Dengue is an infectious disease of viral etiology transmitted by the mosquitoes

Killer cell immunoglobulin-like receptors (KIR) form a group of regulatory molecules that specifically recognise human leukocyte antigen (HLA) class I molecules, modulating the cytolytic activity of natural killer cells. The purpose of this study was to investigate the influence of KIR genes and their class I HLA ligands in susceptibility to dengue fever in a population from southern Brazil through a case-control study. One hundred four subjects with confirmed diagnoses of dengue participated in this study, along with a control group of 172 individuals from the same geographic area. HLA and KIR genotyping was performed by polymerase chain reaction with sequence-specific oligonucleotide probes (PCR-SSOP) and with sequence-specific primer (PCR-SSP) techniques, respectively. Data analysis showed significant differences for the KIR2DS1 (54.8% vs 40.7%, P = 0.03), KIR2DS5 (50.0% vs 36.0%, P = 0.03) and KIR2DL5 (76.0% vs 56.4%, P = 0.001) genes. With regard to KIR-ligand pairs, positive associations with dengue were observed in KIR3DS1-Bw4 (45.2% vs 29.7%, P = 0.01), KIR3DL1-Bw4 (80.7% vs 65.1%, P < 0.001), KIR2DL1-C2 (75.0% vs 62.2%, P = 0.03) and KIR2DS1-C2 (40.4% vs 25.6%, P = 0.01) interactions, and a negative association in KIR2DL3-C1/C1 (18.2% vs 33.1%, P = 0.01). Furthermore, the analysis of KIR haplogroups showed a possible protective factor against dengue fever in individuals with the AA genotype. Taken together, these results suggest the existence of genetic predisposition to dengue fever in the population from southern Brazil.

There has recently been increased interest in the potential health effects of omega-3 polyunsaturated fatty acids on the immune system. Paracoccidioidomycosis is the most important endemic mycosis in Latin America. Macrophages have a fundamental role and act as first line of organism defense. The purpose of this study was to analyze the effect of n-3 fatty acids on the production of PGE2 and NO by mice infected with Pb18 and fed a diet enriched with LNA for 8 weeks. To study the effect of omega-3 fatty acids on macrophage activity during experimental paracoccidioidomycosis, mice were infected with Pb18 and fed a diet supplemented with LNA. PGE2 in the serum of animals was analyzed and NO in the supernatants of macrophages cultured and challenged in vitro with Pb18 was measured. Omega-3 fatty acids seemed to decrease the production of PGE2 in vivo in the infected group fed an LNA-supplemented diet during the 4th and 8th weeks of the experiment. At the same time, we observed an increase in synthesis of NO by peritoneal macrophages in this group. Omega-3 fatty acids thus appear to have an immunomodulatory effect in paracoccidioidomycosis.

These results reinforce the therapeutic benefits of moderate physical exercise for T. cruzi infection.

The HLA-DRB1*13:204 allele differs from HLA*13:64 by two nucleotide substitutions at positions 181 and 189 in the exon 2.

Objective: To evaluate the in vivo and in vitro activity of Canova in experimental infection with Paracoccidioides brasiliensis. Materials and Methods: Mice infected with P. brasiliensis were treated with Canova for 17 weeks. Follow-up measures included the determination of total antibodies, global and differential leukocyte counts. Further, nitric oxide production was determined by adding macrophage cultures to different concentrations of Canova in the presence or absence of P. brasiliensis. Results: The data revealed the protective effect of Canova in P. brasiliensis-infected animals. A higher nitric oxide production was found in the Canova-treated cultures. Conclusion: These data suggest that Canova activates the macrophages by a way that depends, at least in part, on nitric oxide.

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