Peripheral Blood from Rheumatoid Arthritis Patients Shows Decreased T<sub>reg</sub> CD25 Expression and Reduced Frequency of Effector T<sub>reg</sub> Subpopulation
Eunbyeol Go,
Su-Jin Yoo,
Suyoung Choi,
Pureum Sun,
Min Kyung Jung,
Somin Kwon,
Bu Yeon Heo,
Yeeun Kim,
Ju-Gyeong Kang,
Jinhyun Kim,
Eui-Cheol Shin,
Seong Wook Kang,
Jaeyul Kwon
Affiliations
Eunbyeol Go
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Su-Jin Yoo
Department of Internal Medicine, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Suyoung Choi
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Pureum Sun
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Min Kyung Jung
Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
Somin Kwon
Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD 20892, USA
Bu Yeon Heo
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Yeeun Kim
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Ju-Gyeong Kang
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
Jinhyun Kim
Department of Internal Medicine, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Eui-Cheol Shin
Laboratory of Immunology and Infectious Diseases, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
Seong Wook Kang
Department of Internal Medicine, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Jaeyul Kwon
Department of Medical Science, College of Medicine, Chungnam National University, Daejeon 35015, Korea
Rheumatoid arthritis (RA) is a common autoimmune disease characterized by immune cell infiltration of the synovium, leading to the loss of cartilage, bone, and joint function. Although regulatory T (Treg) cells are thought to modulate the initiation and progression of RA, a consensus has yet to be reached regarding the function and composition of Treg cells in RA patients. To address these discrepancies, we analyzed not only the total Treg frequency but also that of Treg subpopulations in the peripheral blood of RA patients and healthy controls by flow cytometry. We found that the total Treg population was not significantly different between RA and control subjects. However, the effector Treg cell subgroup, defined as CD45RA−CD25hi, showed markedly decreased frequency in RA patients. In addition, the total Treg population from RA patients showed a significant decline in the expression of CD25. Both the naïve and effector Treg subgroups also showed marked reduction of CD25 expression in RA patients compared to controls. These data suggest that the decreased frequency of effector Treg cells and overall reduction of CD25 expression in Treg cells in the peripheral blood may be evidence of altered Treg homeostasis associated with RA pathogenesis.
