Gene optimized Hantaan virus M segment DNA vaccine for hemorrhagic fever with renal syndrome

Inventors

SCHMALJOHN, CONNIE

Assignees

United States Department of the Army

Abstract

A synthetic, codon-optimized Hantaan virus (HTNV) full-length M gene open reading frame that consists of a unique nucleotide sequence encoding HTNV proteins. This synthetic gene was cloned into a plasmid to form the first optimized HTNV full-length M gene that elicits neutralizing antibodies in animals when delivered in combination with a similarly optimized Puumala virus (PUUV) DNA vaccine. The invention obviates the need for an extraneous gene sequence that was previously required for expression of the non-optimized HTNV gene. The synthetic gene is engineered into a molecular vaccine system to prevent hemorrhagic fever with renal syndrome (HFRS) caused by infection with HTNV, SEOV, or DOBV. Alternatively, it can be combined with the optimized PUUV DNA vaccine to protect against HFRS caused by any hantavirus.

Core Innovation

The invention is a synthetic, codon-optimized DNA vaccine encoding the full-length M gene open reading frame of the Hantaan virus (HTNV). The synthetic gene has been engineered to maximize mammalian codon availability and remove viral elements that compromise expression, resulting in a vaccine that elicits neutralizing antibodies in animals. This novel vaccine construct does not require extraneous nucleotide sequences previously essential for expression of the non-optimized HTNV gene. The optimized HTNV vaccine can be used alone to prevent hemorrhagic fever with renal syndrome (HFRS) caused by HTNV, Seoul (SEOV), or Dobrava (DOBV) viruses or in combination with a similarly optimized Puumala virus (PUUV) DNA vaccine to protect against all four hantaviruses known to cause HFRS.

The problem being addressed is the lack of a comprehensive, safe, and effective vaccine for HFRS caused by multiple hantaviruses. Existing vaccines, including inactivated rodent-brain-derived vaccines and non-optimized DNA vaccines, have limitations such as safety concerns, poor immunogenicity due to interference when combining HTNV and PUUV vaccines, difficulties in virus culture, and lack of cross-protective immunity. Notably, the prior non-optimized HTNV DNA vaccine exhibited gene-related interference when mixed with the PUUV vaccine, resulting in an immune response predominantly to PUUV and poor responses to HTNV, impeding development of a combined vaccine that covers all HFRS-causing viruses.

This invention overcomes the interference problem by producing a codon-optimized HTNV M segment DNA vaccine that can be co-administered with an optimized PUUV vaccine without reduced immunogenicity to either virus. The optimized gene has improved codon adaptation index, balanced guanine-cytosine content, and removal of negative cis-acting motifs, which improve gene expression and resultant immune responses. Additionally, the vaccine is delivered via advanced methods such as intramuscular or intradermal electroporation, which enhance uptake and immunogenicity. The invention also provides flexibility, safety, and economical scalability for human vaccination against HFRS caused by HTNV, SEOV, PUUV, and DOBV viruses.

Claims Coverage

The patent contains multiple independent claims focusing on methods of administering the optimized HTNV DNA vaccine and its delivery forms.

The claims cover the method of immunizing mammals against HTNV infection with the codon-optimized HTNV M segment DNA vaccine (SEQ ID NO: 1) through multiple administration routes, including advanced delivery systems such as electroporation, particle-mediated epidermal delivery, and nanoparticle encapsulation. This range of delivery methods provides flexibility and efficacy in inducing immune responses.

Stated Advantages

Documented Applications