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Browsing HB - IH - Artigos by Author "Carvalho, A"
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- Study of disease-relevant polymorphisms in the TLR4 and TLR9 genes: a novel method applied to the analysis of the Portuguese populationPublication . Carvalho, A; Marques, A; Maciel, P; Rodrigues, FToll-like receptors (TLRs) are cellular receptors that mediate recognition of microbial challenges and the subsequent inflammatory response. Genetic variations within these inflammation-associated genes may alter host-pathogen defence mechanisms affecting susceptibility towards infectious diseases. Taking into account the significance of these genes, we developed a simple and rapid method based in the bi-directional PCR amplification of specific alleles (Bi-PASA) for genotyping known sequence variants in TLR4 (Asp299Gly and Thr399Ile) and TLR9 (T-1237C) genes. This method allows genotype determination in a single reaction and is amenable to large-scale analysis. We used Bi-PASA to characterize the distribution of these polymorphisms in the Portuguese population. A total of 388 randomly selected blood donors of Portuguese origin (203 females and 185 males) were genotyped and allele frequencies were determined. Among the tested individuals, 11.1% and 10.8% were heterozygous for Asp299Gly and Thr399Ile, respectively. In what concerns the T-1237C variation in TLR9, the variant allele was present in 19.4% of the individuals tested. Besides confirming the usefulness of the Bi-PASA in polymorphism analysis, the data presented provide valuable information on TLR polymorphisms in the Portuguese population that can be used to stratify risk patients with increased susceptibility to infection.
- The rs5743836 polymorphism in TLR9 confers a population-based increased risk of non-Hodgkin lymphomaPublication . Carvalho, A; Cunha, C; Almeida, AJ; Osório, NS; Saraiva, M; Teixeira-Coelho, M; Pedreiro, S; Torrado, E; Domingues, N; Gomes-Alves, AG; Marques, A; Silva MG; Lacerda, JF; Gomes, M; Pinto, AC; Torres, F; Rendeiro, P; Tavares, P; Di Ianni, M; Heutink, P; Bracci, PM; Conde, L; Ludovico, P; Pedrosa, J; Maciel, P; Pitzurra, L; Aversa, F; Marques, H; Paiva, A; Skibola, CF; Romani, L; Castro, AG; Rodrigues, FNon-Hodgkin lymphoma (NHL) has been associated with immunological defects, chronic inflammatory and autoimmune conditions. Given the link between immune dysfunction and NHL, genetic variants in toll-like receptors (TLRs) have been regarded as potential predictive factors of susceptibility to NHL. Adequate anti-tumoral responses are known to depend on TLR9 function, such that the use of its synthetic ligand is being targeted as a therapeutic strategy. We investigated the association between the functional rs5743836 polymorphism in the TLR9 promoter and risk for B-cell NHL and its major subtypes in three independent case-control association studies from Portugal (1160 controls, 797 patients), Italy (468 controls, 494 patients) and the US (972 controls, 868 patients). We found that the rs5743836 polymorphism was significantly overtransmitted in both Portuguese (odds ratio (OR), 1.85; P=7.3E-9) and Italian (OR, 1.84; P=6.0E-5) and not in the US cohort of NHL patients. Moreover, the increased transcriptional activity of TLR9 in mononuclear cells from patients harboring rs5743836 further supports a functional effect of this polymorphism on NHL susceptibility in a population-dependent manner.