Mucosal but not peripheral FOXP3+ regulatory T cells are highly increased in untreated HIV infection and normalize after suppressive HAART.
Recent evidence indicates that regulatory T cells (T(regs)) play an important role in HIV infection. However, although the gastrointestinal mucosa is a key compartment in HIV disease, no data on mucosal T(regs) in HIV infection are available. In this study, we compared the frequency of T(regs) in duodenal mucosa and peripheral blood (PB) of 13 treatment-naive and 13 suppressively treated HIV-infected patients with that of 6 patients with norovirus infection and 12 healthy controls. T(regs) were quantified by immunohistochemistry (CD3/FOXP3) and further characterized (CD25, CTLA-4, GITR) by immunohistochemistry, immunofluorescence, and fluorescence-activated cell sorting (FACS). Both the frequency and the absolute count of mucosal T(regs) were highly increased in untreated HIV patients but were normal in treated HIV patients. In contrast, in peripheral blood of HIV patients, the absolute number of T(regs) was not increased, and their frequency was only slightly elevated. In norovirus infection, frequency of mucosal T(regs) in the CD4+ T-cell subset was not elevated. The high increase in count and frequency of mucosal T(regs) seems to be a characteristic feature of untreated HIV infection, suggesting a significant contribution of T(regs) to the pathogenesis of HIV disease. Their role may be 2-edged: attenuating HIV-induced immune hyperactivation while suppressing the immune response to HIV and mucosal pathogens.
Epple
Hans-Jörg
HJ
Medical Clinic I, Gastroenterology, Rheumatology, Infectiology; Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200 Berlin, Germany. hans-joerg.epple@charite.de
Loddenkemper
Christoph
C
Kunkel
Desirée
D
Tröger
Hanno
H
Maul
Jochen
J
Moos
Verena
V
Berg
Erika
E
Ullrich
Reiner
R
Schulzke
Jörg-Dieter
JD
Stein
Harald
H
Duchmann
Rainer
R
Zeitz
Martin
M
Schneider
Thomas
T
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood; D000943:Antigens, Differentiation / Q000097:blood; D023241:Antiretroviral Therapy, Highly Active; D060908:CTLA-4 Antigen; D005260:Female; D051858:Forkhead Transcription Factors / Q000097:blood*; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D018928:Immunity, Mucosal; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D019562:Viral Load
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit