# Development and maintenance of human glycan and phospholipid antibody repertoires

> **NIH NIH U19** · UNIVERSITY OF ALABAMA AT BIRMINGHAM · 2020 · $355,718

## Abstract

Project 1: Development and maintenance of human glycan and phospholipid antibody repertoires
Project Summary
Natural antibodies (nAbs) exist in the blood of multiple mammalian species in the absence of deliberate
immunization. Reactivity of nAbs with epitopes conserved between pathogens and autologous host antigens
allow these antibodies to perform dual functions in immunity: providing important host defense against infection
and facilitating housekeeping functions important for tissue homeostasis. The mechanisms controlling human
nAb development and maintenance, however, are poorly understood. The goal of this project is to define
mechanisms controlling maturation of the human natural B lymphocyte repertoire and its tissue distribution. We
will achieve this goal by completing a targeted analysis of B cells reactive with conserved carbohydrate and
phospholipid T lymphocyte-independent antigens associated with clinically relevant bacteria and xenoantigens.
Through this approach, we will test our central hypothesis that the selection of innate-like B cell clonotypes and
antigen-specific tuning of the nAb-producing B cell repertoire depend on interactions with autologous antigens
and microbial antigens encountered at mucosal surfaces, which together modulate the entry of B cell clonotypes
into the memory and antibody-secreting B cell compartments. In the first Specific Aim, we will sort-purify single,
indexed carbohydrate- and phospholipid-binding B cells from a cohort of cadaveric human tissue donors.
Immunoglobulin gene expression in these B cells will be analyzed together with expressed cellular phenotype to
determine the distribution of clonal networks of nAb-producing B cells across B cell compartments in multiple
human tissues. We will additionally examine the stability of innate-like B cell clonotypes and specificity of nAb
repertoire by longitudinally sampling human blood after anti-CD20 (rituximab) B cell depletion, to determine the
extent of antigen-reactive clonal B cell extirpation and clonal repertoire recovery during B cell compartment
regeneration. Specific Aim 2 will utilize a novel, high-throughput antibody-cloning and expression platform to
express immunoglobulin gene rearrangements from gene amplicon libraries as recombinant Abs and examine
their binding properties, including antigen affinity and fine specificity. We will additionally examine the effects of
somatic mutation on the binding properties of nAb by assessing the global reactivity of cloned antibodies and
germline-reverted clonotypes using mammalian glycan antigen microarrays. This targeted analysis of antigen-
reactive human B cells will permit analysis of fine antigen-specificity, affinity, and avidity of B cell clonotypes
across human tissues, and the determination of whether these features of the BCR influence the tissue, B cell
subset, and immunoglobulin isotype distribution of certain clones. Because nAb antigens are expressed by
multiple commensal and pathogenic o...

## Key facts

- **NIH application ID:** 9882222
- **Project number:** 5U19AI142737-02
- **Recipient organization:** UNIVERSITY OF ALABAMA AT BIRMINGHAM
- **Principal Investigator:** John Franklin Kearney
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $355,718
- **Award type:** 5
- **Project period:** — → —

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9882222

## Citation

> US National Institutes of Health, RePORTER application 9882222, Development and maintenance of human glycan and phospholipid antibody repertoires (5U19AI142737-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9882222. Licensed CC0.

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