Journal Article

Multi-omics analysis identifies IgG2b class-switching with ALCAM-CD6 co-stimulation in joint-draining lymph nodes during advanced inflammatory-erosive arthritis

Wood, Ronald W., Rangel-Moreno, Javier, Peng, Yue, Pritchett, Elizabeth, Schwarz, Edward M., Quataert, Sally, Becerril-Villanueva, Enrique, Wu, Chia-Lung, Xing, Lianping, Fox, Jeffrey I., Gamboa-Domínguez, Armando, Anolik, Jennifer H., Kenney, H. Mark, Embong, Abdul, Muthukrishnan, Gowrishankar, Ritchlin, Christopher T., Chen, Kiana L., Korman, Benjamin D., Bruno, Jennifer

2023

Overview

Defective lymphatic drainage and translocation of B-cells in inflamed (Bin) joint-draining lymph node sinuses are pathogenic phenomena in patients with severe rheumatoid arthritis (RA). However, the molecular mechanisms underlying this lymphatic dysfunction remain poorly understood. Herein, we utilized multi-omic spatial and single-cell transcriptomics to evaluate altered cellular composition (including lymphatic endothelial cells, macrophages, B-cells, and T-cells) in the joint-draining lymph node sinuses and their associated phenotypic changes and cell-cell interactions during RA development using the tumor necrosis factor transgenic (TNF-Tg) mouse model. Popliteal lymph nodes (PLNs) from wild-type (n=10) and TNF-Tg male mice with \"Early\" (5 to 6-months of age; n=6) and \"Advanced\" (>8-months of age; n=12) arthritis were harvested and processed for spatial transcriptomics. Single-cell RNA sequencing (scRNAseq) was performed in PLNs from the TNF-Tg cohorts (n=6 PLNs pooled/cohort). PLN histopathology and ELISPOT along with ankle histology and micro-CT were evaluated. Histopathology of human lymph nodes and synovia was performed for clinical correlation. Advanced PLN sinuses exhibited an increased expression ratio (Early 0.5 ± 0.1 vs Advanced 1.4 ± 0.5 counts/counts; ) that significantly correlated with reduced talus bone volumes in the afferent ankle (R 0.54, ). Integration of single-cell and spatial transcriptomics revealed the increased IgG2b plasma cells localized in MARCO peri-follicular medullary sinuses. A concomitant decreased expression (Early 2.5 ± 0.74 vs Advanced 1.0 ± 0.50 counts, ) within Advanced PLN sinuses was associated with accumulation of iron-laden Prussian blue positive macrophages in lymph nodes and synovium of Advanced TNF-Tg mice, and further validated in RA clinical samples. T-cells were increased 8-fold in Advanced PLNs, and bioinformatic pathway assessment identified the interaction between ALCAM macrophages and CD6 T-cells as a plausible co-stimulatory mechanism to promote IgG2b class-switching. Collectively, these data support a model of flare in chronic TNF-induced arthritis in which loss of lymphatic flow through affected joint-draining lymph nodes facilitates the interaction between effluxing macrophages and T-cells via ALCAM-CD6 co-stimulation, initiating IgG2b class-switching and plasma cell differentiation of the expanded Bin population. Future work is warranted to investigate immunoglobulin clonality and potential autoimmune consequences, as well as the efficacy of anti-CD6 therapy to prevent these pathogenic events.

• Publisher: Frontiers Media SA,Frontiers Media S.A
• Subject: Activated-Leukocyte Cell Adhesion Molecule / Animals / Ankle / Arthritis / Arthritis, Rheumatoid / B-cells / CD6 antigen / Cell differentiation / Cell interactions / Computed tomography / Endothelial Cells / Enzyme-linked immunosorbent assay / Gene expression / Genomics / Humans / Immunoglobulin Class Switching / Immunoglobulin G / Immunology / Inflammation / lymph node / Lymph nodes / Lymphatic drainage / Lymphatic system / Lymphocytes B / Lymphocytes T / Macrophages / Male / MARCO protein / Mice / Molecular modelling / Multiomics / Pathogenesis / Plasma cells / Rheumatoid arthritis / Scanners / Sensory neurons / single-cell RNA sequencing / Sinuses / spatial transcriptomics / Synovium / Talus / Transcriptomics / Transgenic mice / Tumor necrosis factor / Tumor necrosis factor-TNF