Abstract Details

Title Single-cell Cerebrospinal Fluid Transcriptome Profiling Suggests Dysfunctional Boarder Associated Macrophages Underlying Progression Independent of Relapse Activity in Multiple Sclerosis

Topic Multiple Sclerosis

Presentation(s) P6 - Poster Session 6 (11:45 AM-12:45 PM)

Poster/Presentation
Number 1-011

Objective

To characterize the cellular compartment of cerebrospinal fluid (CSF) in patients with relapsing multiple sclerosis (MS) with and without progression independent from relapse activity (PIRA) and infer differential cell-cell communication between groups.

Background

Occurrence of PIRA is common and associates with future disability. Evaluation of its molecular correlates, through single cell transcriptomics (scRNAseq) and bioinformatic approaches, is still lacking.

Design/Methods

Eight patients with PIRA, 8 without PIRA, 1 control with NMOSD were enrolled. All patients were clinically stable, free from MRI activity and not on disease-modifying therapy in the last 6 months. ScRNA-seq libraries were prepared using the 10x Chromium Single Cell 3′ Solution (10x Genomics). An uniform pipeline of pre-processing with quality control was employed on all samples. Seurat and scDblFinder were employed for the preprocessing step. Azimuth was used for cell type assignment, myeloid cells were manually determined. Cells were annotated and visualized in a UMAP. Differential expressed genes (DEGs) and enrichment analysis were assessed using DESeq2 and SCPA. Cell-cell communication among groups was analyzed with CellChat.

Results Within subclusters of myeloid cells, we identified upregulation of SCL7A5, RASGRP2, CBX6, C1orf56, AC130324.2 and down-regulation of GPNMB, FABP5, ATP1B1 in Boarder Associated Macrophages (BAM) in PIRA group. Gene ontology analysis of upregulated genes yelded terms as B-cell mediated immunity, antigen processing and presentation, T-cell activation, leukocyte cell-cell adhesion. Communication strenght analysis between cells revealed a relative enrichment of CD30 and osteopontin pathways in patients with PIRA. Communication probabilities between cells showed a major involvement of BAM in both CD30 and SPP1 signaling.

Conclusions Patients with PIRA show a specific CSF trascriptome signature in BAM, that emerged from both DEGs, enrichment and cell-cell interaction analysis. These findings confirm intrathecal compartmentalized inflammation at the CNS boarders as a niche that contributes to MS disease progression.

Authors/Disclosures
Damiano Marastoni PRESENTER	The institution of Damiano Marastoni has received research support from Italian MInister of Health .
Ermanna Turano, PhD	Dr. Turano has nothing to disclose.
Francesco Patane, Ms	Mr. Patane has nothing to disclose.
Federica Virla, PhD	Dr. Virla has nothing to disclose.
Daniela Anni, PhD	Dr. Anni has nothing to disclose.
Stefano Ziccardi, PhD	Dr. Ziccardi has nothing to disclose.
Monica Castellucci, PhD	Dr. Castellucci has nothing to disclose.
Elena Zenaro, PhD	Dr. Zenaro has nothing to disclose.
Massimiliano Calabrese (The Multiple Sclerosis Center, University Hospital of Verona)	Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis Pharma. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merck Serono. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Novartis Pharma. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Roche. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Genzyme. Massimiliano Calabrese has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for BMS Celgene. The institution of Massimiliano Calabrese has received research support from Roche.

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