Statement of Work_NS1_ADCC_vaccine 04082022.docx

Statement of Work (SOW)

I. INTRODUCTION/BACKGROUND:

Different FcgRs can modulate the effectiveness of Ab neutralization and Ab-dependent cell cytotoxicity. Vaccines can elicit different subclasses of IgG to engage different FcgR, which has impact on vaccine efficacy. A novel Herpes simplex virus vaccine with a deletion of a gene encoding glycoprotein D (ΔgD) completely protected herpes infection, and the protection is independent of antibody (Ab) neutralization but dependent on IgG2c and FcRIV. When the ΔgD virus was used as a vector to deliver influenza PR8 Hemagglutinin Antigen (HA), the vaccine elicited a dominant IgG2c response and completely protected mice from a lethal challenge, and protection was FcgRIV-dependent. In contrast to the ΔgD::HAPR8, a recombinant HA subunit vaccine delivered in adjuvant alum+MPL elicited less IgG2c response and only partial protection. Currently, dengue NS1 is a subunit vaccine undergoing preclinical development using various platforms. NS1 is released in a patient serum during infection. NS1 is also expressed on the surface of infected cells. Since NS1 is not an antigen displayed on the virion surface, NS1 vaccines cannot elicit conventional neutralizing Ab. Therefore, the protection mechanism of an NS1 vaccine is likely FcgR-dependent, such as ADCC. We hypothesize that delta-g(GJDI)-2 vectored NS1 vaccine will elicit the right IgG subclass, which enhances FcgR-dependent immune activation, such as ADCC. Immunization with delta-g(GJDI)-2-NS1 will elicit a higher level of protection as compared to subunit vaccines delivered in other forms and will mitigate ADE. We will test the hypotheses in immuno-competent and Ag129 IFN receptor knockout mice and investigate the mechanism in FcgR-knockout mice.

II. TECHNICAL REQUIREMENTS:

The contractor is required to do the following:

a) Generate Bxb1 attP plasmids expressing dengue NS1 and E24-NS1 from the DENV-2 serotype using different signal sequences and transmembrane domains and evaluate cell surface expression of the Dengue proteins on transfected cells.

b) Using optimally expressed Dengue genes in the Bxb1 attP plasmid vectors, generate Δg(GJDI)-2::attB recombinant virus strains using the Bxb1 integration system and test for surface expression of Dengue proteins in virus-infected cells.

c) Breed AG129 (IFNAR crossed with interferon-γ receptor knockout) mice and IFNAR mice as models for testing the protective efficacy of recombinant viruses expressing DENV proteins against challenges with DENV strains provided by NMRC. At least 30 double knockout mice need to be produced for the task below in e.

d) Immunize wild-type C57BL/6J mice with recombinant HSV strains expressing DENV-2 antigens and collect serum samples to send to NMRC for immunogenicity evaluation by NMRC (see Experiment-1 layout below).

e) Immunize the AG129-IFNalpha/gamma knockout mice and appropriate controls with the recombinant HSV vaccines and challenge the mice with lethal doses of DENV stock intraperitoneally, and monitor these mice for weight loss and survival. Collect serum and organ samples to send to NMRC for antibody and viremia assessment (see Experiment-2 layout below).

Experiment 1: Day 0 Prime Day 14 Boost Day 42±14 Serum and spleen collection

Vaccination Scheme

Vaccine groups (Experiment 1):

1. PBS control: 10 mice

2. Vector Control: 10 mice

3. Cell lysate control: 10 mice

4. Recombinant vaccine low dose: 10 mice

5. Recombinant vaccine high dose: 10 mice

Experiment 2:

Day 0 Prime Day 14 Boost Day 42±14 Sample collection on half of the mice. Challenge the other half of the mice.

Vaccination and Challenge Scheme Day 42±14 Challenge

Monitor survival of the challenged mice for 14±7 days and endpoint sample collection.

Vaccine groups (Experiment 2):

1. PBS control: 10 mice

2. Vector Control: 10 mice

3. Cell lysate control: 10 mice

4. Recombinant vaccine low dose: 10 mice

5. Recombinant vaccine high dose: 10 mice

III. DELIVERABLES/SCHEDULE:

Deliverables from the contractor:

1. Official IACUC approval – 2 months upon receiving funding.

a. Animal use protocol: Contractor will develop animal use protocol in consultation with NMRC and have it approved by its IACUC.

b. WRAIR-NMRC IACUC Animal Use Appendix: If animal protocol is not in DoD format, contractor will provide this appendix to the PI for DoD approval.

c. Approval from DoD: In addition to the approval from the contractor IACUC, an approval from the DoD is needed. The PI will coordinate approvals from the Animal Care and Use Review Office, U.S. Army Medical Research and Materiel Command.

2. Serum and PBMC samples from Experiment 1 to send to NMRC – 6 months from receiving funding.

3. Serum, PBMC, and organ samples from Experiment 2 to send to NMRC – 12 months from receiving funding.

4. Provide quarterly progress reports and year-end final report.

IV. PAYMENT SCHEDULE

1. 50% award before the start of the project to be allocated to the contractor.

2. 25% award upon completion of deliverable 2.

3. 25% award upon completion of deliverable 3.

V. PLACE OF PERFORMANCE:

The work listed above is to be performed at the contractor’s site.

VI. PERIOD OF PERFORMANCE:

The Project Start date shall be the day the Contractor is awarded the contract. The selected Contractor will initiate laboratory and animal study upon approval of the contract and approval of the protocol by the IACUC. All deliverables should be completed within 12 months from the date the contract is awarded. Contractor should compose a timeline in the proposal based on deliverables.

VII. MONITORING THE PROGRESS:

Progress will be closely monitored by the PI and/or designated personnel via email, teleconference, or site visits as needed. Based upon mutual agreement of schedule, Contractor will provide access to VRDD, NMRC or HJF study personnel to observe procedures.

VIII. ACCEPTANCE CRITERIA

IACUC protocol approved by the contractor’s IACUC.

Completed WRAIR-NMRC IACUC Animal Use Appendix

Vaccinations and specimen collections executed as per the IACUC approved protocol and provided protocols.

Specimens shipped to VRDD/NMRC according to PI’s instructions as they become available.

Acceptance of final report by the PI.

IX. OTHER REQUIREMENTS

None

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