Lost in Translation: Lack of CD4 Expression due to a Novel Genetic Defect.
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ABSTRACT:
SUBMITTER: Lisco A
PROVIDER: S-EPMC7904290 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Idiopathic T-CD4 lymphocytopenia (ICL) is a rare and heterogeneous syndrome characterized by opportunistic infections due to reduced CD4 T-lymphocytes (<300 cells/?l or <20% T-cells) in the absence of HIV infection and other primary causes of lymphopenia. Molecular testing of ICL has revealed defects in genes not specific to CD4 T-cells, with pleiotropic effects on other cell types. Here we report for the first time an absolute CD4 lymphocytopenia (<0.01 CD4+ T-cells/?l) due to an autosomal recessive CD4 gene mutation that completely abrogates CD4 protein expression on the surface membrane of T-cells, monocytes, and dendritic cells. A 45-year-old female born to consanguineous parents consulted because of exuberant, relapsing, and treatment-refractory warts on her hands and feet since the age of 10 years, in the absence of other recurrent infections or symptoms. Serological studies were negative for severe infections, including HIV 1/2, HTLV-1, and syphilis, but positive for CMV and EBV. Blood analysis showed the absence of CD4+ T-cells (<0.01%) with repeatedly increased counts of B-cells, naïve CD8+ T-lymphocytes, and particularly, CD4/CD8 double-negative (DN) TCR??+ TCR??- T-cells (30% of T-cells; 400 cells/?l). Flow cytometric staining of CD4 using monoclonal antibodies directed against five different epitopes, located in two different domains of the protein, confirmed no cell surface membrane or intracytoplasmic expression of CD4 on T-cells, monocytes, and dendritic cells but normal soluble CD4 plasma levels. DN T-cells showed a phenotypic and functional profile similar to normal CD4+ T-cells as regards expression of maturation markers, T-helper and T-regulatory chemokine receptors, TCRv? repertoire, and in vitro cytokine production against polyclonal and antigen-specific stimuli. Sequencing of the CD4 gene revealed a homozygous (splicing) mutation affecting the last bp on intron 7-8, leading to deletion of the juxtamembrane and intracellular domains of the protein and complete abrogation of CD4 expression on the cell membrane. These findings support previous studies in CD4 KO mice suggesting that surrogate DN helper and regulatory T-cells capable of supporting antigen-specific immune responses are produced in the absence of CD4 signaling and point out the need for better understanding the role of CD4 on thymic selection and the immune response.
| S-EPMC6856949 | biostudies-literature
Project description:Translation in cognitive neuroscience remains beyond the horizon, brought no closer by supposed major advances in our understanding of the brain. Unless our explanatory models descend to the individual level-a cardinal requirement for any intervention-their real-world applications will always be limited. Drawing on an analysis of the informational properties of the brain, here we argue that adequate individualisation needs models of far greater dimensionality than has been usual in the field. This necessity arises from the widely distributed causality of neural systems, a consequence of the fundamentally adaptive nature of their developmental and physiological mechanisms. We discuss how recent advances in high-performance computing, combined with collections of large-scale data, enable the high-dimensional modelling we argue is critical to successful translation, and urge its adoption if the ultimate goal of impact on the lives of patients is to be achieved.
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Project description:BackgroundThe return of research results (RoR) remains a complex and well-debated issue. Despite the debate, actual data related to the experience of giving individual results back, and the impact these results may have on clinical care and health outcomes, is sorely lacking. Through the work of the Australian Pancreatic Cancer Genome Initiative (APGI) we: (1) delineate the pathway back to the patient where actionable research data were identified; and (2) report the clinical utilisation of individual results returned. Using this experience, we discuss barriers and opportunities associated with a comprehensive process of RoR in large-scale genomic research that may be useful for others developing their own policies.MethodsWe performed whole-genome (n?=?184) and exome (n?=?208) sequencing of matched tumour-normal DNA pairs from 392 patients with sporadic pancreatic cancer (PC) as part of the APGI. We identified pathogenic germline mutations in candidate genes (n?=?130) with established predisposition to PC or medium-high penetrance genes with well-defined cancer associated syndromes or phenotypes. Variants from candidate genes were annotated and classified according to international guidelines. Variants were considered actionable if clinical utility was established, with regard to prevention, diagnosis, prognostication and/or therapy.ResultsA total of 48,904 germline variants were identified, with 2356 unique variants undergoing annotation and in silico classification. Twenty cases were deemed actionable and were returned via previously described RoR framework, representing an actionable finding rate of 5.1%. Overall, 1.78% of our cohort experienced clinical benefit from RoR.ConclusionReturning research results within the context of large-scale genomics research is a labour-intensive, highly variable, complex operation. Results that warrant action are not infrequent, but the prevalence of those who experience a clinical difference as a result of returning individual results is currently low.
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Project description:Lysosomal dysfunction has been found in many pathological conditions, and methods to improve lysosomal function have been reported to be protective against infarcted hearts. However, the mechanisms underlying lysosomal dysfunction caused by ischemic injury are far less well-established. The retromer complex is implicated in the trafficking of cation-independent mannose 6-phosphate receptor (CI-MPR), which is an important protein tag for the proper transport of lysosomal contents and therefore is important for the maintenance of lysosomal function. In this study, we found that the function of retrograde transport in cardiomyocytes was impaired with ischemia/hypoxia (I/H) treatment, which resulted in a decrease in CI-MPR and an abnormal distribution of lysosomal cathepsins. I/H treatment caused a reduction in TBC1D5 and a blockade of the Rab7 membrane cycle, which impeded retromer binding to microtubules and motor proteins, resulting in an impairment of retrograde transport and a decrease in CI-MPR. We also established that TBC1D5 was an important regulator of the distribution of lysosomal cathepsins. Our findings shed light on the regulatory role of retromer in ischemic injury and uncover the regulatory mechanism of TBC1D5 over retromer.
| S-EPMC8736705 | biostudies-literature
Project description:Sympathovagal imbalance contributes to progressive worsening of HF (HF) and is associated with untoward clinical outcomes. Based on compelling pre-clinical studies which supported the role of autonomic modulation in HF models, a series of clinical studies were initiated using spinal cord stimulation (SCS), vagus nerve stimulation (VNS) and baroreceptor activation therapy (BAT) in patients with HF with a reduced ejection fraction (HFrEF). While the phase II studies with BAT remain encouraging, the larger clinical studies with SCS and VNS have yielded disappointing results. Here we will focus on the pre-clinical studies that supported the role of neuromodulation in the failing heart, as well provide a critical review of the recent clinical trials that have sought to modulate autonomic tone in HF patients. This review will conclude with an analysis of some of the difficulties in translating device-based modulation of the autonomic nervous from pre-clinical models into successful clinical trials, as well as provide suggestions for how to move the field of neuromodulation forward.
| S-EPMC4978351 | biostudies-literature
Project description:ObjectivesTo describe the first American patient with a congenital muscle dystrophy characterized by the presence in muscle of gigantic mitochondria displaced to the periphery of the fibers and to stress the potential origin and effects of the mitochondrial changes.DesignCase report and documentation of a novel mutation in the gene encoding choline kinase beta (CHKB).SettingCollaboration between 2 tertiary care academic institutions.PatientA 2-year-old African American boy with weakness and psychomotor delay.InterventionsDetailed clinical and laboratory studies, including muscle biopsy, biochemical analysis of the mitochondrial respiratory chain, and sequencing of the CHKB gene.Main outcome measuresDefinition of unique mitochondrial changes in muscle.ResultsThis patient had the same clinical and laboratory features reported in the first cohort of patients, but he harbored a novel CHKB mutation and had isolated cytochrome c oxidase deficiency in muscle.ConclusionsBesides confirming the phenotype of CHKB mutations, we propose that this disorder affects the mitochondria-associated membrane and the impaired phospholipid metabolism in the mitochondria-associated membrane causes both the abnormal size and displacement of muscle mitochondria.
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Project description:MicroRNAs (miRNAs) are endogenous, ~22-nucleotide-long, noncoding RNAs that play critical roles in physiology and disease via mechanisms that remain obscure. Although numerous studies implicate miRNAs in repression of translation, more recent reports suggest that the major role of miRNAs is in reduction of target mRNA stability. Because mRNA translation and stability are intimately connected, it has been a challenge to establish whether miRNAs induce translational repression, mRNA decay, or both. If miRNAs reduce both mRNA translation and stability, the timing and contribution of each process to overall repression is unclear. Indeed, it has been debated whether mRNA decay is a cause or consequence of miRNA-mediated translational repression. On the other hand, if these events are mutually exclusive, what determines which mechanism is used? In a recent issue of Science, Bazzini et al (2012) use genome-wide ribosome footprinting and RNA sequencing (RNA-Seq) to demonstrate that in developing zebrafish embryos, miR-430 naturally represses translation initiation of target mRNAs, followed by their deadenylation and decay.
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Project description:BACKGROUND:Coenzyme Q is an essential mitochondrial electron carrier, redox cofactor and a potent antioxidant in the majority of cellular membranes. Coenzyme Q deficiency has been associated with a range of metabolic diseases, as well as with some drug treatments and ageing. METHODS:We used whole exome sequencing (WES) to investigate patients with inherited metabolic diseases and applied a novel ultra-pressure liquid chromatography-mass spectrometry approach to measure coenzyme Q in patient samples. RESULTS:We identified a homozygous missense mutation in the COQ7 gene in a patient with complex mitochondrial deficiency, resulting in severely reduced coenzyme Q levels We demonstrate that the coenzyme Q analogue 2,4-dihydroxybensoic acid (2,4DHB) was able to specifically bypass the COQ7 deficiency, increase cellular coenzyme Q levels and rescue the biochemical defect in patient fibroblasts. CONCLUSION:We report the first patient with primary coenzyme Q deficiency due to a homozygous COQ7 mutation and a potentially beneficial treatment using 2,4DHB.
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Project description:This article discusses challenges of language differences in qualitative research, when participants and the main researcher have the same non-English native language and the non-English data lead to an English publication. Challenges of translation are discussed from the perspective that interpretation of meaning is the core of qualitative research. As translation is also an interpretive act, meaning may get lost in the translation process. Recommendations are suggested, aiming to contribute to the best possible representation and understanding of the interpreted experiences of the participants and thereby to the validity of qualitative research.
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