Fusion protein comprising the extracellular domain of a filovirus glycoprotein fused to an immunoglobulin heavy chain constant region
Inventors
Kaplan, Gerardo • Konduru, Krishnamurthy • Jacques, Jerome • Bavari, Sina • Bradfute, Steven
Assignees
National Institutes of Health NIH • US Department of Health and Human Services
Publication Number
US-9347951-B2
Publication Date
2016-05-24
Expiration Date
2031-10-28
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
This invention provides fusion proteins comprising a Filovirus glycoprotein segment and an immunoglobulin polypeptide segment. The fusion proteins are useful in immunogenic compositions to protect against infections by Filoviruses, such as Ebola virus, in both humans and non-human animals. The fusion proteins are also useful in diagnostic assays to detect Filovirus infections.
Core Innovation
This invention provides fusion proteins comprising a Filovirus glycoprotein segment and an immunoglobulin polypeptide segment. Typically, the Filovirus glycoprotein segment is an extracellular domain from an Ebola virus, particularly the Zaire Ebola virus, Mayinga strain. The immunoglobulin polypeptide segment can be an immunoglobulin heavy chain constant domain polypeptide from IgG1, such as an Fc fragment. The fusion proteins may also include a linker between the glycoprotein segment and the immunoglobulin segment, and can be encoded by nucleic acid sequences exemplified by SEQ ID NO:1 and SEQ ID NO:3.
The fusion proteins are useful in immunogenic compositions to induce protective immune responses against Filovirus infections in humans and non-human animals. They induce both humoral and cellular immunity, including neutralizing antibodies and IFN-γ-positive CD8+ T cells. The fusion proteins undergo native-like processing such as furin cleavage and homotrimer formation, resembling natural GP conformation. Immunogenic compositions comprising these fusion proteins can be administered by various routes including intramuscular injection and may include adjuvants to enhance immune response.
The invention further provides diagnostic methods using these fusion proteins to detect immune responses against Filovirus in biological samples. These methods include detecting antibodies by ELISA, chemiluminescence, or fluorescence assays, and detecting cellular immune responses by assaying cytokines such as IFN-γ and TNF-α. Neutralizing antibodies can also be detected using recombinant Vesicular Stomatitis Virus expressing Filovirus GP in neutralization assays.
The problem being solved addresses the urgent need for safe, effective, and cost-effective vaccines and diagnostic tools against Filoviruses, such as Ebola virus, especially considering their high morbidity and mortality and the lack of licensed therapeutic agents. Existing vaccine candidates either require viral vectors or display limitations in production and immunogenicity. The invention provides standalone subunit vaccine candidates based on fusion proteins that mimic native GP conformations and induce protective immunity, as well as improved diagnostic reagents.
Claims Coverage
The patent includes two independent claims that cover the fusion protein itself and methods of detection of immune response using the fusion protein. The main inventive features relate to the structure of the fusion protein and its use in immunogenic compositions and immunoassays.
Fusion protein comprising specific Filovirus glycoprotein and immunoglobulin segments
A fusion protein comprising a Filovirus glycoprotein segment that includes an extracellular domain and an immunoglobulin polypeptide segment that includes an immunoglobulin heavy chain constant domain polypeptide, wherein the C-terminus of the Filovirus glycoprotein segment is attached to the N-terminus of the immunoglobulin polypeptide segment.
Use of fusion protein in immunogenic compositions
An immunogenic composition comprising the fusion protein, optionally further comprising an adjuvant, to induce protective immune responses against Filovirus infection.
Method of detecting immune response using fusion protein
A method of detecting an immune response against Filovirus in a patient, comprising contacting a biological sample from the patient with the fusion protein and detecting an immune response, which includes detecting antibody binding by ELISA, chemiluminescence, fluorescence assays, or detecting cellular immune responses by detecting cytokines such as IFN-γ or TNF-α.
The claims cover a fusion protein comprising the extracellular domain of a Filovirus glycoprotein fused to an immunoglobulin heavy chain constant domain, immunogenic compositions containing this fusion protein, and methods for detecting Filovirus immune responses using the fusion protein, providing both diagnostic and vaccine applications.
Stated Advantages
The fusion protein undergoes native-like posttranslational modifications and trimer formation, thus resembling natural Filovirus glycoprotein conformation.
The fusion proteins are capable of inducing both humoral and cellular immune responses, including neutralizing antibodies and CD8+ T-cell responses, providing protective immunity against Filovirus infection.
The fusion protein allows for easier purification and increased in vivo and in vitro stability due to the inclusion of the immunoglobulin Fc fragment.
The fusion protein-based vaccine is a safe, effective, and cost-effective subunit vaccine that does not require viral vectors or virus-like particles.
Recombinant VSV expressing Filovirus GP can be used as a surrogate for evaluating neutralizing antibody responses under BSL-2 conditions, facilitating vaccine potency and efficacy assessment.
Documented Applications
Use as a subunit vaccine to induce protective immune responses against Filovirus infection in humans and non-human animals.
Use in immunogenic compositions combined with adjuvants for prophylactic or post-exposure vaccination.
Use in diagnostic assays to detect humoral immune responses by measuring antibodies against Filovirus using ELISA, chemiluminescence, or fluorescence assays.
Use in assays to detect cellular immune responses against Filovirus by cytokine and cell activation assays.
Use in neutralization assays employing recombinant Vesicular Stomatitis Virus expressing Filovirus glycoprotein to detect neutralizing antibodies in biological samples.
Interested in licensing this patent?