Related Experiment Video
Updated: Sep 20, 2026

An Adoptive Transfer Model of Rheumatoid Arthritis in Mice
Published on: June 6, 2025
Proinflammatory role of fractalkine (CX3CL1) in rheumatoid arthritis
Sabine Blaschke1, Michael Koziolek, Andreas Schwarz
1Department of Nephrology and Rheumatology, Georg-August-University of Goettingen, Robert-Koch Strasse 40, 37075 Goettingen, Germany. sblach@gwdg.de
Objective:
Fractalkine (CX3CL1) represents the sole member of the so-called CX3C chemokines. In rheumatoid arthritis (RA), functional studies suggest a role for this chemokine in monocyte chemotaxis and angiogenesis in the rheumatoid synovium. We analyzed the expression of fractalkine within different T cell subsets of the peripheral blood and expression of its receptor CX3CR1 within the rheumatoid synovium to further characterize its pathogenic role in RA.
Methods:
Peripheral blood mononuclear cells (PBMC) were isolated from 17 patients with RA and analyzed by flow cytometry in comparison to healthy blood donors. To identify the T helper cell cytokine profile of fractalkine-expressing cells, flow cytometric analysis of PBMC was performed after stimulation with PMA and ionomycin. Expression of fractalkine and its receptor was characterized in RA synovium by immunohistochemistry and laser capture microdissection microscopy.
Results:
Flow cytometric analysis of fractalkine-expressing T cell subsets revealed a low proportion of fractalkine-expressing CD4+ and CD8+ T cells in both RA patients and controls. In addition, fractalkine was predominantly expressed in CD4+ T cells with a Th1-type cytokine expression profile. In RA synovium, fractalkine was detected in synovial macrophages, dendritic cells, endothelial cells, and a small proportion of T cells. The fractalkine receptor CX3CR1 was found in synovial macrophages, dendritic cells, and T cells as well as in synovial fibroblasts. Fractalkine stimulation of cultured synovial fibroblasts resulted in a marked upregulation of matrix metalloproteinase-2 (MMP-2) production.
Conclusion:
The results suggest that fractalkine may represent a Th1-type chemokine. Upregulation of MMP-2 production in synovial fibroblasts upon fractalkine stimulation in vitro supports the hypothesis of a proinflammatory role of this chemokine in RA.
Related Concept Videos
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
The JAK-STAT Signaling Pathway
Inflammatory Response
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
Inflammatory Bowel Disease III: Crohn's Disease
Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF
Inflammatory Bowel Disease II: Ulcerative Colitis