RESUMO
Ulcerative Colitis (UC) is an inflammatory disease characterized by colonic mucosal lesions associated with an increased risk of carcinogenesis. UC pathogenesis involves environmental and genetic factors. Genetic studies have indicated the association of gene variants coding for the divalent metal ion transporter SLC11A1 protein (formerly NRAMP1) with UC susceptibility in several animal species. Two mouse lines were genetically selected for high (AIRmax) or low (AIRmin) acute inflammatory responses (AIR). AIRmax is susceptible, and AIRmin is resistant to DSS-induced colitis and colon carcinogenesis. Furthermore, AIRmin mice present polymorphism of the Slc11a1 gene. Here we investigated the possible modulating effect of the Slc11a1 R and S variants in DSS-induced colitis by using AIRmin mice homozygous for Slc11a1 R (AIRminRR) or S (AIRminSS) alleles. We evaluated UC by the disease activity index (DAI), considering weight loss, diarrhea, blood in the anus or feces, cytokines, histopathology, and cell populations in the distal colon epithelium. AIRminSS mice have become susceptible to DSS effects, with higher DAI, IL6, G-CSF, and MCP-1 production and morphological and colon histopathological alterations than AIRminRR mice. The results point to a role of the Slc11a1 S allele in DSS colitis induction in the genetic background of AIRmin mice.
Assuntos
Colite Ulcerativa , Colite , Animais , Camundongos , Carcinogênese , Colite/induzido quimicamente , Colite/genética , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/genética , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Suscetibilidade a Doenças , Inflamação/genética , Camundongos Endogâmicos C57BL , Polimorfismo GenéticoRESUMO
Two non-inbred mouse lines, phenotypically selected for maximal (AIRmin) and minimal (AIRmax) acute inflammatory response, show differential susceptibility/resistance to the development of several chemically-induced tumor types. An intercross pedigree of these mice was generated and treated with the chemical carcinogen dimethylhydrazine, which induces lung and intestinal tumors. Genome wide high-density genotyping with the Restriction Site-Associated DNA genotyping (2B-RAD) technique was used to map genetic loci modulating individual genetic susceptibility to both lung and intestinal cancer. Our results evidence new common quantitative trait loci (QTL) for those phenotypes and provide an improved understanding of the relationship between genomic variation and individual genetic predisposition to tumorigenesis in different organs.
Assuntos
Neoplasias do Colo , Locos de Características Quantitativas , Animais , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/genética , Predisposição Genética para Doença , Pulmão , Camundongos , Camundongos EndogâmicosRESUMO
Routine immunization against diphtheria and tetanus has drastically reduced the incidence of these diseases worldwide. Anti-diphtheria/tetanus vaccine has in general aluminum salt as adjuvant in its formulation that can produce several adverse effects. There is a growing interest in developing new adjuvants. In this study, we evaluated the efficiency of SBA-15 as an adjuvant in subcutaneous immunization in mice with diphtheria (dANA) and tetanus (tANA) anatoxins as well as with the mixture of them (dtANA). The tANA molecules and their encapsulation in SBA-15 were characterized using Small-Angle X-ray Scattering (SAXS), Dynamical Light Scattering (DLS), Nitrogen Adsorption Isotherm (NAI), Conventional Circular Dichroism (CD)/Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy, and Tryptophan Fluorescence Spectroscopy (FS). The primary and secondary antibody response elicited by subcutaneous immunization of High (HIII) and Low (LIII) antibody responder mice with dANA, tANA, or dtANA encapsulated in the SBA-15 were determined. We demonstrated that SBA-15 increases the immunogenicity of dANA and tANA antigens, especially when administered in combination. We also verified that SBA-15 modulates the antibody response of LIII mice, turning them into high antibody responder. Thus, these results suggest that SBA-15 may be an effective adjuvant for different vaccine formulations.
Assuntos
Difteria , Tétano , Camundongos , Animais , Imunidade Humoral , Espalhamento a Baixo Ângulo , Difração de Raios X , Difteria/prevenção & controle , Tétano/prevenção & controle , Toxoide Tetânico , Dióxido de Silício/farmacologia , Adjuvantes Imunológicos/farmacologia , Imunização Secundária/métodos , Anticorpos AntibacterianosRESUMO
Rabies is a lethal viral disease that can affect a wide range of mammals. Currently, Rabies virus (RABV) in some European and American countries is maintained primarily in wild species. The regulation of viral replication is one of the critical mechanisms involved in RABV pathogenesis. However, the relationship between replication and the pathogenesis of RABV isolated from wild animals remains poorly understood. In the present study, we evaluated the pathogenicity of the street viruses Nyctinomops laticaudatus bat-associated RABV (NYBRV) and Cerdocyon thous canid-associated RABV (CECRV). Infection of mice with NYBRV led to 33% mortality with rapid disease evolution and marked histopathological changes in the CNS. In contrast, infection with CECRV led to 67% mortality and caused mild neuropathological lesions. The proportion of RABV antigen was significantly higher in the cytoplasm of neuronal cells of the cerebral cortex and in the meninges of mice infected with CECRV and NYBRV, respectively. Moreover, the replication rate of NYBRV was significantly higher (p < 0.001) than that of CECRV in neuroblastoma cells. However, CECRV replicated to a significantly higher titer in epithelial cells. Our results indicate that NYBRV infection results in rapid disease progression accompanied by frequent and intense histopathological alterations in the CNS in mice, and in a high replication rate in neuroblastoma cells. Although, CECRV is more pathogenic in mice, it caused milder histopathological changes in the CNS and replicated more efficiently in epithelial cells. Our data point to a correlation between clinical aspects of disease and the replication of RABV in different cell lines.
Assuntos
Canidae/virologia , Quirópteros/virologia , Vírus da Raiva/isolamento & purificação , Vírus da Raiva/patogenicidade , Raiva/patologia , Raiva/virologia , Animais , Linhagem Celular , Sistema Nervoso Central/patologia , Modelos Animais de Doenças , Histocitoquímica , Camundongos , Neurônios/virologia , Análise de Sobrevida , Virulência , Replicação ViralRESUMO
OBJECTIVE AND DESIGN: AIRmax and AIRmin mice differ in their local acute inflammatory reactions to polyacrylamide beads (Biogel). These lines were developed to identify genes that affect the intensity of the acute inflammatory response (AIR) and to investigate the cellular and molecular mechanisms of acute inflammation. Although these lines are well established, differences in their responses to chronic inflammatory Biogel exposure have not yet been described. We investigated whether the selective process that modified the acute inflammatory responses in these animals also affected the development of their chronic inflammatory responses. RESULTS: Inflammatory exudate cell infiltration was more intense in AIRmax than AIRmin mice at both 48 h and 30 days. Genes involved in signal transduction and immune/inflammatory responses were differentially expressed in the treated skin of AIRmax and AIRmin mice, and divergent expression of some acute inflammatory response genes was detected up to 30 days post-Biogel. However, distinct expression of several pro and anti-inflammatory response genes in both periods was observed. CONCLUSION: These results indicate that the selective process for acute inflammation affected the development of chronic inflammatory responses to Biogel, suggesting common genetic control.
Assuntos
Resinas Acrílicas/farmacologia , Inflamação/genética , Transcriptoma/efeitos dos fármacos , Doença Aguda , Animais , Doença Crônica , Citocinas/genética , Citocinas/imunologia , Feminino , Géis , Inflamação/imunologia , Masculino , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Pele/efeitos dos fármacos , Pele/metabolismoRESUMO
Here, we compared the growth kinetics, cell-to-cell spread, and virus internalization kinetics in N2a cells of RABV variants isolated from vampire bats (V-3), domestic dogs (V-2) and marmosets (V-M) as well as the clinical symptoms and mortality caused by these variants. The replication rate of V-3 was significantly higher than those of V-2 and V-M. However, the uptake and spread of these RABV variants into N2a cells were inversely proportional. Nevertheless, V-3 had longer incubation and evolution periods. Our results provide evidence that the clinical manifestations of infection with bat RABV variant occur at a later time when compared to what was observed with canine and marmoset rabies virus variants.
Assuntos
Quirópteros/virologia , Vírus da Raiva/fisiologia , Raiva/veterinária , Animais , Antígenos Virais , Callithrix/virologia , Linhagem Celular Tumoral , Cães/virologia , Camundongos , Raiva/patologia , Raiva/virologia , Vírus da Raiva/classificaçãoRESUMO
Enteropathogenic Escherichia coli (EPEC), a leading cause of infant diarrhea, is an important public health problem in Brazil and other developing countries. In vitro assays of bacterial adhesion to cultured cells are important tools for studying bacterial pathogenicity but do not reproduce all the events that occur in natural infections. In this study, the effects of oral infection with EPEC on mice selected for their minimal acute inflammatory response (AIR min) were evaluated. Mice were orally infected with EPEC and variations in body weight, bacterial shedding and antibody production observed. The infected animals developed seric and secretory anti-EPEC antibodies; however, neither mortality nor diarrhea was observed. Light microscopy of their intestines demonstrated histological modifications that were not present in controls. However, electron microscopy did not show bacteria attached to the intestinal epithelia to form attaching and effacing lesions, characteristic of EPEC in humans. The bacteria were detected in Peyer's patches and intestinal contents up to 5 hr post-infection. When human anti-EPEC secretory immunoglobulin A or avian immunoglobulin Y antibodies were administered to infected animals, they developed minor histological alterations compared with non-treated animals. In summary, it was found that EPEC triggers immune responses and intestinal histological alterations but does not produce evidence of diarrheal disease in mice infected by the oral route. This study of EPEC experimental infection provides a better understanding of the effects of antibodies on bacterial infections and may provide a suitable model for the design and testing of immunobiological products for active or passive immunization.
Assuntos
Modelos Animais de Doenças , Escherichia coli Enteropatogênica/imunologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/patologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Animais , Anticorpos Antibacterianos/análise , Anticorpos Antibacterianos/sangue , Derrame de Bactérias , Peso Corporal , Feminino , Histocitoquímica , Masculino , Camundongos , Microscopia EletrônicaRESUMO
Polycyclic aromatic hydrocarbons, such as 7,12-dimethylbenz(a)anthracene (DMBA), are environmental pollutants that exert multiple toxic and carcinogenic effects. Studies showed that these effects are mediated by activation of the aryl hydrocarbon receptor (AhR) and modulated by allelic variants of Ahr gene. Here, we investigated the effects of DMBA treatment in the inflammatory response and bone marrow (BM) hematopoietic function of maximal acute inflammatory response (AIRmax) and minimal acute inflammatory response (AIRmin) heterogeneous mouse lines selected for high and low acute inflammatory responsiveness, respectively. The phenotypic selection resulted in the segregation of the Ahr(d) and Ahr(b1) alleles that confer low and high receptor ligand-binding affinity, respectively, in AIRmax and AIRmin mice. We observed a reduction in BM mature granulocyte population in AIRmin mice 24 hours after DMBA treatment while both blast and immature myeloid cells were increased. Proliferation and differentiation of BM myeloid cells in response to in vitro granulocyte-macrophage colony-stimulating factor stimulus were impaired in AIRmin-treated mice. These DMBA effects on myeloid BM cells (BMCs) affected the in vivo leukocyte migration to an inflammatory site induced by polyacrylamide beads (Biogel P-100, Bio-Rad, France) injection in AIRmin mice. On the other hand, these alterations were not observed in DMBA-treated AIRmax mice. These data indicate that DMBA affects myeloid cell differentiation and inflammatory response and Ahr(b1) allele in the genetic background of AIRmin mice contributes to this effect.
Assuntos
9,10-Dimetil-1,2-benzantraceno/toxicidade , Células da Medula Óssea/patologia , Doenças da Medula Óssea/induzido quimicamente , Carcinógenos/toxicidade , Inflamação/induzido quimicamente , Receptores de Hidrocarboneto Arílico/genética , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Doenças da Medula Óssea/patologia , Moléculas de Adesão Celular/análise , Moléculas de Adesão Celular/biossíntese , Linhagem Celular , Citocinas/análise , Citocinas/biossíntese , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/patologia , Peróxido de Hidrogênio/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Receptores de Hidrocarboneto Arílico/metabolismoRESUMO
BACKGROUND: The genetic basis of susceptibility to renal tumorigenesis has not yet been established in mouse strains. Mouse lines derived by bidirectional phenotypic selection on the basis of their maximal (AIRmax) or minimal (AIRmin) acute inflammatory responsiveness differ widely in susceptibility to spontaneous and urethane-induced renal tumorigenesis. To map the functional loci modulating renal tumor susceptibility in these mice, we carried out a genome-wide genetic linkage study, using SNP arrays, in an (AIRmax x AIRmin)F2 intercross population treated with a single urethane dose at 1 week of age and phenotyped for renal tumors at 35 weeks of age. RESULTS: AIRmax mice did not develop renal tumors spontaneously nor in response to urethane, whereas in AIRmin mice renal tumors formed spontaneously (in 52% of animals) and after urethane induction (89%). The tumors had a papillary morphology and were positive for alpha-methylacyl-CoA racemase and negative for CD10. By analysis of 879 informative SNPs in 662 mice, we mapped a single quantitative trait locus modulating the incidence of renal tumors in the (AIRmax x AIRmin)F2 intercross population. This locus, which we named Renal tumor modifier QTL 1 (Rtm1), mapped to chromosome 17 at 23.4 Mb (LOD score = 15.8), with SNPs rs3696835 and rs3719497 flanking the LOD score peak. The A allele of rs3719497 from AIRmin mice was associated with a 2.5-fold increased odds ratio for renal tumor development. The LOD score peak included the Tuberous sclerosis 2 (Tsc2) gene which has already been implicated in kidney disease: loss of function by germline retroviral insertion is associated with spontaneous renal tumorigenesis in the Eker rat, and heterozygous-null Tsc2(+/-) mice develop renal cystadenomas. CONCLUSIONS: We mapped Rtm1 as a single major locus modulating renal tumorigenesis in a murine intercross population. Thus, the AIR mouse lines can be considered a new genetic model for studying the role of germline and somatic molecular alterations in kidney neoplastic disease.
Assuntos
Genoma , Neoplasias Renais/genética , Animais , Cruzamentos Genéticos , Modelos Animais de Doenças , Suscetibilidade a Doenças , Ligação Genética , Genótipo , Neoplasias Renais/epidemiologia , Neoplasias Renais/patologia , Escore Lod , Camundongos , Neprilisina/genética , Neprilisina/metabolismo , Razão de Chances , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Racemases e Epimerases/genética , Racemases e Epimerases/metabolismoRESUMO
Genome-wide linkage analysis using single nucleotide polymorphism arrays was carried out in pedigrees of mice differing in the extent of acute inflammatory response (AIRmax or AIRmin). The AIR phenotype was determined by quantifying the number of infiltrating cells in the 24-h exudate induced by Biogel P-100 s.c. injection and by ex vivo IL-1beta production by leukocytes stimulated with LPS and ATP. We mapped the major inflammatory response modulator 1 locus on chromosome 7, at the 1-logarithm of odds (LOD) confidence interval from 116.75 to 139.75 Mb, linked to the number of infiltrating cells (LOD = 3.61) through the production of IL-1beta (LOD = 9.35). Of several interesting candidate genes mapping to the inflammatory response modulator 1 locus, 28 of these were differentially expressed in the bone marrow of AIRmax and AIRmin mice. These findings represent a step toward the identification of the genes underlying this complex phenotype.
Assuntos
Loci Gênicos/imunologia , Mediadores da Inflamação/fisiologia , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Doença Aguda , Animais , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Mapeamento Cromossômico , Cruzamentos Genéticos , Feminino , Regulação da Expressão Gênica/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-1beta/fisiologia , Escore Lod , Masculino , Camundongos , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/imunologiaRESUMO
Rabies virus (RABV) is a neurotropic virus that causes fatal neuroinflammation in mammals. The insectivorous bat RABV strains are less pathogenic for mice than strains associated with other reservoirs. We characterized the tissue inflammatory response in the CNS of RABV isolated from insectivorous bats. Eptesicus furinalis (EPBRV)-infected mice had a robust inflammatory response and a greater amount of IL-1ß, IL-6 and TNF-α, while Myotis nigricans (MNBRV)-infected mice showed a higher expression of IL-17 and greater activation of IFN-ß. New approaches to understand the inflammatory response to different mechanisms of action may provide insights for the development of novel therapies for rabies.
Assuntos
Quirópteros , Vírus da Raiva , Raiva , Camundongos , Animais , Modelos TeóricosRESUMO
AIRmax and AIRmin mice strains were selected according to the intensity of their acute inflammatory responsiveness. Previous studies have shown that AIR mice differ in their resistance to chemically induced skin tumors and in the development of melanoma metastases, in addition to differences in neutrophil and NK cells activity. In the present work, we aimed to evaluate whether the difference of susceptibility to murine melanoma is associated with NK cytotoxic activity against Yac.1 cells and lymphocyte subsets. Mice were subcutaneously inoculated with B16F10 or S91 melanoma cells. After 7, 14, or 30 days, the animals were euthanized to analyze the number of lymphocyte subsets, cytotoxic activity, and number of cytokine-producing spleen cells. AIRmax mice presented a higher number of CD4+/CD25+ cells than that of AIRmin mice following inoculation of B16F10 cells, whereas inoculation of S91 cells reduced CD4+/CD25+ and increased TCD8+ cell subsets in the AIRmax mice. AIRmax mice had a higher number of interleukin (IL)-10- and IL-12-producing cells and a lower number of interferon-γ-producing cells than those of AIRmin mice at 30 days. The cytotoxic activity of nonadherent spleen cells was similar in both the AIR strains. These results suggest that melanoma cells can induce different responses in AIR mice, possibly owing to alterations in regulatory mechanisms, such as the action of CD4+/CD25+ regulatory T cells and IL-10, in AIRmax mice.
RESUMO
We identified Pycard and BC017158 genes as putative effectors of the Quantitative Trait locus (QTL) that we mapped at distal chromosome 7 named Irm1 for Inflammatory response modulator 1, controlling acute inflammatory response (AIR) and the production of IL-1ß, dependent on the activation of the NLRP3 inflammasome. We obtained the mapping through genome-wide linkage analysis of Single Nucleotide Polymorphisms (SNPs) in a cross between High (AIRmax) and Low (AIRmin) responder mouse lines that we produced by several generations of bidirectional selection for Acute Inflammatory Response. A highly significant linkage signal (LOD score peak of 72) for ex vivo IL-1ß production limited a 4 Mbp interval to chromosome 7. Sequencing of the locus region revealed 14 SNPs between "High" and "Low" responders that narrowed the locus to a 420 Kb interval. Variants were detected in non-coding regions of Itgam, Rgs10 and BC017158 genes and at the first exon of Pycard gene, resulting in an E19K substitution in the protein ASC (apoptosis associated speck-like protein containing a CARD) an adaptor molecule in the inflammasome complex. Silencing of BC017158 inhibited IL1-ß production by stimulated macrophages and the E19K ASC mutation carried by AIRmin mice impaired the ex vivo IL-1ß response and the formation of ASC specks in stimulated cells. IL-1ß and ASC specks play major roles in inflammatory reactions and in inflammation-related diseases. Our results delineate a novel genetic factor and a molecular mechanism affecting the acute inflammatory response.
Assuntos
Proteínas Adaptadoras de Sinalização CARD , Inflamassomos , Animais , Proteínas Adaptadoras de Sinalização CARD/genética , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Ligação Genética , Inflamassomos/genética , Inflamassomos/metabolismo , Inflamação/genética , Inflamação/metabolismo , Camundongos , Locos de Características QuantitativasRESUMO
The inflammatory and autoimmune events preceding clinical symptoms in rheumatoid arthritis (RA) and other autoimmune diseases are difficult to study in human patients. Therefore, animal models that share immunologic and clinical features with human RA, such as pristane-induced arthritis (PIA), are valuable tools for assessing the primordial events related to arthritis susceptibility. PIA-resistant HIII and susceptible LIII mice were injected i.p. with pristane, and peritoneal lavage fluid was harvested in the early (7 days) and late (35 days) preclinical phases of PIA. Chemokine and cytokine levels were measured in lavage supernatant with ELISA, peritoneal inflammatory leukocytes were immunophenotyped by flow cytometry, and gene expression was determined by qRT-PCR. Leukocyte recruitment was quantitatively and qualitatively divergent in the peritoneum of HIII and LIII mice, with an early increase of CC chemokines (CCL2/CCL3/CCL5/CCL12/CCL22) in the susceptible LIII strain. Also, cytokines such as IL-12p40, IL-23, and IL-18 were elevated in LIII mice while IL-6 was increased in HIII animals. The results show that an early peritoneal CC chemokine response is an important feature of arthritis susceptibility and defines potential biomarkers in this model.
Assuntos
Artrite Experimental/imunologia , Artrite Reumatoide/imunologia , Quimiocinas CC/imunologia , Inflamação , Peritônio/imunologia , Animais , Artrite Experimental/induzido quimicamente , Biomarcadores , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Interleucina-6/imunologia , Masculino , Camundongos , Fenótipo , Terpenos/administração & dosagemRESUMO
AIRmax and AIRmin mouse strains phenotypically selected for high and low acute inflammatory responsiveness (AIR) are, respectively, susceptible or resistant to developing hepatocellular carcinoma (HCC) induced by the chemical carcinogens urethane and diethylnitrosamine (DEN). Early production of TNF-α, IL-1ß, and IL-6 in the liver after DEN treatment correlated with tumor development in AIRmax mice. Transcriptome analysis of livers from untreated AIRmax and AIRmin mice showed specific gene expression profiles in each line, which might play a role in their differential susceptibility to HCC. Linkage analysis with SNP markers in F2 (AIRmax×AIRmin) intercross mice revealed two quantitative trait loci (QTL) in chromosomes 2 and 9, which are significantly associated with the number and progression of urethane-induced liver tumors. An independent linkage analysis with an intercross population from A/J and C57BL/6J inbred mice mapped regions in chromosomes 1 and 7 associated with the progression of urethane-induced liver tumors, evidencing the heterogeneity of HCC genetic control.
Assuntos
Animais não Endogâmicos , Carcinoma Hepatocelular/genética , Predisposição Genética para Doença , Inflamação/imunologia , Neoplasias Hepáticas/genética , Alelos , Animais , Carcinogênese/genética , Carcinoma Hepatocelular/imunologia , Modelos Animais de Doenças , Ligação Genética , Endogamia , Inflamação/genética , Interleucina-1beta/genética , Interleucina-6/genética , Neoplasias Hepáticas/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fenótipo , Locos de Características Quantitativas , Transcriptoma , Fatores de Necrose Tumoral/genéticaRESUMO
Pristane-induced arthritis (PIA) in mice is an experimental model that resembles human rheumatoid arthritis, a chronic autoimmune disease that affects joints and is characterized by synovial inflammation and articular cartilage and bone destruction. AIRmax and AIRmin mouse lines differ in their susceptibility to PIA, and linkage analysis in this model mapped arthritis severity QTLs in chromosomes 5 and 8. miRNAs are a class of small RNA molecules that have been extensively studied in the development of arthritis. We analyzed miRNA and gene expression profiles in peritoneal cells of AIRmax and AIRmin lines, in order to evaluate the genetic architecture in this model. Susceptible AIRmax mice showed higher gene (2025 vs 1043) and miRNA (240 vs 59) modulation than resistant AIRmin mice at the onset of disease symptoms. miR-132-3p/212-3p, miR-106-5p, miR-27b-3p, and miR-25-3p were among the miRNAs with the highest expression in susceptible animals, showing a negative correlation with the expression of predicted target genes (Il10, Cd69, and Sp1r1). Our study showed that global gene and miRNA expression profiles in peritoneal cells of susceptible AIRmax and resistant AIRmin lines during pristane-induced arthritis are distinct, evidencing interesting targets for further validation.
Assuntos
Artrite Experimental/genética , Artrite Reumatoide/genética , MicroRNAs/genética , Peritônio/fisiologia , Animais , Artrite Experimental/induzido quimicamente , Células Cultivadas , Suscetibilidade a Doenças , Feminino , Humanos , Interleucina-10/genética , Masculino , Camundongos , Camundongos Mutantes , Peritônio/patologia , Locos de Características Quantitativas/genética , Terpenos/administração & dosagem , TranscriptomaRESUMO
Rabies is a lethal viral infection that can affect almost all mammals, including humans. To better understand the replication of Rabies lyssavirus, we investigated if the viral load in brains naturally infected with rabies influences viral internalization and viral growth kinetics in neuroblastoma cells, and if the viral load affects mortality in mice after intradermal infection. We noted that high initial viral loads in brains (group II) were unfavourable for increasing viral titers during serial passages in neuroblastoma cells when compared to low initial viral loads in brains (group I). In addition, group I strains showed higher viral growth and enhanced internalization efficiency in neuroblastoma cells than group II strains. However, we observed that the dominant virus subpopulation in group II promoted efficient viral infection in the central nervous system in the new host, providing a selective advantage to the virus. Our data indicate that rabies infection in animal models depends on not only the virus strain but also the amount of virus. This study may serve as a basis for understanding the biologic proprieties of Rabies lyssavirus strains with respect to the effects on viral replication and the impact on pathogenesis, improving virus yields for use in vaccine development.
Assuntos
Vírus da Raiva/fisiologia , Raiva/virologia , Replicação Viral , Animais , Encéfalo/virologia , Linhagem Celular Tumoral , Células Cultivadas , Camundongos , Neuroblastoma , Carga Viral , Internalização do VírusRESUMO
Rabies is a fatal and viral zoonosis that causes acute, progressive encephalitis and remains an important concern in public health. In the last few years, there has been a change in the epidemiological profile of rabies after implementing canine rabies control in the Americas, which has led to a significant increase in both human and pet cases of rabies associated with insectivorous bats. Thus, it is important to understand the pathogenesis caused by Rabies virus (RABV) isolates from insectivorous bats. Viral growth kinetics, cell-to-cell spread and virus uptake in vitro were analyzed for RABV isolates from Eptesicus furiralis and Myotis nigricans. For pathogenesis evaluation, mice were inoculated with RABV isolates from Eptesicus furiralis and Myotis nigricans, and clinical signs were observed for 40 days. We observed that the insectivorous bat strains showed a higher replication rate, faster cell-to-cell spread and delayed virus uptake in N2a cells. Furthermore, after the first sign of a clinical infection, mice infected with Myotis nigricans and Eptesicus furiralis isolates succumbed rapidly (6⯱â¯9 days) compared with RABV strains associated with other reservoirs. Our results show that the insectivorous bat RABV strains are less pathogenic for mice than strains associated with other reservoirs. In addition, this study also indicates that the differences in the biological characteristics of the RABV strains are important to their pathogenicity. An enhanced understanding of rabies pathogenesis may be important for the development of novel therapies for humans and in the implementation of rabies control strategies.
Assuntos
Quirópteros/virologia , Vírus da Raiva/patogenicidade , Raiva/patologia , Raiva/virologia , Animais , Modelos Animais de Doenças , Camundongos , Vírus da Raiva/crescimento & desenvolvimento , Vírus da Raiva/isolamento & purificação , Análise de Sobrevida , Fatores de Tempo , Virulência , Internalização do Vírus , Liberação de Vírus , Replicação ViralRESUMO
Two lines of mice selected to produce maximal (AIRmax) or minimal (AIRmin) acute inflammatory reactions (AIR) differ in their susceptibility to infection by Salmonella enterica serotype Typhimurium (S. Typhimurium). The LD(50) for AIRmax mice is 1000 times higher than that observed for AIRmin mice, and higher frequencies of Slc11a1 alleles (known to confer either resistance (R) or high susceptibility (S) to S. Typhimurium) were consistently found in AIRmax and AIRmin mouse lines, respectively. In order to evaluate the effect of the quantitative trait loci (QTL) segregated in AIRmax and AIRmin mice on Slc11a1 dependent susceptibility to S. Typhimurium, the R and S alleles were fixed in homozygosity in AIRmax and AIRmin backgrounds by genotype assisted breedings. These new lines were named AIRmax(RR), AIRmax(SS), AIRmin(RR), and AIRmin(SS). Acute inflammation of Slc11a1(RR) animals was more severe in comparison to their Slc11a1(SS) counterparts, implicating Slc11a1 (or other linked genes) in AIR regulation. The LD(50) of S. Typhimurium was 800-times higher for AIRmax(SS) than for AIRmin(SS), demonstrating that AIR QTL can act as modifiers of the Slc11a1(SS) susceptibility gene. Four microsatellite markers for S. Typhimurium susceptibility QTL described in other mouse lines showed specific allele fixation in AIRmax or AIRmin mice, suggesting that these chromosomal regions also segregate with inflammatory phenotypes.
Assuntos
Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/fisiologia , Locos de Características Quantitativas , Salmonelose Animal/genética , Salmonella typhimurium , Reação de Fase Aguda , Alelos , Animais , Modelos Animais de Doenças , Feminino , Predisposição Genética para Doença , Genótipo , Imunidade Inata , Dose Letal Mediana , Masculino , Camundongos , Camundongos Endogâmicos , Salmonelose Animal/imunologia , Salmonelose Animal/patologiaRESUMO
Exposure to polycyclic aromatic hydrocarbon (PAH) environmental contaminants has been associated with the development of mutations and cancer. 7,12-Dimethylbenz(a)anthracene ( DMBA), a genotoxic agent, reacts with DNA directly, inducing p53-dependent cytotoxicity resulting in cell death by apoptosis or giving rise to cancer. DMBA metabolism largely depends on activation of the aryl hydrocarbon receptor (AhR). Mice phenotypically selected for high (AIRmax) or low (AIRmin) acute inflammatory response present a complete segregation of Ahr alleles endowed with low (Ahr(d)) or high (Ahr(b1)) affinity to PAHs, respectively. To evaluate the role of AhR genetic polymorphism on the bone marrow susceptibility to DMBA, AIRmax and AIRmin mice were treated with a single intraperitoneal injection of DMBA (50mg/kg b.w.) in olive oil. Bone marrow cells (BMCs) were phenotyped by both flow cytometry and cytoslide preparations. Despite a significant decrease in total cell count in BM from AIRmin mice, there was an increase of blast cells and immature neutrophils at 1 and 50 days after DMBA treatment, probably due to a cell-cycle blockade at the G1/S transition leading to immature stage cell production. A panel of proteins related to cell cycle regulation was evaluated in immature BM cells (Lin(-)) by Western Blot, and DNA damage and repair were measured using an alkaline version of the Comet assay. In Lin(-) cells isolated from AIRmin mice, high levels were found in both p53 and p21 protein contents in contrast with the low levels of CDK4 and Ciclin D1. Evaluation of DNA repair in DMBA-treated BMCs, indicated long-lasting genotoxicity and cytotoxicity in BMC from AIRmin mice and a blockade of cell cycle progression. On the other hand, AIRmax mice have a high capacity of DNA damage repair and protection. These mechanisms can be associated with the differential susceptibility to the toxic and carcinogenic effects of DMBA observed in these mice.