Navegando por Palavras-chave "imunidade humoral"
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- ItemSomente MetadadadosAvaliação de sub-população de linfócitos b em crianças com hipogamaglobulinemia(Universidade Federal de São Paulo (UNIFESP), 2014-02-07) Melo, Karina Mescouto de [UNIFESP]; Carvalho, Beatriz Tavares Costa Carvalho [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Introduction: Common Variable Immunodeficiency (CVID) is the main cause of symptomatic hypogammaglobulinemia in all ages, to define the diagnosis other welldefined causes of hypogammaglobulinemia has to be excluded. Phenotypic and functional cellular abnormalities have been described in children with CVID, including reduced number of memory B cell, especially in patients with complications. Objective: To study B and T cell subsets, and T cell cytokine production in children with hypogammaglobulinemia and also in adults with CVID, compared with matched healthy controls. Methodology: Twenty-nine patients (17 children with HG and 12 adults with CVID), and a group of 27 healthy controls (15 adults and 12 children) were allocated in this study. Well-known genetic causes of hypogammaglobulinemia in infancy were excluded in and 9 children were under intravenous immunoglobulin (IVIg) replacement. Whole blood cells were analyzed by flow cytometry, and evaluated as follows: 1 - B cell: naïve, switched and non-switched memory B cell, transitional, CD21low, CD24hiCD38hi , IgM-only and atypical memory B cell; 2 - T cell: naïve, central and peripheral memory, and terminally differentiated T cells; 3 ? Cellular immune response to tetanus toxoid by measurement of intracelular interferon gamma (IFN-?) in CD4+ T cell and CD8+ T cell. Results: Three children with hypogammaglobulinemia had complications, bronchiectasis (2) and autoimmune disease (1). Those under IVIg replacement had lower percentage of switched memory B cells, and children without IVIg had decreased IgM- only memory B cell. We also observed phenotypic and functional changes in T cell compartment in children with hypogammaglobulinemia: an increased percentage of terminally differentiated CD8+ T cells, reduced percentage of central memory CD8 + T cell and diminished IFN-? production by CD8+ T cells after tetanus toxoid stimulus. Adults? patients with ICV showed low percentage of switched memory B cells, increased percentage of naïve B CD21low and IgM-only B cells. Half of adult patients had onset of infections during the infancy, and 83.3% of them had chronic lung disease. Conclusion: Children with hypogammaglobulinemia showed early changes in the B cell subsets with different patterns in those who require IVIG. Changes in cellular immunity indicate that there may be a combined impairment of cellular and humoral immune response in early cases of CVID, which may influence the clinical manifestations in adulthood.
- ItemEmbargoDesenvolvimento de modelos experimentais em C57BL/6 para estudos de coinfecção com o vírus Mayaro e Chikungunya(Universidade Federal de São Paulo, 2023-12-01) Della Casa, Victória Simões [UNIFESP]; Rosa, Daniela Santoro [UNIFESP]; Claser, Carla; http://lattes.cnpq.br/2538167072206937; http://lattes.cnpq.br/1472798853821902; http://lattes.cnpq.br/2139937536934521As mudanças climáticas, ambientais e ecológicas levaram ao aumento recente dos surtos epidêmicos de arboviroses no Brasil, dentre eles o Chikungunya (CHIKV) e o Mayaro (MAYV). Ambos CHIKV e MAYV são membros da família Togaviridae, gênero Alphavirus, do complexo antigênico Semliki Forest e filogeneticamente próximos. Enquanto o CHIKV é o agente causador de surtos no mundo todo, a infecção pelo MAYV representa um problema crescente de saúde pública na América Latina, com casos esporádicos e surtos geograficamente limitados. No entanto, o MAYV permanece extremamente negligenciado, com número de casos ainda subestimado, devido a similaridade dos sintomas clínicos com chikungunya e dengue. Estudos recentes mostraram que a exposição prévia à um alphavírus, desencadeia em indivíduos expostos uma potente resposta humoral capaz de conferir tanto uma proteção contra uma reinfecção, como uma proteção parcial cruzada contra uma reinfecção heteróloga. Dessa forma, esse projeto tem como objetivo estabelecer diferentes modelos de coinfecção com o CHIKV e MAYV em camundongos C57BL/6 adultos imunologicamente competentes, para estudar de que forma essa coinfecção modula a resposta imune humoral mediada por anticorpos e como ela pode alterar o curso da infecção de ambos os vírus. Para isso, será realizada a quantificação da viremia, avaliação dos sinais clínicos da doença, detecção de anticorpos séricos e análise histopatológica.
- ItemAcesso aberto (Open Access)Resposta a antígenos polissacarídicos em pacientes com ataxia-telangiectasia(Sociedade Brasileira de Pediatria, 2006-04-01) Guerra-Maranhão, Maria Cristina [UNIFESP]; Costa-Carvalho, Beatriz Tavares [UNIFESP]; Nudelman, Victor [UNIFESP]; Barros-Nunes, Patrícia [UNIFESP]; Carneiro-Sampaio, Magda Maria Sales; Arslanian, Cristina; Nagao-Dias, Aparecida Tiemi [UNIFESP]; Solé, Dirceu [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Albert Einstein; Universidade de São Paulo (USP); Univ. de São Paulo Instituto de Ciências Biomédicas Laboratório de Imunologia de Mucosas; Universidade Federal do Ceará Faculdade de Farmácia Departamento de Análises Clínicas e ToxicológicasOBJECTIVE: To analyze the production of antibodies to polysaccharide antigens in patients with ataxia-telangiectasia. PATIENTS AND METHODS: We used the ELISA technique to measure the levels of IgG antibodies to serotypes 1, 3, 5, 6B, 9V and 14 of Streptococcus pneumoniae in 14 patients with ataxia-telangiectasia before and after immunization with 23-valent polysaccharide vaccine. Adequate response to individual polysaccharide can be defined as a postimmunization antibody titer equal to or greater than 1.3 µg/ml or as a minimum fourfold increase over the baseline (preimmunization) value. RESULTS: Six (43%) patients showed an absent response to all serotypes analyzed. Four patients showed adequate response to only one serotype, one patient to two serotypes, two patients to three serotypes and only one patient to four out of six serotypes analyzed. No patient had adequate response to all serotypes tested. Postimmunization pneumococcus IgG levels were higher than preimmunization levels to all serotypes analyzed, except for serotype 3. In spite of this, the mean postimmunization levels were lower than 1.3 µg/ml in all serotypes, except for serotype 14. Mean increment was less than four in all serotypes analyzed. CONCLUSION: Our results suggest that patients with ataxia-telangiectasia are at a high risk of having an impaired response to pneumococcus, which may be one of the causes of recurrent sinopulmonary infections in these patients.