Fibroblast-like Synoviocytes Support B-cell Pseudoemperipolesis Via a Stromal Cell-derived Factor-1- and CD106 (VCAM-1)-dependent Mechanism
Overview
Affiliations
B-cell accumulation and formation of ectopic germinal centers are characteristic changes in the diseased joints of patients with rheumatoid arthritis (RA). Earlier studies suggested that interactions between B lymphocytes and specialized synovial "nurse-like" cells peculiar to the RA synovium may be responsible for the homing and sustained survival of B cells in the synovium. However, in this study, we found that B cells spontaneously migrate beneath ordinary fibroblast-like synoviocytes (FLSs) and then experience prolonged survival. FLSs isolated from joints of patients with osteoarthritis also supported this activity, termed B-cell pseudoemperipolesis. We found that FLSs constitutively expressed the chemokine stromal cell-derived factor-1 (SDF-1), and that pertussis toxin or antibodies to the SDF-1 receptor (CXCR4) could inhibit B-cell pseudoemperipolesis. However, expression of SDF-1 is not sufficient, as dermal fibroblasts also expressed this chemokine but were unable to support B-cell pseudoemperipolesis unless previously stimulated with IL-4 to express CD106 (VCAM-1), a ligand for the alpha(4)beta(1) integrin, very-late-antigen-4 (VLA-4 or CD49d). Furthermore, mAb's specific for CD49d and CD106, or the synthetic CS1 fibronectin peptide, could inhibit B-cell pseudoemperipolesis. We conclude that ordinary FLSs can support B-cell pseudoemperipolesis via a mechanism dependent upon fibroblast expression of SDF-1 and CD106.
Biomaterials for Modulating the Immune Microenvironment in Rheumatoid Arthritis.
Wang Q, Ji J, Huang D, Gao C BME Front. 2025; 6:0102.
PMID: 40065832 PMC: 11893043. DOI: 10.34133/bmef.0102.
Tumor microenvironment as a novel therapeutic target for lymphoid leukemias.
Mousavi S, Nouri S, Sadeghipour A, Atashi A Ann Hematol. 2025; .
PMID: 39994019 DOI: 10.1007/s00277-025-06237-w.
Age-Associated B Cells in Autoimmune Diseases: Pathogenesis and Clinical Implications.
Xie G, Chen X, Gao Y, Yang M, Zhou S, Lu L Clin Rev Allergy Immunol. 2025; 68(1):18.
PMID: 39960645 PMC: 11832777. DOI: 10.1007/s12016-025-09021-w.
Applications of single-cell RNA sequencing in rheumatoid arthritis.
Figueiredo M Front Immunol. 2024; 15:1491318.
PMID: 39600707 PMC: 11588722. DOI: 10.3389/fimmu.2024.1491318.
Guo Q, Wang Q, Chen J, Zhao M, Lu T, Guo Z Research (Wash D C). 2024; 7:0459.
PMID: 39257420 PMC: 11385568. DOI: 10.34133/research.0459.