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1.
J Med Chem ; 67(14): 11827-11840, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39013156

RESUMO

Fibroblast activation protein (FAP) has attracted considerable attention as a possible target for the radiotherapy of solid tumors. Unfortunately, initial efforts to treat solid tumors with FAP-targeted radionuclides have yielded only modest clinical responses, suggesting that further improvements in the molecular design of FAP-targeted radiopharmaceutical therapies (RPT) are warranted. In this study, we report several advances on the previously described FAP6 radioligand that increase tumor retention and accelerate healthy tissue clearance. Seven FAP6 derivatives with different linkers or albumin binders were synthesized, radiolabeled, and investigated for their effects on binding and cellular uptake. The radioligands were then characterized in 4T1 tumor-bearing Balb/c mice using both single-photon emission computed tomography (SPECT) and ex vivo biodistribution analyses to identify the conjugate with the best tumor retention and tumor-to-healthy organ ratios. The results reveal an optimized FAP6 radioligand that exhibits efficacy and safety properties that potentially justify its translation into the clinic.


Assuntos
Endopeptidases , Gelatinases , Proteínas de Membrana , Camundongos Endogâmicos BALB C , Compostos Radiofarmacêuticos , Serina Endopeptidases , Tomografia Computadorizada de Emissão de Fóton Único , Animais , Endopeptidases/metabolismo , Camundongos , Distribuição Tecidual , Proteínas de Membrana/metabolismo , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/farmacologia , Compostos Radiofarmacêuticos/uso terapêutico , Gelatinases/metabolismo , Feminino , Serina Endopeptidases/metabolismo , Linhagem Celular Tumoral , Humanos , Ligantes
4.
bioRxiv ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-39026869

RESUMO

Photoprotective melanins in the skin are synthesised by epidermal melanocytes within specialised lysosome-related organelles called melanosomes. Melanosomes coexist with lysosomes; thus, melanocytes employ specific trafficking machineries to ensure correct cargo delivery to either the endolysosomal system or maturing melanosomes. Mutations in some of the protein complexes required for melanogenic cargo delivery, such as biogenesis of lysosome-related organelles complex 1 (BLOC-1), result in hypopigmentation due to mistrafficking of cargo to endolysosomes. We show that hypopigmented BLOC-1-deficient melanocytes retain melanogenic capacity that can be enhanced by treatment with cAMP elevating agents despite the mislocalisation of melanogenic proteins. The melanin formed in BLOC-1-deficient melanocytes is not generated in melanosomes but rather within late endosomes/lysosomes to which some cargoes mislocalise. Although these organelles generally are acidic, a cohort of late endosomes/lysosomes have a sufficiently neutral pH to facilitate melanogenesis, perhaps due to mislocalised melanosomal transporters and melanogenic enzymes. Modulation of the pH of late endosomes/lysosomes by genetic manipulation or via treatment with lysosomotropic agents significantly enhances the melanin content of BLOC-1-deficient melanocytes. Our data suggest that upregulation of mistargeted cargoes can facilitate reprogramming of a subset of endolysosomes to generate some functions of lysosome-related organelles.

5.
Evolution ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38981009

RESUMO

Island biotas provide unparalleled opportunities to examine evolutionary processes. Founder effects and bottlenecks, for example, typically decrease genetic diversity in island populations, while selection for reduced dispersal can increase population structure. Given that support for these generalities mostly comes from single-species analyses, assemblage-level comparisons are needed to clarify how (i) colonization affects the gene pools of interacting insular organisms, and (ii) patterns of genetic differentiation vary within assemblages of organisms. Here, we use genome-wide sequence data from ultraconserved elements (UCEs) to compare genetic diversity and population structure of mainland and island populations of nine ant species in coastal southern California. As expected, island populations (from Santa Cruz Island) had lower expected heterozygosity and Watterson's theta compared to mainland populations (from the Lompoc Valley). Island populations, however, exhibited smaller genetic distances among samples, indicating less population subdivision. Within the focal assemblage, pairwise Fst values revealed pronounced interspecific variation in mainland-island differentiation, which increases with gyne body size. Our results reveal population differences across an assemblage of interacting species, and illuminate general patterns of insularization in ants. Compared to single-species studies, our analysis of nine conspecific population pairs from the same island-mainland system offers a powerful approach to studying fundamental evolutionary processes.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38963736

RESUMO

Cluster analysis plays an indispensable role in machine learning and data mining. Learning a good data representation is crucial for clustering algorithms. Recently, deep clustering (DC), which can learn clustering-friendly representations using deep neural networks (DNNs), has been broadly applied in a wide range of clustering tasks. Existing surveys for DC mainly focus on the single-view fields and the network architectures, ignoring the complex application scenarios of clustering. To address this issue, in this article, we provide a comprehensive survey for DC in views of data sources. With different data sources, we systematically distinguish the clustering methods in terms of methodology, prior knowledge, and architecture. Concretely, DC methods are introduced according to four categories, i.e., traditional single-view DC, semi-supervised DC, deep multiview clustering (MVC), and deep transfer clustering. Finally, we discuss the open challenges and potential future opportunities in different fields of DC.

7.
Hepatol Commun ; 8(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38967582

RESUMO

BACKGROUND: Fibrosis-4 (FIB4) is a recommended noninvasive test to assess hepatic fibrosis among patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we used FIB4 trajectory over time (ie, "slope" of FIB4) as a surrogate marker of liver fibrosis progression and examined if FIB4 slope is associated with clinical and genetic factors among individuals with clinically defined MASLD within the Million Veteran Program Cohort. METHODS: In this retrospective cohort study, FIB4 slopes were estimated through linear regression for participants with clinically defined MASLD and FIB4 <2.67 at baseline. FIB4 slope was correlated with demographic parameters and clinical outcomes using logistic regression and Cox proportional hazard models. FIB4 slope as a quantitative phenotype was used in a genome-wide association analysis in ancestry-specific analysis and multiancestry meta-analysis using METAL. RESULTS: FIB4 slopes, generated from 98,361 subjects with MASLD (16,045 African, 74,320 European, and 7996 Hispanic), showed significant associations with sex, ancestry, and cardiometabolic risk factors (p < 0.05). FIB4 slopes also correlated strongly with hepatic outcomes and were independently associated with time to cirrhosis. Five genetic loci showed genome-wide significant associations (p < 5 × 10-8) with FIB4 slope among European ancestry subjects, including 2 known (PNPLA3 and TM6SF2) and 3 novel loci (TERT 5.1 × 10-11; LINC01088, 3.9 × 10-8; and MRC1, 2.9 × 10-9). CONCLUSIONS: Linear trajectories of FIB4 correlated significantly with time to progression to cirrhosis, with liver-related outcomes among individuals with MASLD and with known and novel genetic loci. FIB4 slope may be useful as a surrogate measure of fibrosis progression.


Assuntos
Progressão da Doença , Estudo de Associação Genômica Ampla , Cirrose Hepática , Humanos , Masculino , Feminino , Cirrose Hepática/genética , Cirrose Hepática/complicações , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Idoso , Proteínas de Membrana/genética , Fígado Gorduroso/genética , Biomarcadores , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/complicações , Aciltransferases , Fosfolipases A2 Independentes de Cálcio
8.
Nat Commun ; 15(1): 5652, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969659

RESUMO

Abdominal aortic aneurysm has a high heritability and often co-occurs with other cardiometabolic disorders, suggesting shared genetic susceptibility. We investigate this commonality leveraging recent GWAS studies of abdominal aortic aneurysm and 32 cardiometabolic traits. We find significant genetic correlations between abdominal aortic aneurysm and 21 of the cardiometabolic traits investigated, including causal relationships with coronary artery disease, hypertension, lipid traits, and blood pressure. For each trait pair, we identify shared causal variants, genes, and pathways, revealing that cholesterol metabolism and inflammation are shared most prominently. Additionally, we show the tissue and cell type specificity in the shared signals, with strong enrichment across traits in the liver, arteries, adipose tissues, macrophages, adipocytes, and fibroblasts. Finally, we leverage drug-gene databases to identify several lipid-lowering drugs and antioxidants with high potential to treat abdominal aortic aneurysm with comorbidities. Our study provides insight into the shared genetic mechanism between abdominal aortic aneurysm and cardiometabolic traits, and identifies potential targets for pharmacological intervention.


Assuntos
Aneurisma da Aorta Abdominal , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Inflamação , Metabolismo dos Lipídeos , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Humanos , Metabolismo dos Lipídeos/genética , Inflamação/genética , Inflamação/metabolismo , Polimorfismo de Nucleotídeo Único , Hipertensão/genética , Doença da Artéria Coronariana/genética
9.
medRxiv ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39006437

RESUMO

Background: Breastfeeding has been associated with maternal and infant health benefits but has been inversely associated with body mass index (BMI) prepartum. Breastfeeding and BMI are both linked to socioeconomic factors. Methods: Data from parous female participants with available breastfeeding information from the Million Veteran Program cohort was included. BMI at enrollment and earliest BMI available were extracted, and polygenic scores (PGS) for BMI were calculated. We modeled breastfeeding for one month or more as a function of BMI at enrollment; earliest BMI where available pre-pregnancy; and PGS for BMI. We conducted Mendelian randomization for breastfeeding initiation using PGS as an instrumental variable. Results: A higher BMI predicted a lower likelihood of breastfeeding for one month or more in all analyses. A +5 kg/m 2 BMI pre-pregnancy was associated with a 24% reduced odds of breastfeeding, and a +5 kg/m 2 genetically predicted BMI was associated with a 17% reduced odds of breastfeeding. Conclusions: BMI predicts a lower likelihood of breastfeeding for one month or longer. Given the high success of breastfeeding initiation regardless of BMI in supportive environments as well as potential health benefits, patients with elevated BMI may benefit from additional postpartum breastfeeding support.

11.
Adv Sci (Weinh) ; : e2401077, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039808

RESUMO

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is a major global health concern, particularly affecting those with weakened immune systems, including the elderly. CD4+ T cell response is crucial for immunity against M.tb, but chronic infections and aging can lead to T cell exhaustion and senescence, worsening TB disease. Mitochondrial dysfunction, prevalent in aging and chronic diseases, disrupts cellular metabolism, increases oxidative stress, and impairs T-cell functions. This study investigates the effect of mitochondrial transplantation (mito-transfer) on CD4+ T cell differentiation and function in aged mouse models and human CD4+ T cells from elderly individuals. Mito-transfer in naïve CD4+ T cells is found to promote protective effector and memory T cell generation during M.tb infection in mice. Additionally, it improves elderly human T cell function by increasing mitochondrial mass and altering cytokine production, thereby reducing markers of exhaustion and senescence. These findings suggest mito-transfer as a novel approach to enhance aged CD4+ T cell functionality, potentially benefiting immune responses in the elderly and chronic TB patients. This has broader implications for diseases where mitochondrial dysfunction contributes to T-cell exhaustion and senescence.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38990709

RESUMO

Background: The Surgical Infection Society (SIS) published evidence-based guidelines for the management of intra-abdominal infection (IAI) in 1992, 2002, 2010, and 2017. Here, we present the most recent guideline update based on a systematic review of current literature. Methods: The writing group, including current and former members of the SIS Therapeutics and Guidelines Committee and other individuals with content or guideline expertise within the SIS, working with a professional librarian, performed a systematic review using PubMed/Medline, the Cochrane Library, Embase, and Web of Science from 2016 until February 2024. Keyword descriptors combined "surgical site infections" or "intra-abdominal infections" in adults limited to randomized controlled trials, systematic reviews, and meta-analyses. Additional relevant publications not in the initial search but identified during literature review were included. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system was utilized to evaluate the evidence. The strength of each recommendation was rated strong (1) or weak (2). The quality of the evidence was rated high (A), moderate (B), or weak (C). The guideline contains new recommendations and updates to recommendations from previous IAI guideline versions. Final recommendations were developed by an iterative process. All writing group members voted to accept or reject each recommendation. Results: This updated evidence-based guideline contains recommendations from the SIS for the treatment of adult patients with IAI. Evidence-based recommendations were developed for antimicrobial agent selection, timing, route of administration, duration, and de-escalation; timing of source control; treatment of specific pathogens; treatment of specific intra-abdominal disease processes; and implementation of hospital-based antimicrobial agent stewardship programs. Summary: This document contains the most up-to-date recommendations from the SIS on the prevention and management of IAI in adult patients.

13.
J Rheumatol ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009384

RESUMO

At the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting, members were updated on a number of ongoing activities during the key project update session. These activities included the Axial Involvement in Psoriatic Arthritis (AXIS) cohort, the Axial Psoriatic Arthritis Molecular and Clinical Characterization study, the Diagnostic Ultrasound Enthesitis Tool (DUET) study, the Sex- and Gender-Based Analysis of the Effectiveness of Advanced Therapies in Psoriatic Arthritis (SAGE-PsA) study, the Health Initiatives in Psoriasis and Psoriatic Arthritis Consortium European States (HIPPOCRATES), the GRAPPA slide library, and the GRAPPA treatment recommendations.

14.
J Rheumatol ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009388

RESUMO

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) started in August 2003 with 40 initial participants and celebrated its 20th anniversary with 1036 members, many of whom attended the annual meeting in Dublin, Ireland, on July 15 to 17, 2023. GRAPPA arose from a need experienced by psoriatic arthritis (PsA) and psoriasis (PsO) investigators to meet to address questions related to psoriatic disease (PsD). Though other groups were meeting at the time to classify and discuss PsA, GRAPPA arose from a desire to include international clinical and investigational researchers of both dermatology and rheumatology. The organization has built awareness of PsO and PsA, developed and validated research assessment tools to measure clinical status and disease outcomes, published multiple treatment recommendations, supported basic and clinical research on PsD pathophysiology, fostered interactions across research fields, and educated the future generation of PsO and PsA researchers. The group continues to focus on major priorities affecting patients with PsD and will continue evolving in the next decades.

15.
Nanoscale Adv ; 6(15): 3923-3933, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39050949

RESUMO

Subcritical water extraction (SWE) is an emerging green and efficient hydrothermal technology, that offers superior performance in active material extraction, scalability, and reduction of harsh process chemicals, in biomass conversion. Regarding biomaterials, traditional isolation methods for cellulose nanocrystals (CNCs) are reliant on harsh chemicals (i.e., strong acid), which are expensive with little to no recyclability. This paper explores SWE as a nanotechnology platform to produce CNCs under the principle of "less is more" - by using low content (1 wt%) of phosphoric acid under subcritical conditions. Acid-catalyzed digestion of woody biomass afforded CNCs desirable physico-chemical features that are dependent on the process parameters (temperature, pressure, and time). Process temperature had a major impact on the reduction of fiber sizes (macroscale to nanoscale), fiber degradation, and fiber coloration (white to black). Electron microscopy revealed rod-like structures, with varying particle size distribution (100-500 nm), dominated by process time. However, colloidal stability was low (versus acid-hydrolyzed CNCs) due to the low charges on the surface of CNCs. Interestingly, vibrational spectroscopy reveals the effect of process pressure on biomass conversion to CNCs (with cellulose I structure) evidenced by Raman spectroscopy and solid-state fluorometry. The produced (bio)nanomaterials possessed a degree of crystallinity (∼70%) comparable to those produced via acid hydrolysis, with higher thermal stability, enhancing their applicability over a wide range of heat-intensive processes required for nanocomposite applications in biomedical and automotive industries, among others.

16.
Alzheimers Dement ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041435

RESUMO

INTRODUCTION: Tau-positron emission tomography (PET) outcome data of patients with Alzheimer's disease (AD) cannot currently be meaningfully compared or combined when different tracers are used due to differences in tracer properties, instrumentation, and methods of analysis. METHODS: Using head-to-head data from five cohorts with tau PET radiotracers designed to target tau deposition in AD, we tested a joint propagation model (JPM) to harmonize quantification (units termed "CenTauR" [CTR]). JPM is a statistical model that simultaneously models the relationships between head-to-head and anchor point data. JPM was compared to a linear regression approach analogous to the one used in the amyloid PET Centiloid scale. RESULTS: A strong linear relationship was observed between CTR values across brain regions. Using the JPM approach, CTR estimates were similar to, but more accurate than, those derived using the linear regression approach. DISCUSSION: Preliminary findings using the JPM support the development and adoption of a universal scale for tau-PET quantification. HIGHLIGHTS: Tested a novel joint propagation model (JPM) to harmonize quantification of tau PET. Units of common scale are termed "CenTauRs". Tested a Centiloid-like linear regression approach. Using five cohorts with head-to-head tau PET, JPM outperformed linearregressionbased approach. Strong linear relationship was observed between CenTauRs values across brain regions.

17.
Diabetes Care ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954432

RESUMO

OBJECTIVE: To examine changes in glomerular hyperfiltration and other measures of kidney function in youth with type 2 diabetes treated with dulaglutide or placebo. RESEARCH DESIGN AND METHODS: Post hoc analysis was performed on kidney laboratory data from 154 youths (age 10-18 years) with type 2 diabetes enrolled in a completed placebo-controlled glycemic control trial of dulaglutide. RESULTS: Mean estimated glomerular filtration rate (eGFR) decreased from baseline to 26 weeks in participants treated with dulaglutide versus placebo (-5.8 vs. -0.1 mL/min/1.73 m2; P = 0.016). Decreases in eGFR were observed primarily in participants with baseline glomerular hyperfiltration. At 26 weeks, the prevalence of both glomerular hyperfiltration and proteinuria increased with placebo but decreased with dulaglutide (P = 0.014 and 0.004 vs. placebo, respectively). CONCLUSIONS: Dulaglutide was associated with attenuated glomerular hyperfiltration and proteinuria in youth with type 2 diabetes. The impact of these changes on the risk of diabetic kidney disease is unclear.

18.
Int J Surg ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869970

RESUMO

INTRODUCTION: Despite advanced infection control practices including preoperative antibiotic prophylaxis, surgical site infection (SSI) remains a challenge. This study aimed to test whether local administration of a novel prolonged-release Doxycycline-Polymer-Lipid Encapsulation matriX (D-PLEX) before wound closure, concomitantly with standard of care (SOC), reduces the incidence of incisional SSI after elective abdominal colorectal surgery. MATERIALS AND METHODS: This was a phase 3 randomized, controlled, double-blind, multinational study (SHIELD 1) between June 2020 to June 2022. Patients with at least one abdominal incision length >10 cm were randomized 1:1 to the investigational arm (D-PLEX+SOC) or control (SOC) arm . The primary outcome was a composite of incisional SSI, incisional reintervention, and all-cause mortality. RESULTS: A total of 974 patients were analyzed, of whom 579 (59.4%) were male. The mean age (±SD) was 64.2±13.0 years. The primary outcome occurred in 9.3% of D-PLEX patients versus 12.1% (SOC) (risk difference estimate [RDE], -2.8%; 95% CI [-6.7%, 1.0%], P=0.1520). In a pre-specified analysis by incision length, a reduction in the primary outcome was observed in the >20 cm subpopulation: 8% (D-PLEX) versus 17.5% (SOC) (RDE, -9.4%; 95% CI [-15.5%, -3.2%], P=0.0032). In the >10 to ≤20 cm subgroup, no reduction was observed: 9.9% versus 7.9% (RDE, 2.0%; 95% CI [-2.8%, 6.7%], P=0.4133). Exploratory post-hoc analyses of patients with increased SSI risk (≥1 patient-specific comorbidity) indicated a reduction in the incidence of the primary outcome: 9.0% (D-PLEX) versus 13.7% (SOC) (RDE, -4.8%; 95% CI [-9.5%, -0.1%], P=0.0472). The D-PLEX safety profile was good (no difference in treatment-emergent adverse events between the groups). CONCLUSIONS: The SHIELD-1 study did not meet its primary outcome of reduced incisional SSI, incisional reinterventions, or all-cause mortality. Pre-specified and post-hoc analyses suggested that D-PLEX may reduce the incidence of the primary outcome event in patients with increased SSI risk, including lengthy incisions.

19.
J Nucl Med ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871387

RESUMO

Because of upregulated expression on cancer-associated fibroblasts, fibroblast activation protein (FAP) has emerged as an attractive biomarker for the imaging and therapy of solid tumors. Although many FAP ligands have already been developed for radiopharmaceutical therapies (RPTs), most suffer from inadequate tumor uptake, insufficient tumor residence times, or off-target accumulation in healthy tissues, suggesting a need for further improvements. Methods: A new FAP-targeted RPT with a novel ligand (FAP8-PEG3-IP-DOTA) was designed by combining the desirable features of several previous ligand-targeted RPTs. Uptake and retention of [111In]In or [177Lu]Lu-FAP8-PEG3-IP-DOTA were assessed in KB, HT29, MDA-MB-231, and 4T1 murine tumor models by radioimaging or ex vivo biodistribution analyses. Radiotherapeutic potencies and gross toxicities were also investigated by monitoring tumor growth, body weight, and tissue damage in tumor-bearing mice. Results: FAP8-PEG3-IP-DOTA exhibited high affinity (half-maximal inhibitory concentration, 1.6 nM) and good selectivity for FAP relative to its closest homologs, prolyl oligopeptidase (half-maximal inhibitory concentration, ∼14.0 nM) and dipeptidyl peptidase-IV (half-maximal inhibitory concentration, ∼860 nM). SPECT/CT scans exhibited high retention in 2 different solid tumor models and minimal uptake in healthy tissues. Quantitative biodistribution analyses revealed tumor-to-healthy-tissue ratios of more than 5 times for all major organs, and live animal studies demonstrated 65%-93% suppression of tumor growth in all 4 models tested, with minimal or no evidence of systemic toxicity. Conclusion: We conclude that [177Lu]Lu-FAP8-PEG3-IP-DOTA constitutes a promising and safe RPT candidate for FAPα-targeted radionuclide therapy of solid tumors.

20.
Vet Res ; 55(1): 69, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822400

RESUMO

Current diagnostic methods for Johne's disease in cattle allow reliable detection of infections with Mycobacterium avium ssp. paratuberculosis (MAP) not before animals are 2 years of age. Applying a flow cytometry-based approach (FCA) to quantify a MAP-specific interferon-gamma (IFN-γ) response in T cell subsets, the present study sought to monitor the kinetics of the cell-mediated immune response in experimentally infected calves. Six MAP-negative calves and six calves, orally inoculated with MAP at 10 days of age, were sampled every 4 weeks for 52 weeks post-inoculation (wpi). Peripheral blood mononuclear cells (PBMC) were stimulated with either purified protein derivatives (PPD) or whole cell sonicates derived from MAP (WCSj), M. avium ssp. avium or M. phlei for 6 days followed by labeling of intracellular IFN-γ in CD4+ and CD8+ T cells. No antigen-specific IFN-γ production was detectable in CD8+ cells throughout and the responses of CD4+ cells of MAP-infected and control calves were similar up to 12 wpi. However, the mean fluorescence intensity (MFI) for the detection of IFN-γ in CD4+ cells after WCSj antigen stimulation allowed for a differentiation of animal groups from 16 wpi onwards. This approach had a superior sensitivity (87.8%) and specificity (86.8%) to detect infected animals from 16 wpi onwards, i.e., in an early infection stage, as compared to the IFN-γ release assay (IGRA). Quantification of specific IFN-γ production at the level of individual CD4+ cells may serve, therefore, as a valuable tool to identify MAP-infected juvenile cattle.


Assuntos
Linfócitos T CD4-Positivos , Doenças dos Bovinos , Citometria de Fluxo , Interferon gama , Mycobacterium avium subsp. paratuberculosis , Paratuberculose , Animais , Bovinos , Paratuberculose/imunologia , Paratuberculose/diagnóstico , Paratuberculose/microbiologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Mycobacterium avium subsp. paratuberculosis/fisiologia , Interferon gama/metabolismo , Citometria de Fluxo/veterinária , Citometria de Fluxo/métodos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/microbiologia , Linfócitos T CD4-Positivos/imunologia , Biomarcadores
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