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27 result(s) for "Aoki, Maria P."
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Purinergic signaling modulates CD4+ T cells with cytotoxic potential during Trypanosoma cruzi infection
Chagas disease, caused by Trypanosoma cruzi , is endemic to Latin America and is characterized by chronic inflammation of cardiac tissues due to parasite persistence. Hypoxia within infected tissues may trigger the stabilization of HIF-1 and be linked to ATP release. Extracellular ATP exhibits microbicidal effects but is scavenged by CD39 and CD73 ectonucleotidases, which ultimately generate adenosine (ADO), a potent immunosuppressor. Here, we comprehensively study the importance of HIF-1 stabilization and the CD39/CD73/ADO axis, on CD4 + T cells with the cytotoxic phenotype, in facilitating the persistence of T. cruzi . Myocardial infection induces prominent areas of hypoxia, which is concomitant with HIF-1α stabilization in T cells and linked to early expansion of CD39 + CD73 + CD4 + T cell infiltrating population. Functional assays further demonstrate that HIF-1 stabilization and CD73 activity are associated with impaired CD4 + T cell cytotoxic potential. RNA-Seq analysis reveals that HIF-1 and purinergic signaling pathways are overrepresented in cardiac tissues of patients with end-stage Chagas disease. The findings highlight a major effect of purinergic signaling on CD4 + T cells with potential cytotoxic capacity in the setting of T. cruzi infection and have translational implications for therapy.
CD73 activity controls cytotoxic CD4 T-cell response driving myocardial pathology in chronic Chagas disease
Chagas disease, caused by Trypanosoma cruzi , is the major cause of infectious cardiopathology worldwide. Although cytotoxic CD4 T-cells (CD4 CTLs) have recently been recognized as crucial effectors in infections and inflammation, the mechanisms that control their differentiation and impact on pathological outcomes remain largely undefined. Here, we demonstrate that the ectonucleotidase CD73, which generates adenosine from extracellular AMP, acts as a key immunoregulator of CD4 CTL response during T. cruzi infection. Using murine models, we found that infection induced a robust expansion of CD4 T-cells expressing granzyme B, perforin, and IFN-γ. CD73 deficiency improved parasite control and amplified the frequency and cytotoxic program of CD4 T-cells during the acute phase. However, the absence of CD73 also led to sustained cardiac inflammation, extensive fibrosis, and impaired contractility during chronic infection. In patients with asymptomatic chronic Chagas disease, circulating CD4 T-cells exhibited elevated granzyme B expression, predominantly within the CD73 - subset. Consistently, cardiac tissue from patients with chronic terminal Chagas cardiomyopathy showed transcriptomic enrichment of granzyme B ( GZMB ), perforin ( PRF1 ), and IFN-γ ( IFNG ), with CD4 T-cells as the major contributors. Together, these findings identify CD73 ectoenzyme as a critical immunometabolic checkpoint that modulates CD4 CTL responses, revealing a dual role for this pathway in controlling infection and limiting tissue damage.
Anti-inflammatory Role of Galectin-8 During Trypanosoma cruzi Chronic Infection
Galectins are animal lectins with high affinity for β-galactosides that drive the immune response through several mechanisms. In particular, the role of galectin-8 (Gal-8) in inflammation remains controversial. To analyze its role in a chronic inflammatory environment, we studied a murine model of infection. The parasite induces alterations that lead to the development of chronic cardiomyopathy and/or megaviscera in 30% of infected patients. The strong cardiac inflammation along with fibrosis leads to cardiomyopathy, the most relevant consequence of Chagas disease. By analyzing infected wild-type (iWT) and Gal-8-deficient (iGal-8KO) C57BL/6J mice at the chronic phase (4-5 months post-infection), we observed that the lack of Gal-8 favored a generalized increase in heart, skeletal muscle, and liver inflammation associated with extensive fibrosis, unrelated to tissue parasite loads. Remarkably, increased frequencies of neutrophils and macrophages were observed within cardiac iGal-8KO tissue by flow cytometry. It has been proposed that Gal-8, as well as other galectins, induces the surface expression of the inner molecule phosphatidylserine on activated neutrophils, which serves as an \"eat-me\" signal for macrophages, favoring viable neutrophil removal and tissue injury protection, a process known as preaparesis. We found that the increased neutrophil rates could be associated with the absence of Gal-8-dependent preaparesis, leading to a diminished neutrophil-clearing capability in macrophages. Thus, our results support that Gal-8 exerts an anti-inflammatory role in chronic infection.
Purinergic signaling modulates CD4.sup.+ T cells with cytotoxic potential during Trypanosoma cruzi infection
Chagas disease, caused by Trypanosoma cruzi, is endemic to Latin America and is characterized by chronic inflammation of cardiac tissues due to parasite persistence. Hypoxia within infected tissues may trigger the stabilization of HIF-1 and be linked to ATP release. Extracellular ATP exhibits microbicidal effects but is scavenged by CD39 and CD73 ectonucleotidases, which ultimately generate adenosine (ADO), a potent immunosuppressor. Here, we comprehensively study the importance of HIF-1 stabilization and the CD39/CD73/ADO axis, on [CD4.sup.+] T cells with the cytotoxic phenotype, in facilitating the persistence of T. cruzi. Myocardial infection induces prominent areas of hypoxia, which is concomitant with HIF-1[alpha] stabilization in T cells and linked to early expansion of [CD39.sup.+][CD73.sup.+][CD4.sup.+] T cell infiltrating population. Functional assays further demonstrate that HIF-1 stabilization and CD73 activity are associated with impaired [CD4.sup.+] T cell cytotoxic potential. RNA-Seq analysis reveals that HIF-1 and purinergic signaling pathways are overrepresented in cardiac tissues of patients with end-stage Chagas disease. The findings highlight a major effect of purinergic signaling on [CD4.sup.+] T cells with potential cytotoxic capacity in the setting of T. cruzi infection and have translational implications for therapy.
Omega-3-Supplemented Fat Diet Drives Immune Metabolic Response in Visceral Adipose Tissue by Modulating Gut Microbiota in a Mouse Model of Obesity
Obesity is a chronic, relapsing, and multifactorial disease characterized by excessive accumulation of adipose tissue (AT), and is associated with inflammation mainly in white adipose tissue (WAT) and an increase in pro-inflammatory M1 macrophages and other immune cells. This milieu favors the secretion of cytokines and adipokines, contributing to AT dysfunction (ATD) and metabolic dysregulation. Numerous articles link specific changes in the gut microbiota (GM) to the development of obesity and its associated disorders, highlighting the role of diet, particularly fatty acid composition, in modulating the taxonomic profile. The aim of this study was to analyze the effect of a medium-fat-content diet (11%) supplemented with omega-3 fatty acids (D2) on the development of obesity, and on the composition of the GM compared with a control diet with a low fat content (4%) (D1) over a 6-month period. The effect of omega-3 supplementation on metabolic parameters and the modulation of the immunological microenvironment in visceral adipose tissue (VAT) was also evaluated. Six-weeks-old mice were adapted for two weeks and then divided into two groups of eight mice each: a control group D1 and the experimental group D2. Their body weight was recorded at 0, 4, 12, and 24 weeks post-differential feeding and stool samples were simultaneously collected to determine the GM composition. Four mice per group were sacrificed on week 24 and their VAT was taken to determine the immune cells phenotypes (M1 or M2 macrophages) and inflammatory biomarkers. Blood samples were used to determine the glucose, total LDL and HDL cholesterol LDL, HDL and total cholesterol, triglycerides, liver enzymes, leptin, and adiponectin. Body weight measurement showed significant differences at 4 (D1 = 32.0 ± 2.0 g vs. D2 = 36.2 ± 4.5 g, p-value = 0.0339), 12 (D1 = 35.7 ± 4.1 g vs. D2 = 45.3 ± 4.9 g, p-value = 0.0009), and 24 weeks (D1 = 37.5 ± 4.7 g vs. D2 = 47.9 ± 4.7, p-value = 0.0009). The effects of diet on the GM composition changed over time: in the first 12 weeks, α and β diversity differed considerably according to diet and weight increase. In contrast, at 24 weeks, the composition, although still different between groups D1 and D2, showed changes compared with previous samples, suggesting the beneficial effects of omega-3 fatty acids in D2. With regard to metabolic analysis, the results did not reveal relevant changes in biomarkers in accordance with AT studies showing an anti-inflammatory environment and conserved structure and function, which is in contrast to reported findings for pathogenic obesity. In conclusion, the results suggest that the constant and sustained administration of omega-3 fatty acids induced specific changes in GM composition, mainly with increases in Lactobacillus and Ligilactobacillus species, which, in turn, modulated the immune metabolic response of AT in this mouse model of obesity.
MICROBIOTA AT THE CROSS ROAD OF DIET AND HEALTH: HOW DIETARY FATS SHAPE BACTERIAL LAND-SCAPE AND INFLUENCE GLOBAL HEALTH
Host-gut microbiota (GM) interactions play a pivotal role in shaping the delicate balance between health and disease within the human body. The impact of dietary factors, specifically high fat content diets on GM composition has been widely demonstrated. We have previously shown that the constant and sustained administration of Omega-3 fatty acids induced specific changes in GM composition, modulating the immune metabolic response of visceral adipose tissue (VAT) in our mouse model of obesity. We now set out to determine if this effect is Omega-3 dose-dependent. To achieve this, C57BL/6J(B6) mice were fed for 24 weeks with three diets, two with medium content total fat, but different Omega-3 content and a control diet. GM composition, metabolic biomarkers and immune cells in VAT were analyzed. A distinctive segregation of GM composition, a significantly higher proportion of regulatory T cells (CD45+CD4+FoxP3+), Omega-3 dose dependent and increased levels of leptin and cholesterol with no differences in adiponectin values were found in fat fed groups. Simple mediation analyses revealed significant associations between the microbial profile and immunometabolic regulation. To remark is the capacity of Lachnospiraceae UCG- 001 to modulate levels of leptin, glucose, and cholesterol through the stimulation of CD45+CD4+FOXP3+IL10+ cells. Our findings suggest a modulatory effect of omega-3 fatty acids on the microbiota, the metabolism, and the immunoregulatory capacity of VAT, supporting the hypothesis that alteration of the GM composition by omega-3 fatty acids may be a promising approach in managing obesity and associated metabolic diseases.
Metabolic profiles of soybean roots during early stages of Fusarium tucumaniae infection
Soybean germplasm exhibits various levels of resistance to Fusarium tucumaniae, the main causal agent of sudden death syndrome (SDS) of soybean in Argentina. In this study, two soybean genotypes, one susceptible (NA 4613) and one partially resistant (DM 4670) to SDS infection, were inoculated with F. tucumaniae. Disease symptoms were scored at 7, 10, 14, and 25 days post-inoculation (dpi). The greatest difference in the area under the disease progress curve (AUDPC) values among genotypes was observed at 25 dpi. In order to detect early metabolic markers that could potentially discriminate between susceptible and resistant genotypes, gas chromatography–mass spectrometry (GC-MS) analyses of root samples were performed. These analyses show higher levels of several amino acids and the polyamine cadaverine in the inoculated than in the uninoculated susceptible cultivar at 7 dpi. Principal component analysis (PCA) revealed that the metabolic profile of roots harvested at the earliest time points from the inoculated susceptible genotype was clearly differentiated from the rest of the samples. Furthermore, variables associated with the first principal component were mainly amino acids. Taken together, the results indicate that the pathogen induced the susceptible plant to accumulate amino acids in roots at early time points after infection, suggesting that GC-MS-based metabolomics could be used for the rapid characterization of cultivar response to SDS.
Observing Antarctic Bottom Water in the Southern Ocean
Dense, cold waters formed on Antarctic continental shelves descend along the Antarctic continental margin, where they mix with other Southern Ocean waters to form Antarctic Bottom Water (AABW). AABW then spreads into the deepest parts of all major ocean basins, isolating heat and carbon from the atmosphere for centuries. Despite AABW’s key role in regulating Earth’s climate on long time scales and in recording Southern Ocean conditions, AABW remains poorly observed. This lack of observational data is mostly due to two factors. First, AABW originates on the Antarctic continental shelf and slope where in situ measurements are limited and ocean observations by satellites are hampered by persistent sea ice cover and long periods of darkness in winter. Second, north of the Antarctic continental slope, AABW is found below approximately 2 km depth, where in situ observations are also scarce and satellites cannot provide direct measurements. Here, we review progress made during the past decades in observing AABW. We describe 1) long-term monitoring obtained by moorings, by ship-based surveys, and beneath ice shelves through bore holes; 2) the recent development of autonomous observing tools in coastal Antarctic and deep ocean systems; and 3) alternative approaches including data assimilation models and satellite-derived proxies. The variety of approaches is beginning to transform our understanding of AABW, including its formation processes, temporal variability, and contribution to the lower limb of the global ocean meridional overturning circulation. In particular, these observations highlight the key role played by winds, sea ice, and the Antarctic Ice Sheet in AABW-related processes. We conclude by discussing future avenues for observing and understanding AABW, impressing the need for a sustained and coordinated observing system.
Overall efficacy of HPV-16/18 AS04-adjuvanted vaccine against grade 3 or greater cervical intraepithelial neoplasia: 4-year end-of-study analysis of the randomised, double-blind PATRICIA trial
Cervical intraepithelial neoplasia grade 2 or greater (CIN2+) is the surrogate endpoint used in licensure trials of human papillomavirus (HPV) vaccines. Vaccine efficacy against CIN3+, the immediate precursor to invasive cervical cancer, is more difficult to measure because of its lower incidence, but provides the most stringent evidence of potential cancer prevention. We report vaccine efficacy against CIN3+ and adenocarcinoma in situ (AIS) in the end-of-study analysis of PATRICIA (PApilloma TRIal against Cancer In young Adults). Healthy women aged 15–25 years with no more than six lifetime sexual partners were included in PATRICIA, irrespective of their baseline HPV DNA status, HPV-16 or HPV-18 serostatus, or cytology. Women were randomly assigned (1:1) to receive an HPV-16/18 AS04-adjuvanted vaccine or a control hepatitis A vaccine via an internet-based central randomisation system using a minimisation algorithm to account for age ranges and study sites. The patients and study investigators were masked to allocated vaccine. The primary endpoint of PATRICIA has been reported previously. In the present end-of-study analysis, we focus on CIN3+ and AIS in the populations of most clinical interest, the total vaccinated cohort (TVC) and the TVC-naive. The TVC comprised all women who received at least one vaccine dose, approximating catch-up populations and including sexually active women (vaccine n=9319; control=9325). The TVC-naive comprised women with no evidence of oncogenic HPV infection at baseline, approximating early adolescent HPV exposure (vaccine n=5824; control=5820). This study is registered with ClinicalTrials.gov, number NCT00122681. Vaccine efficacy against CIN3+ associated with HPV-16/18 was 100% (95% CI 85·5–100) in the TVC-naive and 45·7% (22·9–62·2) in the TVC. Vaccine efficacy against all CIN3+ (irrespective of HPV type in the lesion and including lesions with no HPV DNA detected) was 93·2% (78·9–98·7) in the TVC-naive and 45·6% (28·8–58·7) in the TVC. In the TVC-naive, vaccine efficacy against all CIN3+ was higher than 90% in all age groups. In the TVC, vaccine efficacy against all CIN3+ and CIN3+ associated with HPV-16/18 was highest in the 15–17 year age group and progressively decreased in the 18–20 year and 21–25 year age groups. Vaccine efficacy against all AIS was 100% (31·0–100) and 76·9% (16·0–95·8) in the TVC-naive and TVC, respectively. Serious adverse events occurred in 835 (9·0%) and 829 (8·9%) women in the vaccine and control groups, respectively; only ten events (0·1%) and five events (0·1%), respectively, were considered to be related to vaccination. PATRICIA end-of-study results show excellent vaccine efficacy against CIN3+ and AIS irrespective of HPV DNA in the lesion. Population-based vaccination that incorporates the HPV-16/18 vaccine and high coverage of early adolescents might have the potential to substantially reduce the incidence of cervical cancer. GlaxoSmithKline Biologicals.