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Wang J, Liang K, Chen L, Su X, Liao D, Yu J, He J. Unveiling the stealthy tactics: mycoplasma's immune evasion strategies. Front Cell Infect Microbiol 2023; 13:1247182. [PMID: 37719671 PMCID: PMC10502178 DOI: 10.3389/fcimb.2023.1247182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 08/09/2023] [Indexed: 09/19/2023] Open
Abstract
Mycoplasmas, the smallest known self-replicating organisms, possess a simple structure, lack a cell wall, and have limited metabolic pathways. They are responsible for causing acute or chronic infections in humans and animals, with a significant number of species exhibiting pathogenicity. Although the innate and adaptive immune responses can effectively combat this pathogen, mycoplasmas are capable of persisting in the host, indicating that the immune system fails to eliminate them completely. Recent studies have shed light on the intricate and sophisticated defense mechanisms developed by mycoplasmas during their long-term co-evolution with the host. These evasion strategies encompass various tactics, including invasion, biofilm formation, and modulation of immune responses, such as inhibition of immune cell activity, suppression of immune cell function, and resistance against immune molecules. Additionally, antigen variation and molecular mimicry are also crucial immune evasion strategies. This review comprehensively summarizes the evasion mechanisms employed by mycoplasmas, providing valuable insights into the pathogenesis of mycoplasma infections.
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Affiliation(s)
- Jingyun Wang
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Keying Liang
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Li Chen
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Xiaoling Su
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Daoyong Liao
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Jianwei Yu
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
- Department of Public Health Laboratory Sciences, School of Public Health, Hengyang Medical School, University of South China, Hengyang, Hunan, China
| | - Jun He
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, Hunan, China
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2
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Sommer K, Kowald S, Chopra-Dewasthaly R. Serum Resistance of Mycoplasma agalactiae Strains and Mutants Bearing Different Lipoprotein Profiles. Pathogens 2022; 11:pathogens11091036. [PMID: 36145468 PMCID: PMC9501237 DOI: 10.3390/pathogens11091036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 12/05/2022] Open
Abstract
In order to spread systemically, resistance against complement and other factors present in serum is an important trait in pathogenic bacteria. The variable proteins of Mycoplasma agalactiae (Vpmas) have been shown to affect differential adhesion, invasion and immune evasion, and undergo high-frequency phase-variation in expression. However, nothing is known about their involvement in M. agalactiae’s serum susceptibility. To evaluate this, the PG2 strain, the GM139 strain and the six Vpma phase-locked mutants (PLMs, PLMU to PLMZ) were tested for their ability to survive in the presence of non-sensitized and sensitized sheep serum, as well as guinea pig complement. Additionally, the reactivity of the sensitized sheep serum was analysed on the strains via western blotting. Overall data demonstrate PG2 strain to be more susceptible to sheep serum compared to the GM139 strain bearing a different Vpma profile. Significant differences were also observed between the different PLMs, with PLMU and PLMX showing the highest serum susceptibility in serum, while the other PLMs expressing longer Vpma proteins were more resistant. The results are in good correlation with previous studies where shorter lipoprotein variants contributed to a higher susceptibility to complement. Since none of the tested strains and PLMs were susceptible to non-sensitized sheep serum, antibodies seem to play an important role in serum killing.
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Sheep Infection Trials with 'Phase-Locked' Vpma Expression Variants of Mycoplasma agalactiae-Towards Elucidating the Role of a Multigene Family Encoding Variable Surface Lipoproteins in Infection and Disease. Microorganisms 2022; 10:microorganisms10040815. [PMID: 35456865 PMCID: PMC9025108 DOI: 10.3390/microorganisms10040815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/27/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022] Open
Abstract
The significance of large multigene families causing high-frequency surface variations in mycoplasmas is not well-understood. Previously, VpmaY and VpmaU clonal variants of the Vpma family of lipoproteins of M. agalactiae were compared via experimental sheep infections using the two corresponding ‘Phase-Locked Mutants’. However, nothing is known about the infectivity of the remaining four Vpma expression variants VpmaX, VpmaW, VpmaZ and VpmaV as they were never evaluated in vivo. Here, in vivo infection and disease progression of all six Vpma expressers constituting the Vpma family of type strain PG2 were compared using the corresponding xer1-disrupted PLMs expressing single well-characterized Vpmas. Each of the six PLMs were separately evaluated using the intramammary sheep infection model along with the control phase-variable wildtype strain PG2. Thorough bacteriological, pathological and clinical examinations were performed, including assessment of milk quality, quantity and somatic cell counts. Altogether, the results indicated that the inability to vary the Vpma expression phase does not hamper the initiation of infection leading to mastitis for all six PLMs, except for PLMU, which showed a defect in host colonization and multiplication for the first 24 h p.i. and pathological/bacteriological analysis indicated a higher potential for systemic spread for PLMV and PLMX. This is the first study in which all isogenic expression variants of a large mycoplasma multigene family are tested in the natural host.
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4
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Goto S, Konnai S, Hirano Y, Kohara J, Okagawa T, Maekawa N, Sajiki Y, Watari K, Minato E, Kobayashi A, Gondaira S, Higuchi H, Koiwa M, Tajima M, Taguchi E, Uemura R, Yamada S, Kaneko MK, Kato Y, Yamamoto K, Toda M, Suzuki Y, Murata S, Ohashi K. Upregulation of PD-L1 Expression by Prostaglandin E 2 and the Enhancement of IFN-γ by Anti-PD-L1 Antibody Combined With a COX-2 Inhibitor in Mycoplasma bovis Infection. Front Vet Sci 2020; 7:12. [PMID: 32154274 PMCID: PMC7045061 DOI: 10.3389/fvets.2020.00012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 01/08/2020] [Indexed: 12/12/2022] Open
Abstract
Bovine mycoplasmosis caused by Mycoplasma bovis results in pneumonia and mastitis in cattle. We previously demonstrated that the programmed death 1 (PD-1)/PD-ligand 1 (PD-L1) pathway is involved in immune dysfunction during M. bovis infection and that prostaglandin E2 (PGE2) suppressed immune responses and upregulated PD-L1 expression in Johne's disease, a bacterial infection in cattle. In this study, we investigated the role of PGE2 in immune dysfunction and the relationship between PGE2 and the PD-1/PD-L1 pathway in M. bovis infection. In vitro stimulation with M. bovis upregulated the expressions of PGE2 and PD-L1 presumably via Toll-like receptor 2 in bovine peripheral blood mononuclear cells (PBMCs). PGE2 levels of peripheral blood in infected cattle were significantly increased compared with those in uninfected cattle. Remarkably, plasma PGE2 levels were positively correlated with the proportions of PD-L1+ monocytes in M. bovis-infected cattle. Additionally, plasma PGE2 production in infected cattle was negatively correlated with M. bovis-specific interferon (IFN)-γ production from PBMCs. These results suggest that PGE2 could be one of the inducers of PD-L1 expression and could be involved in immunosuppression during M. bovis infection. In vitro blockade assays using anti-bovine PD-L1 antibody and a cyclooxygenase 2 inhibitor significantly upregulated the M. bovis-specific IFN-γ response. Our study findings might contribute to the development of novel therapeutic strategies for bovine mycoplasmosis that target PGE2 and the PD-1/PD-L1 pathway.
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Affiliation(s)
- Shinya Goto
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Satoru Konnai
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yuki Hirano
- Agriculture Research Department, Animal Research Center, Hokkaido Research Organization, Shintoku, Japan
| | - Junko Kohara
- Agriculture Research Department, Animal Research Center, Hokkaido Research Organization, Shintoku, Japan
| | - Tomohiro Okagawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Naoya Maekawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yamato Sajiki
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Kei Watari
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Erina Minato
- Department of Veterinary Clinical Medicine, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Atsuhi Kobayashi
- Department of Veterinary Clinical Medicine, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Satoshi Gondaira
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
| | - Hidetoshi Higuchi
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
| | - Masateru Koiwa
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
| | - Motoshi Tajima
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
| | | | - Ryoko Uemura
- Department of Veterinary Medical Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan
| | - Shinji Yamada
- Department of Antibody Drug Development, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Mika K Kaneko
- Department of Antibody Drug Development, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Graduate School of Medicine, Tohoku University, Sendai, Japan.,New Industry Creation Hatchery Center, Tohoku University, Sendai, Japan
| | - Keiichi Yamamoto
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Research and Development Center, Fuso Pharmaceutical Industries, Ltd., Osaka, Japan
| | - Mikihiro Toda
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,New Business and International Business Development, Fuso Pharmaceutical Industries, Ltd., Osaka, Japan
| | - Yasuhiko Suzuki
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Division of Bioresources, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan.,Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Japan
| | - Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan
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5
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Lim S, Yun HK, Kang KM, Lee BL, Won R, Lee IH. Interactions between Mycoplasma pulmonis and immune systems in the mealworm beetle, Tenebrio molitor. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 114:103231. [PMID: 31479697 DOI: 10.1016/j.ibmb.2019.103231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/23/2019] [Accepted: 08/28/2019] [Indexed: 06/10/2023]
Abstract
Mycoplasmas, the smallest self-replicating organisms, are unique in that they lack cell walls but possess distinctive plasma membranes containing sterol acquired from their growth environment. Although mycoplasmas are known to be successful pathogens in a wide range of animal hosts, including humans, the molecular basis for their virulence and interaction with the host immune systems remains largely unknown. This study was conducted to elucidate the biochemical relationship between mycoplasma and the insect immune system. We investigated defense reactions of Tenebrio molitor that were activated in response to infection with Mycoplasma pulmonis. The results revealed that T. molitor larvae were more resistant to mycoplasma infection than normal bacteria equipped with cell walls. Intruding M. pulmonis cells were effectively killed by toxins generated from activation of the proPO cascade in hemolymph, but not by cellular reactions or antimicrobial peptides. It was determined that these different anti-mycoplasma effects of T. molitor immune components were primarily attributable to surface molecules of M. pulmonis such as phospholipids occurring in the outer leaflet of the membrane lipid bilayer. While phosphatidylcholine, a phospholipid derived from the growth environment, contributed to the resistance of M. pulmonis against antimicrobial peptides produced by T. molitor, phosphatidylglycerol was responsible for triggering activation of the proPO cascade.
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Affiliation(s)
- Sooa Lim
- Department of Food & Pharmaceutical Engineering, Hoseo University, Asan, Chungnam, 336-795, South Korea
| | - Hwa-Kyung Yun
- Department of Biofood & Medical Sciences, Hanseo University, 360 Daegok-ri, Haemi-myen, Seosan, Chungnam, 356-706, South Korea
| | - Ki Mo Kang
- Department of Biotechnology, Hoseo University, Asan, Chungnam, 336-795, South Korea
| | - Bok Luel Lee
- National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Busan, 609-735, South Korea
| | - Ran Won
- Department of Biomedical Laboratory Science, Division of Health Sciences, Dongseo University, Busan, 47011, South Korea
| | - In Hee Lee
- Department of Biotechnology, Hoseo University, Asan, Chungnam, 336-795, South Korea.
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6
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Deeney AS, Maglennon GA, Chapat L, Crussard S, Jolivet E, Rycroft AN. Mycoplasma hyopneumoniae evades phagocytic uptake by porcine alveolar macrophages in vitro. Vet Res 2019; 50:51. [PMID: 31234931 PMCID: PMC6591956 DOI: 10.1186/s13567-019-0667-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/10/2019] [Indexed: 01/24/2023] Open
Abstract
Mycoplasma hyopneumoniae, the agent of porcine enzootic pneumonia (EP), is able to persist in the lung tissue and evade destruction by the host for several weeks. To understand the mechanism of pathogen survival, phagocytic uptake of M. hyopneumoniae by primary porcine alveolar macrophages was investigated. Intracellular location and survival of the pathogen were explored using gentamicin survival assays, flow cytometry and confocal microscopy of M. hyopneumoniae 232 labelled with green fluorescent protein (GFP). Following 1 h and 16 h of co-incubation, few viable M. hyopneumoniae were recovered from inside macrophages. Flow cytometric analysis of macrophages incubated with M. hyopneumoniae expressing GFP indicated that the mycoplasmas became associated with macrophages, but were shown to be extracellular when actin-dependent phagocytosis was blocked with cytochalasin D. Confocal microscopy detected GFP-labelled M. hyopneumoniae inside macrophages and the numbers increased modestly with time of incubation. Neither the addition of porcine serum complement or convalescent serum from EP-recovered pigs was able to enhance engulfment of M. hyopneumoniae. This investigation suggests that M. hyopneumoniae evades significant uptake by porcine alveolar macrophages and this may be a mechanism of immune escape by M. hyopneumoniae in the porcine respiratory tract.
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Affiliation(s)
- Alannah S Deeney
- Department of Pathobiology and Population Science, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, UK.
| | - Gareth A Maglennon
- AstraZeneca UK Ltd., Cambridge Biomedical Campus, Cambridge, CB2 0AA, UK
| | | | | | | | - Andrew N Rycroft
- Department of Pathobiology and Population Science, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, AL9 7TA, UK
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7
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Calcutt MJ, Lysnyansky I, Sachse K, Fox LK, Nicholas RAJ, Ayling RD. Gap analysis of Mycoplasma bovis disease, diagnosis and control: An aid to identify future development requirements. Transbound Emerg Dis 2018; 65 Suppl 1:91-109. [PMID: 29582590 DOI: 10.1111/tbed.12860] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Indexed: 01/07/2023]
Abstract
There is a worldwide problem of disease caused by Mycoplasma (M.) bovis in cattle; it has a significant detrimental economic and animal welfare impact on cattle rearing. Infection can manifest as a plethora of clinical signs including mastitis, pneumonia, arthritis, keratoconjunctivitis, otitis media and genital disorders that may result in infertility and abortion. Current diagnosis and control information are reviewed and analysed to identify gaps in knowledge of the causative organism in respect of the disease pathology, diagnosis and control methods. The main considerations are as follows: no vaccines are commercially available; antimicrobial resistance is increasing; diagnostic and antimicrobial sensitivity testing needs to be improved; and a pen-side test would facilitate more rapid diagnosis and implementation of treatment with antimicrobials. More data on host susceptibility, stress factors, immune response and infectious dose levels are required. The impact of asymptomatic carriers, M. bovis survival in the environment and the role of wildlife in transmitting the disease also needs investigation. To facilitate development of vaccines, further analysis of more M. bovis genomes, its pathogenic mechanisms, including variable surface proteins, is required, along with reproducible disease models.
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Affiliation(s)
| | | | - K Sachse
- Friedrich-Loeffler-Institut, Jena, Germany.,Department of RNA Bioinformatics and High-Throughput Analysis, Faculty of Mathematics and Computer Science, Friedrich-Schiller-Universität, Jena, Germany
| | - L K Fox
- Washington State University, Pullman, WA, USA
| | | | - R D Ayling
- Animal and Plant Health Agency, Addlestone, UK
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Xer1-independent mechanisms of Vpma phase variation in Mycoplasma agalactiae are triggered by Vpma-specific antibodies. Int J Med Microbiol 2017; 307:443-451. [DOI: 10.1016/j.ijmm.2017.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/24/2017] [Accepted: 10/23/2017] [Indexed: 11/23/2022] Open
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9
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Chopra-Dewasthaly R, Spergser J, Zimmermann M, Citti C, Jechlinger W, Rosengarten R. Vpma phase variation is important for survival and persistence of Mycoplasma agalactiae in the immunocompetent host. PLoS Pathog 2017; 13:e1006656. [PMID: 28957426 PMCID: PMC5634654 DOI: 10.1371/journal.ppat.1006656] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 10/10/2017] [Accepted: 09/19/2017] [Indexed: 12/26/2022] Open
Abstract
Despite very small genomes, mycoplasmas retain large multigene families encoding variable antigens whose exact role in pathogenesis needs to be proven. To understand their in vivo significance, we used Mycoplasma agalactiae as a model exhibiting high-frequency variations of a family of immunodominant Vpma lipoproteins via Xer1-mediated site-specific recombinations. Phase-Locked Mutants (PLMs) expressing single stable Vpma products served as first breakthrough tools in mycoplasmology to study the role of such sophisticated antigenic variation systems. Comparing the general clinical features of sheep infected with a mixture of phase-invariable PLMs (PLMU and PLMY) and the wild type strain, it was earlier concluded that Vpma phase variation is not necessary for infection. Conversely, the current study demonstrates the in vivo indispensability of Vpma switching as inferred from the Vpma phenotypic and genotypic analyses of reisolates obtained during sheep infection and necropsy. PLMY and PLMU stably expressing VpmaY and VpmaU, respectively, for numerous in vitro generations, switched to new Vpma phenotypes inside the sheep. Molecular genetic analysis of selected 'switchover' clones confirmed xer1 disruption and revealed complex new rearrangements like chimeras, deletions and duplications in the vpma loci that were previously unknown in type strain PG2. Another novel finding is the differential infection potential of Vpma variants, as local infection sites demonstrated an almost complete dominance of PLMY over PLMU especially during early stages of both conjunctival and intramammary co-challenge infections, indicating a comparatively better in vivo fitness of VpmaY expressors. The data suggest that Vpma antigenic variation is imperative for survival and persistence inside the immunocompetent host, and although Xer1 is necessary for causing Vpma variation in vitro, it is not a virulence factor because alternative Xer1-independent mechanisms operate in vivo, likely under the selection pressure of the host-induced immune response. This singular study highlights exciting new aspects of mycoplasma antigenic variation systems, including the regulation of expression by host factors.
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Affiliation(s)
- Rohini Chopra-Dewasthaly
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
| | - Joachim Spergser
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
| | - Martina Zimmermann
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
| | - Christine Citti
- UMR1225, INRA, ENVT, Ecole Nationale Vétérinaire, 23 Chemin des Capelles, Toulouse, France
| | - Wolfgang Jechlinger
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
| | - Renate Rosengarten
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna, Austria
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10
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Xiong Q, Zhang B, Wang J, Ni B, Ji Y, Wei Y, Xiao S, Feng Z, Liu M, Shao G. Characterization of the role in adherence of Mycoplasma hyorhinis variable lipoproteins containing different repeat unit copy numbers. Vet Microbiol 2016; 197:39-46. [PMID: 27938681 DOI: 10.1016/j.vetmic.2016.10.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 10/21/2016] [Accepted: 10/28/2016] [Indexed: 10/20/2022]
Abstract
Mycoplasma hyorhinis (M. hyorhinis) is an important pathogen of pigs. In previous studies, the variable lipoprotein (Vlp) family has been shown to play a role in mediating M. hyorhinis cytoadhesion. Herein, we performed several experiments to study the function of each Vlp family member in detail, especially examining the cytoadhesion functional domain and how the repeat unit copy number impacts on function. Recombinant proteins rVlpII, composed of region II from all seven Vlp members; rVlpIII, composed of repeat peptides from region III of all of Vlp members; as well as a series of recombinant rVlp proteins for each member containing different repeat unit copy numbers were constructed. All of the proteins were expressed in Escherichia coli and purified by affinity chromatography. The recombinant proteins, as well as seven keyhole limpet hemocyanin-conjugated Vlp peptides containing two copies of the repeat unit, were analyzed for their adherence to swine tracheal epithelial cells using a microtiter plate adherence assay. Both rVlpII and rVlpIII proteins were able to bind to cell membrane proteins. Among the repeat unit peptides, only PepVlpB and PepVlpG were able to bind to cell membrane proteins. All of the Vlp members had cytoadhesion capability. The adhesion abilities of the proteins containing 0 or 3 copies of the repeat unit were stronger than those of the proteins containing 12 copies. For rVlpA, rVlpB, rVlpD, rVlpF and rVlpG, the proteins containing no copies bound stronger than the proteins containing 3 copies. In contrast, the adherence of rVlpC3 was stronger than that of rVlpC0. There was no significant difference between the adherence of rVlpE3 and that of rVlpE0. Our results suggest that the major cytoadhesion sites of Vlps are mainly contained in region II, the function of which would be blocked by region III when region III is longer.
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Affiliation(s)
- Qiyan Xiong
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Bixiong Zhang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China; Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Jia Wang
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Bo Ni
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Yan Ji
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Yanna Wei
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Shaobo Xiao
- Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhixin Feng
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Maojun Liu
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China
| | - Guoqing Shao
- Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China; Jiangsu Collaborative Innovation Center for Meat Production, Processing and Quality control, Nanjing 210014, China.
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11
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Daubenspeck JM, Liu R, Dybvig K. Rhamnose Links Moonlighting Proteins to Membrane Phospholipid in Mycoplasmas. PLoS One 2016; 11:e0162505. [PMID: 27603308 PMCID: PMC5014317 DOI: 10.1371/journal.pone.0162505] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 08/23/2016] [Indexed: 11/18/2022] Open
Abstract
Many proteins that have a primary function as a cytoplasmic protein are known to have the ability to moonlight on the surface of nearly all organisms. An example is the glycolytic enzyme enolase, which can be found on the surface of many types of cells from bacteria to human. Surface enolase is not enzymatic because it is monomeric and oligomerization is required for glycolytic activity. It can bind various molecules and activate plasminogen. Enolase lacks a signal peptide and the mechanism by which it attaches to the surface is unknown. We found that treatment of whole cells of the murine pathogen Mycoplasma pulmonis with phospholipase D released enolase and other common moonlighting proteins. Glycostaining suggested that the released proteins were glycosylated. Cytoplasmic and membrane-bound enolase was isolated by immunoprecipitation. No post-translational modification was detected on cytoplasmic enolase, but membrane enolase was associated with lipid, phosphate and rhamnose. Treatment with phospholipase released the lipid and phosphate from enolase but not the rhamnose. The site of rhamnosylation was identified as a glutamine residue near the C-terminus of the protein. Rhamnose has been found in all species of mycoplasma examined but its function was previously unknown. Mycoplasmas are small bacteria with have no peptidoglycan, and rhamnose in these organisms is also not associated with polysaccharide. We suggest that rhamnose has a central role in anchoring proteins to the membrane by linkage to phospholipid, which may be a general mechanism for the membrane association of moonlighting proteins in mycoplasmas and perhaps other bacteria.
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Affiliation(s)
- James M. Daubenspeck
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294, United States of America
| | - Runhua Liu
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294, United States of America
| | - Kevin Dybvig
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, 35294, United States of America
- * E-mail:
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Interaction of cationic antimicrobial peptides with Mycoplasma pulmonis. FEBS Lett 2013; 587:3321-6. [PMID: 23994526 DOI: 10.1016/j.febslet.2013.08.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/07/2013] [Accepted: 08/09/2013] [Indexed: 11/23/2022]
Abstract
We investigated the mode of action underlying the anti-mycoplasma activity of cationic antimicrobial peptides (AMPs) using four known AMPs and Mycoplasma pulmonis as a model mycoplasma. Scanning electron microscopy revealed that the integrity of the M. pulmonis membrane was significantly damaged within 30 min of AMPs exposure, which was confirmed by measuring the uptake of propidium iodine into the mycoplasma cells. The anti-mycoplasma activity of AMPs was found to depend on the binding affinity for phosphatidylcholine, which was incorporated into the mycoplasma membrane from the growth medium and preferentially distributed in the outer leaflet of the lipid bilayer.
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13
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Jordan DS, Daubenspeck JM, Dybvig K. Rhamnose biosynthesis in mycoplasmas requires precursor glycans larger than monosaccharide. Mol Microbiol 2013; 89:918-28. [PMID: 23826905 DOI: 10.1111/mmi.12320] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2013] [Indexed: 11/30/2022]
Abstract
Despite the apparent absence of genes coding for the known pathways for biosynthesis, the monosaccharide rhamnose was detected in the d configuration in Mycoplasma pneumoniae and Mycoplasma pulmonis, and in both the d and l configurations in Mycoplasma arthritidis. Surprisingly, the monosaccharide glucose was not a precursor for rhamnose biosynthesis and was not incorporated at detectable levels in glucose-containing polysaccharides or glycoconjugates. In contrast, carbon atoms from starch, a polymer of glucose, were incorporated into rhamnose in each of the three species examined. When grown in a serum-free medium supplemented with starch, M. arthritidis synthesized higher levels of rhamnose, with a shift in the relative amounts of the d and l configurations. Our findings suggest the presence of a novel pathway for rhamnose synthesis that is widespread in the genus Mycoplasma.
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Affiliation(s)
- David S Jordan
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
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14
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CpG underrepresentation and the bacterial CpG-specific DNA methyltransferase M.MpeI. Proc Natl Acad Sci U S A 2012; 110:105-10. [PMID: 23248272 DOI: 10.1073/pnas.1207986110] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Cytosine methylation promotes deamination. In eukaryotes, CpG methylation is thought to account for CpG underrepresentation. Whether scarcity of CpGs in prokaryotic genomes is diagnostic for methylation is not clear. Here, we report that Mycoplasms tend to be CpG depleted and to harbor a family of constitutively expressed or phase variable CpG-specific DNA methyltransferases. The very CpG poor Mycoplasma penetrans and its constitutively active CpG-specific methyltransferase M.MpeI were chosen for further characterization. Genome-wide sequencing of bisulfite-converted DNA indicated that M.MpeI methylated CpG target sites both in vivo and in vitro in a locus-nonselective manner. A crystal structure of M.MpeI with DNA at 2.15-Å resolution showed that the substrate base was flipped and that its place in the DNA stack was taken by a glutamine residue. A phenylalanine residue was intercalated into the "weak" CpG step of the nonsubstrate strand, indicating mechanistic similarities in the recognition of the short CpG target sequence by prokaryotic and eukaryotic DNA methyltransferases.
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Shaw BM, Daubenspeck JM, Simmons WL, Dybvig K. EPS-I polysaccharide protects Mycoplasma pulmonis from phagocytosis. FEMS Microbiol Lett 2012. [PMID: 23190331 DOI: 10.1111/1574-6968.12048] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Few mycoplasmal polysaccharides have been described and little is known about their role in pathogenesis. The infection of mice with Mycoplasma pulmonis has been utilized in many in vivo and in vitro studies to gain a better understanding of host-pathogen interactions during chronic respiratory infection. Although alveolar macrophages have a primary role in host defence, M. pulmonis is killed inefficiently in vitro. One antiphagocytic factor produced by the mycoplasma is the family of phase- and size-variable Vsa lipoproteins. However, bacteria generally employ multiple strategies for combating host defences, with capsular polysaccharide often having a key role. We show here that mutants lacking the EPS-I polysaccharide of M. pulmonis exhibit increased susceptibility to binding and subsequent killing by alveolar macrophages. These results give further insight into how mycoplasmas are able to avoid the host immune system and sustain a chronic infection.
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Affiliation(s)
- Brandon M Shaw
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
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