# SPMs, linoleic acid, and antibody levels in obesity

> **NIH NIH R03** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2021 · $74,780

## Abstract

PROJECT SUMMARY
Numerous studies have defined how obesity impairs chronic inflammation. In contrast, far less is known about
how obesity impairs humoral immunity, which is responsible for antibody production. Establishing underlying
factors that link obesity with impaired antibody production is critical given that obese individuals have increased
susceptibility to viral/bacterial infections and poor responses to differing vaccinations. At a molecular level,
antibody production is regulated, in part, by specialized pro-resolving mediators (SPMs). SPMs are potent
immunoresolvants synthesized from polyunsaturated fatty acids such as docosahexaenoic acid (DHA). We and
others have found that SPMs synthesized from DHA boost antibody production upon influenza infection and
vaccination. Furthermore, DHA-derived SPMs are deficient in obesity and associated with an elevation in
linoleic acid in obese mice. Linoleic acid is extremely abundant in the western diet and may be a major reason
why SPMs are deficient in the obese. Collectively, our data lead us to test the central hypothesis that obese
subjects that do not effectively produce antibodies upon influenza vaccination have decreased circulating
levels of DHA-derived SPMs and increased levels of linoleic acid. To address this hypothesis, we will rely on
analyses of blood samples stored from a large clinical study in which subjects were stratified as responders
(i.e. lean and obese individuals that produced antibody) and non-responders (i.e. lean and obese subjects that
did not effectively produce antibody) upon the seasonal trivalent inactivated influenza vaccine. The approach
will rely on mass spectrometry based metabololipidomic analyses, gas chromatography with flame ionization
detection, and ELISAs. Impact: This proposal will establish key links between impaired antibody production
and obesity at the human level. This will set the basis for future mechanistic studies and investigation of SPMs
and linoleic acid as potential modifiable variables in humans to improve outcomes in response to viral
infections/vaccinations. Completion of this proposal will had provided insight into a major public health burden,
which is the convergence of an infectious disease (influenza) with a noncommunicable disease (obesity).

## Key facts

- **NIH application ID:** 10189019
- **Project number:** 1R03AI159308-01
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** SAAME R SHAIKH
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $74,780
- **Award type:** 1
- **Project period:** 2021-01-28 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10189019

## Citation

> US National Institutes of Health, RePORTER application 10189019, SPMs, linoleic acid, and antibody levels in obesity (1R03AI159308-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10189019. Licensed CC0.

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