# Identification of complex cellular phenotypes and their interactions in MS lesions

> **NIH NIH R21** · YALE UNIVERSITY · 2021 · $209,375

## Abstract

Scientific abstract
Infiltrating lymphocytes, macrophages and astrocytes are major drivers of multiple sclerosis
(MS) lesion pathology, yet their exact roles in lesion formation are still poorly understood. Key to
the function of these cells is their phenotypic heterogeneity as well as their spatial interactions
within the lesion environment. This information cannot be obtained with standard
immunohistochemistry, which does not allow for high parameter profiling, or with single cell
approaches, which do not capture spatial information.
We propose here to use a novel approach, highly multiplexed imaging, to profile single cells in
acute and chronic active MS lesions. To this end, we will employ iterative indirect
immunofluorescence imaging (4i), an immunofluorescence-based method which allows for
staining with >40 antibodies on a single histological section, and subsequently perform spatial
analysis using a powerful computational pipeline.
In aim 1, we will use an antibody panel against 32 markers of myeloid cell and astrocyte
function to (i) characterize macrophage and astrocyte subpopulations, (ii) determine their
distribution within MS lesions and (iii) define their interactions with other cell types such as
lymphocytes. Thus, our analysis will provide phenotypes and specific phenotypic interactions
that drive demyelination in acute lesions, and low-grade inflammation in chronic active lesions,
In aim 2, we will comprehensively assess immune checkpoints in MS lesions, a highly complex
and redundant system, that modulates T cell activation. We will use a total of 41 antibodies to
determine expression of co-inhibitory/stimulatory receptors on different T cell subpopulations,
and their corresponding ligands on surrounding cells. This will deliver the specific checkpoints
that drive loss of tolerance in lymphocytes in acute and chronic MS lesions.
By profiling complex cellular states within spatial context in MS lesions, we will obtain previously
inaccessible histological information. Our data will ultimately provide targets for therapeutic
intervention during acute lesion formation and in chronic progressive MS.

## Key facts

- **NIH application ID:** 10085201
- **Project number:** 5R21AI149731-02
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** David Pitt
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $209,375
- **Award type:** 5
- **Project period:** 2020-01-14 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10085201

## Citation

> US National Institutes of Health, RePORTER application 10085201, Identification of complex cellular phenotypes and their interactions in MS lesions (5R21AI149731-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10085201. Licensed CC0.

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