Role of popliteal lymph node stromal cells during the onset of rheumatoid arthritis

• Applicant: Professor Dr. Mario M. Zaiss
• Subject Area: Rheumatology ; Immunology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 536972786

Once considered primarily as scaffold cells providing a structure to facilitate the meeting of B, T and dendritic cells (DC), lymph node stromal cells (LNSC) recently gained more attention because of their shown ability to actively regulate immune cell functions. Here, we are interested in investigating the role of a specific LNSC subset, the CCL19-positive fibroblastic reticular cells (FRC) specifically in the popliteal lymph nodes (pLN) during the initiation of rheumatoid arthritis (RA). RA is a systemic, autoimmune disease characterized by joint inflammation and destruction. It is well recognised that a state of autoimmunity precedes the development of clinical symptoms, for up to 15 years, in 40-80% of RA patients. During that autoimmune phase, first RA-specific autoantibodies are detected. Of interest, during this long autoimmunity phase no cellular changes in the synovium of the joints have been observed. However, there are reports showing significant changes in cellularity of pLN, that are the direct joint draining LN in RA, years before synovial inflammation of the joints in RA patients appears. Therefore, we hypothesize that the pLN plays an important role during the transition from systemic autoimmunity to the onset of local joint inflammation in RA.

• DFG Programme: Research Grants