FOXP3+ T regulatory cells in idiopathic inflammatory myopathies.
FOXP3+ T regulatory cells (Tregs) are considered key players in the maintenance of immune homeostasis. Here we studied the presence and potential role of FOXP3+ Tregs in myositis. CD3 and FOXP3 expression in dermatomyositis, polymyositis and inclusion body myositis was assessed by immunohistochemistry and real-time PCR. FOXP3+ Tregs were found in close proximity to effector cells and their numbers correlated with the degree of inflammation. Despite divergent pathogenetic concepts, we observed no differences in the frequency of FOXP3 immunoreactive cells or FOXP3 mRNA expression between different myositis entities. Functional assays using human myoblasts as targets of CD8+ cells demonstrate that Tregs are capable to inhibit the lytic activity of cytotoxic cells. Our data suggest that FOXP3 Tregs serve to counterbalance muscle destruction by cytotoxic T cells in myositis.
Department of Neurology, Julius-Maximilians-University, Wuerzburg, Germany.
Anne
A
Waschbisch
Nicholas
N
Schwab
Tobias
T
Ruck
Max-Philipp
MP
Stenner
Heinz
H
Wiendl
D017252:CD3 Complex / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D005470:Fluorometry / Q000379:methods; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D032446:Myoblasts / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D009220:Myositis / Q000276:immunology* / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
D017252:CD3 Complex; D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger