SEQUENCE LISTING

The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety. Said ASCII copy, created on Jun. 29, 2020, is named 096630-0190_SL.txt and is 51,501 bytes in size.

FIELD OF INVENTION

The present disclosure relates generally to the field of infectious disease therapy, and, in particular, nucleic acid vaccines for treating or preventing viral, bacterial, or other microbial infections. The disclosure provides compositions and methods for effectively delivering to cells of the mononuclear phagocyte system (e.g., antigen presenting cells) and other immune cells a nucleic acid encoding an immunogenic peptide. The disclosure further provides methods of treating or preventing a viral, bacterial, or other microbial disease or infection by administering to a patient a vaccine comprising a nucleic acid that encodes an immunogenic peptide, such that the immunogenic peptide is expressed in vivo, thereby activating the patient's immune system to attack the virus or bacteria that expresses the immunogenic peptide.

BACKGROUND OF THE INVENTION

The following discussion is merely provided to aid the reader in understanding the disclosure and is not admitted to describe or constitute prior art thereto.

Infectious diseases caused by viruses, bacteria, and other microbes are a global public health threat. Globalization and increased international travel and commerce have created an environment that allows global disease to spread quickly throughout the world.

Coronavirus disease 2019 (COVID-19; also referred to as novel coronavirus pneumonia or 2019-nCoV acute respiratory disease) is exemplary of the kind of public health threat that can rapidly emerge without warning. COVID-19 is an infectious disease caused by the virus severe respiratory syndrome coronavirus 2 (SARS-CoV-2) (also referred to as novel coronavirus 2019, or 2019-nCoV). The disease was first identified in December 2019 and spread globally, causing a pandemic. Symptoms of COVID-19 include fever, cough, shortness of breath, fatigue, headache, loss of smell, nasal congestion, sore throat, coughing up sputum, pain in muscles or joints, chills, nausea, vomiting, and diarrhea. In severe cases, symptoms can include difficulty waking, confusion, blueish face or lips, coughing up blood, decreased white blood cell count, and kidney failure. Complications can include pneumonia, viral sepsis, acute respiratory distress syndrome, and kidney failure.

COVID-19 is especially threatening to public health because the virus is highly contagious, and studies currently indicate that it can be spread by asymptomatic carriers or by those who are pre-symptomatic. Likewise, the early stage of the disease is slow-progressing enough that carriers may not realize they are infected, leading them to expose numerous others to the virus. The combination of COVID-19's ease of transmission, its high rate of hospitalization, and its death rate make the virus a substantial public health risk, especially for countries without a healthcare system equipped to provide supportive care to pandemic-level numbers of patients. There is not yet a vaccine or specific antiviral treatment for COVID-19 and accordingly, there is a pressing need for treatments or cures.

SARS-CoV-2 is not the only coronavirus that causes disease. It is a β-coronavirus, a genus of coronaviruses that includes other human pathogens, including SARS-CoV (the causative agent of SARS), MERS-CoV (the causative agent of MERS), and HCoV-OC43 (a causative agent of the common cold). The infectivity of these viruses, and the severity of the diseases they cause, varies widely. β-coronavirus can also manifest as zoonotic infections, spread to and from humans and animals. Additionally, non-human species such as camels, bats, tigers, non-human primates, and rabbits can be susceptible to β-coronavirus. Accordingly, there is a pressing need for treatments or cures to multiple coronaviruses.

However, this need is not limited solely to coronaviruses. The next public health threat may emerge from a different type of virus or a bacteria or another type of microbe. Thus, there is a need for a vaccine platform technology that can quickly and adroitly address any infectious disease by training the immune system to recognize a given pathogen.

The immune system is made up of a variety of types of cells that are able to detect the presence of pathogens or pathologic cells in the body and remove them from the body. Sometimes this occurs when a foreign agent is enveloped by immune system cells and destroyed or carried out of the body. If living host cells have been invaded by a bacterial cell or virus, the immune system cells may target and destroy that infected cell or they may target the invading pathogen directly.

For example, monocytic cells are a type of antigen presenting cell that normally patrol the body in search of foreign, non-self-antigens, such as bacteria. Monocytic cells phagocytize bacteria, which are then digested to smaller antigenic portions in the lysosome. The resultant bacterial antigens are cycled back to the cell surface of these cells for presentation to the humoral and cellular arms of the immune system. This antigen presenting function is instrumental in the development of a host immune response to a given foreign, non-self-antigen, as the monocytes load the antigen on MEW class I and II molecules and prime CD8+ and CD4+ T cells, which then mount a specific immune response against the antigen.

Despite this understanding of the antigen presenting process, historically, it has been difficult to develop vaccines that effectively and consistently produce a sustained immunogenic response in a host to a particular antigen. Moreover, scale up and production for widespread use is exceedingly difficult. Most modern vaccines utilize whole virus or bacteria that have been killed or enfeebled prior to administration, or they utilize an isolated peptide or glycopeptide that has shown immunogenicity. Both of these types of vaccines are difficult to produce in mass, requiring large-scale bioreactors, extensive growth and production time, and often delicate and cost-intensive isolation/purification processes.

In contrast to whole pathogens (e.g., virus or bacteria) or peptides/glycopeptides, nucleic acid sequences (e.g., plasmids or expression vectors) are comparatively simple to produce in mass. Nucleic acid sequences can be quickly and reproducibly duplicated far more rapidly than peptides or pathogens, but historically, nucleic acid-based vaccines have achieved little clinical success, mostly due to the difficulty of effectively delivering nucleic acids in vivo. Indeed, with previous nucleic acid vaccines, less than 1% of the cells at an injection site of a nucleic acid vaccine actually take up the vaccine nucleic acid and far less express the encoded protein. For an effective immune response to be achieved, a nucleic acid must be delivered to a specific class of cells—antigen presenting cells (APCs)—and directly injected nucleic acid vaccines rarely reach this target.

Thus, there is a need in the art for a platform for nucleic acid vaccines. The present disclosure fulfills that need by providing multiple vaccine platforms that efficiently and effectively deliver nucleic acids to antigen presenting cells, which can then express an immunogenic peptide(s) encoded by the nucleic acid, thereby inducing a robust immune response to the immunogenic peptide.

SUMMARY OF THE INVENTION

Described herein are nucleic acid vaccines and methods of using the same for treating or preventing infections (i.e., diseases caused by viruses, bacteria, or other microbes).

In one aspect, the disclosure provides a vaccine comprising: (i) a base particle, (ii) a lysosome-evading component attached to the base particle, and (iii) a nucleic acid sequence encoding an immunogenic peptide.

In some embodiments, the base particle is a yeast cell wall particle (YCWP). In some embodiments, the base particle may be a bead (e.g., a ferro-magnetic bead).

In some embodiments, the lysosome-evading component is a non-infectious virus, such as a non-infectious adenovirus. In some embodiments, the non-infectious virus is also non-replicative. In some embodiments, the non-infectious virus is an enfeebled virus. In some embodiments, the lysosome-evading component is a quadrivalent influenza vaccine.

In some embodiments, the lysosome-evading component is a protein (e.g., a lytic protein). In some embodiments, the protein is a hexon protein, a penton protein, melittin, or LL37.

In some embodiments, the nucleic acid encoding the immunogenic peptide is comprised within an expression vector or plasmid.

In some embodiments, the immunogenic peptide is derived from a virus, bacteria, or other microbe. In some embodiments, the virus is a coronavirus, such as SARS-CoV-2.

In some embodiments, the immunogenic peptide is a viral spike protein or an immunogenic fragment thereof. In some embodiments, the immunogenic peptide comprises SEQ ID NO: 1 (i.e., the spike protein of SARS-CoV-2) or an immunogenic fragment thereof.

In some embodiments, the base particle is modified or coated with polyethyleneimine (PEI). For example, in some embodiments, the base particle may be a PEI-modified YCWP. In some embodiments, the base particle may be a PEI-modified bead.

In some embodiments, the lysosome-evading component is attached to the base particle by an antibody. For example, in some embodiments, the lysosome-evading component may be an adenovirus, which is attached to the based particle via an anti-hexon protein antibody.

In some embodiments, the base particle is modified or coated with succinimidyl 3-(2-pyridyldithio)propionate (SPDP). For example, in some embodiments, the base particle may be a SPDP-modified YCWP. In some embodiments, the base particle may be a SPDP-modified bead. In some embodiments, melittin or LL37 may be crosslinked to the base particle (e.g., a YCWP) by the SPDP.

In some embodiments, the vaccine particle is a size that allows it to be preferentially phagocytized by a monocytic cell, such as an antigen presenting cell.

In another aspect, the present disclosure provides a vaccine comprising: (i) yeast cell wall particle (YCWP) that is surface modified with polyethyleneimine (PEI), (ii) an adenovirus attached to the YCWP, and (iii) a nucleic acid sequence encoding a viral spike protein. In some embodiments, the adenovirus is attached to the YCWP indirectly via an anti-hexon protein antibody. In some embodiments, the adenovirus is non-infectious and non-replicative. In some embodiments, the viral spike protein is a SARS-CoV-2 spike protein. In some embodiments, the viral spike protein comprises SEQ ID NO: 1.

In another aspect, the present disclosure provides a vaccine comprising: (i) a non-infectious and non-replicative virus comprising polylysine cross-linked to one or more surface-exposed glutamine residues, and (ii) a nucleic acid sequence encoding an immunogenic peptide. In some embodiments, the virus is an adenovirus. In some embodiments, the one or more surface-exposed glutamine residues are located in the knob domain of an adenovirus fiber protein. In some embodiments, the nucleic acid encoding the immunogenic peptide is comprised within an expression vector or plasmid. In some embodiments, the immunogenic peptide is derived from a virus, bacteria, or other microbe. In some embodiments, the virus is a coronavirus, such as SARS-CoV-2. In some embodiments, the immunogenic peptide is a viral spike protein or an immunogenic fragment thereof. In some embodiments, the immunogenic peptide comprises SEQ ID NO: 1 or an immunogenic fragment thereof.

In another aspect, the present disclosure provides methods of treating or preventing an infectious disease in a patient comprising administering to a patient that may be exposed to an infectious disease a vaccine of any one of the foregoing aspects or embodiments.

In another aspect, the present disclosure provides methods of stimulating the immune system in a patient comprising administering to a patient a vaccine of any one of the foregoing aspects or embodiments.

In some embodiments of the disclosed methods, the vaccine is administered intradermally.

In some embodiments of the disclosed methods, the vaccine is phagocytosed by a monocytic cell and the monocytic cell subsequently expresses the immunogenic peptide and presents the immunogenic peptide on its surface.

In some embodiments of the disclosed methods, the infectious disease is caused by a virus or bacteria. In some embodiments, the infectious disease is coronavirus disease 2019 (COVID-19).

In another aspect, the present disclosure provides a vaccine according to any of the foregoing aspects or embodiments for use in preventing an infectious disease in a subject comprising administering the vaccine to the subject.

In another aspect, the present disclosure provides a vaccine according to any of the foregoing aspects or embodiments for use in stimulating the immune system of a subject in need thereof.

In another aspect, the present disclosure provides uses of the vaccine of any of the foregoing aspects or embodiments to prevent an infectious disease in a subject.

In another aspect, the present disclosure provides uses of the vaccine of any of the foregoing aspects or embodiments for stimulating the immune system of a subject in need thereof.

In another aspect, the present disclosure provides methods of preventing coronavirus disease 2019 (COVID-19) in a subject comprising, administering to a subject a vaccine comprising: (i) yeast cell wall particle (YCWP) that is surface modified with polyethyleneimine (PEI), (ii) an adenovirus attached to the YCWP, and (iii) a nucleic acid sequence encoding a viral spike protein from SARS-CoV-2 or an immunogenic fragment thereof. In some embodiments, the adenovirus is attached to the YCWP indirectly via an anti-hexon protein antibody. In some embodiments of the methods of preventing COVID-19, the adenovirus is non-infectious and non-replicative. In some embodiments, the viral spike protein comprises SEQ ID NO: 1. In some embodiments, the vaccine is administered intradermally. In some embodiments, the vaccine is phagocytosed by a monocytic cell and the monocytic cell subsequently expresses the immunogenic peptide and presents the immunogenic peptide on its surface. In some embodiments, the subject produces antibodies that specifically bind to the spike protein from SARS-CoV-2 as a result of administration of the vaccine.

The foregoing general description and following detailed description are exemplary and explanatory and not limiting of the disclosure.

