WO2021236045A1

WO2021236045A1 - Vaccine for prevention of and/or immunization against sars-cov-2

Info

Publication number: WO2021236045A1
Application number: PCT/TR2021/050461
Authority: WO
Inventors: Huseyin ALAGOZ; Mehmet Ali ERGUN; Ahmet Caglar OZKETEN; Hasan Huseyin KAZAN; Murat Erdem; Emrullah Gorkem GUNBAS
Original assignee: Turkiye Saglik Enstituleri Baskanligi
Priority date: 2020-05-21
Filing date: 2021-05-14
Publication date: 2021-11-25
Also published as: TR202007978A2

Abstract

The present invention relates to a vaccine for use in struggle against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that aims immunization by a Devkor protein sequence which is formed based on a receptor binding domain (RBD) of spike protein (S) in SARS-CoV- 2. The present application further discloses a formulation for enhancing the efficacy of the vaccine, a carrier structure therefore, and exemplary ways for administering said vaccine.

Description

VACCINE FOR PREVENTION OF AND/OR IMMUNIZATION AGAINST SARS-CoV-2

Technical Field of the Invention

The present invention relates to a vaccine for use in struggle against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that aims immunization by a recombinant protein (hereinafter named as "Devkor") which is formed based on a receptor binding domain (RBD) of spike protein (S) in SARS-CoV-2.

Background of the Invention

SARS-CoV-2 causes disease by entering into a cell via angiotensin-converting enzyme 2 (ACE2) which is a transmembrane protein, as in the case with another coronavirus SARS-CoV that caused an epidemic in 2003. SARS-Cov-2 binds to ACE2 via RBD disposed on its S protein.

The vaccine studies particularly focus on S protein, because it is the most unprotected protein present in the structure of SARS-CoV-2. In the document with the title "Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody" (DOI: 10.1080/22221751.2020.1729069), it is shown that antibodies can be present which can bind only to RBD on the S protein. The use of the related RBD in improving the immunity against SARS-CoV in rodents is disclosed in the document with the title "Cross-neutralization of human and palm civet severe acute respiratory syndrome coronaviruses by antibodies targeting the receptor-binding domain of spike protein" (DOI: 10.4049/jimmunol.l76.10.6085). On the other hand, attempts for developing immunity only via RBD brings a concern related to 'antibody-dependent enhancement' effect.

Worldwide studies continue for developing a vaccine that is effective against SARS-CoV-2 in human and that triggers production of antibodies which do not cause any antibody- dependent enhancement effect.

Summary of the Invention

The present invention relates to a formulation that triggers a protective and preventive immune against SARS-CoV-2 in humans (release of non-specific antibodies and interferons); furthermore, the present invention relates to a vaccine that triggers the development of specific antibodies that bind to RBD on the S protein (spike protein) of the respective virus. For developing immunity and for protection against external factors; the recombinant protein sequence (Devkor) produced in alternative hosts is formulated with a protective vegetal adjuvant (excipient 1) and a mixture of DNA oligonucleotides with respective specific sequences (excipients 2 and 3), to obtain a vaccine composition that is both intraperitoneally and nasally administrable. The subject-matter of the present invention can be utilized in two different formulations which can be classified as a non-conjugated recombinant protein, and as a recombinant protein that is conjugated on a nanoparticle.

Brief Description of the Figure

The figure described below is presented to provide a better understanding of the present invention.

Fig.l shows a schematic view of a virus-like structure formed in partial complexes of Devkor protein according to the present invention, that is conjugated on a gold nanoparticle.

Reference signs shown in the figure are listed as follows:

1. Devkor

2. Protein scaffold

3. Nanoparticle (core)

Detailed Description of the Invention

In principle, the vaccine according to the present invention is designed as follows: a protein sequence (named hereby as 'Devkor') which comprises an RBD on an S protein of SARS-CoV- 2 is produced on alternative hosts; then isolated and purified by modification using specific peptide sequences. The protein is produced on hosts (eucaryotic insect, mice or human cells etc.), then isolated with affinity chromatography, and purified such that the protein does not include endotoxins. The purified Devkor is converted into a vaccine composition by addition of delta inulin which is a vegetal adjuvant, and by addition of DNA oligonucleotides. Such Devkor can be applied (without modification), or as conjugated onto a nanoparticle for enhancing the efficiency thereof by converting the protein into a particle that mimicks the virus, and thereby enabling the avoidance from host defence enzymes (e.g., proteases). Devkor nanoparticles which are designed to achieve these aims, can be described as follows: the Devkor (1) comprises a core (3) formed from gold nanoparticles, and a protein scaffold (2) that forms a bridge and that does not constitute a protein corona.

Devkor (as such, or conjugated as a nanoparticle) comprises at least two adjuvants and a liquid in an amount that is sufficient for application. Said liquid can include water and further excipients that are dissolved or emulsified in water.

Devkor (1) comprises the RBD aminoacid sequence of Sequence No.l shown in Table 1, and extension sequences in N and C terminal ends for isolation and expression.

Table 1.

Gold nanoparticles (3) serve as a carrier for Devkor (1) and protein scaffold (2) complex. The gold nanoparticles (3) and the Devkor (1) and protein scaffold (2) complex conjugated thereon, form a virus-like structure for triggering the immune system to produce antibodies that bind to the RBD (1) of S protein on SARS-CoV-2.

The gold nanoparticles (3) preferably have a diameter that is smaller than 200 nm.

When applied in the form of protein as such, the vaccine is preferably to be administered in an amount within the range between 1 pg and 100 pg. Devkor (1) can be connected to the protein scaffold (2) with a single reaction, and can be conjugated to the gold nanoparticle over a respective Thiol group.

The vaccine according to the present invention can be preferably applied nasally in a spray form. Per kilograms, based on body weight; the vaccine can preferably be administered in total dosages which comprise up to 5 milligrams of Devkor, up to 5 milligrams of DNA adjuvant (excipients 2 and 3) and delta inulin (excipient 1) in an amount that corresponds to 100 folds of said DNA adjuvant. The total dosage can be administered in divided doses or as a single dose.

SEQUENCE LISTING

<110>

<120> VACCINE BASED ON RECEPTOR BINDING DOMAIN FOR SARS-COV-2

<130>

<140>

<141>

<150>

<151>

<160> 1

<210> 1 <211> 197 <212> PRT <213> SARS-CoV-2

<300>

<313>

<400>

Asn lie Thr Asn Leu Cys Pro Phe Gly Glu

1 5 10

Val Phe Asn Ala Thr Arg Phe Ala Ser Val

15 20

Tyr Ala Trp Asn Arg Lys Arg lie Ser Asn

25 30

Cys Val Ala Asp Tyr Ser Val Leu Tyr Asn

35 40

Ser Ala Ser Phe Ser Thr Phe Lys Cys Tyr

45 50

Gly Val Ser Pro Thr Lys Leu Asn Asp Leu

55 60

Cys Phe Thr Asn Val Tyr Ala Asp Ser Phe

65 70

Val lie Arg Gly Asp Glu Val Arg Gin lie

75 80

Ala Pro Gly Gin Thr Gly Lys lie Ala Asp

85 90 Tyr Asn Tyr Lys Leu Pro Asp Asp Phe Thr 95 100

Gly Cys Val lie Ala Trp Asn Ser Asn Asn

105 110

Leu Asp Ser Lys Val Gly Gly Asn Tyr Asn

115 120

Tyr Leu Tyr Arg Leu Phe Arg Lys Ser Asn

125 130

Leu Lys Pro Phe Glu Arg Asp lie Ser Thr

135 140

Glu H e Tyr Gin Ala Gly Ser Thr Pro Cys

145 150

Asn Gly Val Glu Gly Phe Asn Cys Tyr Phe

155 160

Pro Leu Gin Ser Tyr Gly Phe Gin Pro Thr

165 170

Asn Gly Val Gly Tyr Gin Pro Tyr Arg Val

175 180

Val Val Leu Ser Phe Glu Leu Leu His Ala

185 190

Pro Ala Thr Val Cys Gly Pro

195

Claims

1. A vaccine comprising a complex of a Devkor (1) which includes a receptor binding domain (RBD) on S protein of SARS-CoV-2, or one or more protein sequences which include aminoacid sequences with a similarity of at least 30% to a protein sequence of the Devkor (1), and a protein scaffold (2); said complex being conjugated to one or more gold nanoparticles (3).

2. The vaccine according to claim 1, wherein the RBD (1) is as shown in the Sequence No.l.

3. The vaccine according to claim 1, wherein the gold nanoparticles (3) have a diameter smaller than 200 nm.

4. A preventive and immunity developing drug composition, comprising one or more proteins with an at least 30% homological similarity to the protein sequence of Devkor; and/or further comprising delta inulin and a DNA oligonucleotide adjuvant formulation as excipients.

5. The vaccine according to any of claims 1 to 4, for administering nasally and/or via other administration routes.

6. The vaccine composition according to any of claims 1 to 5, for administration in a total dosage which comprises up to 5 milligrams of Devkor, up to 5 milligrams of DNA adjuvant (excipients 2 and 3) and delta inulin in an amount that corresponds to 100 folds of said DNA adjuvant, per kilograms, based on body weight.