1
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Kumar P, Vyas P, Faisal SM, Chang YF, Akif M. Crystal structure of a variable region segment of Leptospira host-interacting outer surface protein, LigA, reveals the orientation of Ig-like domains. Int J Biol Macromol 2023:125445. [PMID: 37336372 DOI: 10.1016/j.ijbiomac.2023.125445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/21/2023]
Abstract
Leptospiral immunoglobulin-like (Lig) protein family is a surface-exposed protein from the pathogenic Leptospira. The Lig protein family has been identified as an essential virulence factor of L. interrogan. One of the family members, LigA, contains 13 homologous tandem repeats of bacterial Ig-like (Big) domains in its extracellular portion. It is crucial in binding with the host's Extracellular matrices (ECM) and complement factors. However, its vital role in the invasion and evasion of pathogenic Leptospira, structural details, and domain organization of the extracellular portion of this protein are not explored thoroughly. Here, we described the first high-resolution crystal structure of a variable region segment (LigA8-9) of LigA at 1.87 Å resolution. The structure showed some remarkably distinctive aspects compared with the most closely related Immunoglobulin superfamily (IgSF) members. The structure illustrated the relative orientation of two domains and highlighted the role of the linker region in the domain orientation. We also observed an apparent electron density of Ca2+ ions coordinated with a proper interacting geometry within the protein. Molecular dynamic simulations demonstrated the involvement of a linker salt bridge in providing rigidity between the two domains. Our study proposes an overall arrangement of Ig-like domains in the LigA protein. The structural understanding of the extracellular portion of LigA and its interaction with the ECM provides insight into developing new therapeutics directed toward leptospirosis.
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Affiliation(s)
- Pankaj Kumar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India
| | - Pallavi Vyas
- Laboratory of Vaccine Immunology, National Institute of Animal Biotechnology, Gachibowli, Hyderabad, Telangana, India
| | - Syed M Faisal
- Laboratory of Vaccine Immunology, National Institute of Animal Biotechnology, Gachibowli, Hyderabad, Telangana, India
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Mohd Akif
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India.
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2
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Prapong S, Tansiri Y, Sritrakul T, Sripattanakul S, Sopitthummakhun A, Katzenmeier G, Hsieh CL, McDonough SP, Prapong T, Chang YF. Leptospira borgpetersenii Leucine-Rich Repeat Proteins Provide Strong Protective Efficacy as Novel Leptospiral Vaccine Candidates. Trop Med Infect Dis 2022; 8:tropicalmed8010006. [PMID: 36668913 PMCID: PMC9863753 DOI: 10.3390/tropicalmed8010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Leucine-rich repeat (LRR) proteins are advocated for being assessed in vaccine development. Leptospiral LRR proteins were identified recently in silico from the genome of Leptospira borgpetersenii serogroup Sejroe, the seroprevalence of leptospiral infections of cattle in Thailand. Two LRR recombinant proteins, rKU_Sej_LRR_2012M (2012) and rhKU_Sej_LRR_2271 (2271), containing predicted immunogenic epitopes, were investigated for their cross-protective efficacies in an acute leptospirosis model with heterologous Leptospira serovar Pomona, though, strains from serogroup Sejroe are host-adapted to bovine, leading to chronic disease. Since serovar Pomona is frequently reported as seropositive in cattle, buffaloes, pigs, and dogs in Thailand and causes acute and severe leptospirosis in cattle by incidental infection, the serogroup Sejroe LRR proteins were evaluated for their cross-protective immunity. The protective efficacies were 37.5%, 50.0%, and 75.0% based on the survival rate for the control, 2012, and 2271 groups, respectively. Sera from 2012-immunized hamsters showed weak bactericidal action compared to sera from 2271-immunized hamsters (p < 0.05). Therefore, bacterial tissue clearances, inflammatory responses, and humoral and cell-mediated immune (HMI and CMI) responses were evaluated only in 2271-immunized hamsters challenged with virulent L. interrogans serovar Pomona. The 2271 protein induced prompt humoral immune responses (p < 0.05) and leptospiral tissue clearance, reducing tissue inflammation in immunized hamsters. In addition, protein 2271 and its immunogenic peptides stimulated splenocyte lymphoproliferation and stimulated both HMI and CMI responses by activating Th1 and Th2 cytokine gene expression in vaccinated hamsters. Our data suggest that the immunogenic potential renders rhKU_Sej_LRR_2271 protein a promising candidate for the development of a novel cross-protective vaccine against animal leptospirosis.
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Affiliation(s)
- Siriwan Prapong
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
- The Interdisciplinary Graduate Program in Genetic Engineering, The Graduate School, Kasetsart University, Bangkok 10900, Thailand
- Center for Advanced Studies for Agriculture and Food (CASAF), Kasetsart University, Bangkok 10900, Thailand
- Correspondence: ; Tel.: +66-871-264-148
| | - Yada Tansiri
- Faculty of Medicine, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand
| | - Tepyuda Sritrakul
- Department of Veterinary Public Health, Faculty of Veterinary Medicine, Kasetsart University, Kamphaengsaen Campus, Nakorn Pathom 73140, Thailand
| | - Sineenat Sripattanakul
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
- The Interdisciplinary Graduate Program in Genetic Engineering, The Graduate School, Kasetsart University, Bangkok 10900, Thailand
| | - Aukkrimapann Sopitthummakhun
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
- Center for Advanced Studies for Agriculture and Food (CASAF), Kasetsart University, Bangkok 10900, Thailand
| | - Gerd Katzenmeier
- Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Chin-Lin Hsieh
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Sean P. McDonough
- Department of Biomedical Science, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Teerasak Prapong
- Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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3
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Maia MAC, Bettin EB, Barbosa LN, de Oliveira NR, Bunde TT, Pedra ACK, Rosa GA, da Rosa EEB, Seixas Neto ACP, Grassmann AA, McFadden J, Dellagostin OA, McBride AJA. Challenges for the development of a universal vaccine against leptospirosis revealed by the evaluation of 22 vaccine candidates. Front Cell Infect Microbiol 2022; 12:940966. [PMID: 36275031 PMCID: PMC9586249 DOI: 10.3389/fcimb.2022.940966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Leptospirosis is a neglected disease of man and animals that affects nearly half a million people annually and causes considerable economic losses. Current human vaccines are inactivated whole-cell preparations (bacterins) of Leptospira spp. that provide strong homologous protection yet fail to induce a cross-protective immune response. Yearly boosters are required, and serious side-effects are frequently reported so the vaccine is licensed for use in humans in only a handful of countries. Novel universal vaccines require identification of conserved surface-exposed epitopes of leptospiral antigens. Outer membrane β-barrel proteins (βb-OMPs) meet these requirements and have been successfully used as vaccines for other diseases. We report the evaluation of 22 constructs containing protein fragments from 33 leptospiral βb-OMPs, previously identified by reverse and structural vaccinology and cell-surface immunoprecipitation. Three-dimensional structures for each leptospiral βb-OMP were predicted by I-TASSER. The surface-exposed epitopes were predicted using NetMHCII 2.2 and BepiPred 2.0. Recombinant constructs containing regions from one or more βb-OMPs were cloned and expressed in Escherichia coli. IMAC-purified recombinant proteins were adsorbed to an aluminium hydroxide adjuvant to produce the vaccine formulations. Hamsters (4-6 weeks old) were vaccinated with 2 doses containing 50 – 125 μg of recombinant protein, with a 14-day interval between doses. Immunoprotection was evaluated in the hamster model of leptospirosis against a homologous challenge (10 – 20× ED50) with L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni strain Fiocruz L1-130. Of the vaccine formulations, 20/22 were immunogenic and induced significant humoral immune responses (IgG) prior to challenge. Four constructs induced significant protection (100%, P < 0.001) and sterilizing immunity in two independent experiments, however, this was not reproducible in subsequent evaluations (0 – 33.3% protection, P > 0.05). The lack of reproducibility seen in these challenge experiments and in other reports in the literature, together with the lack of immune correlates and commercially available reagents to characterize the immune response, suggest that the hamster may not be the ideal model for evaluation of leptospirosis vaccines and highlight the need for evaluation of alternative models, such as the mouse.
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Affiliation(s)
- Mara A. C. Maia
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Everton B. Bettin
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Liana N. Barbosa
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Natasha R. de Oliveira
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Tiffany T. Bunde
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Ana Carolina K. Pedra
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Guilherme A. Rosa
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Elias E. B. da Rosa
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Amilton C. P. Seixas Neto
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - André A. Grassmann
- Department of Medicine, University of Connecticut Health, Farmington, CT, United States
| | - Johnjoe McFadden
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Odir A. Dellagostin
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
| | - Alan J. A. McBride
- Biotechnology Unit, Technological Development Centre, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
- *Correspondence: Alan J. A. McBride,
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4
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Characterization of novel nuclease and protease activities among Leptospiral immunoglobulin-like proteins. Arch Biochem Biophys 2022; 727:109349. [PMID: 35820644 DOI: 10.1016/j.abb.2022.109349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 06/01/2022] [Accepted: 07/03/2022] [Indexed: 11/24/2022]
Abstract
Bacterial immunoglobulin-like (BIg) domain containing proteins play a variety of biological functions. Leptospiral Immunoglobulin-like (Lig) proteins are well-known virulence factors located on the surface of the pathogenic Leptospira that act during adhesion, invasion, and immune evasion. The Lig proteins have many roles and have been designated as multifaceted proteins. However, the hydrolyzing function of Lig proteins is not yet investigated in detail. Here, we report novel in-vitro nuclease and protease activities in the Ig-like domain of LigA protein. All Ig-like domains were able to cleave DNA in the presence of a divalent ion, but not RNA. Site-directed mutagenesis revealed Mg+2 binding residues in the Ig-like domain of LigA7. The basis of novel nuclease activity may be associated with protein adopting different conformation in the presence of divalent ions and substrate as investigated by change of intrinsic fluorescence. The docking of a stretch of double-strand DNA shows the binding on the positive surface of the protein. In addition, the protein is also observed to cleave a general protease substrate, β-casein, in our experimental condition. Our results proposed that the novel functions may be associated with neutrophil extracellular Trap (NET) evasion. Overall this study enhances the basic knowledge of non-nuclease proteins involved in the DNA cleavage activity and makes the foundation to explore its in-vivo activity in pathogenic Leptospira and other pathogens as well. Moreover, this information may be utilized to develop preventive strategies to interfere with Leptospira immune evasion.
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5
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Kumar P, Lata S, Shankar UN, Akif M. Immunoinformatics-Based Designing of a Multi-Epitope Chimeric Vaccine From Multi-Domain Outer Surface Antigens of Leptospira. Front Immunol 2021; 12:735373. [PMID: 34917072 PMCID: PMC8670241 DOI: 10.3389/fimmu.2021.735373] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Accurate information on antigenic epitopes within a multi-domain antigen would provide insights into vaccine design and immunotherapy. The multi-domain outer surface Leptospira immunoglobulin-like (Lig) proteins LigA and LigB, consisting of 12–13 homologous bacterial Ig (Big)-like domains, are potential antigens of Leptospira interrogans. Currently, no effective vaccine is available against pathogenic Leptospira. Both the humoral immunity and cell-mediated immunity of the host play critical roles in defending against Leptospira infection. Here, we used immunoinformatics approaches to evaluate antigenic B-cell lymphocyte (BCL) and cytotoxic T-lymphocyte (CTL) epitopes from Lig proteins. Based on certain crucial parameters, potential epitopes that can stimulate both types of adaptive immune responses were selected to design a chimeric vaccine construct. Additionally, an adjuvant, the mycobacterial heparin-binding hemagglutinin adhesin (HBHA), was incorporated into the final multi-epitope vaccine construct with a suitable linker. The final construct was further scored for its antigenicity, allergenicity, and physicochemical parameters. A three-dimensional (3D) modeled construct of the vaccine was implied to interact with Toll-like receptor 4 (TLR4) using molecular docking. The stability of the vaccine construct with TLR4 was predicted with molecular dynamics simulation. Our results demonstrate the application of immunoinformatics and structure biology strategies to develop an epitope-specific chimeric vaccine from multi-domain proteins. The current findings will be useful for future experimental validation to ratify the immunogenicity of the chimera.
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Affiliation(s)
- Pankaj Kumar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Surabhi Lata
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Umate Nachiket Shankar
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Mohd Akif
- Laboratory of Structural Biology, Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
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6
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Behera SK, Sabarinath T, Mishra PKK, Deneke Y, Kumar A, ChandraSekar S, Senthilkumar K, Verma M, Ganesh B, Gurav A, Hota A. Immunoinformatic Study of Recombinant LigA/BCon1-5 Antigen and Evaluation of Its Diagnostic Potential in Primary and Secondary Binding Tests for Serodiagnosis of Porcine Leptospirosis. Pathogens 2021; 10:1082. [PMID: 34578116 PMCID: PMC8466556 DOI: 10.3390/pathogens10091082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/05/2021] [Accepted: 08/16/2021] [Indexed: 11/20/2022] Open
Abstract
Leptospirosis is responsible for hampering the productivity of swine husbandry worldwide. The aim of this study was to assess the efficacy of bioinformatics tools in predicting the three-dimensional structure and immunogenicity of recombinant LigBCon1-5 (rLigBCon1-5) antigen. A battery of bioinformatics tools such as I-TASSER, ProSA and SAVES v6.0 were used for the prediction and assessment of the predicted structure of rLigBCon1-5 antigen. Bepipred-2.0, DiscoTope v2.0 and ElliPro servers were used to predict linear and conformational epitopes while T-cell epitopes were predicted using NetMHCpan 4.1 and IEDB recommended 2.22 method for MHC Class I and II peptides respectively. The results obtained using various in silico methods were then compared with wet lab experiments comprising of both primary (IgG Dot ELISA Dipstick test) and secondary-binding assays (Latex Agglutination Test [LAT]) to screen 1153 porcine serum samples. The three-dimensional structure of rLigA/BCon1-5 protein as predicted by I-TASSER was found to be reliable by Ramachandran Plot and ProSA. The ElliPro server suggested 10 and three potential linear and conformational B-cell-epitopes, respectively, on the peptide backbone of the rLigA/BCon1-5 protein. The DiscoTope prediction server suggested 47 amino acid residues to be part of B-cell antigen. Ten of the most efficient peptides for MHC-I and II grooves were predicted by NetMHCpan 4.1 and IEDB recommended 2.22 method, respectively. Of these, three peptides can serve dual functions as it can fit both MHC I and II grooves, thereby eliciting both humoral-and cell-mediated immune responses. The prediction of these computational approaches proved to be reliable since rLigBCon1-5 antigen-based IgG Dot ELISA Dipstick test and LAT gave results in concordance to gold standard test, the Microscopic Agglutination Test (MAT), for serodiagnosis of leptospirosis. Both the IgG Dot ELISA Dipstick test and LAT were serodiagnostic assays ideally suited for peripheral level of animal health care system as "point of care" tests for the detection of porcine leptospirosis.
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Affiliation(s)
- Sujit Kumar Behera
- Department of Epidemiology & Public Health, Central University of Tamil Nadu, Tiruvarur 610001, India;
| | - Thankappan Sabarinath
- Clinical Bacteriological Laboratory, Indian Council of Agricultural Research—Indian Veterinary Research Institute, Mukteshwar, Nainital 263138, India
| | - Prasanta Kumar K. Mishra
- Faculty of Veterinary and Animal Sciences, Rajiv Gandhi South Campus, Banaras Hindu University, Mirzapur 231001, India;
| | - Yosef Deneke
- School of Veterinary Medicine, Jimma University, Jimma 378, Ethiopia;
| | - Ashok Kumar
- Krishi Bhawan, Indian Council of Agricultural Research, New Delhi 110001, India;
| | - Shanmugam ChandraSekar
- Biochemistry Laboratory, Indian Council of Agricultural Research—Indian Veterinary Research Institute, Mukteshwar, Nainital 263138, India;
| | - Kuppusamy Senthilkumar
- Zoonoses Research Laboratory, Tamil Nadu Veterinary and Animal Sciences University, Chennai 600051, India;
| | - MedRam Verma
- Livestock Economics & Statistics Division, Indian Council of Agricultural Research—Indian Veterinary Research Institute, Bareilly 243122, India;
| | | | - Amol Gurav
- Temperate Animal Husbandry Division, ICAR—Indian Veterinary Research Institute (IVRI), Mukteshwar, Nainital 263138, India;
| | - Abhishek Hota
- Department of Animal Science, Centurion University of Technology and Management, Paralakhemundi 761211, India;
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7
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Schuler EJA, Marconi RT. The Leptospiral General Secretory Protein D (GspD), a secretin, elicits complement-independent bactericidal antibody against diverse Leptospira species and serovars. Vaccine X 2021; 7:100089. [PMID: 33733085 PMCID: PMC7941034 DOI: 10.1016/j.jvacx.2021.100089] [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: 10/29/2020] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 11/21/2022] Open
Abstract
Leptospirosis, the most common zoonotic infection worldwide, is a multi-system disorder affecting the kidney, liver, and lungs. Infections can be asymptomatic, self-limiting or progress to multi-organ system failure and pulmonary hemorrhage. The incidence of canine and human leptospirosis is steadily increasing worldwide. At least sixty-four Leptospira species and several hundred lipopolysaccharide-based serovars have been defined. Preventive vaccines are available for use in veterinary medicine and limited use in humans in some countries. All commercially available vaccines are bacterin formulations that consist of a combination of laboratory cultivated strains of different lipopolysaccharide serotypes. The development of a broadly protective subunit vaccine would represent a significant step forward in efforts to combat leptospirosis in humans, livestock, and companion animals worldwide. Here we investigate the potential of General secretory protein D (GspD; LIC11570), a secretin, to serve as a possible antigen in a multi-valent vaccine formulation. GspD is conserved, expressed in vitro, antigenic during infection and elicits antibody with complement independent bactericidal activity. Importantly, antibody to GspD is bactericidal against diverse Leptospira species of the P1 subclade. Epitope mapping localized the bactericidal epitopes to the N-terminal N0 domain of GspD. The data within support further exploration of GspD as a candidate for inclusion in a next generation multi-protein subunit vaccine.
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Affiliation(s)
- EJA. Schuler
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, 1112 E Clay St., Richmond, VA 23298, USA
| | - RT. Marconi
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, 1112 E Clay St., Richmond, VA 23298, USA
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8
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Haake DA, Matsunaga J. Leptospiral Immunoglobulin-Like Domain Proteins: Roles in Virulence and Immunity. Front Immunol 2021; 11:579907. [PMID: 33488581 PMCID: PMC7821625 DOI: 10.3389/fimmu.2020.579907] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/05/2020] [Indexed: 02/03/2023] Open
Abstract
The virulence mechanisms required for infection and evasion of immunity by pathogenic Leptospira species remain poorly understood. A number of L. interrogans surface proteins have been discovered, lying at the interface between the pathogen and host. Among these proteins, the functional properties of the Lig (leptospiral immunoglobulin-like domain) proteins have been examined most thoroughly. LigA, LigB, and LigC contain a series of, 13, 12, and 12 closely related domains, respectively, each containing a bacterial immunoglobulin (Big) -like fold. The multidomain region forms a mostly elongated structure that exposes a large surface area. Leptospires wield the Lig proteins to promote interactions with a range of specific host proteins, including those that aid evasion of innate immune mechanisms. These diverse binding events mediate adhesion of L. interrogans to the extracellular matrix, inhibit hemostasis, and inactivate key complement proteins. These interactions may help L. interrogans overcome the physical, hematological, and immunological barriers that would otherwise prevent the spirochete from establishing a systemic infection. Despite significant differences in the affinities of the LigA and LigB proteins for host targets, their functions overlap during lethal infection of hamsters; virulence is lost only when both ligA and ligB transcription is knocked down simultaneously. Lig proteins have been shown to be promising vaccine antigens through evaluation of a variety of different adjuvant strategies. This review serves to summarize current knowledge of Lig protein roles in virulence and immunity and to identify directions needed to better understand the precise functions of the Lig proteins during infection.
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Affiliation(s)
- David A. Haake
- Division of Infectious Diseases, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Departments of Medicine, and Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
| | - James Matsunaga
- Research Service, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA, United States
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9
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Izac JR, O'Bier NS, Oliver LD, Camire AC, Earnhart CG, LeBlanc Rhodes DV, Young BF, Parnham SR, Davies C, Marconi RT. Development and optimization of OspC chimeritope vaccinogens for Lyme disease. Vaccine 2020; 38:1915-1924. [PMID: 31959423 PMCID: PMC7085410 DOI: 10.1016/j.vaccine.2020.01.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/18/2022]
Abstract
Experimental Outer surface protein (Osp) C based subunit chimeritope vaccinogens for Lyme disease (LD) were assessed for immunogenicity, structure, ability to elicit antibody (Ab) responses to divergent OspC proteins, and bactericidal activity. Chimeritopes are chimeric epitope based proteins that consist of linear epitopes derived from multiple proteins or multiple variants of a protein. An inherent advantage to chimeritope vaccinogens is that they can be constructed to trigger broadly protective Ab responses. Three OspC chimeritope proteins were comparatively assessed: Chv1, Chv2 and Chv3. The Chv proteins possess the same set of 18 linear epitopes derived from 9 OspC type proteins but differ in the physical ordering of epitopes or by the presence or absence of linkers. All Chv proteins were immunogenic in mice and rats eliciting high titer Ab. Immunoblot and enzyme linked immunosorbent assays demonstrated that the Chv proteins elicit IgG that recognizes a diverse array of OspC type proteins. The panel included OspC proteins produced by N. American and European strains of the LD spirochetes. Rat anti-Chv antisera uniformly labeled intact, non-permeabilized Borreliella burgdorferi demonstrating that vaccinal Ab can bind to targets that are naturally presented on the spirochete cell surface. Vaccinal Ab also displayed potent complement dependent-Ab mediated killing activity. This study highlights the ability of OspC chimeritopes to serve as vaccinogens that trigger potentially broadly protective Ab responses. In addition to the current use of an OspC chimeritope in a canine LD vaccine, chimeritopes can serve as key components of human LD subunit vaccines.
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Affiliation(s)
- Jerilyn R Izac
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States
| | - Nathaniel S O'Bier
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States
| | - Lee D Oliver
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States
| | - Andrew C Camire
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States
| | - Christopher G Earnhart
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States
| | | | - Brandon F Young
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Stuart R Parnham
- Dept. Biochem. & Biophysics, The University of North Carolina, Chapel Hill, NC 27599, United States
| | - Christopher Davies
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States
| | - Richard T Marconi
- Dept. Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0678, United States.
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10
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Ptak CP, Akif M, Hsieh C, Devarajan A, He P, Xu Y, Oswald RE, Chang Y. Comparative screening of recombinant antigen thermostability for improved leptospirosis vaccine design. Biotechnol Bioeng 2018; 116:260-271. [DOI: 10.1002/bit.26864] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 10/29/2018] [Accepted: 11/07/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Christopher P. Ptak
- Department of Population Medicine and Diagnostic SciencesCollege of Veterinary Medicine, Cornell UniversityIthaca New York
- Department of Molecular MedicineCollege of Veterinary Medicine, Cornell UniversityIthaca New York
| | - Mohd. Akif
- Department of Population Medicine and Diagnostic SciencesCollege of Veterinary Medicine, Cornell UniversityIthaca New York
- Department of BiochemistryUniversity of HyderabadHyderabad India
| | - Ching‐Lin Hsieh
- Department of Population Medicine and Diagnostic SciencesCollege of Veterinary Medicine, Cornell UniversityIthaca New York
| | - Alex Devarajan
- Department of Molecular MedicineCollege of Veterinary Medicine, Cornell UniversityIthaca New York
| | - Ping He
- Department of Microbiology and ImmunologyInstitutes of Medical Science, Shanghai Jiao Tong University School of MedicineShanghai China
| | - Yinghua Xu
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug ControlBeijing China
| | - Robert E. Oswald
- Department of Molecular MedicineCollege of Veterinary Medicine, Cornell UniversityIthaca New York
| | - Yung‐Fu Chang
- Department of Population Medicine and Diagnostic SciencesCollege of Veterinary Medicine, Cornell UniversityIthaca New York
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Santos JC, Nascimento ALT. Chimeras could help in the fight against leptospirosis. eLife 2018; 7:34087. [PMID: 29350615 PMCID: PMC5774897 DOI: 10.7554/elife.34087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 01/07/2023] Open
Abstract
Understanding the structure of an antigen can guide the design of improved antigen-based vaccines.
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Affiliation(s)
- Jademilson C Santos
- Laboratório Especial de Desenvolvimento de Vacinas-Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil
| | - Ana Lucia To Nascimento
- Laboratório Especial de Desenvolvimento de Vacinas-Centro de Biotecnologia, Instituto Butantan, São Paulo, Brazil
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