Invited Lectures
Nurse-Like Cells Forming Pathological Foci in Bone Marrow and Involved Synovia of RA
2020 Volume 39 Issue 2 Pages 45-52
Details
2020 Volume 39 Issue 2 Pages 45-52
Objective: We have tried to know pathological cells which foster inflammatory cells in involved organs of patients with RA.
Methods: Nurse-like cells (RA-NLCs) from bone marrow and synovial tissue of RA were established using the similar methods by which Wekerle H established the thymic nurse cells (16). Analyses using transmission electron microscope (TEM) and dual immunofluorescence staining studies were carried out by Sawai's group.
Results: RA-NLCs were established from bone marrow and synovial tissue of patients with RA, and found to promote maturation and differentiation of B cells as well as T cells. RA-NLCs also supported two step differentiations of monocytes; differentiation into tartrate-resistant acid phosphatase (TRAP) -positive mononuclear cells and then into multinucleated giant bone-resorbing cells. By TEM, the characteristic dendritic cells (the DCs) were observed in RA synovial tissue forming direct physical interactions (pseudoemperipolesis) with adjacent plasma cells (PCs). The numbers of PCs in various areas tended to correlate with those of the DCs, which appeared to form survival niches for PCs. Quantitative dual immunofluorescence staining studies of these areas indicated that the majority of CD14＋DCs showing RA-NLC functions were CD14＋CD15＋myelocytes.
Conclusion: In patients with RA, abnormal CD14＋CD15＋myelocytes having RA-NLC function were found to be produced in bone marrow and form survival niches for chronic inflammation of involved organs.
