Increased presence of FOXP3+ regulatory T cells in inflamed muscle of patients with active juvenile dermatomyositis compared to peripheral blood

• Published in: PloS one Vol. 9; no. 8; p. e105353
• Main Authors: Vercoulen, Yvonne, Bellutti Enders, Felicitas, Meerding, Jenny, Plantinga, Maud, Elst, Elisabeth F, Varsani, Hemlata, van Schieveen, Christa, Bakker, Mette H, Klein, Mark, Scholman, Rianne C, Spliet, Wim, Ricotti, Valeria, Koenen, Hans J P M, de Weger, Roel A, Wedderburn, Lucy R, van Royen-Kerkhof, Annet, Prakken, Berent J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 26-08-2014; Public Library of Science (PLoS)
• Subjects: Adolescent; Arthritis; Biology and Life Sciences; Biopsy; Blood; CD25 antigen; CD4 antigen; Cell activation; Child; Child, Preschool; Children & youth; Childrens health; Cytokines; Cytometry; Dermatomyositis; Dermatomyositis - blood; Dermatomyositis - immunology; Dermatomyositis - pathology; Disease; Disease control; Dystrophy; Female; Flow cytometry; Forkhead Transcription Factors - analysis; Forkhead Transcription Factors - immunology; Foxp3 protein; Homeostasis; Hospitals; Humans; Immunohistochemistry; Immunology; Immunoregulation; Infant; Infiltration; Laboratories; Lymphocytes; Lymphocytes T; Male; Medicine and Health Sciences; Microvasculature; Muscles; Muscles - immunology; Muscles - pathology; Muscular dystrophy; Pathogenesis; Patients; Pediatrics; Peripheral blood; Phenotypes; Regulators; Remission; Rheumatology; T-Lymphocytes, Regulatory - immunology; T-Lymphocytes, Regulatory - pathology; San Francisco California; Netherlands; United Kingdom > UK; United States > US; Ireland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0105353

Juvenile dermatomyositis (JDM) is an immune-mediated inflammatory disease affecting the microvasculature of skin and muscle. CD4+ CD25+ FOXP3+ regulatory T cells (Tregs) are key regulators of immune homeostasis. A role for Tregs in JDM pathogenesis has not yet been established. Here, we explored Treg presence and function in peripheral blood and muscle of JDM patients. We analyzed number, phenotype and function of Tregs in blood from JDM patients by flow cytometry and in vitro suppression assays, in comparison to healthy controls and disease controls (Duchenne's Muscular Dystrophy). Presence of Tregs in muscle was analyzed by immunohistochemistry. Overall, Treg percentages in peripheral blood of JDM patients were similar compared to both control groups. Muscle biopsies of new onset JDM patients showed increased infiltration of numbers of T cells compared to Duchenne's muscular dystrophy. Both in JDM and Duchenne's muscular dystrophy the proportion of FOXP3+ T cells in muscles were increased compared to JDM peripheral blood. Interestingly, JDM is not a self-remitting disease, suggesting that the high proportion of Tregs in inflamed muscle do not suppress inflammation. In line with this, peripheral blood Tregs of active JDM patients were less capable of suppressing effector T cell activation in vitro, compared to Tregs of JDM in clinical remission. These data show a functional impairment of Tregs in a proportion of patients with active disease, and suggest a regulatory role for Tregs in JDM inflammation.