998 resultados para 4 hydroxynonenal
Resumo:
This study evaluated two vaccine candidates for their effectiveness in protecting BALB/c mice against Leishmania chagasiinfection. These immunogenic preparations were composed of Leishmania amazonensisor Leishmania braziliensisantigenic extracts in association with saponin adjuvant. Mice were given three subcutaneous doses of one of these vaccine candidates weekly for three weeks and four weeks later challenged with promastigotes of L. chagasiby intravenous injection. We observed that both vaccine candidates induced a significant reduction in the parasite load of the liver, while the L. amazonensisantigenic extract also stimulated a reduction in spleen parasite load. This protection was associated with a suppression of both interleukin (IL)-10 and IL-4 cytokines by spleen cells in response to L. chagasiantigen. No change was detected in the production of IFN- 47;. Our data show that these immunogenic preparations reduce the type 2 immune response leading to the control of parasite replication.
Resumo:
The CTLA-4 protein is expressed in activated T cells and plays an essential role in the immune response through its regulatory effect on T cell activation. Polymorphisms of the CTLA-4 gene have been correlated with autoimmune, neoplastic and infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) in CTLA-4, -318C/T in the promoter and +49A/G in exon 1 and paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients and 76 healthy controls had their allele, genotype and haplotype frequencies determined. The genetic admixture structure of the patients and controls was evaluated to eliminate ancestral bias. The comparison of frequencies indicated no significant differences between patients and controls that could link the SNPs to PCM. Groups were admixture matched with no difference observed in population ancestry inference, indicating that the absence of association between CTLA-4 polymorphisms and PCM could not be attributed to ancestral bias. This study showed that there was no association between the CTLA-4 SNPs -318 and +49 and the resistance or susceptibility to PCM.
Resumo:
Toll-like receptors (TLRs) recognise pathogen-derived molecules and influence immunity to control parasite infections. This study aimed to evaluate the mRNA expression of TLRs 2 and 4, the expression and production of the cytokines interleukin (IL)-12, interferon (IFN)- 47;, tumor necrosis factor (TNF)- 45;, IL-17, IL-10 and transforming growth factor (TGF)- 46; and the production of nitric oxide (NO) in the spleen of mice infected with Leishmania chagasi. It also aimed to evaluate any correlations between mRNA expression TLR2 and 4 and cytokines and NO production. Infection resulted in increased TLR2-4, IL-17, TNF- 45; and TGF- 46; mRNA expression during early infection, with decreased expression during late infection correlating with parasite load. IFN- 47; and IL-12 mRNA expression decreased at the peak of parasitism. IL-10 mRNA expression increased throughout the entire time period analysed. Although TGF- 46;, TNF- 45; and IL-17 were highly produced during the initial phase of infection, IFN- 47; and IL-12 exhibited high production during the final phase of infection. IL-10 and NO showed increased production throughout the evaluated time period. In the acute phase of infection, there was a positive correlation between TLR2-4, TNF- 45;, IL-17, NO, IL-10 and TGF- 46; expression and parasite load. During the chronic phase of infection, there was a positive correlation between TLR2-4, TNF- 45;, IL-17 and TGF- 46; expression and parasite load. Our data suggest that infection by L. chagasi resulted in modulation of TLRs 2 and 4 and cytokines.
