Navegando por Palavras-chave "antibody response"
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- ItemSomente MetadadadosAcquisition of Serum Antibodies Reactive With Enterohemorrhagic Escherichia coli Virulence-Associated Factors by Healthy Brazilian Children and Adults(Lippincott Williams & Wilkins, 2009-12-01) Palmeira, Patricia; Carbonare, Solange B.; Guth, Beatriz E. C. [UNIFESP]; Carbonare, Cristiane B.; Pontes, Gerlandia N.; Tino-De-Franco, Milene; Zapata-Quintanilla, Lucy B.; Carneiro-Sampaio, Magda; Universidade Federal de São Paulo (UNIFESP); Butantan InstBackground: Patients with hemorrhagic colitis or hemolytic uremic syndrome due to enterohemorrhagic Escherichia coli (EHEC) develop serum IgM and IgG response to lipopolysaccharide (LPS) and to virulence factors such as intimin. the small numbers of cases of diarrhea associated with EHEC strains in Brazil suggests a pre-existing immunity probably due to previous contact with diarrheagenic E. coli. Our aim was to evaluate the development of the serum antibody repertoire to EHEC virulence factors in Brazilian children and adults.Methods: Serum IgM and IgG antibodies were determined by enzyme-linked immunosorbent assay with LPS O111, LPS O26, and LPS O157 in 101 children between 2 months and 10 years of age and in 100 adult sera, by immunoblotting with protein membrane extracts and purified beta intimin; the ability of adult sera to neutralize Shiga toxin2 was also investigated.Results: Children older than 24 months had IgM concentrations reactive with the 3 LPS equivalent to those seen in the adult group, and significantly higher than the group of younger children (P < 0.05). Anti-O26 and anti-O157 LPS IgG concentrations were equivalent between the 2 groups of children and were significantly different from the adult group (P < 0.05). the anti-O111 LPS IgG levels in older children were intermediate between the younger group, and adults (P < 0.05). Immunoblotting revealed strong protein reactivity, including the conserved and variable regions of beta intimin and more than 50% of the adult samples neutralized Shiga toxin 2.Conclusions: Our results demonstrate an increasing anti-LPS and antiprotein antibody response with age, which could provide protection against EHEC infections.
- ItemSomente MetadadadosAntibody response after vaccination with tetanus and diphtheria toxoids in human T-cell lymphotropic virus type 1 asymptomatic carriers(Elsevier B.V., 2008-06-02) Biasutti, Claudia; Moraes-Pinto, Maria Isabel [UNIFESP]; Segurado, Aluisio C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
- ItemSomente MetadadadosAntibody response against plasmid-encoded toxin (Pet) and the protein involved in intestinal colonization (Pic) in children with diarrhea produced by enteroaggregative Escherichia coli(Elsevier B.V., 2005-02-01) Bellini, E. M.; Elias Junior, Waldir Pereira [UNIFESP]; Gomes, Tania Aparecida Tardelli [UNIFESP]; Tanaka, T. L.; Taddei, C. R.; Huerta, R.; Navarro-Garcia, F.; Martinez, M. B.; Universidade de São Paulo (USP); Inst Butantan; Universidade Federal de São Paulo (UNIFESP); CINVESTAVEnteroaggregative Escherichia eoli (EAEC) is an emerging cause of pediatric and adult travellers diarrhea. the mechanism by which EAEC induce diarrhea is not completely known. Two serine protease autotransporter proteins, named Pet and Pic have been identified in EAEC strains. Pet has enterotoxic and cytotoxic activities, while the role of Pic in pathogenesis may lie on its mucinolytic activity. Little is known about Pet and Pic biological activities in vivo. in this study the antibody responses against these autotransporter proteins in convalescent children is investigated. Fifteen (83%) children showed specific antibodies against Pet or Pic in their sera. IgG and IgM antibodies were the main isotype found. Specific antibodies against Pic, but not against Pet, were detected in sera from age-matched control group. These data show that specific anti-Pet and anti-Pic antibodies are produced during the course of a natural EAEC infection in children. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosHuman antibody responses of patients living in endemic areas for schistosomiasis to the tegumental protein Sm29 identified through genomic studies(Blackwell Publishing, 2006-06-01) Cardoso, F. C.; Pacifico, RNA; Mortara, Renato Arruda [UNIFESP]; Oliveira, S. C.; Universidade Federal de Minas Gerais (UFMG); Universidade Federal de São Paulo (UNIFESP)Surface proteins of schistosomes are exposed to host tissues and thus present as potential candidate molecules for the development of new intervention strategies. Herein, we have identified a new tegumental protein of Schistosoma mansoni, termed Sm29. in silico analysis revealed a signal peptide, three glycosylation sites and a transmembrane region on Sm29 amino acid sequence. Sm29 transcription in mammalian developmental stages cDNA libraries of S. mansoni was verified by PCR using specific primers for Sm29 nucleotide sequence and it revealed the presence of transcripts in schistosomula and adult worm stages of the parasite. Sm29 (40-169) fragment was produced in Escherichia coli and purified by affinity chromatography to be used in the immunological assays. Confocal microscopy confirmed bioinformatic studies, revealing that Sm29 is a membrane-bound protein localized on the tegument of S. mansoni adult worm. ELISA was performed using rSm29 protein to investigate the antibody isotype profile to Sm29 in sera of patients living in endemic areas for schistosomiasis. IgG1 and IgG3 subclass antibodies to rSm29 were predominant in sera of individuals naturally resistant to infection and resistant to re-infection whereas low levels of IgM, IgA or IgE were measured. Since, IgG1 and IgG3 are involved in parasite killing and in protective immunity the findings reported here suggest the use of Sm29 as a potential candidate vaccine against schistosomiasis.