Defective functions of circulating CD4+ CD25+ and CD4+ CD25− T cells in patients with chronic ordinary urticaria

• Published in: Journal of dermatological science 2008-08, Vol.51 (2), p.121-130
• Main Authors: Chen, Wu-Charng, Chiang, Bor-Luen, Liu, H. Eugene, Leu, Sy-Jye, Lee, Yueh-Lun
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Autoimmunity - immunology; Autoimmunity - physiology; Case-Control Studies; CD3 Complex - metabolism; CD4 +CD25 + regulatory T cells; CD4 +CD25 − T cells; Cell Proliferation; Child; Child, Preschool; Chronic Disease; Chronic ordinary urticaria; Cytokines; Dermatology; Female; Forkhead Transcription Factors - metabolism; FOXP3; Humans; Interleukin-2 Receptor alpha Subunit - genetics; Interleukin-2 Receptor alpha Subunit - metabolism; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - physiology; Male; RNA, Messenger - metabolism; Suppressive function; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - pathology; T-Lymphocytes, Regulatory - physiology; Transforming Growth Factor beta - metabolism; Urticaria - blood; Urticaria - metabolism; Urticaria - physiopathology
• ISSN: 0923-1811; 1873-569X
• DOI: 10.1016/j.jdermsci.2008.02.012

Summary Background Patients with chronic ordinary urticaria (CU) are divided into two groups: 30–50% have chronic autoimmune urticaria, and the remainder have chronic idiopathic urticaria. CD4+ CD25+ regulatory T (Treg) cells play critical roles in maintaining peripheral tolerance and preventing autoimmunity, but the characteristics of Treg cells have not yet been defined in CU. Objective To identify whether CD4+ T cells play an important immunoregulatory role in the etiology of CU, we determined the frequencies and functions of circulating CD4+ CD25+ and CD4+ CD25− T cells in CU patients and healthy control subjects, with special focus on the characteristics of CD4+ CD25+ T cells. Methods Peripheral blood mononuclear cells (PBMCs) were obtained from CU and healthy controls in this study. The frequency of CD4+ CD25+ T cells in PBMCs was detected by flow cytometry. The expression levels of forkhead box P3 (FOXP3) and transforming growth factor-β (TGF-β) in CD4+ CD25+ T cells were detected by real-time PCR. Furthermore, the suppressive function of CD4+ CD25+ T cells was analyzed. Additionally, the Th1/Th2 cytokine secretory profile in mitogen-stimulated CD4+ CD25− T cells was measured by ELISA. Results An increased frequency of CD4+ CD25+ T cells was observed in CU patients ( n = 19) compared to control subjects ( n = 7). No significant difference was detected in the expression levels of FOXP3 or TGF-β between CU patients ( n = 14) and control subjects ( n = 7). Strikingly, the suppressive capacity of CD4+ CD25+ Treg cells from 2 of 5 CU patients was partially defective. We also found that cytokine production from CD4+ CD25− T cells was significantly reduced in CU patients ( n = 9) compared to healthy donors ( n = 11). Conclusions Our data demonstrate that CD4+ CD25+ and CD4+ CD25− T cells in PBMCs exhibit defective functions in CU patients.