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Barbosa MS, Sampaio BA, Spergser J, Rosengarten R, Marques LM, Chopra-Dewasthaly R. Mycoplasma agalactiae Vaccines: Current Status, Hurdles, and Opportunities Due to Advances in Pathogenicity Studies. Vaccines (Basel) 2024; 12:156. [PMID: 38400139 PMCID: PMC10892753 DOI: 10.3390/vaccines12020156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
Contagious agalactia (CA) is a serious multietiological disease whose classic etiological agent is Mycoplasma agalactiae and which causes high morbidity and mortality rates in infected herds. CA is classified as a notifiable disease by the World Organization for Animal Health due to its significant worldwide economic impact on livestock, primarily involving goat and sheep farms. The emergence of atypical symptoms and strains of M. agalactiae in wildlife ungulates reestablishes its highly plastic genome and is also of great epidemiological significance. Antimicrobial therapy is the main form of control, although several factors, such as intrinsic antibiotic resistance and the selection of resistant strains, must be considered. Available vaccines are few and mostly inefficient. The virulence and pathogenicity mechanisms of M. agalactiae mainly rely on surface molecules that have direct contact with the host. Because of this, they are essential for the development of vaccines. This review highlights the currently available vaccines and their limitations and the development of new vaccine possibilities, especially considering the challenge of antigenic variation and dynamic genome in this microorganism.
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Affiliation(s)
- Maysa Santos Barbosa
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitoria da Conquista 45029-094, Brazil; (M.S.B.)
| | | | - Joachim Spergser
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Wien, Austria
| | - Renate Rosengarten
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Wien, Austria
| | - Lucas Miranda Marques
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitoria da Conquista 45029-094, Brazil; (M.S.B.)
- Department of Microbiology, State University of Santa Cruz (UESC), Ilheus 45662-900, Brazil
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Sao Paulo 05508-000, Brazil
| | - Rohini Chopra-Dewasthaly
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Wien, Austria
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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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Mugunthan SP, Kannan G, Chandra HM, Paital B. Infection, Transmission, Pathogenesis and Vaccine Development against Mycoplasma gallisepticum. Vaccines (Basel) 2023; 11:vaccines11020469. [PMID: 36851345 PMCID: PMC9967393 DOI: 10.3390/vaccines11020469] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/12/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Mycoplasma sp. comprises cell wall-less bacteria with reduced genome size and can infect mammals, reptiles, birds, and plants. Avian mycoplasmosis, particularly in chickens, is primarily caused by Mycoplasma gallisepticum (MG) and Mycoplasma synoviae. It causes infection and pathology mainly in the respiratory, reproductive, and musculoskeletal systems. MG is the most widely distributed pathogenic avian mycoplasma with a wide range of host susceptibility and virulence. MG is transmitted both by horizontal and vertical routes. MG infection induces innate, cellular, mucosal, and adaptive immune responses in the host. Macrophages aid in phagocytosis and clearance, and B and T cells play critical roles in the clearance and prevention of MG. The virulent factors of MG are adhesion proteins, lipoproteins, heat shock proteins, and antigenic variation proteins, all of which play pivotal roles in host cell entry and pathogenesis. Prevention of MG relies on farm and flock biosecurity, management strategies, early diagnosis, use of antimicrobials, and vaccination. This review summarizes the vital pathogenic mechanisms underlying MG infection and recapitulates the virulence factors of MG-host cell adhesion, antigenic variation, nutrient transport, and immune evasion. The review also highlights the limitations of current vaccines and the development of innovative future vaccines against MG.
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Affiliation(s)
| | - Ganapathy Kannan
- Institute of Infection, Veterinary & Ecology Sciences (IVES), University of Liverpool, Neston, Cheshire CH64 7TE, UK
| | - Harish Mani Chandra
- Department of Biotechnology, Thiruvalluvar University, Vellore 632115, India
- Correspondence: (H.M.C.); (B.P.)
| | - Biswaranjan Paital
- Redox Regulation Laboratory, Department of Zoology, College of Basic Science and Humanities, Odisha University of Agriculture and Technology, Bhubaneswar 751003, India
- Correspondence: (H.M.C.); (B.P.)
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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: 0] [Impact Index Per Article: 0] [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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Mugunthan SP, Harish MC. In silico structural homology modeling and functional characterization of Mycoplasma gallisepticum variable lipoprotein hemagglutin proteins. Front Vet Sci 2022; 9:943831. [PMID: 35990271 PMCID: PMC9386052 DOI: 10.3389/fvets.2022.943831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 07/01/2022] [Indexed: 11/13/2022] Open
Abstract
Mycoplasma gallisepticum variable lipoprotein hemagglutin (vlhA) proteins are crucial for immune evasion from the host cells, permitting the persistence and survival of the pathogen. However, the exact molecular mechanism behind the immune evasion function is still not clear. In silico physiochemical analysis, domain analysis, subcellular localization, and homology modeling studies have been carried out to predict the structural and functional properties of these proteins. The outcomes of this study provide significant preliminary data for understanding the immune evasion by vlhA proteins. In this study, we have reported the primary, secondary, and tertiary structural characteristics and subcellular localization, presence of the transmembrane helix and signal peptide, and functional characteristics of vlhA proteins from M. gallisepticum strain R low. The results show variation between the structural and functional components of the proteins, signifying the role and diverse molecular mechanisms in functioning of vlhA proteins in host immune evasion. Moreover the 3D structure predicted in this study will pave a way for understanding vlhA protein function and its interaction with other molecules to undergo immune evasion. This study forms the basis for future experimental studies improving our understanding in the molecular mechanisms used by vlhA proteins.
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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: 0] [Impact Index Per Article: 0] [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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Barbosa MS, Marques LM, Timenetsky J, Rosengarten R, Spergser J, Chopra-Dewasthaly R. Host cell interactions of novel antigenic membrane proteins of Mycoplasma agalactiae. BMC Microbiol 2022; 22:93. [PMID: 35395771 PMCID: PMC8991494 DOI: 10.1186/s12866-022-02512-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/30/2022] [Indexed: 11/30/2022] Open
Abstract
Background Mycoplasma agalactiae is the main etiological agent of Contagious Agalactia syndrome of small ruminants notifiable to the World Organization for Animal Health. Despite serious economic losses, successful vaccines are unavailable, largely because its colonization and invasion factors are not well understood. This study evaluates the role of two recently identified antigenic proteins (MAG_1560, MAG_6130) and the cytadhesin P40 in pathogenicity related phenotypes. Results Adhesion to HeLa and sheep primary mammary stromal cells (MSC) was evaluated using ELISA, as well as in vitro adhesion assays on monolayer cell cultures. The results demonstrated MAG_6130 as a novel adhesin of M. agalactiae whose capacity to adhere to eukaryotic cells was significantly reduced by specific antiserum. Additionally, these proteins exhibited significant binding to plasminogen and extracellular matrix (ECM) proteins like lactoferrin, fibrinogen and fibronectin, a feature that could potentially support the pathogen in host colonization, tissue migration and immune evasion. Furthermore, these proteins played a detrimental role on the host cell proliferation and viability and were observed to activate pro-apoptotic genes indicating their involvement in cell death when eukaryotic cells were infected with M. agalactiae. Conclusions To summarize, the hypothetical protein corresponding to MAG_6130 has not only been assigned novel adhesion functions but together with P40 it is demonstrated for the first time to bind to lactoferrin and ECM proteins thereby playing important roles in host colonization and pathogenicity. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02512-2.
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Affiliation(s)
- Maysa Santos Barbosa
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, A-1210, Austria.,Present Address: Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Lucas Miranda Marques
- Present Address: Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil. .,Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista, Brazil.
| | - Jorge Timenetsky
- Present Address: Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Renate Rosengarten
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, A-1210, Austria
| | - Joachim Spergser
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, A-1210, Austria
| | - Rohini Chopra-Dewasthaly
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, A-1210, Austria.
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Predominant Single Stable VpmaV Expression in Strain GM139 and Major Differences with Mycoplasma agalactiae Type Strain PG2. Animals (Basel) 2022; 12:ani12030265. [PMID: 35158589 PMCID: PMC8833448 DOI: 10.3390/ani12030265] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/12/2022] [Accepted: 01/17/2022] [Indexed: 01/27/2023] Open
Abstract
Simple Summary MALDI-ToF MS analysis demonstrates major differences between Mycoplasma agalactiae type strain PG2 and strain GM139. Evaluation of the Vpma (variable proteins of M. agalactiae) phenotypic profiles of these two strains reveals that unlike PG2, GM139 expresses a single Vpma, namely VpmaV, and without any visible phase variation. Although the presence of only one Vpma seems to be sufficient for the pathogenesis of the GM139 strain, the absence of phase variation can compromise immune system evasion and spread to other anatomical sites in the host. Abstract Although mycoplasmas have a reduced genome and no cell wall, they have important mechanisms for the antigenic variation in surface lipoproteins that modulate their interactions with the host. Mycoplasma agalactiae, the main etiological agent of contagious agalactia, has a multigene family involved in the high-frequency phase variation in surface lipoproteins called variable proteins of M. agalactiae (Vpmas). The Vpma lipoproteins are involved in the immune evasion, colonization, dissemination, and persistence of M. agalactiae in the host. In this paper, we evaluate the Vpma phenotypic profiles of two different strains of M. agalactiae, namely, GM139 and the type strain PG2, to assess possible correlations between Vpma phase variability and the geographic localization, animal origin, and pathogenicity of these two strains. Using monospecific Vpma antibodies against individual Vpmas in immunoblots, we demonstrate that, unlike PG2, which expresses six Vpma proteins with high-frequency phase variation, colonies of GM139 predominantly express VpmaV and do not exhibit any sectoring phenotype for any Vpma. Since VpmaV is one of the most important Vpmas for cell adhesion and invasion, its predominant sole expression in GM139 without high-frequency variation may be the basis of the differential pathogenicity of GM139 and PG2. Additionally, MALDI-ToF MS analysis also demonstrates significant differences between these two strains and their relatedness with other M. agalactiae strains.
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Abstract
Mycoplasmas are small, genome-reduced bacteria. They are obligate parasites that can be found in a wide range of host species, including the majority of livestock animals and humans. Colonization of the host can result in a wide spectrum of outcomes. In many cases, these successful parasites are considered commensal, as they are found in the microbiota of asymptomatic carriers. Conversely, mycoplasmas can also be pathogenic, as they are associated with a range of both acute and chronic inflammatory diseases which are problematic in veterinary and human medicine. The chronicity of mycoplasma infections and the ability of these bacteria to infect even recently vaccinated individuals clearly indicate that they are able to successfully evade their host’s humoral immune response. Over the years, multiple strategies of immune evasion have been identified in mycoplasmas, with a number of them aimed at generating important antigenic diversity. More recently, mycoplasma-specific anti-immunoglobulin strategies have also been characterized. Through the expression of the immunoglobulin-binding proteins protein M or mycoplasma immunoglobulin binding (MIB), mycoplasmas have the ability to target the host’s antibodies and to prevent them from interacting with their cognate antigens. In this review, we discuss how these discoveries shed new light on the relationship between mycoplasmas and their host’s immune system. We also propose that these strategies should be taken into consideration for future studies, as they are key to our understanding of mycoplasma diseases' chronic and inflammatory nature and are probably a contributing factor to reduce vaccine efficacy.
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Barbosa MS, Alves RPDS, Rezende IDS, Pereira SS, Campos GB, Freitas LM, Chopra-Dewasthaly R, Ferreira LCDS, Guimarães AMDS, Marques LM, Timenetsky J. Novel antigenic proteins of Mycoplasma agalactiae as potential vaccine and serodiagnostic candidates. Vet Microbiol 2020; 251:108866. [PMID: 33099078 DOI: 10.1016/j.vetmic.2020.108866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/22/2020] [Indexed: 10/23/2022]
Abstract
Contagious agalactia (CA) is a serious disease notifiable to the World Organisation for Animal Health (OIE) causing severe economic losses to sheep and goat producers worldwide. Mycoplasma agalactiae, considered as its main etiological agent, inflicts a variety of symptoms in infected animals, including keratoconjunctivitis, mastitis, arthritis, ankylosis, abortions, stillbirths and granular vulvovaginitis. Despite its significance, developing a successful vaccine remains elusive, mostly due to the lack of knowledge about M. agalactiae's pathogenicity factors and pathogenic mechanisms, including its "core" antigens. The aim of this study was to identify, characterize and express antigenic proteins of M. agalactiae as potential vaccine candidates. Predicted proteins of type strain PG2 were analyzed using bioinformatic algorithms to assess their cellular localization and to identify their linear and conformational epitopes for B cells. Out of a total of 156 predicted membrane proteins, three were shortlisted as potential antigenic surface proteins, namely [MAG_1560 (WP_011949336.1), MAG_6130 (WP_011949770.1) and P40 (WP_011949418.1)]. These proteins were expressed in recombinant Escherichia coli strains. Purified proteins were evaluated for their antigenicity using Western blot and ELISA using sera of M. agalactiae-naturally infected and non-infected sheep and goats. All 3 proteins were specifically recognized by the tested sera of M. agalactiae-infected animals. Also, specific rabbit antisera raised against each of these 3 proteins confirm their membrane localization using TritonX-114 phase partioning, Western and colony immunoblotting. In conclusion, our study successfully identified P40 (as proof of concept and validation) and two novel antigenic M. agalactiae proteins as potential candidates for developing effective CA vaccines.
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Affiliation(s)
- Maysa Santos Barbosa
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Rubens Prince Dos Santos Alves
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Izadora de Souza Rezende
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Samuel Santos Pereira
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Guilherme Barreto Campos
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil; Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil
| | - Leandro Martins Freitas
- Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil
| | - Rohini Chopra-Dewasthaly
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Luís Carlos de Souza Ferreira
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Ana Marcia de Sá Guimarães
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Lucas Miranda Marques
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil; Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil.
| | - Jorge Timenetsky
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
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All living cells are cognitive. Biochem Biophys Res Commun 2020; 564:134-149. [PMID: 32972747 DOI: 10.1016/j.bbrc.2020.08.120] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/28/2020] [Accepted: 08/19/2020] [Indexed: 12/24/2022]
Abstract
All living cells sense and respond to changes in external or internal conditions. Without that cognitive capacity, they could not obtain nutrition essential for growth, survive inevitable ecological changes, or correct accidents in the complex processes of reproduction. Wherever examined, even the smallest living cells (prokaryotes) display sophisticated regulatory networks establishing appropriate adaptations to stress conditions that maximize the probability of survival. Supposedly "simple" prokaryotic organisms also display remarkable capabilities for intercellular signalling and multicellular coordination. These observations indicate that all living cells are cognitive.
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Orlov M, Garanina I, Fisunov GY, Sorokin A. Comparative Analysis of Mycoplasma gallisepticum vlhA Promoters. Front Genet 2018; 9:569. [PMID: 30519256 PMCID: PMC6258824 DOI: 10.3389/fgene.2018.00569] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/06/2018] [Indexed: 12/15/2022] Open
Abstract
Mycoplasma gallisepticum is an intracellular parasite affecting respiratory tract of poultry that belongs to class Mollicutes. M. gallisepticum features numerous variable lipoprotein hemagglutinin genes (vlhA) that play a role in immune escape. The vlhA promoters have a set of distinct properties in comparison to promoters of the other genes. The vlhA promoters carry a variable GAA repeats region at approximately 40 nts upstream of transcription start site. The promoters have been considered active only in the presence of exactly 12 GAA repeats. The mechanisms of vlhA expression regulation and GAA number variation are not described. Here we tried to understand these mechanisms using different computational methods. We conducted a comparative analysis among several M. gallisepticum strains. Nucleotide sequences analysis showed the presence of highly conserved regions flanking repeated trinucleotides that are not linked to GAA number variation. VlhA genes with 12 GAA repeats and their orthologs in 12 M. gallisepticum strains are more conserved than other vlhA genes and have narrower GAA number distribution. We conducted comparative analysis of physicochemical profiles of M. gallisepticum vlhA and sigma-70 promoters. Stress-induced duplex destabilization (SIDD) profiles showed that sigma-70 group is characterized by the common to prokaryotic promoters sharp maxima while vlhA promoters are hardly destabilized with the region between GAA repeats and transcription start site having zero opening probability. Electrostatic potential profiles of vlhA promoters indicate the presence of the distinct patterns that appear to govern initial stages of specific DNA-protein recognition. Open state dynamics profiles of vlhA demonstrate the pattern that might facilitate transcription bubble formation. Obtained data could be the basis for experimental identification of mechanisms of phase variation in M. gallisepticum.
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Affiliation(s)
- Mikhail Orlov
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Irina Garanina
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical-Biological Agency, Moscow, Russia
| | - Gleb Y Fisunov
- Federal Research and Clinical Center of Physical-Chemical Medicine, Federal Medical-Biological Agency, Moscow, Russia
| | - Anatoly Sorokin
- Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
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Hegde S, Zimmermann M, Rosengarten R, Chopra-Dewasthaly R. Novel role of Vpmas as major adhesins of Mycoplasma agalactiae mediating differential cell adhesion and invasion of Vpma expression variants. Int J Med Microbiol 2017; 308:263-270. [PMID: 29229193 DOI: 10.1016/j.ijmm.2017.11.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 11/10/2017] [Accepted: 11/21/2017] [Indexed: 11/28/2022] Open
Abstract
Mycoplasma agalactiae exhibits antigenic variation by switching the expression of multiple surface lipoproteins called Vpmas. Although implicated to have a significant influence on the pathogenicity, their exact role in pathogen-host interactions has not been investigated so far. Initial attachment to host cells is regarded as one of the most important steps for colonization but this pathogen lacks the typical mycoplasma attachment organelle. The aim of this study was to determine the role of Vpmas in adhesion of M. agalactiae to host cells. 'Phase-Locked' Mutants (PLMs) steadily expressing single well-characterized Vpma lipoproteins served as ideal tools to evaluate the role of each of the six Vpmas in cytadhesion, which was otherwise not possible due to the high-frequency switching of Vpmas in the wildtype strain PG2. Using in vitro adhesion assays with HeLa and sheep mammary epithelial (MECs) and stromal (MSCs) cells, we could demonstrate differences in the adhesion capabilities of each of the six PLMs compared to the wildtype strain. The PLMV mutant expressing VpmaV exhibited the highest adhesion rate, whereas PLMU, which expresses VpmaU showed the lowest adhesion values explaining the reduced in vivo fitness of PLMU in sheep during experimental intramammary and conjunctival infections. Furthermore, adhesion inhibition assays using Vpma-specific polyclonal antisera were performed to confirm the role of Vpmas in M. agalactiae cytadhesion. This led to a significant decrease (p<0.05) in the adhesion percentage of each PLM. Immunofluorescence staining of TX-114 phase proteins extracted from each PLM showed binding of the respective Vpma to HeLa cells and MECs proving the direct role of Vpmas in cytadhesion. Furthermore, as adhesion is a prerequisite for cell invasion, the ability of the six PLMs to invade HeLa cells was also evaluated using the gentamicin protection assay. The results showed a strong correlation between the adhesion rates and invasion frequencies of the individual PLMs. This is the first report that describes a novel function of Vpma proteins in cell adhesion and invasion. Besides the variability of these proteins causing surface antigenic variation, the newly identified phenotypes are likely to play critical roles in the pathogenicity potential of this ruminant pathogen.
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Affiliation(s)
- Shrilakshmi Hegde
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Martina Zimmermann
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Renate Rosengarten
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Rohini Chopra-Dewasthaly
- Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria.
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