SAMAR FRESCHI DE BARROS
Índice h a partir de 2011
6
Projetos de Pesquisa
Unidades Organizacionais
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/19 - Laboratório de Histocompatibilidade e Imunidade Celular, Hospital das Clínicas, Faculdade de Medicina
LIM/19 - Laboratório de Histocompatibilidade e Imunidade Celular, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
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- Rheumatic Heart Disease: Pathogenesis and Vaccine(2018) GUILHERME, L.; BARROS, S. Freschi de; KOHLER, K. F.; SANTOS, S. R.; FERREIRA, F. Morais; SILVA, W. R.; ALENCAR, R.; POSTOL, E.; KALIL, J.Rheumatic fever (RF) and rheumatic heart disease (RHD) follow untreated S. pyogenes throat infections in children who present susceptible genes that favor the development of autoimmune reactions. In this review, we focus on the genes that confer susceptibility and on the autoimmune reactions that occur due to molecular mimicry between human-tissue proteins and streptococcal M protein. Polyarthritis is the initial manifestation, which can evolve to carditis and severe valve damage; these culminate in rheumatic heart disease (RHD) or Sydenham's chorea, which affects the central nervous system. A perspective on vaccine development to prevent the disease is also discussed.
- Analysis of the coverage capacity of the StreptInCor candidate vaccine against Streptococcus pyogenes(2014) AMICIS, Karine M. De; BARROS, Samar Freschi de; ALENCAR, Raquel E.; POSTOL, Edilberto; MARTINS, Carlo de Oliveira; ARCURI, Helen Andrade; GOULART, Cibelly; KALIL, Jorge; GUILHERME, LuizaStreptococcus pyogenes is responsible for infections as pharyngitis, sepsis, necrotizing fasciitis and streptococcal toxic shock syndrome. The M protein is the major bacterial antigen and consists of both polymorphic N-terminal portion and a conserved region. In the present study, we analyzed the in vitro ability of StreptInCor a C-terminal candidate vaccine against S. pyogenes to induce antibodies to neutralize/opsonize the most common S. pyogenes strains in Sao Paulo by examining the recognition by sera from StreptInCor immunized mice. We also evaluated the presence of cross-reactive antibodies against human heart valve tissue. Anti-StreptInCor antibodies were able to neutralize/opsonize at least 5 strains, showing that immunization with StreptInCor is effective against several S. pyogenes strains and can prevent infection and subsequent sequelae without causing autoimmune reactions.
- Rheumatic fever: From pathogenesis to vaccine perspectives(2023) GUILHERME, L.; BRANCO, C. E.; BARROS, S. F. De; KALIL, J.Rheumatic fever (RF) is considered a model of autoimmune disease due to untreated throat infection by S. pyogenes that affects children and teenagers. The autoimmune process is believed to be the basis of all of the clinical manifestations; for instance, arthritis by immune complex deposition, chorea by antibody binding to neuronal cells, skin and subcutaneous manifestations that are mediated by a delayed hypersensitivity reaction, and carditis that is caused by cross-reactive antibodies and T cells. This chapter presents an overview of the mechanisms leading to the tissue lesions, treatment, and future possibilities of a vaccine against S. pyogenes. © 2023 Elsevier Inc. All rights reserved.
- Rheumatic Fever and Rheumatic Heart Disease(2017) GUILHERME, L.; SAMPAIO, R. O.; BARROS, S. Freschi de; KöHLER, K. F.; SPINA, G. S.; TARASOUTCHI, F.; KALIL, J.Rheumatic fever (RF) is the prototype of postinfectious autoimmune diseases. Similarities of structure and/or spatial conformation between Streptococcus pyogenes and human tissue proteins lead to autoimmune reactions due to molecular mimicry. The activation of T and B lymphocytes involves several genetically controlled molecules that act in both the innate and adaptive immune response. In this chapter, we describe the strains of bacteria that are more commonly involved in the development of RF worldwide as well as the genetic predisposition of diverse ethnic groups. The disease manifests in susceptible children and teenagers, usually starting as polyarthritis or Sydenham's chorea. This condition generally occurs several months after streptococcal infection. Erythema marginatum and subcutaneous nodules are rare cutaneous manifestation, and carditis is the most serious sequelae and can lead to severe valve damage and rheumatic heart disease (RHD). The immune mechanisms that lead to the diverse manifestations mentioned above are discussed. The diagnosis and treatment, particularly the revision of Jones Criteria in the era of Doppler echocardiography, as well as the perspective of vaccine development, are also presented. © 2017 Elsevier Inc. All rights reserved.