# Functional Antibody Study

> **NIH NIH U19** · HENRY M. JACKSON FDN FOR THE ADV MIL/MED · 2020 · $162,807

## Abstract

PROJECT SUMMARY/ABSTRACT
 The overall objective of Core D: Functional Antibody Study Core is to provide a consistent,
experimentally controlled and validated platform for evaluating functional antibody responses after vaccination
with Neisseria gonorrhoeae antigens that are identified through the projects of the Gonorrhea Vaccine
Cooperative Research Center (GV CRC). Serum bactericidal activity and opsonophagocytosis have been
implicated in the protective immune response against pathogenic Neisseria, and both depend upon antibody
binding to the bacterial surface. Evaluation of these three parameters of the functional antibody response is
critical to understanding if a vaccine has the potential to elicit protective immunity. Therefore, Core D is critical
to the success of the GV CRC. Core D will provide services to all four research projects and will interact routinely
with the other Cores of this CRC, which offer distinct yet complementary expertises. For Core D to enable
successful completion of the projects in the GV CRC, we propose three Specific Aims: 1) Bacterial Antibody
Surface Binding: We will use imaging flow cytometry to quantify the ability of antibodies in sera from immunized
mice to bind to the surface of intact N. gonorrhoeae. Bacteria of diverse strain backgrounds will be evaluated. 2)
Serum Bactericidal Activity (SBA): We will measure the ability of antibodies in sera from immunized mice or
humans immunized with N. meningitidis serogroup B vaccine to elicit SBA against a panel of N. gonorrhoeae
strains, using antibody-depleted pooled normal human serum as the source of active complement. In addition to
conventional colony count, we will pilot and optimize a high-throughput quantitative assay using a fluorometric
metabolic dye as a surrogate measure of SBA. 3) Opsonphagocytic Activity (OPA): We will measure the ability
of the antibodies in sera from immunized mice and N. meningitidis serogroup B-immunized humans to enhance
OPA-dependent killing of N. gonorrhoeae, using HL-60 human promyelocytes as the phagocyte along with
complement factor 6-depleted pooled normal human serum. In addition, we will use flow cytometry platforms
employed in our laboratory in order to develop a high-throughput quantitative assay to measure OPA-dependent
binding and internalization of N. gonorrhoeae. Overall, results from Core D will help the GV CRC and the field in
general to establish the correlate(s) of protection for vaccines against gonorrhea, which to date are poorly
understood. When integrated with results from other Cores in the GV CRC, the findings from Core D will
contribute to selection of the most promising antigen(s) and platform(s) for the advancement of a novel vaccine
for gonorrhea towards licensure.

## Key facts

- **NIH application ID:** 9900723
- **Project number:** 5U19AI144180-02
- **Recipient organization:** HENRY M. JACKSON FDN FOR THE ADV MIL/MED
- **Principal Investigator:** Alison K Criss
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $162,807
- **Award type:** 5
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9900723

## Citation

> US National Institutes of Health, RePORTER application 9900723, Functional Antibody Study (5U19AI144180-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9900723. Licensed CC0.

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