MYRTHES ANNA MARAGNA TOLEDO BARROS
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/60 - Laboratório de Imunologia Clínica e Alergia, Hospital das Clínicas, Faculdade de Medicina
LIM/60 - Laboratório de Imunologia Clínica e Alergia, Hospital das Clínicas, Faculdade de Medicina
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Resultados de Busca
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bookPart Imunodeficiências Primárias(2016) KOKRON, Cristina Maria; BARROS, Myrthes ToledobookPart Autoimunidade(2016) BARROS, Myrthes Toledo; GRECCO, Octávio- IL-10-Producing Regulatory B Cells Are Decreased in Patients with Common Variable Immunodeficiency(2016) BARSOTTI, Nathalia Silveira; ALMEIDA, Rafael Ribeiro; COSTA, Priscilla Ramos; BARROS, Myrthes Toledo; KALIL, Jorge; KOKRON, Cristina MariaCommon variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency in adults. CVID patients often present changes in the frequency and function of B lymphocytes, reduced number of Treg cells, chronic immune activation, recurrent infections, high incidence of autoimmunity and increased risk for malignancies. We hypothesized that the frequency of B10 cells would be diminished in CVID patients because these cells play an important role in the development of Treg cells and in the control of T cell activation and autoimmunity. Therefore, we evaluated the frequency of B10 cells in CVID patients and correlated it with different clinical and immunological characteristics of this disease. Forty-two CVID patients and 17 healthy controls were recruited for this study. Cryo-preserved PBMCs were used for analysis of T cell activation, frequency of Treg cells and characterization of B10 cells by flow cytometry. IL-10 production by sorted B cells culture and plasma sCD14 were determined by ELISA. We found that CVID patients presented decreased frequency of IL-10-producing CD24(hi)CD38(hi) B cells in different cell culture conditions and decreased frequency of IL-10-producing CD24(hi)CD27(+) B cells stimulated with CpG+PIB. Moreover, we found that CVID patients presented lower secretion of IL-10 by sorting-purified B cells when compared to healthy controls. The frequency of B10 cells had no correlation with autoimmunity, immune activation and Treg cells in CVID patients. This work suggests that CVID patients have a compromised regulatory B cell compartment which is not correlated with clinical and immunological characteristics presented by these individuals.
- Inversion of the V delta 1 to V delta 2 gamma delta T cell ratio in CVID is not restored by IVIg and is associated with immune activation and exhaustion(2016) PAQUIN-PROULX, Dominic; BARSOTTI, Nathalia Silveira; SANTOS, Bianca A. N.; MARINHO, Ana Karolina B. B.; KOKRON, Cristina M.; CARVALHO, Karina I.; BARROS, Myrthes T.; KALIL, Jorge; NIXON, Douglas F.; KALLAS, Esper G.Common variable immunodeficiency (CVID) is defined by low levels of IgG and IgA, but perturbations in T cells are also commonly found. However, there is limited information on gamma delta T cells in CVID patients. Newly diagnosed CVID patients (n=15) were enrolled before and after intravenous IgG (IVIg) replacement therapy. Cryopreserved peripheral blood mononuclear cells were then used to study gamma delta T cells and CVID patients were compared to healthy controls (n=22). The frequency and absolute count of V delta 1 gamma delta T cells was found to be increased in CVID (median 0.60% vs 2.64%, P<0.01 and 7.5 vs 39, P<0.01 respectively), while they were decreased for V delta 2 gamma delta T cells (median, 2.36% vs 0.74%, P<0.01 and 37.8 vs 13.9, P<0.01 respectively) resulting in an inversion of the V delta 1 to V delta 2 ratio (0.24 vs 1.4, P<0.001). Markers of immune activation were elevated on all subsets of gamma delta T cells, and HLA-DR expression was associated with an expansion of V delta 1 gamma delta T cells (r=0.73, P=0.003). Elevated PD-1 expression was found only on V delta 2 gamma delta T cells (median 1.15% vs 3.08%, P<0.001) and was associated with the decrease of V delta 2 gamma delta T cells (r=-0.67, P=0.007). IVIg had no effect on the frequency of V delta 1 and V delta 2 gamma delta T cells or HLA-DR expression, but alleviated CD38 expression on V delta 1 gamma delta T cells (median MFI 965 vs 736, P<0.05). These findings suggest that immunological perturbations of gamma delta T cells are a general feature associated with CVID and are only partially reversed by IVIg therapy.
conferenceObject IL-10-PRODUCING REGULATORY B CELLS ARE DECREASED IN PATIENTS WITH COMMON VARIABLE IMMUNODEFICIENCY(2016) BARSOTTI, Nathalia Silveira; ALMEIDA, Rafael Ribeiro; BARROS, Myrthes Toledo; KALIL, Jorge; KOKRON, Cristina M.