RESUMEN
Influenza A virus causes annual epidemics which affect millions of people worldwide. A recent Influenza pandemic brought new awareness over the health impact of the disease. It is thought that a severe inflammatory response against the virus contributes to disease severity and death. Therefore, modulating the effects of inflammatory mediators may represent a new therapy against Influenza infection. Platelet activating factor (PAF) receptor (PAFR) deficient mice were used to evaluate the role of the gene in a model of experimental infection with Influenza A/WSN/33 H1N1 or a reassortant Influenza A H3N1 subtype. The following parameters were evaluated: lethality, cell recruitment to the airways, lung pathology, viral titers and cytokine levels in lungs. The PAFR antagonist PCA4248 was also used after the onset of flu symptoms. Absence or antagonism of PAFR caused significant protection against flu-associated lethality and lung injury. Protection was correlated with decreased neutrophil recruitment, lung edema, vascular permeability and injury. There was no increase of viral load and greater recruitment of NK1.1(+) cells. Antibody responses were similar in WT and PAFR-deficient mice and animals were protected from re-infection. Influenza infection induces the enzyme that synthesizes PAF, lyso-PAF acetyltransferase, an effect linked to activation of TLR7/8. Therefore, it is suggested that PAFR is a disease-associated gene and plays an important role in driving neutrophil influx and lung damage after infection of mice with two subtypes of Influenza A. Further studies should investigate whether targeting PAFR may be useful to reduce lung pathology associated with Influenza A virus infection in humans.
Asunto(s)
Apoptosis , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Lesión Pulmonar/metabolismo , Lesión Pulmonar/virología , Infecciones por Orthomyxoviridae/prevención & control , Glicoproteínas de Membrana Plaquetaria/fisiología , Receptores Acoplados a Proteínas G/fisiología , Animales , Western Blotting , Pollos , Dihidropiridinas/farmacología , Modelos Animales de Enfermedad , Mediadores de Inflamación/metabolismo , Subtipo H1N1 del Virus de la Influenza A/genética , Lesión Pulmonar/prevención & control , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Infecciones por Orthomyxoviridae/metabolismo , Infecciones por Orthomyxoviridae/virología , Factor de Activación Plaquetaria/genética , Factor de Activación Plaquetaria/metabolismo , Glicoproteínas de Membrana Plaquetaria/antagonistas & inhibidores , ARN Mensajero/genética , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tasa de Supervivencia , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , Carga ViralRESUMEN
Leprosy is a chronic infectious disease that remains a major challenge to public health in endemic countries. Increasing evidence has highlighted the importance of microbiota for human general health and, as such, the study of skin microbiota is of interest. But while studies are continuously revealing the complexity of human skin microbiota, the microbiota of leprous cutaneous lesions has not yet been characterized. Here we used Sanger and massively parallel small sub-unit rRNA (SSU) rRNA gene sequencing to characterize the microbiota of leprous lesions, and studied how it differs from the bacterial skin composition of healthy individuals previously described in the literature. Taxonomic analysis of leprous lesions revealed main four phyla: Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, with Proteobacteria presenting the highest diversity. There were considerable differences in the distribution of Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria, with the first two phyla enriched and the other markedly diminished in the leprous lesions, when compared with healthy skin. Propionibacterium, Corynebacterium and Staphylococcus, resident and abundant in healthy skin, were underrepresented in skin from leprous lesions. Most of the taxa found in skin from leprous lesions are not typical in human skin and potentially pathogenic, with the Burkholderia, Pseudomonas and Bacillus genera being overrepresented. Our data suggest significant shifts of the microbiota with emergence and competitive advantage of potentially pathogenic bacteria over skin resident taxa.
RESUMEN
Immunological adjuvants that induce T cell-mediate immunity (TCMI) with the least side effects are needed for the development of human vaccines. Glycoinositolphospholipids (GIPL) and CpGs oligodeoxynucleotides (CpG ODNs) derived from the protozoa parasite Trypanosoma cruzi induce potent pro-inflammatory reaction through activation of Toll-Like Receptor (TLR)4 and TLR9, respectively. Here, using mouse models, we tested the T. cruzi derived TLR agonists as immunological adjuvants in an antitumor vaccine. For comparison, we used well-established TLR agonists, such as the bacterial derived monophosphoryl lipid A (MPL), lipopeptide (Pam3Cys), and CpG ODN. All tested TLR agonists were comparable to induce antibody responses, whereas significant differences were noticed in their ability to elicit CD4(+) T and CD8(+) T cell responses. In particular, both GIPLs (GTH, and GY) and CpG ODNs (B344, B297 and B128) derived from T. cruzi elicited interferon-gamma (IFN-γ) production by CD4(+) T cells. On the other hand, the parasite derived CpG ODNs, but not GIPLs, elicited a potent IFN-γ response by CD8(+) T lymphocytes. The side effects were also evaluated by local pain (hypernociception). The intensity of hypernociception induced by vaccination was alleviated by administration of an analgesic drug without affecting protective immunity. Finally, the level of protective immunity against the NY-ESO-1 expressing melanoma was associated with the magnitude of both CD4(+) T and CD8(+) T cell responses elicited by a specific immunological adjuvant.
Asunto(s)
Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer/inmunología , Inmunidad Celular/inmunología , Proteínas de la Membrana/inmunología , Linfocitos T/inmunología , Trypanosoma cruzi/inmunología , Adyuvantes Inmunológicos , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Humanos , Melanoma/inmunología , Melanoma/metabolismo , RatonesRESUMEN
In this work, we explored an original vaccination protocol using recombinant influenza and adenovirus. We constructed recombinant influenza viruses harboring dicistronic NA segments containing the surface antigen 2 (SAG2) from Toxoplasma gondii under control of the duplicated 3' promoter. Recombinant influenza viruses were able to drive the expression of the foreign SAG2 sequence in cell culture and to replicate efficiently both in cell culture and in lungs of infected mice. In addition, mice primed with recombinant influenza virus and boosted with a recombinant adenovirus encoding SAG2 elicited both humoral and cellular immune responses specific for SAG2. Moreover, when immunized animals were challenged with the cystogenic P-Br strain of T. gondii, they displayed up to 85% of reduction in parasite burden. These results demonstrate the potential use of recombinant influenza vectors harboring the dicistronic segments in the development of vaccines against infectious diseases.