RESUMO
Raven's advanced progressive matrices (APM) comprise two types of representational codes, namely visuo-spatial and verbal-analytical, that are used to solve APM puzzles. Studies using analytical, behavioral, and imaging methods have supported the multidimensional perspectives of APM puzzles. The visuo-spatial code is expected to recruit operations more responsive to the visual perception tasks. In contrast, the verbal-analytical code is expected to use operations more responsive to the logical reasoning task and may entail different cognitive strategies. Acknowledging different representational codes used in APM puzzle-solving is critical for a better understanding of APM's performance and their relationship with other tasks, especially creative reasoning. We used the eye-tracking method to investigate the role of two representational codes, visuo-spatial and verbal-analytical, in strategies involved in solving APM puzzles and in generating an APM-like puzzle by using a creative-reasoning task (CRT). Participants took longer time to complete the verbal-analytical than visuo-spatial puzzles. In addition, visuo-analytical than visual-spatial puzzles showed higher progressive and regressive saccade counts, suggesting the use of more response elimination than constructive matching strategies employed while solving verbal-analytical than visuo-spatial puzzles. We observed higher CRT scores when it followed verbal-analytical (Mdn = 84) than visuo-spatial (Mdn = 73) APM puzzles, suggesting puzzle-solving specific strategies affect puzzle-creating task performance. The advantage of verbal-analytical over visuo-spatial puzzle-solving has been discussed in light of shared cognitive processing between APM puzzle-solving and APM-like puzzle-creating task performance.
RESUMO
Loss of oral tolerance (LOT) to gluten, driven by dendritic cell (DC) priming of gluten-specific T helper 1 (Th1) cell immune responses, is a hallmark of celiac disease (CeD) and can be triggered by enteric viral infections. Whether certain commensals can moderate virus-mediated LOT remains elusive. Here, using a mouse model of virus-mediated LOT, we discovered that the gut-colonizing protist Tritrichomonas (T.) arnold promotes oral tolerance and protects against reovirus- and murine norovirus-mediated LOT, independent of the microbiota. Protection was not attributable to antiviral host responses or T. arnold-mediated innate type 2 immunity. Mechanistically, T. arnold directly restrained the proinflammatory program in dietary antigen-presenting DCs, subsequently limiting Th1 and promoting regulatory T cell responses. Finally, analysis of fecal microbiomes showed that T. arnold-related Parabasalid strains are underrepresented in human CeD patients. Altogether, these findings will motivate further exploration of oral-tolerance-promoting protists in CeD and other immune-mediated food sensitivities.
Assuntos
Antígenos , Imunidade Inata , Animais , Camundongos , Humanos , Dieta , Glutens , Células Dendríticas , Tolerância ImunológicaRESUMO
Clonal hematopoiesis (CH) represents clonal expansion of mutated hematopoietic stem cells detectable in the peripheral blood or bone marrow through next generation sequencing. The current prevailing model posits that CH mutations detected in the peripheral blood mirror bone marrow mutations with clones widely disseminated across hematopoietic compartments. We sought to test the hypothesis that all clones are disseminated throughout hematopoietic tissues by comparing CH in hip vs peripheral blood specimens collected at the time of hip replacement surgery. Here, we show that patients with osteoarthritis have a high prevalence of CH, which involve genes encoding epigenetic modifiers and DNA damage repair pathway proteins. Importantly, we illustrate that CH, including clones with variant allele frequencies >10%, can be confined to specific bone marrow spaces and may be eliminated through surgical excision. Future work will define whether clones with somatic mutations in particular genes or clonal fractions of certain sizes are either more likely to be localized or are slower to disseminate into the peripheral blood and other bony sites.
Assuntos
Medula Óssea , Hematopoiese Clonal , Humanos , Hematopoese/genética , Células-Tronco Hematopoéticas/metabolismo , Células ClonaisRESUMO
The triggers that drive interferon-γ (IFNγ)-producing CD8 T cell (Tc1 cell)-mediated autoimmune hepatitis (AIH) remain obscure. Here, we show that lack of hematopoietic Tet methylcytosine dioxygenase 2 (Tet2), an epigenetic regulator associated with autoimmunity, results in the development of microbiota-dependent AIH-like pathology, accompanied by hepatic enrichment of aryl hydrocarbon receptor (AhR) ligand-producing pathobionts and rampant Tc1 cell immunity. We report that AIH-like disease development is dependent on both IFNγ and AhR signaling, as blocking either reverts ongoing AIH-like pathology. Illustrating the critical role of AhR-ligand-producing pathobionts in this condition, hepatic translocation of the AhR ligand indole-3-aldehyde (I3A)-releasing Lactobacillus reuteri is sufficient to trigger AIH-like pathology. Finally, we demonstrate that I3A is required for L. reuteri-induced Tc1 cell differentiation in vitro and AIH-like pathology in vivo, both of which are restrained by Tet2 within CD8 T cells. This AIH-disease model may contribute to the development of therapeutics to alleviate AIH.
Assuntos
Proteínas de Ligação a DNA , Dioxigenases , Hepatite Autoimune , Limosilactobacillus reuteri , Fígado , Microbiota , Animais , Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Disbiose/complicações , Hepatite Autoimune/etiologia , Hepatite Autoimune/patologia , Interferon gama , Ligantes , Fígado/imunologia , Fígado/microbiologia , Camundongos , Microbiota/genética , Microbiota/imunologia , Linfócitos T CitotóxicosRESUMO
Endocannabinoids (eCBs) and transient receptor potential (TRP) channels are associated with thermoregulation; however, there are many gaps in the understanding of how these signaling systems work together in responding to changes in temperature. TRPV1, a calcium-permeable ion channel, is activated by capsaicin, elevated temperature, the eCB Anandamide, and over 15 additional endogenous lipids. There is also evidence for signaling crosstalk between TRPV1 and the eCB receptor, CB1. We recently found that activation of TRPV1-HEK cells by capsaicin increases the production of the eCB, 2-arachidonoyl glycerol (2-AG), suggesting a molecular link between these receptors. Here, we tested the hypothesis that TRPV1 activation by capsaicin drives regulation of a wider-range of lipid signaling molecules and is time and dose-dependent. We also tested the hypothesis that changes in temperature that drive changes in calcium mobilization in TRPV1-HEK will likewise drive similar changes in lipid signaling molecule regulation. Lipid analysis was conducted by partial purification of methanolic extracts on C18 solid phase extraction columns followed by HPLC/MS/MS. Capsaicin increased the release of 2-acyl glycerols (2-AG, 2-linoleoyl glycerol, 2-oleoyl glycerol), in a concentration- and time-dependent manner, whereas levels of N-acyl ethanolamines (NAEs), including Anandamide, were significantly decreased. Analogous changes in 2-acyl glycerols and NAEs were measured upon ramping the temperature from 37 to 45°C. In contrast, opposite effects were measured when analyzing lipids after they were maintained at 27°C and then quickly ramped to 37°C, wherein 2-acyl glycerol levels decreased and NAEs increased. These results provide further evidence that the eCB system and TRPV1 have integrated signaling functions that are associated with the molecular response to temperature variation.
RESUMO
Death due to sepsis remains a persistent threat to critically ill patients confined to the intensive care unit and is characterized by colonization with multi-drug-resistant healthcare-associated pathogens. Here we report that sepsis in mice caused by a defined four-member pathogen community isolated from a patient with lethal sepsis is associated with the systemic suppression of key elements of the host transcriptome required for pathogen clearance and decreased butyrate expression. More specifically, these pathogens directly suppress interferon regulatory factor 3. Fecal microbiota transplant (FMT) reverses the course of otherwise lethal sepsis by enhancing pathogen clearance via the restoration of host immunity in an interferon regulatory factor 3-dependent manner. This protective effect is linked to the expansion of butyrate-producing Bacteroidetes. Taken together these results suggest that fecal microbiota transplantation may be a treatment option in sepsis associated with immunosuppression.
Assuntos
Transplante de Microbiota Fecal , Imunidade , Sepse/imunologia , Sepse/terapia , Animais , Ácido Butírico/metabolismo , Fezes/química , Microbioma Gastrointestinal , Trato Gastrointestinal/patologia , Inibidores de Histona Desacetilases/farmacologia , Humanos , Fator Regulador 3 de Interferon/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Sepse/microbiologia , Transdução de Sinais , Transcrição GênicaRESUMO
Intestinal reovirus infection can trigger T helper 1 (TH1) immunity to dietary antigen, raising the question of whether other viruses can have a similar impact. Here we show that the acute CW3 strain of murine norovirus, but not the persistent CR6 strain, induces TH1 immunity to dietary antigen. This property of CW3 is dependent on its major capsid protein, a virulence determinant. Transcriptional profiling of mesenteric lymph nodes following infection reveals an immunopathological signature that does not segregate with protective immunity but with loss of oral tolerance, in which interferon regulatory factor 1 is critical. These data show that viral capacity to trigger specific inflammatory pathways at sites where T cell responses to dietary antigens take place interferes with the development of tolerance to an oral antigen. Collectively, these data provide a foundation for the development of therapeutic strategies to prevent TH1-mediated complex immune disorders triggered by viral infections.
Assuntos
Infecções por Caliciviridae/imunologia , Dieta , Norovirus/imunologia , Norovirus/patogenicidade , Ovalbumina/imunologia , Células Th1/imunologia , Administração Oral , Animais , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/imunologia , Doença Celíaca/imunologia , Modelos Animais de Doenças , Feminino , Células HEK293 , Humanos , Imunidade , Inflamação , Fator Regulador 1 de Interferon/imunologia , Linfonodos , Camundongos , Camundongos Endogâmicos C57BL , Ovalbumina/administração & dosagem , Eliminação de Partículas ViraisRESUMO
Exposure to airborne toxins can trigger headaches, but the mechanisms are not well understood. Some environmental toxins, such as acrolein, activate transient receptor potential ankyrin 1 (TRPA1), a receptor involved in pain sensation that is highly expressed in the trigeminovascular system. It has been shown in rat models that repeated exposure to acrolein induces trigeminovascular sensitization to both TRPA1 and TRP vanilloid 1 (TRPV1) agonists, a phenomenon linked to headache. In this study, we test the hypothesis that the sensitization of trigeminovascular responses in rats after acrolein exposure via inhalation is associated with changes in levels of endogenous lipids, including TRPV1 agonists, in the trigeminal ganglia, trigeminal nucleus, and cerebellum. Lipidomics analysis of 80 lipids was performed on each tissue after acute acrolein, chronic acrolein, or room air control. Both acute and chronic acrolein exposure drove widespread alterations in lipid levels. After chronic acrolein exposure, levels of all 6 N-acyl ethanolamines in the screening library, including the endogenous cannabinoid and TRPV1 agonist, N-arachidonoyl ethanolamine, were elevated in trigeminal tissue and in the cerebellum. This increase in TRPV1 ligands by acrolein exposure may indicate further downstream signaling, in that we also show here that a combination of these TRPV1 endogenous agonists increases the potency of the individual ligands in TRPV1-HEK cells. In addition to these TRPV1 agonists, 3 TRPV3 antagonists, 4 TRPV4 agonists, and 25 orphan lipids were up and down regulated after acrolein exposure. These data support the hypothesis that lipid signaling may represent a mechanism by which repeated exposure to the TRPA1 agonist and environmental toxin, acrolein, drives trigeminovascular sensitization.