Dataset Information

Utility of Hybrid Transferrin Binding Protein Antigens for Protection Against Pathogenic Neisseria Species.

ABSTRACT: The surface transferrin receptor proteins from Neisseria gonorrhoeae have been recognized as ideal vaccine targets due to their critical role in survival in the human male genitourinary tract. Recombinant forms of the surface lipoprotein component of the receptor, transferrin binding protein B (TbpB), can be readily produced at high levels in the Escherichia coli cytoplasm and is suitable for commercial vaccine production. In contrast, the integral outer membrane protein, transferrin binding protein A (TbpA), is produced at relatively low levels in the outer membrane and requires detergents for solubilization and stabilization, processes not favorable for commercial applications. Capitalizing on the core ?-barrel structural feature common to the lipoprotein and integral outer membrane protein we engineered the lipoprotein as a scaffold for displaying conserved surface epitopes from TbpA. A stable version of the C-terminal domain of TbpB was prepared by replacing four larger exposed variable loops with short linking peptide regions. Four surface regions from the plug and barrel domains of Neisseria TbpA were transplanted onto this TbpB C-lobe scaffold, generating stable hybrid antigens. Antisera generated in mice and rabbits against the hybrid antigens recognized TbpA at the surface of Neisseria meningitidis and inhibited transferrin-dependent growth at levels comparable or better than antisera directed against the native TbpA protein. Two of the engineered hybrid antigens each elicited a TbpA-specific bactericidal antibody response comparable to that induced by TbpA. A hybrid antigen generated using a foreign scaffold (TbpB from the pig pathogen Haemophilus parasuis) displaying neisserial TbpA loop 10 was evaluated in a model of lower genital tract colonization by N. gonorrhoeae and a model of invasive infection by N. meningitidis. The loop 10 hybrid antigen was as effective as full length TbpA in eliminating N. gonorrhoeae from the lower genital tract of female mice and was protective against the low dose invasive infection by N. meningitidis. These results demonstrate that TbpB or its derivatives can serve as an effective scaffold for displaying surface epitopes of integral outer membrane antigens and these antigens can elicit protection against bacterial challenge.

SUBMITTER: Fegan JE

PROVIDER: S-EPMC6389628 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Utility of Hybrid Transferrin Binding Protein Antigens for Protection Against Pathogenic Neisseria Species.

Fegan Jamie E JE Calmettes Charles C Islam Epshita A EA Ahn Sang Kyun SK Chaudhuri Somshukla S Yu Rong-Hua RH Gray-Owen Scott D SD Moraes Trevor F TF Schryvers Anthony B AB

Frontiers in immunology 20190219

The surface transferrin receptor proteins from <i>Neisseria gonorrhoeae</i> have been recognized as ideal vaccine targets due to their critical role in survival in the human male genitourinary tract. Recombinant forms of the surface lipoprotein component of the receptor, transferrin binding protein B (TbpB), can be readily produced at high levels in the <i>Escherichia coli</i> cytoplasm and is suitable for commercial vaccine production. In contrast, the integral outer membrane protein, transferr ...[more]

PMID: 30837995

Similar Datasets

Project description:There is a pressing need for a gonorrhea vaccine due to the high disease burden associated with gonococcal infections globally and the rapid evolution of antibiotic resistance in Neisseria gonorrhoeae (Ng). Current gonorrhea vaccine research is in the stages of antigen discovery and the identification of protective immune responses, and no vaccine has been tested in clinical trials in over 30 years. Recently, however, it was reported in a retrospective case-control study that vaccination of humans with a serogroup B Neisseria meningitidis (Nm) outer membrane vesicle (OMV) vaccine (MeNZB) was associated with reduced rates of gonorrhea. Here we directly tested the hypothesis that Nm OMVs induce cross-protection against gonorrhea in a well-characterized female mouse model of Ng genital tract infection. We found that immunization with the licensed Nm OMV-based vaccine 4CMenB (Bexsero) significantly accelerated clearance and reduced the Ng bacterial burden compared to administration of alum or PBS. Serum IgG and vaginal IgA and IgG that cross-reacted with Ng OMVs were induced by 4CMenB vaccination by either the subcutaneous or intraperitoneal routes. Antibodies from vaccinated mice recognized several Ng surface proteins, including PilQ, BamA, MtrE, NHBA (known to be recognized by humans), PorB, and Opa. Immune sera from both mice and humans recognized Ng PilQ and several proteins of similar apparent molecular weight, but MtrE was only recognized by mouse serum. Pooled sera from 4CMenB-immunized mice showed a 4-fold increase in serum bactericidal50 titers against the challenge strain; in contrast, no significant difference in bactericidal activity was detected when sera from 4CMenB-immunized and unimmunized subjects were compared. Our findings directly support epidemiological evidence that Nm OMVs confer cross-species protection against gonorrhea, and implicate several Ng surface antigens as potentially protective targets. Additionally, this study further defines the usefulness of murine infection model as a relevant experimental system for gonorrhea vaccine development.

Project description:Acinetobacter baumannii is an important human pathogen causing substantial mortality in hospitalized patients for which treatment with antibiotics has become problematic due to growing antibiotic resistance. In an attempt to develop alternative strategies for dealing with these serious infections surface antigens are being considered as targets for vaccines or immunotherapy. The surface receptor proteins required for zinc acquisition in Gram-negative bacterial pathogens have been proposed as vaccine targets due to their crucial role for growth in the human host. In this study we selected the putative ZnuD outer membrane receptor from A. baumannii as a target for vaccine development. Due to challenges in production of an integral outer membrane protein for vaccine production, we adopted a recently described hybrid antigen approach in which surface epitopes from the Neisseria meningitidis TbpA receptor protein were displayed on a derivative of the C-lobe of the surface lipoprotein TbpB, named the loopless C-lobe (LCL). A structural model for ZnuD was generated and four surface loops were selected for hybrid antigen production by computational approaches. Hybrid antigens were designed displaying the four selected loops (2, 5, 7, and 11) individually or together in a single hybrid antigen. The hybrid antigens along with ZnuD and the LCL scaffold were produced in the E. coli cytoplasm either as soluble antigens or as inclusion bodies, that were used to generate soluble antigens upon refolding. Mice were immunized with the hybrid antigens, ZnuD or LCL and then used in an A. baumannii sepsis model to evaluate their ability to protect against infection. As expected, the LCL scaffold did not induce a protective immune response, enabling us to attribute observed protection to the displayed loops. Immunization with the refolded ZnuD protein protected 63% of the mice while immunization with hybrid antigens displaying individual loops achieved between 25 and 50% protection. Notably, the mice immunized with the hybrid antigen displaying the four loops were completely protected from infection.

Project description:Acinetobacter baumannii is a human bacterial pathogen of increasing concern in clinical settings due to the emergence of antibiotic resistant strains and the lack of effective therapeutics. Researchers have been exploring new treatment options such as novel drug candidates and vaccines to prevent severe infections and mortality. Bacterial surface antigens that are essential to A. baumannii for acquiring micronutrients (e.g. iron, zinc) from nutrient restricted environments are being considered as targets for vaccines or immunotherapy due to their crucial role for growth and pathogenesis in the human host. BauA, the outer membrane receptor for the siderophore acinetobactin was targeted for vaccine development in this study. Due to challenges in the commercial production of membrane proteins for vaccines, a novel hybrid antigen method developed by our group was used. Exposed loops of BauA were selected and displayed on a foreign scaffold to generate novel hybrid antigens designed to elicit an immune response against the native BauA protein. The potential epitopes were incorporated into a scaffold derived from the C-lobe of Neisseria meningitidis transferrin binding protein B (TbpB), named the loopless C-lobe (LCL). Hybrid proteins displaying three selected loops (5, 7 and 8) individually or in combination were designed and produced and evaluated in an A. baumannii murine sepsis model as vaccine antigens. Immunization with the recombinant BauA protein protected 100% of the mice while immunization with hybrid antigens displaying individual loops achieved between 50 and 100% protection. The LCL scaffold did not induce a protective immune response, enabling us to attribute the observed protection elicited by the hybrid antigens to the displayed loops. Notably, the mice immunized with the hybrid antigen displaying loop 7 were completely protected from infection. Taken together, these results suggest that our hybrid antigen approach is a viable method for generating novel vaccine antigens that target membrane surface proteins necessary for bacterial growth and pathogenesis and the loop 7 hybrid antigen can be a foundation for approaches to combat A. baumannii infections.

Dataset Information

Utility of Hybrid Transferrin Binding Protein Antigens for Protection Against Pathogenic Neisseria Species.

Publications

Utility of Hybrid Transferrin Binding Protein Antigens for Protection Against Pathogenic Neisseria Species.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets