SOW_Recombinant Protein Production for CVV Investigation.pdf

Title: Recombinant Protein Production for CVV Investigation The period of performance of this contract is 9/28/2024 to 9/27/2025

SECTION 1 – BACKGROUND

Centers for Disease Control and Prevention’s (CDC’s) Influenza Division (ID) is responsible for the development of Candidate Vaccine Viruses (CVVs) based on circulating and novel influenza strains.

CVVs are reassortment viruses that are used as the starting materials for seasonal and pandemic vaccines.

To facilitate the development of the CVVs, CDC uses recombinant proteins and antibodies to characterize how antigenicity and immunogenicity may change with both natural and engineered mutations in the viral genome.

Developing these CVVs involves engineering specific mutations into the virus's genetic sequence, particularly in regions encoding critical proteins like hemagglutinin (HA) and neuraminidase (NA), the primary antigenic targets of the immune response. These engineered mutations can potentially improve the immunogenicity of the CVV, i.e., its ability to elicit a strong and effective immune response.

Recombinant glycoproteins, such as HA, NA, or SARS-CoV-2-Spike, and antibodies are crucial tools in this process. Recombinant glycoproteins can be produced in the lab and used to study the effects of the engineered mutations on the proteins' structure and function. They can also be used in various assays to evaluate how well antibodies elicited by the vaccine can recognize and bind to these proteins—a measure of the vaccine's potential effectiveness.

Similarly, recombinant antibodies—which are essentially lab-made versions of the antibodies that the immune system would produce in response to vaccination—can be used to assess the antigenicity of the mutated proteins, i.e., their ability to bind to these antibodies.

Testing recombinant glycoproteins and antibodies is a crucial part of developing and evaluating CVVs, as it allows the CDC to understand how engineered mutations might impact the antigenicity and immunogenicity of the vaccine and, thereby, its potential effectiveness against the influenza virus. By expanding the CDC’s in-house capacity to generate recombinants, additional mutations can be tested, likely leading to improved final production of CVVs.

SUBSECTION A – Definitions

1. Recombinant Protein: A recombinant protein is a protein that is derived from recombinant DNA technology, where a DNA sequence coding for the protein is inserted into a plasmid, which is then introduced into a host organism (often a bacterium or yeast) to produce the protein.

2. Recombinant Antibody: A recombinant antibody is an antibody that is produced through recombinant DNA technology. The genes that encode the antibody are inserted into a vector, which is then expressed in a host organism, producing the antibody.

3. BLI (Bio-Layer Interferometry): BLI is a label-free technology for measuring biomolecular interactions. It is based on measuring the interference pattern of white light reflected from two surfaces: a layer of immobilized protein on the biosensor tip and an internal reference layer. Virology and vaccines are often used between receptor proteins/molecules (e.g., sialic acids for influenza) and viral glycoproteins or between viral proteins and antibodies.

4. ELISA (Enzyme-Linked Immunosorbent Assay): ELISA is a common laboratory technique used to measure the concentration of an antigen (often a protein) in a sample. It involves an antibody linked to an enzyme; the interaction of the antibody with its antigen causes a color change that can be measured.

5. SPR (Surface Plasmon Resonance): SPR measures the interaction of molecules in real-time without the need for labeling. It works by detecting changes in refractive index at a sensor surface due to molecular binding. It is often used to characterize the same dynamics as BLI assays but trades greater sensitivity for significant increases in cost, complexity, and chance of failure. Therefore, modern workflows often screen binding complexes in BLI before selecting a few to continue in SPR.

6. Candidate Vaccine Virus (CVV): An engineered or wild-type virus used to manufacture or develop vaccines, created within regulated environments.

7. SDS-PAGE>90%: is a protein quality control specification. SDS-PAGE stands for Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis, a common method used in biochemistry, genetics, and molecular biology to separate proteins based on their electrophoretic mobility, which is a function of the length of the polypeptide chain or the protein's mass. When a protein sample is said to be "SDS-PAGE >90%", it means that when analyzed by SDS-PAGE, the protein of interest constitutes more than 90% of the total protein content. This purity measure suggests that the protein sample is highly pure and predominantly contains the target protein.

8. SEC-HPLC >95%: is a protein quality control specification. SEC stands for Size Exclusion Chromatography, which is a method of separating molecules based on their size. HPLC stands for High- Performance Liquid Chromatography (formally High-Pressure), a technique used to separate a mixture of compounds in analytical chemistry and biochemistry with the purpose of identifying, quantifying or purifying the individual components of the mixture. When a protein sample is said to have "SEC-HPLC >90%", it means that when analyzed by size exclusion chromatography using high performance liquid chromatography, more than 90% of the sample is the desired protein. This indicates a very high level of purity in the sample, with higher confidence in the result than obtainable from SDS-PAGE.

9. HEK293: is a Human Embryonic Kidney (HEK) cell line, which was historically Frank Graham’s 293rd attempt at culturing the cells. One of the most common uses of HEK293 cells is as a mammalian production cell line for recombinant proteins. The cells can be transfected with plasmids containing the gene for the protein of interest, along with other necessary elements like promoters and selection markers. The cells then use their own cellular machinery to produce the protein, which can be harvested and purified.

10. CDC (Centers for Disease Control and Prevention): The Government entity that needs the work proposed.

11. Offeror: an entity that provides a proposal to CDC for listed work.

12. Contractor: entity, if any, awarded a contract to perform proposed work.

SECTION 2 – PURPOSE/OBJECTIVE

The overall objective is to provide the Influenza Division with recombinant proteins and antibodies and then help further characterize selected proteins and antibodies in forming binding complexes and binding kinetics (the interactions between two molecules, such as a receptor and viral attachment glycoprotein).

The Vaccine Preparedness Team of the Virology, from the Virology Surveillance and Diagnosis Branch within the Influenza Division of the CDC, shall be the principal scientific and technical party representing the Government’s needs, working with an undetermined Contractor from selected Offerors.

Proteins and/or antibodies created from the proposed work, whether or not they have also been sent to the CDC, and/or proteins, antibodies, or sera from the CDC may be sent to the Contractor for further characterization tests, not to exceed those listed in §3 and §4.

SECTION 3 – SCOPE OF WORK

The Contractor shall provide the following:

(a) Sixty-five (65) small-scale preparations of recombinant viral proteins expressed in a mammalian production line (HEK293 or similar), starting from the digital sequence provided. Proteins will be expressed and purified by SDS-PAGE with a minimum yield of 1mg and a target purity of greater than

90% (SDS-PAGE>90%).

SECTION 4 – TASKS TO BE PERFORMED

Task 1: Sixty-five (65) small-scale preparations of recombinant viral proteins expressed in a mammalian production line:

1. Produced in HEK293 or similar cells.

2. The CDC will provide a digital sequence.

3. Contractor to perform gene synthesis and vector construction.

4. Then, the expression from said vector in sufficient volume is used to ensure minimum yield following purification.

5. Minimum yield is 1mg per preparation.

6. Target purity is SDS-PAGE>90%

SECTION 5 – GOVERNMENT-FURNISHED PROPERTY

The Government (CDC) will furnish digital genetic sequences to create the recombinant problems.

SECTION 6 – PLACE OF PERFORMANCE AND CONTRACT SUPPORT HOURS

SUBSECTION A – PLACE OF PERFORMANCE

Work will be conducted entirely at the Contractor’s facility.

SECTION 7 – TRAVEL

No travel is anticipated for this award.

SECTION 8 – DELIVERABLES/REPORTING SCHEDULE

Deliverables will be presented to a Subject Matter Expert (SME) from the Influenza Division in an electric format (PDF).

Task Deliverable Quantity/Format Due Date Deliver To 1: Small-scale preparations of recombinant viral proteins

1mg Protein 65 preparations, lyophilized or resuspended in industry-standard buffer

Four weeks post-delivery of sequence

SME

SECTION 9 – REFERENCE MATERIALS

None.

SECTION 10 – MINIMUM VENDOR QUALIFICATIONS

1. Proven capacity of to create purified recombinant proteins and antibodies from mammalian cell lines.

2. Ability to perform ELISA assays with screen-scale antibody preparations.

3. Ability to perform BLI assays with biotinylated HA sialic acid receptor analogues

4. Ability to perform SPR assays with recombinant antibodies and proteins.

SECTION 11 – ADDITIONAL REQUIREMENTS

Information Security and Privacy The Contractor (and/or any subcontractor) shall not have access to, host, and/or maintain any Government information system(s) related to the proposed work. All data will be provided via a secured web portal or service (e.g., Amazon Web Services or FileShare). No sensitive data, patient information, or personally identifiable information will be provided to the Contractor based on the proposed work.

Section 508 Compliance

Electronic and Information Technology Accessibility

(a) Section 508 of the Rehabilitation Act of 1973 (29 U.S.C. 794d), as amended by the Workforce Investment Act of 1998 and the Architectural and Transportation Barriers Compliance Board Electronic and Information (EIT) Accessibility Standards (36 CFR part 1194), require that when Federal agencies develop, procure, maintain, or use electronic and information technology, Federal employees with disabilities have access to and use of information and data that is comparable to the access and use by Federal employees who are not individuals with disabilities, unless an undue burden would be imposed on the agency. Section 508 also requires that individuals with disabilities, who are members of the public seeking information or services from a Federal agency, have access to and use of information and data that is comparable to that provided to the public who are not individuals with disabilities, unless an undue burden would be imposed on the agency.

(b) Accordingly, any offeror responding to this solicitation must comply with established HHS EIT accessibility standards. Information about Section 508 is available at http://www.hhs.gov/web/508. The complete text of the Section 508 Final Provisions can be accessed at http://www.access-aboard.gov/sec508/standards.htm.

(c) The Section 508 accessibility standards applicable to this contract are: 1194.

205 WCAG 2.0 Level A & AA Success Criteria

302 Functional Performance Criteria

502 Inoperability with Assistive Technology

504 Authoring Tools

602 Support Documentation

603 Support Services

In order to facilitate the Government's determination whether proposed EIT supplies meet applicable Section 508 accessibility standards, offerors must submit an HHS Section 508 Product Assessment Template, in accordance with its completion instructions. The purpose of the template is to assist HHS acquisition and program officials in determining whether proposed EIT supplies conform to applicable Section 508 accessibility standards. The template allows offerors or developers to self-evaluate their supplies and documentation detail - whether they conform to a specific Section 508 accessibility standard, and any underway remediation efforts addressing conformance issues. Instructions for preparing the HHS Section 508 Evaluation Template are available under Section 508 policy on the HHS Web site http://hhs.gov/web/508.

In order to facilitate the Government's determination whether proposed EIT services meet applicable Section 508 accessibility standards, offerors must provide enough information to assist the Government in determining that the EIT services conform to Section 508 accessibility standards, including any underway remediation efforts addressing conformance issues.

(d) Respondents to this solicitation must identify any exception to Section 508 requirements. If a offeror claims its supplies or services meet applicable Section 508 accessibility standards, and it is later determined by the Government, i.e., after award of a contract or order, that supplies or services delivered do not conform http://www.hhs.gov/web/508 http://www.access-aboard.gov/sec508/standards.htm http://www.access-aboard.gov/sec508/standards.htm http://hhs.gov/web/508 to the accessibility standards, remediation of the supplies or services to the level of conformance specified in the contract will be the responsibility of the Contractor at its expense.

(e) Electronic content must be accessible to HHS acceptance criteria. Checklist for various formats are available at http://508.hhs.gov/, or from the Section 508 Coordinator listed at https://www.hhs.gov/web/section-508/additional-resources/section-508-contacts/index.html. Materials that are final items for delivery should be accompanied by the appropriate checklist, except upon approval of the Contracting Officer or Representative.

(End of verbiage) http://508.hhs.gov/ https://www.hhs.gov/web/section-508/additional-resources/section-508-contacts/index.html