ABSTRACT
<p><b>OBJECTIVE</b>To investigate of the relationship of the immunosuppression induced by Measles virus in adult patients and CD4+ CD25+ regulatory T cell.</p><p><b>METHODS</b>Thirty-four patients with measles and 27 healthy control subjects were included in this study. The whole blood was collected and CD4+ CD25+ cell and FoxP3+ cell were analyzed by flow cytometry, and CD4+ CD25- and CD4+ CD25+ T lymphocytes were isolated from PBMCs of patients with measles or healthy donors, CD4+ CD25- T cells were cultured in absence or presence of anti-CD3, or BCG, or live attenuated MV. The cell culture supernatant was collected after 72 hours and the concentration of IFN-gamma and IL-10 was determined.</p><p><b>RESULTS</b>Compared to healthy donors, we observed a reduction of the number of white blood cells and lymphocytes in patients with measles, but there was not significantly different in the frequency of CD4+ CD25+ T cells and CD4+ CD25high T cells within the total CD4+ population in the blood. Treg from both measles patients and healthy controls significantly inhibited IFN-gamma production by CD4+ CD25- T cells in response to anti-CD3 stimulation.</p><p><b>CONCLUSION</b>Induction and expansion of Treg may not represent a mechanism involved in the establishment of immune suppression by MV.</p>