Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.270
Filtrar
Más filtros

Intervalo de año de publicación
1.
Immunity ; 57(7): 1648-1664.e9, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38876098

RESUMEN

Allogeneic T cell expansion is the primary determinant of graft-versus-host disease (GVHD), and current dogma dictates that this is driven by histocompatibility antigen disparities between donor and recipient. This paradigm represents a closed genetic system within which donor T cells interact with peptide-major histocompatibility complexes (MHCs), though clonal interrogation remains challenging due to the sparseness of the T cell repertoire. We developed a Bayesian model using donor and recipient T cell receptor (TCR) frequencies in murine stem cell transplant systems to define limited common expansion of T cell clones across genetically identical donor-recipient pairs. A subset of donor CD4+ T cell clonotypes differentially expanded in identical recipients and were microbiota dependent. Microbiota-specific T cells augmented GVHD lethality and could target microbial antigens presented by gastrointestinal epithelium during an alloreactive response. The microbiota serves as a source of cognate antigens that contribute to clonotypic T cell expansion and the induction of GVHD independent of donor-recipient genetics.


Asunto(s)
Enfermedad Injerto contra Huésped , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/microbiología , Animales , Ratones , Ratones Endogámicos C57BL , Linfocitos T CD4-Positivos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Microbiota/inmunología , Selección Clonal Mediada por Antígenos , Trasplante Homólogo , Teorema de Bayes , Trasplante de Células Madre/efectos adversos , Ratones Endogámicos BALB C , Microbioma Gastrointestinal/inmunología , Trasplante de Células Madre Hematopoyéticas/efectos adversos
2.
Immunity ; 56(4): 687-694, 2023 04 11.
Artículo en Inglés | MEDLINE | ID: mdl-37044059

RESUMEN

Type 2 immunity defends against macro-parasites and can cause allergic diseases. Our understanding of the mechanisms governing the initiation of type 2 immunity is limited, whereas we know more about type 1 immune responses. Type 2 immunity can be triggered by a wide array of inducers that do not share common features and via diverse pathways and mechanisms. To address the complexity of the type 2 initiation pathways, we suggest a framework that conceptualizes different modes of induction of type 2 immunity. We discuss categories of type 2 inducers and their immunogenicity, types of tissue perturbations that are caused by these inducers, sensing strategies for the initiation of Th2 immune responses, and categorization of the signals that are produced in response to type 2 challenges. We describe tissue-specific examples of functional disruption that could lead to type 2 inflammation and propose that different sensing strategies that operate at the tissue level converge on the initiation of type 2 immune responses.


Asunto(s)
Hipersensibilidad , Inmunidad , Humanos , Inflamación , Células Th2
3.
Immunity ; 56(8): 1876-1893.e8, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37480848

RESUMEN

Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic stem cell transplantation (SCT), and severe intestinal manifestation is the major cause of early mortality. Intestinal microbiota control MHC class II (MHC-II) expression by ileal intestinal epithelial cells (IECs) that promote GVHD. Here, we demonstrated that genetically identical mice of differing vendor origins had markedly different intestinal microbiota and ileal MHC-II expression, resulting in discordant GVHD severity. We utilized cohousing and antibiotic treatment to characterize the bacterial taxa positively and negatively associated with MHC-II expression. A large proportion of bacterial MHC-II inducers were vancomycin sensitive, and peri-transplant oral vancomycin administration attenuated CD4+ T cell-mediated GVHD. We identified a similar relationship between pre-transplant microbes, HLA class II expression, and both GVHD and mortality in a large clinical SCT cohort. These data highlight therapeutically tractable mechanisms by which pre-transplant microbial taxa contribute to GVHD independently of genetic disparity.


Asunto(s)
Microbioma Gastrointestinal , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Ratones , Animales , Vancomicina , Enfermedad Injerto contra Huésped/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Hematopoyéticas/métodos , Trasplante Homólogo/efectos adversos
4.
Proc Natl Acad Sci U S A ; 121(27): e2406734121, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38913897

RESUMEN

The Merovingian period (5th to 8th cc AD) was a time of demographic, socioeconomic, cultural, and political realignment in Western Europe. Here, we report the whole-genome shotgun sequence data of 30 human skeletal remains from a coastal Late Merovingian site of Koksijde (675 to 750 AD), alongside 18 remains from two Early to Late Medieval sites in present-day Flanders, Belgium. We find two distinct ancestries, one shared with Early Medieval England and the Netherlands, while the other, minor component, reflecting likely continental Gaulish ancestry. Kinship analyses identified no large pedigrees characteristic to elite burials revealing instead a high modularity of distant relationships among individuals of the main ancestry group. In contrast, individuals with >90% Gaulish ancestry had no kinship links among sampled individuals. Evidence for population structure and major differences in the extent of Gaulish ancestry in the main group, including in a mother-daughter pair, suggests ongoing admixture in the community at the time of their burial. The isotopic and genetic evidence combined supports a model by which the burials, representing an established coastal nonelite community, had incorporated migrants from inland populations. The main group of burials at Koksijde shows an abundance of >5 cM long shared allelic intervals with the High Medieval site nearby, implying long-term continuity and suggesting that similarly to Britain, the Early Medieval ancestry shifts left a significant and long-lasting impact on the genetic makeup of the Flemish population. We find substantial allele frequency differences between the two ancestry groups in pigmentation and diet-associated variants, including those linked with lactase persistence, likely reflecting ancestry change rather than local adaptation.


Asunto(s)
Linaje , Humanos , Historia Medieval , Bélgica , Entierro/historia , Genética de Población/métodos , Femenino , Masculino , ADN Antiguo/análisis , Inglaterra , Migración Humana , Arqueología , Países Bajos , Genoma Humano
5.
N Engl J Med ; 389(26): 2446-2456, 2023 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-37952133

RESUMEN

BACKGROUND: A strategy of administering a transfusion only when the hemoglobin level falls below 7 or 8 g per deciliter has been widely adopted. However, patients with acute myocardial infarction may benefit from a higher hemoglobin level. METHODS: In this phase 3, interventional trial, we randomly assigned patients with myocardial infarction and a hemoglobin level of less than 10 g per deciliter to a restrictive transfusion strategy (hemoglobin cutoff for transfusion, 7 or 8 g per deciliter) or a liberal transfusion strategy (hemoglobin cutoff, <10 g per deciliter). The primary outcome was a composite of myocardial infarction or death at 30 days. RESULTS: A total of 3504 patients were included in the primary analysis. The mean (±SD) number of red-cell units that were transfused was 0.7±1.6 in the restrictive-strategy group and 2.5±2.3 in the liberal-strategy group. The mean hemoglobin level was 1.3 to 1.6 g per deciliter lower in the restrictive-strategy group than in the liberal-strategy group on days 1 to 3 after randomization. A primary-outcome event occurred in 295 of 1749 patients (16.9%) in the restrictive-strategy group and in 255 of 1755 patients (14.5%) in the liberal-strategy group (risk ratio modeled with multiple imputation for incomplete follow-up, 1.15; 95% confidence interval [CI], 0.99 to 1.34; P = 0.07). Death occurred in 9.9% of the patients with the restrictive strategy and in 8.3% of the patients with the liberal strategy (risk ratio, 1.19; 95% CI, 0.96 to 1.47); myocardial infarction occurred in 8.5% and 7.2% of the patients, respectively (risk ratio, 1.19; 95% CI, 0.94 to 1.49). CONCLUSIONS: In patients with acute myocardial infarction and anemia, a liberal transfusion strategy did not significantly reduce the risk of recurrent myocardial infarction or death at 30 days. However, potential harms of a restrictive transfusion strategy cannot be excluded. (Funded by the National Heart, Lung, and Blood Institute and others; MINT ClinicalTrials.gov number, NCT02981407.).


Asunto(s)
Anemia , Transfusión Sanguínea , Infarto del Miocardio , Humanos , Anemia/sangre , Anemia/etiología , Anemia/terapia , Transfusión Sanguínea/métodos , Transfusión de Eritrocitos/efectos adversos , Transfusión de Eritrocitos/métodos , Hemoglobinas/análisis , Infarto del Miocardio/sangre , Infarto del Miocardio/complicaciones , Infarto del Miocardio/mortalidad , Infarto del Miocardio/terapia , Recurrencia
6.
Blood ; 143(16): 1656-1669, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38295333

RESUMEN

ABSTRACT: Autologous stem cell transplantation (ASCT) is the standard of care consolidation therapy for eligible patients with myeloma but most patients eventually progress, an event associated with features of immune escape. Novel approaches to enhance antimyeloma immunity after ASCT represent a major unmet need. Here, we demonstrate that patient-mobilized stem cell grafts contain high numbers of effector CD8 T cells and immunosuppressive regulatory T cells (Tregs). We showed that bone marrow (BM)-residing T cells are efficiently mobilized during stem cell mobilization (SCM) and hypothesized that mobilized and highly suppressive BM-derived Tregs might limit antimyeloma immunity during SCM. Thus, we performed ASCT in a preclinical myeloma model with or without stringent Treg depletion during SCM. Treg depletion generated SCM grafts containing polyfunctional CD8 T effector memory cells, which dramatically enhanced myeloma control after ASCT. Thus, we explored clinically tractable translational approaches to mimic this scenario. Antibody-based approaches resulted in only partial Treg depletion and were inadequate to recapitulate this effect. In contrast, a synthetic interleukin-2 (IL-2)/IL-15 mimetic that stimulates the IL-2 receptor on CD8 T cells without binding to the high-affinity IL-2Ra used by Tregs efficiently expanded polyfunctional CD8 T cells in mobilized grafts and protected recipients from myeloma progression after ASCT. We confirmed that Treg depletion during stem cell mobilization can mitigate constraints on tumor immunity and result in profound myeloma control after ASCT. Direct and selective cytokine signaling of CD8 T cells can recapitulate this effect and represent a clinically testable strategy to improve responses after ASCT.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Mieloma Múltiple , Humanos , Mieloma Múltiple/patología , Linfocitos T Reguladores , Trasplante de Células Madre Hematopoyéticas/métodos , Movilización de Célula Madre Hematopoyética/métodos , Trasplante Autólogo , Trasplante de Células Madre
7.
Mol Cell ; 69(3): 371-384.e6, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29395061

RESUMEN

SLFN11 sensitizes cancer cells to a broad range of DNA-targeted therapies. Here we show that, in response to replication stress induced by camptothecin, SLFN11 tightly binds chromatin at stressed replication foci via RPA1 together with the replication helicase subunit MCM3. Unlike ATR, SLFN11 neither interferes with the loading of CDC45 and PCNA nor inhibits the initiation of DNA replication but selectively blocks fork progression while inducing chromatin opening across replication initiation sites. The ATPase domain of SLFN11 is required for chromatin opening, replication block, and cell death but not for the tight binding of SLFN11 to chromatin. Replication stress by the CHK1 inhibitor Prexasertib also recruits SLFN11 to nascent replicating DNA together with CDC45 and PCNA. We conclude that SLFN11 is recruited to stressed replication forks carrying extended RPA filaments where it blocks replication by changing chromatin structure across replication sites.


Asunto(s)
Proteínas Nucleares/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Camptotecina , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Cromatina/metabolismo , Daño del ADN , ADN Helicasas/metabolismo , Replicación del ADN/genética , Replicación del ADN/fisiología , ADN de Cadena Simple/genética , ADN de Cadena Simple/metabolismo , Humanos , Proteínas de Mantenimiento de Minicromosoma/metabolismo , Proteínas Nucleares/metabolismo , Pirazinas , Pirazoles , Proteína de Replicación A/metabolismo
8.
Proc Natl Acad Sci U S A ; 120(19): e2221542120, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37126703

RESUMEN

Laboratory models are critical to basic and translational microbiology research. Models serve multiple purposes, from providing tractable systems to study cell biology to allowing the investigation of inaccessible clinical and environmental ecosystems. Although there is a recognized need for improved model systems, there is a gap in rational approaches to accomplish this goal. We recently developed a framework for assessing the accuracy of microbial models by quantifying how closely each gene is expressed in the natural environment and in various models. The accuracy of the model is defined as the percentage of genes that are similarly expressed in the natural environment and the model. Here, we leverage this framework to develop and validate two generalizable approaches for improving model accuracy, and as proof of concept, we apply these approaches to improve models of Pseudomonas aeruginosa infecting the cystic fibrosis (CF) lung. First, we identify two models, an in vitro synthetic CF sputum medium model (SCFM2) and an epithelial cell model, that accurately recapitulate different gene sets. By combining these models, we developed the epithelial cell-SCFM2 model which improves the accuracy of over 500 genes. Second, to improve the accuracy of specific genes, we mined publicly available transcriptome data, which identified zinc limitation as a cue present in the CF lung and absent in SCFM2. Induction of zinc limitation in SCFM2 resulted in accurate expression of 90% of P. aeruginosa genes. These approaches provide generalizable, quantitative frameworks for microbiological model improvement that can be applied to any system of interest.


Asunto(s)
Infecciones Bacterianas , Fibrosis Quística , Infecciones por Pseudomonas , Humanos , Ecosistema , Infecciones por Pseudomonas/microbiología , Transcriptoma , Células Epiteliales/microbiología , Medios de Cultivo/metabolismo , Fibrosis Quística/microbiología , Pseudomonas aeruginosa/genética , Esputo/microbiología
9.
Mol Biol Evol ; 41(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38285634

RESUMEN

Rainforest hunter-gatherers from Southeast Asia are characterized by specific morphological features including a particularly dark skin color (D), short stature (S), woolly hair (W), and the presence of steatopygia (S)-fat accumulation localized in the hips (DSWS phenotype). Based on previous evidence in the Andamanese population, we first characterized signatures of adaptive natural selection around the calcium-sensing receptor gene in Southeast Asian rainforest groups presenting the DSWS phenotype and identified the R990G substitution (rs1042636) as a putative adaptive variant for experimental follow-up. Although the calcium-sensing receptor has a critical role in calcium homeostasis by directly regulating the parathyroid hormone secretion, it is expressed in different tissues and has been described to be involved in many biological functions. Previous works have also characterized the R990G substitution as an activating polymorphism of the calcium-sensing receptor associated with hypocalcemia. Therefore, we generated a knock-in mouse for this substitution and investigated organismal phenotypes that could have become adaptive in rainforest hunter-gatherers from Southeast Asia. Interestingly, we found that mouse homozygous for the derived allele show not only lower serum calcium concentration but also greater body weight and fat accumulation, probably because of enhanced preadipocyte differentiation and lipolysis impairment resulting from the calcium-sensing receptor activation mediated by R990G. We speculate that such differential features in humans could have facilitated the survival of hunter-gatherer groups during periods of nutritional stress in the challenging conditions of the Southeast Asian tropical rainforests.


Asunto(s)
Polimorfismo Genético , Receptores Sensibles al Calcio , Animales , Humanos , Ratones , Calcio , Fenotipo , Receptores Sensibles al Calcio/genética , Selección Genética
10.
Am J Hum Genet ; 109(5): 953-960, 2022 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-35460607

RESUMEN

We report an autosomal recessive, multi-organ tumor predisposition syndrome, caused by bi-allelic loss-of-function germline variants in the base excision repair (BER) gene MBD4. We identified five individuals with bi-allelic MBD4 variants within four families and these individuals had a personal and/or family history of adenomatous colorectal polyposis, acute myeloid leukemia, and uveal melanoma. MBD4 encodes a glycosylase involved in repair of G:T mismatches resulting from deamination of 5'-methylcytosine. The colorectal adenomas from MBD4-deficient individuals showed a mutator phenotype attributable to mutational signature SBS1, consistent with the function of MBD4. MBD4-deficient polyps harbored somatic mutations in similar driver genes to sporadic colorectal tumors, although AMER1 mutations were more common and KRAS mutations less frequent. Our findings expand the role of BER deficiencies in tumor predisposition. Inclusion of MBD4 in genetic testing for polyposis and multi-tumor phenotypes is warranted to improve disease management.


Asunto(s)
Poliposis Adenomatosa del Colon , Neoplasias Colorrectales , Neoplasias de la Úvea , Poliposis Adenomatosa del Colon/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Endodesoxirribonucleasas/genética , Predisposición Genética a la Enfermedad , Células Germinativas/patología , Mutación de Línea Germinal/genética , Humanos , Neoplasias de la Úvea/genética
11.
Trends Immunol ; 43(5): 355-365, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35370095

RESUMEN

The essentially monomorphic human antigen presentation molecule HLA-E is an interesting candidate target to enable vaccination irrespective of genetic diversity. Predictive HLA-E peptide-binding motifs have been refined to facilitate HLA-E peptide discovery. HLA-E can accommodate structurally divergent peptides of both self and microbial origin. Intracellular processing and presentation pathways for peptides by HLA-E for T cell receptor (TCR) recognition remain to be elucidated. Recent studies show that, unlike canonical peptides, inhibition of the transporter associated with antigen presentation (TAP) is essential to allow HLA-E antigen presentation in cytomegalovirus (CMV) infection and possibly also of other non-canonical peptides. We propose three alternative and TAP-independent MHC-E antigen-presentation pathways, including for Mycobacterium tuberculosis infections. These insights may help in designing potential HLA-E targeting vaccines against tumors and pathogens.


Asunto(s)
Presentación de Antígeno , Tuberculosis , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Proteínas de Transporte de Membrana , Péptidos , Vacunación
12.
Brain ; 147(4): 1264-1277, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-37939785

RESUMEN

Bottom-of-sulcus dysplasia (BOSD) is increasingly recognized as a cause of drug-resistant, surgically-remediable, focal epilepsy, often in seemingly MRI-negative patients. We describe the clinical manifestations, morphological features, localization patterns and genetics of BOSD, with the aims of improving management and understanding pathogenesis. We studied 85 patients with BOSD diagnosed between 2005-2022. Presenting seizure and EEG characteristics, clinical course, genetic findings and treatment response were obtained from medical records. MRI (3 T) and 18F-FDG-PET scans were reviewed systematically for BOSD morphology and metabolism. Histopathological analysis and tissue genetic testing were performed in 64 operated patients. BOSD locations were transposed to common imaging space to study anatomical location, functional network localization and relationship to normal MTOR gene expression. All patients presented with stereotyped focal seizures with rapidly escalating frequency, prompting hospitalization in 48%. Despite 42% patients having seizure remissions, usually with sodium channel blocking medications, most eventually became drug-resistant and underwent surgery (86% seizure-free). Prior developmental delay was uncommon but intellectual, language and executive dysfunction were present in 24%, 48% and 29% when assessed preoperatively, low intellect being associated with greater epilepsy duration. BOSDs were missed on initial MRI in 68%, being ultimately recognized following repeat MRI, 18F-FDG-PET or image postprocessing. MRI features were grey-white junction blurring (100%), cortical thickening (91%), transmantle band (62%), increased cortical T1 signal (46%) and increased subcortical FLAIR signal (26%). BOSD hypometabolism was present on 18F-FDG-PET in 99%. Additional areas of cortical malformation or grey matter heterotopia were present in eight patients. BOSDs predominated in frontal and pericentral cortex and related functional networks, mostly sparing temporal and occipital cortex, and limbic and visual networks. Genetic testing yielded pathogenic mTOR pathway variants in 63% patients, including somatic MTOR variants in 47% operated patients and germline DEPDC5 or NPRL3 variants in 73% patients with familial focal epilepsy. BOSDs tended to occur in regions where the healthy brain normally shows lower MTOR expression, suggesting these regions may be more vulnerable to upregulation of MTOR activity. Consistent with the existing literature, these results highlight (i) clinical features raising suspicion of BOSD; (ii) the role of somatic and germline mTOR pathway variants in patients with sporadic and familial focal epilepsy associated with BOSD; and (iii) the role of 18F-FDG-PET alongside high-field MRI in detecting subtle BOSD. The anatomical and functional distribution of BOSDs likely explain their seizure, EEG and cognitive manifestations and may relate to relative MTOR expression.


Asunto(s)
Epilepsia Refractaria , Epilepsias Parciales , Síndromes Epilépticos , Malformaciones del Desarrollo Cortical , Humanos , Fluorodesoxiglucosa F18 , Malformaciones del Desarrollo Cortical/genética , Epilepsias Parciales/diagnóstico por imagen , Epilepsias Parciales/genética , Epilepsias Parciales/patología , Epilepsia Refractaria/diagnóstico por imagen , Epilepsia Refractaria/genética , Epilepsia Refractaria/cirugía , Imagen por Resonancia Magnética/métodos , Convulsiones/complicaciones , Serina-Treonina Quinasas TOR , Proteínas Activadoras de GTPasa/genética
13.
Immunol Rev ; 301(1): 30-47, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33529407

RESUMEN

Vaccination strategies against mycobacteria, focusing mostly on classical T- and B-cells, have shown limited success, encouraging the addition of alternative targets. Classically restricted T-cells recognize antigens presented via highly polymorphic HLA class Ia and class II molecules, while donor-unrestricted T-cells (DURTs), with few exceptions, recognize ligands via genetically conserved antigen presentation molecules. Consequently, DURTs can respond to the same ligands across diverse human populations. DURTs can be activated either through cognate TCR ligation or via bystander cytokine signaling. TCR-driven antigen-specific activation of DURTs occurs upon antigen presentation via non-polymorphic molecules such as HLA-E, CD1, MR1, and butyrophilin, leading to the activation of HLA-E-restricted T-cells, CD1-restricted T-cells, mucosal-associated invariant T-cells (MAITs), and TCRγδ T-cells, respectively. NK cells and innate lymphoid cells (ILCs), which lack rearranged TCRs, are activated through other receptor-triggering pathways, or can be engaged through bystander cytokines, produced, for example, by activated antigen-specific T-cells or phagocytes. NK cells can also develop trained immune memory and thus could represent cells of interest to mobilize by novel vaccines. In this review, we summarize the latest findings regarding the contributions of DURTs, NK cells, and ILCs in anti-M tuberculosis, M leprae, and non-tuberculous mycobacterial immunity and explore possible ways in which they could be harnessed through vaccines and immunotherapies to improve protection against Mtb.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Humanos , Inmunidad Innata , Células Asesinas Naturales , Receptores de Antígenos de Linfocitos T gamma-delta
14.
J Biol Chem ; 299(11): 105292, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37769710

RESUMEN

S100 proteins are a subfamily of EF-hand calcium-binding proteins found primarily in vertebrate animals. They are distinguished by binding of transition metals and functioning in both the intracellular and extracellular milieu. S100A7 functions in the protection of the skin and mucous membranes and is a biomarker in inflammatory skin disease. A recent study of Neisseria gonorrhoeae infection revealed that human but not murine S100A7 could be used to evade host nutritional immunity. To understand the molecular basis for this difference, we carried out a comparative analysis of the physical and structural properties of human and murine S100A7. The X-ray crystal structure of Ca2+-loaded mouse S100A7 (mS100A7) was determined to 1.69 Å resolution, and Ca2+-induced conformational changes were assessed by NMR. Unlike human S100A7 (hS100A7), which exhibits conformational changes in response to binding of Ca2+, no significant changes in mS100A7 were detected. Dynamic light scattering, circular dichroism, and a competition chelator assay were used to compare the Zn2+ affinity and the effects of ion binding on mS100A7 versus hS100A7. Alignment of their sequences revealed a substantial difference in the C-terminal region, which is an important mediator of protein-protein interactions, suggesting a rationale for the specificity of N. gonorrhoeae for hS100A7. These data, along with more detailed analysis of S100A7 sequence conservation across different species, support the proposal that, although hS100A7 is highly conserved in many mammals, the murine protein is a distinct ortholog. Our results highlight the potential limitations of using mouse models for studying bacterial infections in humans.


Asunto(s)
Dermatitis , Gonorrea , Animales , Humanos , Ratones , Proteínas de Unión al Calcio/metabolismo , Mamíferos/metabolismo , Proteína A7 de Unión a Calcio de la Familia S100 , Proteínas S100/genética , Proteínas S100/metabolismo , Zinc/metabolismo
15.
Int J Obes (Lond) ; 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38879729

RESUMEN

BACKGROUND AND OBJECTIVES: Dual amylin and calcitonin receptor agonists (DACRAs) are therapeutic candidates in the treatment of obesity with beneficial effects on weight loss superior to suppression of food intake. Hence, suggesting effects on energy expenditure by possibly targeting mitochondria in metabolically active tissue. METHODS: Male rats with HFD-induced obesity received a DACRA, KBP-336, every third day for 8 weeks. Upon study end, mitochondrial respiratory capacity (MRC), - enzyme activity, - transcriptional factors, and -content were measured in perirenal (pAT) and inguinal adipose tissue. A pair-fed group was included to examine food intake-independent effects of KBP-336. RESULTS: A vehicle-corrected weight loss (23.4 ± 2.8%) was achieved with KBP-336, which was not observed to the same extent with the food-restricted weight loss (12.4 ± 2.8%) (P < 0.001). Maximal coupled respiration supported by carbohydrate and lipid-linked substrates was increased after KBP-336 treatment independent of food intake in pAT (P < 0.01). Moreover, oligomycin-induced leak respiration and the activity of citrate synthase and ß-hydroxyacetyl-CoA-dehydrogenase were increased with KBP-336 treatment (P < 0.05). These effects occurred without changes in mitochondrial content in pAT. CONCLUSIONS: These findings demonstrate favorable effects of KBP-336 on MRC in adipose tissue, indicating an increased energy expenditure and capacity to utilize fatty acids. Thus, providing more mechanistic insight into the DACRA-induced weight loss.

16.
Immunity ; 43(5): 945-58, 2015 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-26588780

RESUMEN

Epithelial cells orchestrate pulmonary homeostasis and pathogen defense and play a crucial role in the initiation of allergic immune responses. Maintaining the balance between homeostasis and inappropriate immune activation and associated pathology is particularly complex at mucosal sites that are exposed to billions of potentially antigenic particles daily. We demonstrated that epithelial cell-derived cytokine TGF-ß had a central role in the generation of the pulmonary immune response. Mice that specifically lacked epithelial cell-derived TGF-ß1 displayed a reduction in type 2 innate lymphoid cells (ILCs), resulting in suppression of interleukin-13 and hallmark features of the allergic response including airway hyperreactivity. ILCs in the airway lumen were primed to respond to TGF-ß by expressing the receptor TGF-ßRII and ILC chemoactivity was enhanced by TGF-ß. These data demonstrate that resident epithelial cells instruct immune cells, highlighting the central role of the local environmental niche in defining the nature and magnitude of immune reactions.


Asunto(s)
Células Epiteliales/inmunología , Inmunidad Innata/inmunología , Pulmón/inmunología , Linfocitos/inmunología , Factor de Crecimiento Transformador beta1/inmunología , Animales , Células Cultivadas , Interleucina-13/inmunología , Ratones , Proteínas Serina-Treonina Quinasas/inmunología , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/inmunología , Hipersensibilidad Respiratoria/inmunología
17.
Faraday Discuss ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38766993

RESUMEN

Collisions of optically centrifuged CO2 molecules with J = 244-282 (Erot = 22 800-30 300 cm-1) are investigated with high-resolution transient IR absorption spectroscopy to reveal collisional and orientational phenomena of molecules with hyper-thermal rotational energies. The optical centrifuge is a non-resonant optical excitation technique that uses ultrafast, 800 nm chirped pulses to drive molecules to extreme rotational states through sequential Raman transitions. The extent of rotational excitation is controlled by tuning the optical bandwidth of the excitation pulses. Frequencies of 30 R-branch ν3 fundamental IR probe transitions are measured for the J = 186-282 states of CO2, expanding beyond previously reported IR transitions up to J = 128. The optically centrifuged molecules have oriented angular momentum and unidirectional rotation. Polarization-sensitive transient IR absorption of individual rotational states of optically centrifuged molecules and their collision products reveals information about collisional energy transfer, relaxation kinetics, and dynamics of rotation-to-translation energy transfer. The transient IR probe also measures the extent of polarization anisotropy. Rotational energy transfer for lower energy molecules is discussed in terms of statistical models and a comparison highlights the role of increasing energy gap with J and angular momentum of the optically centrifuged molecules.

18.
BMC Neurol ; 24(1): 65, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38360580

RESUMEN

BACKGROUND: In patients with aneurysmal subarachnoid hemorrhage suitable for endovascular coiling and neurosurgical clip-reconstruction, the aneurysm treatment decision-making process could be improved by considering heterogeneity of treatment effect and durability of treatment. We aimed to develop and validate a tool to predict individualized treatment benefit of endovascular coiling compared to neurosurgical clip-reconstruction. METHODS: We used randomized data (International Subarachnoid Aneurysm Trial, n = 2143) to develop models to predict 2-month functional outcome and to predict time-to-rebleed-or-retreatment. We modeled for heterogeneity of treatment effect by adding interaction terms of treatment with prespecified predictors and with baseline risk of the outcome. We predicted outcome with both treatments and calculated absolute treatment benefit. We described the patient characteristics of patients with ≥ 5% point difference in the predicted probability of favorable functional outcome (modified Rankin Score 0-2) and of no rebleed or retreatment within 10 years. Model performance was expressed with the c-statistic and calibration plots. We performed bootstrapping and leave-one-cluster-out cross-validation and pooled cluster-specific c-statistics with random effects meta-analysis. RESULTS: The pooled c-statistics were 0.72 (95% CI: 0.69-0.75) for the prediction of 2-month favorable functional outcome and 0.67 (95% CI: 0.63-0.71) for prediction of no rebleed or retreatment within 10 years. We found no significant interaction between predictors and treatment. The average predicted benefit in favorable functional outcome was 6% (95% CI: 3-10%) in favor of coiling, but 11% (95% CI: 9-13%) for no rebleed or retreatment in favor of clip-reconstruction. 134 patients (6%), young and in favorable clinical condition, had negligible functional outcome benefit of coiling but had a ≥ 5% point benefit of clip-reconstruction in terms of durability of treatment. CONCLUSIONS: We show that young patients in favorable clinical condition and without extensive vasospasm have a negligible benefit in functional outcome of endovascular coiling - compared to neurosurgical clip-reconstruction - while at the same time having a substantially lower probability of retreatment or rebleeding from neurosurgical clip-reconstruction - compared to endovascular coiling. The SHARP prediction tool ( https://sharpmodels.shinyapps.io/sharpmodels/ ) could support and incentivize a multidisciplinary discussion about aneurysm treatment decision-making by providing individualized treatment benefit estimates.


Asunto(s)
Aneurisma Roto , Embolización Terapéutica , Procedimientos Endovasculares , Aneurisma Intracraneal , Hemorragia Subaracnoidea , Humanos , Hemorragia Subaracnoidea/cirugía , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/cirugía , Resultado del Tratamiento , Aneurisma Roto/complicaciones , Aneurisma Roto/cirugía
19.
J Immunol ; 209(8): 1555-1565, 2022 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-36096642

RESUMEN

Tuberculosis (TB) remains one of the deadliest infectious diseases worldwide, posing great social and economic burden to affected countries. Novel vaccine approaches are needed to increase protective immunity against the causative agent Mycobacterium tuberculosis (Mtb) and to reduce the development of active TB disease in latently infected individuals. Donor-unrestricted T cell responses represent such novel potential vaccine targets. HLA-E-restricted T cell responses have been shown to play an important role in protection against TB and other infections, and recent studies have demonstrated that these cells can be primed in vitro. However, the identification of novel pathogen-derived HLA-E binding peptides presented by infected target cells has been limited by the lack of accurate prediction algorithms for HLA-E binding. In this study, we developed an improved HLA-E binding peptide prediction algorithm and implemented it to identify (to our knowledge) novel Mtb-derived peptides with capacity to induce CD8+ T cell activation and that were recognized by specific HLA-E-restricted T cells in Mycobacterium-exposed humans. Altogether, we present a novel algorithm for the identification of pathogen- or self-derived HLA-E-presented peptides.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Antígenos Bacterianos , Linfocitos T CD8-positivos , Epítopos de Linfocito T , Antígenos de Histocompatibilidad Clase I , Humanos , Péptidos , Antígenos HLA-E
20.
Epilepsy Behav ; 154: 109706, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38518671

RESUMEN

Non-human primates (NHPs) have played a crucial role in our understanding of epilepsy, given their striking similarities with humans. Through their use, we have gained a deeper understanding of the neurophysiology and pathophysiology of epileptic seizures, and they have proven invaluable allies in developing anti-seizure therapies. This review explores the history of NHPs as natural models of epilepsy, discusses the findings obtained after exposure to various chemoconvulsant drugs and focal electrical stimulation protocols that helped uncover important mechanisms related to epilepsy, examines diverse treatments to prevent and manage epilepsy, and addresses essential ethical issues in research. In this review, we aim to emphasize the important role of NHPs in epilepsy research and summarize the benefits and challenges associated with their use as models.


Asunto(s)
Epilepsia , Primates , Animales , Humanos , Modelos Animales de Enfermedad , Epilepsia/fisiopatología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA