoshida H, Murayama SY, Takahashi T, Tsuchimoto K, Uchiyama T, Ubukata K. Dermal mast cells reduce progressive tissue necrosis caused by subcutaneous infection with Streptococcus pyogenes in mice. J Med Microbiol 2010; 60:128-134. [PMID: 20884771 DOI: 10.1099/jmm.0.020495-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A single subcutaneous (s.c.) infection with 1×10(7) c.f.u. GAS472, a group A streptococcus (GAS) serotype M1 strain isolated from the blood of a patient suffering from streptococcal toxic shock syndrome, led to severe damage of striated muscle layers in the feet of mast cell (MC)-deficient WBB6F(1)-Kit(W)/Kit(W-v) (W/W(v)) mice 72 h after infection. In contrast, no damage was recognized in striated muscle layers in the feet of the control WBB6F(1)-Kit(+/+) (+/+) mice 72 h after infection. In addition, adoptively transferred MCs reduced progressive tissue necrosis of the feet of W/W(v) mice after infection. However, there was no significant difference in the mortality rates between the W/W(v) and +/+ mice, or between the human CD46-expressing transgenic (Tg) mouse bone marrow-derived cultured MC-reconstituted W/W(v) and non-Tg mouse bone marrow-derived cultured MC-reconstituted W/W(v) mice after infection. Consequently, although MCs can help to reduce the severity of necrosis of the feet caused by s.c. infection with GAS472, such reduction of tissue necrosis scarcely improves the mortality rates of these mice. Moreover, human CD46 does not play a crucial role in the MC-mediated innate immune defence against GAS infection.
Collapse
Affiliation(s)
- Hidenori Matsui
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Yukie Sekiya
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Tetsufumi Takahashi
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Masahiko Nakamura
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Ken'ichi Imanishi
- Department of Microbiology and Immunology, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Haruno Yoshida
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Somay Yamagata Murayama
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takashi Takahashi
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Kanji Tsuchimoto
- Center for Clinical Pharmacy and Clinical Sciences, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Takehiko Uchiyama
- College of Human Science, Tokiwa University, 1-430-1 Miwa, Mito-shi, Ibaraki 310-8585, Japan.,Department of Microbiology and Immunology, Tokyo Women's Medical University School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Kimiko Ubukata
- Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| |
Collapse
|
19
|
Sakurai F, Nakashima K, Yamaguchi T, Ichinose T, Kawabata K, Hayakawa T, Mizuguchi H. Adenovirus serotype 35 vector-induced innate immune responses in dendritic cells derived from wild-type and human CD46-transgenic mice: Comparison with a fiber-substituted Ad vector containing fiber proteins of Ad serotype 35. J Control Release 2010; 148:212-8. [PMID: 20800630 DOI: 10.1016/j.jconrel.2010.08.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/22/2010] [Accepted: 08/19/2010] [Indexed: 12/16/2022]
Abstract
Recently, much attention has focused on replication-incompetent adenovirus (Ad) vectors containing fiber proteins derived from species B Ad serotype 35 (Ad35) (Ad5F35) and Ad vectors fully constructed from Ad35 as vaccine vectors expressing antigens. However, differences in the transduction properties, including the induction of innate immunity, of Ad5F35 and Ad35 vectors have not been properly and fully examined, partly because the transduction properties of these Ad vectors should be evaluated using nonhuman primates or human CD46-transgenic (CD46TG) mice, which ubiquitously express the primary receptor of Ad35, human CD46, in a pattern similar to that of humans. In the present study, we evaluated innate immune responses of mouse dendritic cells (mDCs) derived from bone marrow cells of wild-type (WT) and CD46TG mice following transduction with Ad serotype 5 (Ad5), fiber-substituted Ad5F35, or Ad35 vectors. Ad5F35 and Ad35 vectors mediated more efficient transduction in mDCs derived from CD46TG mice (CD46TG-mDCs) than did Ad5 vectors. Upregulation of costimulatory molecules and inflammatory cytokine induction by Ad5F35 and Ad35 vectors were significantly higher than those by Ad5 vectors in CD46TG-mDCs. However, the induction properties of the innate immune responses were different between Ad5F35 and Ad35 vectors. Ad35 vectors induced higher levels of costimulatory molecule expression and inflammatory cytokine production than did Ad5F35 vectors in CD46TG-mDCs. Furthermore, intravenous administration of Ad35 vectors in WT and CD46TG mice resulted in higher levels of serum interleukin (IL)-6 and IL-12 compared with administration of Ad5F35 vectors, which exhibited almost mock-transduced levels of these inflammatory cytokines. This study indicates that innate immune responses by Ad35 and Ad5F35 vectors are distinct even although both Ad vectors recognize human CD46 as a receptor.
Collapse
Affiliation(s)
- Fuminori Sakurai
- Laboratory of Gene Transfer and Regulation, National Institute of Biomedical Innovation, Ibaraki-City, Osaka, Japan.
| | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
Group A Streptococcus (GAS) is a human-specific pathogen that is highly prevalent throughout the world. The vast majority of GAS infections lead to a mild disease involving the epithelial surfaces of either the throat or skin. The concept of distinct sets of 'throat' and 'skin' strains of GAS has long been conceived. From an ecological standpoint, the epithelium of the throat and skin are important because it is where the organism is most successful in reproducing and transmitting to new hosts. This article examines key features of the epidemiology, population biology and molecular pathogenesis that underlie the tissue site preferences for infection exhibited by GAS, with an emphasis on work from our laboratory on skin tropisms. Recombinational replacement with orthologous gene forms, following interspecies transfer, appears to be an important genetic step leading up to the exploitation of new niches by GAS.
Collapse
Affiliation(s)
- Debra E Bessen
- Department of Microbiology & Immunology, New York Medical College, Valhalla, NY 10573, USA, Tel.: +1 914 594 4193, Fax: +1 914 594 4176
| | | |
Collapse
|