976 resultados para GENE-THERAPY
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BACKGROUND: To perform a comprehensive study on the relationship between vitamin D metabolism and the response to interferon-α-based therapy of chronic hepatitis C. METHODOLOGY/PRINCIPAL FINDINGS: Associations between a functionally relevant polymorphism in the gene encoding the vitamin D 1α-hydroxylase (CYP27B1-1260 rs10877012) and the response to treatment with pegylated interferon-α (PEG-IFN-α) and ribavirin were determined in 701 patients with chronic hepatitis C. In addition, associations between serum concentrations of 25-hydroxyvitamin D(3) (25[OH]D(3)) and treatment outcome were analysed. CYP27B1-1260 rs10877012 was found to be an independent predictor of sustained virologic response (SVR) in patients with poor-response IL28B genotypes (15% difference in SVR for rs10877012 genotype AA vs. CC, p = 0.02, OR = 1.52, 95% CI = 1.061-2.188), but not in patients with favourable IL28B genotype. Patients with chronic hepatitis C showed a high prevalence of vitamin D insufficiency (25[OH]D(3)<20 ng/mL) during all seasons, but 25(OH)D(3) serum levels were not associated with treatment outcome. CONCLUSIONS/SIGNIFICANCE: Our study suggests a role of bioactive vitamin D (1,25[OH](2)D(3), calcitriol) in the response to treatment of chronic hepatitis C. However, serum concentration of the calcitriol precursor 25(OH)D(3) is not a suitable predictor of treatment outcome.
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Résumé : Un nombre croissant de cas de malaria chez les voyageurs et migrants a été rapporté. Bien que l'analyse microscopique des frottis sanguins reste traditionnellement l'outil diagnostic de référence, sa fiabilité dépend considérablement de l'expertise de l'examinateur, pouvant elle-même faire défaut sous nos latitudes. Une PCR multiplex en temps réel a donc été développée en vue d'une standardisation du diagnostic. Un ensemble d'amorces génériques ciblant une région hautement conservée du gène d'ARN ribosomial 18S du genre Plasmodium a tout d'abord été conçu, dont le polymorphisme du produit d'amplification semblait suffisant pour créer quatre sondes spécifiques à l'espèce P. falciparum, P. malariae, P. vivax et P. ovale. Ces sondes utilisées en PCR en temps réel se sont révélées capables de détecter une seule copie de plasmide de P. falciparum, P. malariae, P. vivax et P. ovale spécifiquement. La même sensibilité a été obtenue avec une sonde de screening pouvant détecter les quatre espèces. Quatre-vingt-dix-sept échantillons de sang ont ensuite été testés, dont on a comparé la microscopie et la PCR en temps réel pour 66 (60 patients) d'entre eux. Ces deux méthodes ont montré une concordance globale de 86% pour la détection de plasmodia. Les résultats discordants ont été réévalués grâce à des données cliniques, une deuxième expertise microscopique et moléculaire (laboratoire de Genève et de l'Institut Suisse Tropical de Bâle), ainsi qu'à l'aide du séquençage. Cette nouvelle analyse s'est prononcé en faveur de la méthode moléculaire pour tous les neuf résultats discordants. Sur les 31 résultats positifs par les deux méthodes, la même réévaluation a pu donner raison 8 fois sur 9 à la PCR en temps réel sur le plan de l'identification de l'espèce plasmodiale. Les 31 autres échantillons ont été analysés pour le suivi de sept patients sous traitement antimalarique. Il a été observé une baisse rapide du nombre de parasites mesurée par la PCR en temps réel chez six des sept patients, baisse correspondant à la parasitémie déterminée microscopiquement. Ceci suggère ainsi le rôle potentiel de la PCR en temps réel dans le suivi thérapeutique des patients traités par antipaludéens. Abstract : There have been reports of increasing numbers of cases of malaria among migrants and travelers. Although microscopic examination of blood smears remains the "gold standard" in diagnosis, this method suffers from insufficient sensitivity and requires considerable expertise. To improve diagnosis, a multiplex real-time PCR was developed. One set of generic primers targeting a highly conserved region of the 18S rRNA gene of the genus Plasmodium was designed; the primer set was polymorphic enough internally to design four species-specific probes for P. falciparum, P. vivax, P. malarie, and P. ovale. Real-time PCR with species-specific probes detected one plasmid copy of P. falciparum, P. vivax, P. malariae, and P. ovale specifically. The same sensitivity was achieved for all species with real-time PCR with the 18S screening probe. Ninety-seven blood samples were investigated. For 66 of them (60 patients), microscopy and real-time PCR results were compared and had a crude agreement of 86% for the detection of plasmodia. Discordant results were reevaluated with clinical, molecular, and sequencing data to resolve them. All nine discordances between 18S screening PCR and microscopy were resolved in favor of the molecular method, as were eight of nine discordances at the species level for the species-specific PCR among the 31 samples positive by both methods. The other 31 blood samples were tested to monitor the antimalaria treatment in seven patients. The number of parasites measured by real-time PCR fell rapidly for six out of seven patients in parallel to parasitemia determined microscopically. This suggests a role of quantitative PCR for the monitoring of patients receiving antimalaria therapy.
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To study factors associated with anemia and its effect on survival in HIV-infected persons treated with modern combined antiretroviral therapy (cART), we characterized the prevalence of anemia in the Veterans Aging Cohort Study (VACS) and used a candidate gene approach to identify proinflammatory gene single nucleotide polymorphisms (SNPs) associated with anemia in HIV disease. The study comprised 1597 HIV(+) and 865 HIV(-) VACS subjects with DNA, blood, and annotated clinical data available for analysis. Anemia was defined according to World Health Organization criteria (hemoglobin < 13 g/dL and < 12 g/dL in men and women, respectively). The prevalence of anemia in HIV(+) and HIV(-) subjects was 23.1% and 12.9%, respectively. Independent of HIV status, anemia was present in 23.4% and 8% in blacks and whites, respectively. Analysis of our candidate genes revealed that the leptin -2548 G/A SNP was associated with anemia in HIV(+), but not HIV(-), patients, with the AA and AG genotypes significantly predicting anemia (P < .003 and P < .039, respectively, logistic regression). This association was replicated in an independent cohort of HIV(+) women. Our study provides novel insight into the association between genetic variability in the leptin gene and anemia in HIV(+) individuals.
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Macrophages play key roles in inflammatory disorders. Therefore, they are targets of treatments aiming at their local destruction in inflammation sites. However, injection of low molecular mass therapeutics, including photosensitizers, in inflamed joints results in their rapid efflux out of the joints, and poor therapeutic index. To improve selective uptake and increase retention of therapeutics in inflamed tissues, hydrophilic nanogels based on chitosan, of which surface was decorated with hyaluronate and which were loaded with one of three different anionic photosensitizers were developed. Optimal uptake of these functionalized nanogels by murine RAW 264.7 or human THP-1 macrophages as models was achieved after <4h incubation, whereas only negligible uptake by murine fibroblasts used as control cells was observed. The uptake by cells and the intracellular localization of the photosensitizers, of the fluorescein-tagged chitosan and of the rhodamine-tagged hyaluronate were confirmed by fluorescence microscopy. Photodynamic experiments revealed good cell photocytotoxicity of the photosensitizers entrapped in the nanogels. In a mouse model of rheumatoid arthritis, injection of free photosensitizers resulted in their rapid clearance from the joints, while nanogel-encapsulated photosensitizers were retained in the inflamed joints over a longer period of time. The photodynamic treatment of the inflamed joints resulted in a reduction of inflammation comparable to a standard corticoid treatment. Thus, hyaluronate-chitosan nanogels encapsulating therapeutic agents are promising materials for the targeted delivery to macrophages and long-term retention of therapeutics in leaky inflamed articular joints.
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Elevated serum ferritin levels may reflect a systemic inflammatory state as well as increased iron storage, both of which may contribute to an unfavorable outcome of chronic hepatitis C (CHC). We therefore performed a comprehensive analysis of the role of serum ferritin and its genetic determinants in the pathogenesis and treatment of CHC. To this end, serum ferritin levels at baseline of therapy with pegylated interferon-alpha and ribavirin or before biopsy were correlated with clinical and histological features of chronic hepatitis C virus (HCV) infection, including necroinflammatory activity (N = 970), fibrosis (N = 980), steatosis (N = 886), and response to treatment (N = 876). The association between high serum ferritin levels (> median) and the endpoints was assessed by logistic regression. Moreover, a candidate gene as well as a genome-wide association study of serum ferritin were performed. We found that serum ferritin ≥ the sex-specific median was one of the strongest pretreatment predictors of treatment failure (univariate P < 0.0001, odds ratio [OR] = 0.45, 95% confidence interval [CI] = 0.34-0.60). This association remained highly significant in a multivariate analysis (P = 0.0002, OR = 0.35, 95% CI = 0.20-0.61), with an OR comparable to that of interleukin (IL)28B genotype. When patients with the unfavorable IL28B genotypes were stratified according to high versus low ferritin levels, SVR rates differed by > 30% in both HCV genotype 1- and genotype 3-infected patients (P < 0.001). Serum ferritin levels were also independently associated with severe liver fibrosis (P < 0.0001, OR = 2.67, 95% CI = 1.68-4.25) and steatosis (P = 0.002, OR = 2.29, 95% CI = 1.35-3.91), but not with necroinflammatory activity (P = 0.3). Genetic variations had only a limited impact on serum ferritin levels. Conclusion: In patients with CHC, elevated serum ferritin levels are independently associated with advanced liver fibrosis, hepatic steatosis, and poor response to interferon-alpha-based therapy.
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RESUME La radiothérapie est utilisée avec succès pour le traitement d'un grand nombre de pathologies tumorales (1). Cependant, les récidives post-actiniques sont associées à un risque accru de développer des métastases régionales et à distance (2, 3). La prise en charge de ce type de patients demeure insatisfaisante à l'heure actuelle, principalement parce que les mécanismes physio-pathologiques sous- sous-jacents restent mal compris. Etant donné le rôle primordial du stroma dans la progression tumorale (4) et l'importance des effets de la radiothérapie sur le micro-environnement des tumeurs (5), nous avons émis l'hypothèse que la radiothérapie pouvait engendrer des modifications stromales susceptibles de contribuer à l'émergence d'un phénotype tumoral plus agressif. Nous avons observé que l'exposition préalable d'un environnement tumoral à des radiations ionisantes engendre une inhibition locale et à long terme de l'angiogenèse. Cette inhibition conduit à la création d'un environnement tumoral hypoxique favorisant l'invasion et la métastatisation tumorale. Les mécanismes sous-jacents impliquent l'activation de gènes prométastatiques sous le contrôle du facteur de transcription HIF-1, ainsi que la sélection hypoxique de cellules hautement invasives et métastatiques. Par des analyses de profile d'expression génétique ainsi que par des analyses fonctionnelles, nous avons identifié la protéine matri-cellulaire CYR61 ainsi que ses partenaires d'interaction, les intégrines aVb5/aVb3, comme médiateurs importants de ces effets. De plus, une corrélation significative a également été trouvée entre le niveau d'expression de CYR61 et le taux d'hypoxie dans un grand nombre de carcinomes mammaires chez l'humain. Une association a aussi été observée entre le niveau d'expression de CYR61 et le pronostic de patientes souffrant d'un cancer du sein traité par chimiothérapie adjuvante. Globalement ces résultats identifient l'interaction entre la protéine CYR61 et ses récepteurs aVb5/aVb3 comme un mécanisme important du processus de métastatisation et en font une cible thérapeutique potentielle pour le traitement de patients souffrant d'une récidive tumorale après un traitement de radiothérapie. Finalement, bien que l'inhibition de l'angiogenèse soit locale dans ce cas particulier, nos résultats justifient une surveillance particulière des patients souffrant d'une pathologie tumorale et étant au bénéfice d'un traitement inhibiteur de l'angiogenèse. SUMMARY Radiotherapy is successfully used to treat a large variety of tumours (1 ). However, cancer patients experiencing local recurrent disease after radiation therapy are at increased risk of developing regional and distant metastasis (2, 3). The clinical management of this condition represents a difficult and challenging issue, mainly because the underlying physio-pathological mechanisms remain poorly understood. Given the well established role of the tumour stroma in promoting cancer progression (4) and since radiotherapy is known to persistently alter the tumour microenvironment (5), we hypothesized that ionising radiations may generate stromal modifications contributing to the metastatic spread of relapsing tumours. Here, we report that irradiation of the prospective tumour microenvironment promotes tumour invasion and metastasis through a mechanism of local and sustained impairment of angiogenesis leading to both HIF-1 dependent activation of pro-metastatic genes and hypoxia-mediated selection of highly metastatic tumour cell variants. Through gene expression profiling and functional experiments, we identified the matricellular signalling protein CYR61 and its interaction partners aVb5/ aVb3 integrins as critical mediators of these effects. Furthermore, we found a significant correlation between CYR61 expression and the hypoxic status of a large number of human mammary carcinomas. A positive correlation between increased levels of CYR61 expression and shorter relapse free survival was also identified in breast cancer patients treated with adjuvant chemotherapy. Together, these results identify CYR61 and aVb5/aVb3 integrins as critical mediators of metastasis and potential therapeutic targets to improve outcome in patients with post-radiation tumour recurrences. Finally, although inhibition of angiogenesis is local in this setting, our data warrant close monitoring of tumour progression in patients under anti-angiogenic therapy.
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Few biopharmaceutical preparations developed from biologicals are available for tissue regeneration and scar management. When developing biological treatments with cellular therapy, selection of cell types and establishment of consistent cell banks are crucial steps in whole-cell bioprocessing. Various cell types have been used in treatment of wounds to reduce scar to date including autolog and allogenic skin cells, platelets, placenta, and amniotic extracts. Experience with fetal cells show that they may provide an interesting cell choice due to facility of outscaling and known properties for wound healing without scar. Differential gene profiling has helped to point to potential indicators of repair which include cell adhesion, extracellular matrix, cytokines, growth factors, and development. Safety has been evidenced in Phase I and II clinical fetal cell use for burn and wound treatments with different cell delivery systems. We present herein that fetal cells present technical and therapeutic advantages compared to other cell types for effective cell-based therapy for wound and scar management.
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Epigenetic silencing of essential components of DNA repair pathways is a common event in many tumor types, and comprise O6-methylguanine-DNA methyltransferase (MGMT), human mut L homolog 1 (hMLH1), Werner syndrome gene (WRN), breast cancer susceptibility gene 1 (BRCA1), and genes of the Fanconi anemia pathway. Most interestingly, some of these alterations become the Achilles heel of the affected tumors upon treatment with certain classes of anticancer agents. That is, patients whose tumors carry such defects can be stratified for respective therapy rendering some classic DNA damaging agents, such as alkylators or DNA crosslinking agents, into "targeted therapies." Here we review some of the affected repair pathways that, when inactivated, sensitize the tumors to specific drugs and are thus exploitable for individualized therapy.
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BACKGROUND & AIMS: Genetic variation in the interleukin 28B (IL28B) gene has been associated with the response to interferon-alfa/ribavirin therapy in hepatitis C virus (HCV) genotype 1-infected patients. The importance of three IL28B single nucleotide polymorphisms (rs8099917, rs12980275 and rs12979860) for HCV genotype 2/3-infected patients is unknown. METHODS: In patients with chronic hepatitis C genotype 2/3 (n=267), IL28B host genotypes (rs8099917, rs12980275 and rs12979860) were analyzed for associations with sustained virologic response (SVR) to antiviral therapy with (pegylated) interferon-alfa and ribavirin and with respect to epidemiological, biochemical, and virological parameters. For comparison, hepatitis C genotype 1 patients (n=378) and healthy controls (n=200) were included. RESULTS: The rs12979860 CC genotype, lower age, and genotype 2 were significantly associated with SVR in HCV genotype 2/3-infected patients (p=0.01, p=0.03 and p=0.03, respectively). No association was observed for rs8099917 and rs12980275. In addition, an SVR in patients with rapid virologic response (RVR) was associated with the rs12979860 CC genotype (p=0.05), while for non-RVR no association was found. Furthermore, a significant association with a higher baseline viral load was observed for all three IL28B genotypes in genotype 1/2/3-infected patients. Finally, increasing frequencies of the rs12979860 CC genotypes were observed in genotype 1- (33.9%), genotype 3- (38.9%), and genotype 2-infected (51.9%) patients in comparison with healthy controls (49.0%) (p<0.01). CONCLUSIONS: In genotype 2/3-infected patients, rs12979860 was significantly associated with SVR. The frequency of the rs12979860 CC genotype is lower in HCV genotype 1 vs. genotype 2/3 patients. All major IL28B genotypes are associated with HCV-RNA concentration.
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BACKGROUND & AIMS: Pazopanib has demonstrated clinical benefit in patients with advanced renal cell carcinoma (RCC) and is generally well tolerated. However, transaminase elevations have commonly been observed. This 2-stage study sought to identify genetic determinants of alanine transaminase (ALT) elevations in pazopanib-treated white patients with RCC.¦METHODS: Data from two separate clinical studies were used to examine the association of genetic polymorphisms with maximum on-treatment ALT levels.¦RESULTS: Of 6852 polymorphisms in 282 candidate genes examined in an exploratory dataset of 115 patients, 92 polymorphisms in 40 genes were significantly associated with ALT elevation (p<0.01). Two markers (rs2858996 and rs707889) in the HFE gene, which are not yet known to be associated with hemochromatosis, showed evidence for replication. Because of multiple comparisons, there was a 12% likelihood the replication occurred by chance. These two markers demonstrated strong linkage disequilibrium (r(2)=0.99). In the combined dataset, median (25-75th percentile) maximum ALT values were 1.2 (0.7-1.9), 1.1 (0.8-2.5), and 5.4 (1.9-7.6)×ULN for rs2858996 GG (n=148), GT (n=82), and TT (n=1 2) genotypes, respectively. All 12 TT patients had a maximum ALT>ULN, and 8 (67%) had ALT≥3×ULN. The odds ratio (95% CI) for ALT≥3×ULN for TT genotype was 39.7 (2.2-703.7) compared with other genotypes. As a predictor of ALT≥3×ULN, the TT genotype had a negative predictive value of 0.83 and positive predictive value of 0.67. No TT patients developed liver failure.¦CONCLUSIONS: The rs2858996/rs707889 polymorphisms in the HFE gene may be associated with reversible ALT elevation in pazo-panib-treated patients with RCC.
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Background- Cardiac hypertrophy involves growth responses to a variety of stimuli triggered by increased workload. It is an independent risk factor for heart failure and sudden death. Mammalian target of rapamycin (mTOR) plays a key role in cellular growth responses by integrating growth factor and energy status signals. It is found in 2 structurally and functionally distinct multiprotein complexes called mTOR complex (mTORC) 1 and mTORC2. The role of each of these branches of mTOR signaling in the adult heart is currently unknown. Methods and Results- We generated mice with deficient myocardial mTORC1 activity by targeted ablation of raptor, which encodes an essential component of mTORC1, during adulthood. At 3 weeks after the deletion, atrial and brain natriuretic peptides and β-myosin heavy chain were strongly induced, multiple genes involved in the regulation of energy metabolism were altered, but cardiac function was normal. Function deteriorated rapidly afterward, resulting in dilated cardiomyopathy and high mortality within 6 weeks. Aortic banding-induced pathological overload resulted in severe dilated cardiomyopathy already at 1 week without a prior phase of adaptive hypertrophy. The mechanism involved a lack of adaptive cardiomyocyte growth via blunted protein synthesis capacity, as supported by reduced phosphorylation of ribosomal S6 kinase 1 and 4E-binding protein 1. In addition, reduced mitochondrial content, a shift in metabolic substrate use, and increased apoptosis and autophagy were observed. Conclusions- Our results demonstrate an essential function for mTORC1 in the heart under physiological and pathological conditions and are relevant for the understanding of disease states in which the insulin/insulin-like growth factor signaling axis is affected such as diabetes mellitus and heart failure or after cancer therapy.
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BACKGROUND: Several studies have established Glioblastoma Multiforme (GBM) prognostic and predictive models based on age and Karnofsky Performance Status (KPS), while very few studies evaluated the prognostic and predictive significance of preoperative MR-imaging. However, to date, there is no simple preoperative GBM classification that also correlates with a highly prognostic genomic signature. Thus, we present for the first time a biologically relevant, and clinically applicable tumor Volume, patient Age, and KPS (VAK) GBM classification that can easily and non-invasively be determined upon patient admission. METHODS: We quantitatively analyzed the volumes of 78 GBM patient MRIs present in The Cancer Imaging Archive (TCIA) corresponding to patients in The Cancer Genome Atlas (TCGA) with VAK annotation. The variables were then combined using a simple 3-point scoring system to form the VAK classification. A validation set (N = 64) from both the TCGA and Rembrandt databases was used to confirm the classification. Transcription factor and genomic correlations were performed using the gene pattern suite and Ingenuity Pathway Analysis. RESULTS: VAK-A and VAK-B classes showed significant median survival differences in discovery (P = 0.007) and validation sets (P = 0.008). VAK-A is significantly associated with P53 activation, while VAK-B shows significant P53 inhibition. Furthermore, a molecular gene signature comprised of a total of 25 genes and microRNAs was significantly associated with the classes and predicted survival in an independent validation set (P = 0.001). A favorable MGMT promoter methylation status resulted in a 10.5 months additional survival benefit for VAK-A compared to VAK-B patients. CONCLUSIONS: The non-invasively determined VAK classification with its implication of VAK-specific molecular regulatory networks, can serve as a very robust initial prognostic tool, clinical trial selection criteria, and important step toward the refinement of genomics-based personalized therapy for GBM patients.
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Gene correction at the site of the mutation in the chromosome is the absolute way to really cure a genetic disease. The oligonucleotide (ODN)-mediated gene repair technology uses an ODN perfectly complementary to the genomic sequence except for a mismatch at the base that is mutated. The endogenous repair machinery of the targeted cell then mediates substitution of the desired base in the gene, resulting in a completely normal sequence. Theoretically, it avoids potential gene silencing or random integration associated with common viral gene augmentation approaches and allows an intact regulation of expression of the therapeutic protein. The eye is a particularly attractive target for gene repair because of its unique features (small organ, easily accessible, low diffusion into systemic circulation). Moreover therapeutic effects on visual impairment could be obtained with modest levels of repair. This chapter describes in details the optimized method to target active ODNs to the nuclei of photoreceptors in neonatal mouse using (1) an electric current application at the eye surface (saline transpalpebral iontophoresis), (2) combined with an intravitreous injection of ODNs, as well as the experimental methods for (3) the dissection of adult neural retinas, (4) their immuno-labelling, and (5) flat-mounting for direct observation of photoreceptor survival, a relevant criteria of treatment outcomes for retinal degeneration.
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Colorectal cancer (CRC) is a major cause of cancer mortality. Whereas some patients respond well to therapy, others do not, and thus more precise, individualized treatment strategies are needed. To that end, we analyzed gene expression profiles from 1,290 CRC tumors using consensus-based unsupervised clustering. The resultant clusters were then associated with therapeutic response data to the epidermal growth factor receptor-targeted drug cetuximab in 80 patients. The results of these studies define six clinically relevant CRC subtypes. Each subtype shares similarities to distinct cell types within the normal colon crypt and shows differing degrees of 'stemness' and Wnt signaling. Subtype-specific gene signatures are proposed to identify these subtypes. Three subtypes have markedly better disease-free survival (DFS) after surgical resection, suggesting these patients might be spared from the adverse effects of chemotherapy when they have localized disease. One of these three subtypes, identified by filamin A expression, does not respond to cetuximab but may respond to cMET receptor tyrosine kinase inhibitors in the metastatic setting. Two other subtypes, with poor and intermediate DFS, associate with improved response to the chemotherapy regimen FOLFIRI in adjuvant or metastatic settings. Development of clinically deployable assays for these subtypes and of subtype-specific therapies may contribute to more effective management of this challenging disease.
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The CD8 T cell response generatedby gene-based vaccines is importantfor protective immunity againstmany infectious diseases but its complexityis incompletely understood.Here, we report that different vaccinesencoding HIV Env elicit qualitativelydistinct CD8 T cells that wereidentified by patterns of gene expressionin individual cells. Three alternativeprime-boost vector combinationsstimulated antigen-specific CD8 Tcell populations of similar magnitudeand function by intracellular cytokinestaining; however, single cell geneexpression profiling enabled the discriminationof distinct CM and EMCD8 cells elicited by the three vaccines.Two previously unrecognizedCD8 T cell subsets have been definedby their coexpression of Eomes,Cxcr3 and Ccr7; or Klrk1, Klrg1 andCcr5 in CM and EM cells respectively.