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1.
Front Oncol ; 14: 1334546, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38344208

RESUMO

Background: With the increasing use of radiomics in cancer diagnosis and treatment, it has been applied by some researchers to the preoperative risk assessment of endometrial cancer (EC) patients. However, comprehensive and systematic evidence is needed to assess its clinical value. Therefore, this study aims to investigate the application value of radiomics in the diagnosis and treatment of EC. Methods: Pubmed, Cochrane, Embase, and Web of Science databases were retrieved up to March 2023. Preoperative risk assessment of EC included high-grade EC, lymph node metastasis, deep myometrial invasion status, and lymphovascular space invasion status. The quality of the included studies was appraised utilizing the RQS scale. Results: A total of 33 primary studies were included in our systematic review, with an average RQS score of 7 (range: 5-12). ML models based on radiomics for the diagnosis of malignant lesions predominantly employed logistic regression. In the validation set, the pooled c-index of the ML models based on radiomics and clinical features for the preoperative diagnosis of endometrial malignancy, high-grade tumors, lymph node metastasis, lymphovascular space invasion, and deep myometrial invasion was 0.900 (95%CI: 0.871-0.929), 0.901 (95%CI: 0.877-0.926), 0.906 (95%CI: 0.882-0.929), 0.795 (95%CI: 0.693-0.897), and 0.819 (95%CI: 0.705-0.933), respectively. Conclusions: Radiomics shows excellent accuracy in detecting endometrial malignancies and in identifying preoperative risk. However, the methodological diversity of radiomics results in significant heterogeneity among studies. Therefore, future research should establish guidelines for radiomics studies based on different imaging sources. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=364320 identifier CRD42022364320.

2.
J Am Chem Soc ; 145(29): 16228-16237, 2023 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-37460135

RESUMO

EGFR tyrosine kinase inhibitors have made remarkable success in targeted cancer therapy. However, therapeutic resistance inevitably occurred and EGFR-targeting therapy has been demonstrated to have limited efficacy or utility in glioblastoma, colorectal cancer, and hepatocellular carcinoma. Therefore, there is a high demand for the development of new targets to inhibit EGFR signaling. Herein, we found that the EGFR oncogene proximal promoter sequence forms a unique type of snap-back loop containing G-quadruplex (G4), which can be targeted by small molecules. For the first time, we determined the NMR solution structure of this snap-back EGFR-G4, a three-tetrad-core, parallel-stranded G4 with naturally occurring flanking residues at both the 5'-end and 3'-end. The snap-back loop located at the 3'-end region forms a stable capping structure through two stacked G-triads connected by multiple potential hydrogen bonds. Notably, the flanking residues are consistently absent in reported snap-back G4s, raising the question of whether such structures truly exist under in vivo conditions. The resolved EGFR-G4 structure has eliminated the doubt and showed distinct structural features that distinguish it from the previously reported snap-back G4s, which lack the flanking residues. Furthermore, we found that the snap-back EGFR-G4 structure is highly stable and can form on an elongated DNA template to inhibit DNA polymerase. The unprecedented high-resolution EGFR-G4 structure has thus contributed a promising molecular target for developing alternative EGFR signaling inhibitors in cancer therapeutics. Meanwhile, the two stacked triads may provide an attractive site for specific small-molecule targeting.


Assuntos
Quadruplex G , Neoplasias , Humanos , Regiões Promotoras Genéticas , Oncogenes , Receptores ErbB/genética
3.
Ann Med ; 55(1): 908-919, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36896567

RESUMO

RESEARCH OBJECTIVE: To explore the diagnostic value of circ-DENN domain containing 4 C (circDENND4C) in epithelial ovarian cancer (EOC) and the corresponding mechanism. METHODS: We determined the expression of circDENND4C and miR-200b/c in tissues and serum specimens as well as EOC cell lines using qRT-PCR. Basic clinical data, and serum HE4 and CAl25 levels were acquired from patients' clinical records. Expression-related correlations and the diagnostic value of serum circDENND4C in EOC were also estimated. CCK-8 and flow cytometry were performed to detect the effect of circDENND4C on cell proliferation and apoptosis. RESULTS: circDENND4C level was lowest while miR-200b/c was highest in EOC tissues, followed by benign and normal tissues. Similarly, serum circDENND4C was lowest while miR-200b/c was highest in EOC patients. Moreover, serum circDENND4C was lower in patients with benign ovarian tumors than in healthy women, while miR-200b/c expression was higher. circDENND4C was negatively associated with miR-200b/c in EOC tissues and serum specimens, and serum circDENND4C was also negatively correlated with serum HE4 and CAl25 in EOC patients. circDENND4C expression in both tissue and serum was negatively related to FIGO and TNM stage, and tumor size in EOC. Serum circDENND4C could distinguish healthy persons from patients with benign ovarian tumors and EOC, and they showed a higher specificity and accuracy than serum CA125 or HE4 in EOC diagnosis. circDENND4C upregulation significantly suppressed EOC cell proliferation and facilitated apoptosis by downregulating miR-200b/c in vitro. CONCLUSIONS: Summarily, circDENND4C acts as a tumor inhibitor by downregulating miR-200b/c in EOC and could be a possible tumor marker for EOC diagnosis.KEY MESSAGEScircDENND4C expression was lowest while miR-200b/c was highest in EOC tissues or serums, followed by benign and normal tissues or serums.circDENND4C was involved in malignant progression of EOC, concretely, overexpression of circDENND4C suppressed EOC cell proliferation and stimulated apoptosis via downregulating miR-200b/c, and circDENND4C expression in both tissue and serum was closely related to FIGO and TNM stages and tumor size in EOC.Serum circDENND4C showed a higher specificity and accuracy than serum CA125 or HE4 in EOC diagnosis.HIGHLIGHTScircDENND4C expression was lowest while miR-200b/c was highest in EOC tissues, followed by benign and normal tissues.Serum circDENND4C was lowest while miR-200b/c was highest in EOC patients, followed by benign patients and healthy women.Overexpression of circDENND4C suppresses EOC cell proliferation and stimulates apoptosis via downregulating miR-200b/c.circDENND4C expression in both tissue and serum was closely related to FIGO and TNM stage and tumor size in EOC.Serum circDENND4C showed a higher specificity and accuracy than serum CA125 or HE4 in EOC diagnosis.


Assuntos
MicroRNAs , Neoplasias Epiteliais e Glandulares , Neoplasias Ovarianas , Humanos , Feminino , Carcinoma Epitelial do Ovário/diagnóstico , Carcinoma Epitelial do Ovário/genética , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genética , Biomarcadores Tumorais/genética , Antígeno Ca-125/genética , MicroRNAs/genética , Neoplasias Epiteliais e Glandulares/diagnóstico , Neoplasias Epiteliais e Glandulares/genética
4.
Nat Commun ; 13(1): 6016, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224201

RESUMO

KRAS is one of the most highly mutated oncoproteins, which is overexpressed in various human cancers and implicated in poor survival. The G-quadruplex formed in KRAS oncogene promoter (KRAS-G4) is a transcriptional modulator and amenable to small molecule targeting. However, no available KRAS-G4-ligand complex structure has yet been determined, which seriously hinders the structure-based rational design of KRAS-G4 targeting drugs. In this study, we report the NMR solution structures of a bulge-containing KRAS-G4 bound to berberine and coptisine, respectively. The determined complex structure shows a 2:1 binding stoichiometry with each compound recruiting the adjacent flacking adenine residue to form a "quasi-triad plane" that stacks over the two external G-tetrads. The binding involves both π-stacking and electrostatic interactions. Moreover, berberine and coptisine significantly lowered the KRAS mRNA levels in cancer cells. Our study thus provides molecular details of ligand interactions with KRAS-G4 and is beneficial for the design of specific KRAS-G4-interactive drugs.


Assuntos
Berberina , Quadruplex G , Adenina , Berberina/análogos & derivados , Berberina/farmacologia , Genes ras , Humanos , Ligantes , Proteínas Proto-Oncogênicas p21(ras)/genética , RNA Mensageiro
5.
Mol Ther ; 30(2): 632-643, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-34563673

RESUMO

Macrophages constitute a major component in human hepatocellular carcinoma (HCC) and perform various functions to facilitate disease progression. Reprogramming or reconstituting the tumor surveillance phenotypes of macrophages represents an attractive immunotherapeutic strategy in cancer treatments. The current study identified CD169 as a potential target for macrophage repolarization since it signified a population of macrophages positively correlated with an activated immune signature and better prognosis of patients with HCC. In vitro experiments revealed that a low dose of type I interferon (IFN) could effectively reprogram human monocyte-derived macrophages to upregulate CD169 expression, and such induced CD169+ macrophages exhibited significantly enhanced phagocytotic and CD8+ T cell-activating capacities compared to controls. A low dose of IFNα also inhibited hepatoma growth in mice in vivo, presumably through polarizing the CD169+ macrophage population and enhancing CD8+ T cell activities. Notably, IFNα also induced substantial PD-L1 expression on macrophages in vivo, and thus blockade of PD-L1 could further increase the anti-tumor efficacy of IFNα in the treatment of HCC. We propose a low dose of IFNα in combination with a PD-L1 blocking agent as a potential anti-tumor therapeutic strategy via its effects on macrophage polarization.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Antígeno B7-H1 , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Ativação de Macrófagos , Macrófagos/metabolismo , Camundongos , Microambiente Tumoral
6.
Aging (Albany NY) ; 13(12): 16367-16380, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34157683

RESUMO

S100A9 is differentially expressed in various cell types and is associated with the development, progression and metastasis of various cancers. However, the expression, distribution, and clinical significance of S100A9 in hepatocellular carcinoma (HCC) remain unclear. In the present study, The Cancer Genome Atlas (TCGA) database was used to examine S100A9 gene expression in HCC; we found that S100A9 expression was associated with HCC prognosis. In addition, S100A9 protein expression was assessed by immunohistochemistry analysis of tissues from 382 HCC patients. We found that the infiltration of S100A9+ cells in both tumor and nontumor tissues could predict poor overall survival (P = 0.0329, tumor; P = 0.0003, nontumor) and a high recurrence risk (P = 0.0387, tumor; P = 0.0015, nontumor) in our tissue microarray analysis. Furthermore, immunofluorescence double staining revealed that the primary S100A9-expressing cells in adjacent nontumoral tissue were CD15+ neutrophils, and both CD68+ macrophages and CD15+ neutrophils expressed S100A9 in HCC tumor tissues. Taken together, the results suggest that high S100A9+ cell density predicts a poor prognosis in HCC patients, and S100A9 expression could potentially serve as an independent prognostic marker for HCC.


Assuntos
Calgranulina B/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Contagem de Células , Linhagem Celular Tumoral , Bases de Dados como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Células Mieloides/patologia , Prognóstico , Microambiente Tumoral
7.
J Clin Immunol ; 40(2): 321-328, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31903518

RESUMO

Cartilage-hair hypoplasia (CHH) is an autosomal recessive, short limb skeletal dysplasia with a variable immunologic phenotype. The spectrum of immune function ranges from clinically normal to severe combined immunodeficiency (SCID). Multiple studies have shown that abnormal immune parameters may not predict severe outcomes. Newborn screening (NBS) using T cell receptor excision circle (TREC) assay can now effectively identify infants with severe T cell deficiency who are at risk for SCID. NBS has allowed for cost-effective identification of patients with SCID and improved outcomes with hematopoietic stem cell transplant (HSCT). Ohio reports two abnormal TREC results: decreased and absent TREC. This study evaluated the laboratory and clinical differences in eight Amish patients with CHH with an abnormal TREC result on the NBS. There were four patients with absent TREC and four patients with decreased TREC. The absent TREC patients had lower CD3, CD4, naïve CD4, CD8 cells, and phytohemagglutinin (PHA)-induced lymphocyte proliferation. Three patients with absent TREC were diagnosed with SCID and two underwent successful HSCT. Patients with absent TREC experienced more CHH-related morbidity including anemia requiring transfusion, Hirschsprung's disease, and failure to thrive. No patients with decreased TREC required HSCT. Our study indicates that CHH patients with absent TREC tend to have more severe immunological and clinical phenotype than patients with decreased TREC. Confirmation of these trends in a larger group would guide providers and parents in a timely referral for HSCT, or cost-effective surveillance monitoring of children with a life-threatening illness.


Assuntos
Amish , Patologia Molecular/métodos , Receptores de Antígenos de Linfócitos T/genética , Imunodeficiência Combinada Severa/diagnóstico , Linfócitos T/imunologia , Síndromes de Tricotiodistrofia/diagnóstico , Células Cultivadas , Pré-Escolar , Estudos de Coortes , Seguimentos , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Recém-Nascido , Ativação Linfocitária , Triagem Neonatal , Prognóstico , Imunodeficiência Combinada Severa/genética , Resultado do Tratamento , Síndromes de Tricotiodistrofia/genética
8.
Hepatol Int ; 14(1): 80-95, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31802389

RESUMO

BACKGROUND: Sorafenib is the most widely used first-line treatment for patients with advanced hepatocellular carcinoma (HCC), but such treatment provides only limited survival benefits that might be related to the immune status of distinct tumor microenvironments. A fundamental understanding of the distribution and phenotypes of T lymphocytes in tumors will undoubtedly lead to the development of novel immunotherapeutic strategies that could possibly enhance the efficacy of sorafenib treatments. METHODS: Flow cytometry, immunohistochemistry and immunofluorescence analyses were performed to detect the infiltration and distribution of various leukocyte populations, and the expression of different immune checkpoint molecules in fresh HCC tumor tissues. Correlations among indicating genes were calculated in 365 patients with HCC from The Cancer Genome Atlas (TCGA) data set, and the cumulative overall survival time was calculated using the Kaplan-Meier method. Moreover, role of adenosinergic pathway on sorafenib anti-tumor efficacy was investigated using both subcutaneous and orthotopic transplantation tumor model in immune competent C57BL/6 mice. RESULTS: We revealed that levels of CD3+ and CD8+ T cells were significantly downregulated in HCC tumor tissue, so were the infiltration of CD169+ cells (a Mφ subpopulation with T cell activation capacities) and their contact with CD8+ cells in tumor milieus. Moreover, levels of PD-1 and CD39 expression were significantly upregulated in human HCC-infiltrating CD4+ and CD8+ T cells, and CD39+CD8+ T cells exhibited a CD69+PD-1+perforinlowIFNγlow "exhausted" phenotype. Levels of both CD39+ T cells infiltration and adenosine receptor ADORA2B expression in tumor tissues were negatively correlated with overall survival of patients with HCC. Accordingly, mice treated with sorafenib in combination with adenosine A2B receptor blockage reagents exhibited significantly reduced tumor progression compared with control groups. CONCLUSIONS: These results suggest that adenosinergic pathway might represent an applicable target for sorafenib-combined-therapies in human HCC.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Sorafenibe/administração & dosagem , Sorafenibe/farmacologia , Análise de Sobrevida , Microambiente Tumoral , Adulto Jovem
9.
Heliyon ; 5(10): e02733, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31720471

RESUMO

Effective extraction of natural antioxidants from cheap plant sources is still a problem. In this paper, an excellent method of ultrasound-assisted extraction of phenolic compounds from Ajuga ciliata Bunge was studied. The effects of four factors including ethanol volume fraction, ultrasonic time, ultrasonic temperature and material liquid ratio were discussed. After single factor experiments had been investigated, a 4-factor, 3-level Box-Behnken design experiment was used to obtain the model optimum conditions, which are shown as follows: ethanol volume fraction of 41%, liquid-solid ratio of 35:1 mL/g, ultrasonic temperature of 60 °C and ultrasonic time of 50 min. Under these conditions, the experimental productivity is 3.552 mg/g. The spectra of Fourier infrared and energy dispersive X-ray suggest that phenolic compounds exist in the extracts. Besides, free radical scavenging potentials of superoxide anion, hydroxyl and DPPH were measured to evaluate their antioxidant properties. This study proves that the ultrasonic-assisted extraction technique can extract phenolic compounds with antioxidant capacity from Ajuga ciliata Bunge.

10.
Blood ; 126(8): e1-e10, 2015 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-26124495

RESUMO

Growing interest in natural killer (NK) cell-based therapy for treating human cancer has made it imperative to develop new tools to measure early events in cell death. We recently demonstrated that protease-cleavable luciferase biosensors detect granzyme B and pro-apoptotic caspase activation within minutes of target cell recognition by murine cytotoxic lymphocytes. Here we report successful adaptation of the biosensor technology to assess perforin-dependent and -independent induction of death pathways in tumor cells recognized by human NK cell lines and primary cells. Cell-cell signaling via both Fc receptors and NK-activating receptors led to measurable luciferase signal within 15 minutes. In addition to the previously described aspartase-cleavable biosensors, we report development of granzyme A and granzyme K biosensors, for which no other functional reporters are available. The strength of signaling for granzyme biosensors was dependent on perforin expression in IL-2-activated NK effectors. Perforin-independent induction of apoptotic caspases was mediated by death receptor ligation and was detectable after 45 minutes of conjugation. Evidence of both FasL and TRAIL-mediated signaling was seen after engagement of Jurkat cells by perforin-deficient human cytotoxic lymphocytes. Although K562 cells have been reported to be insensitive to TRAIL, robust activation of pro-apoptotic caspases by NK cell-derived TRAIL was detectable in K562 cells. These studies highlight the sensitivity of protease-cleaved luciferase biosensors to measure previously undetectable events in live cells in real time. Further development of caspase and granzyme biosensors will allow interrogation of additional features of granzyme activity in live cells including localization, timing, and specificity.


Assuntos
Apoptose/fisiologia , Técnicas Biossensoriais , Granzimas/imunologia , Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Neoplasias/imunologia , Caspases/imunologia , Linhagem Celular Tumoral , Ativação Enzimática/fisiologia , Citometria de Fluxo , Granzimas/administração & dosagem , Humanos , Immunoblotting , Células Jurkat , Células K562 , Proteínas Recombinantes , Transfecção
11.
Pediatrics ; 135(2): e547-50, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25583920

RESUMO

Anaphylaxis presents in children with rapid involvement of typically 2 or more organ systems including cutaneous, gastrointestinal, and respiratory. Caustic ingestions (CI) may also present with acute involvement of cutaneous, gastrointestinal, and respiratory systems. We present 2 cases of "missed diagnosis" that illustrate how CI presenting with respiratory symptoms can be mistaken for anaphylaxis owing to these similarities. Both of these patients had delay in appropriate care for CI as a result. These cases demonstrate the importance of considering CI in children who have gastrointestinal symptoms, respiratory distress, and oropharyngeal edema.


Assuntos
Anafilaxia/diagnóstico , Cáusticos/intoxicação , Erros de Diagnóstico , Acidentes Domésticos , Broncoscopia , Pré-Escolar , Detergentes/toxicidade , Endoscopia do Sistema Digestório , Humanos , Laringoscopia , Masculino , Revelação da Verdade
12.
J Immunol ; 193(2): 519-28, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24928990

RESUMO

Activation of caspase-mediated apoptosis is reported to be a hallmark of both granzyme B- and Fas-mediated pathways of killing by CTLs; however, the kinetics of caspase activation remain undefined owing to an inability to monitor target cell-specific apoptosis in real time. We have overcome this limitation by developing a novel biosensor assay that detects continuous, protease-specific activity in target cells. Biosensors were engineered from a circularly permuted luciferase, linked internally by either caspase 3/7 or granzyme B/caspase 8 cleavage sites, thus allowing activation upon proteolytic cleavage by the respective proteases. Coincubation of murine CTLs with target cells expressing either type of biosensor led to a robust luminescent signal within minutes of cell contact. The signal was modulated by the strength of TCR signaling, the ratio of CTL/target cells, and the type of biosensor used. Additionally, the luciferase signal at 30 min correlated with target cell death, as measured by a (51)Cr-release assay. The rate of caspase 3/7 biosensor activation was unexpectedly rapid following granzyme B- compared with Fas-mediated signal induction in murine CTLs; the latter appeared gradually after a 90-min delay in perforin- or granzyme B-deficient CTLs. Remarkably, the Fas-dependent, caspase 3/7 biosensor signal induced by perforin-deficient human CTLs was also detectable after a 90-min delay when measured by redirected killing. Thus, we have used a novel, real-time assay to demonstrate the distinct pattern of caspase activation induced by granzyme B versus Fas in human and murine CTLs.


Assuntos
Caspases/imunologia , Granzimas/imunologia , Linfócitos T Citotóxicos/imunologia , Receptor fas/imunologia , Animais , Apoptose/imunologia , Sítios de Ligação/genética , Caspase 3/genética , Caspase 3/imunologia , Caspase 3/metabolismo , Caspase 7/genética , Caspase 7/imunologia , Caspase 7/metabolismo , Caspases/genética , Caspases/metabolismo , Linhagem Celular Tumoral , Testes Imunológicos de Citotoxicidade/métodos , Citotoxicidade Imunológica/genética , Citotoxicidade Imunológica/imunologia , Ativação Enzimática/imunologia , Granzimas/genética , Granzimas/metabolismo , Humanos , Luciferases/genética , Luciferases/metabolismo , Medições Luminescentes/métodos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Perforina/genética , Perforina/imunologia , Perforina/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/metabolismo , Fatores de Tempo , Receptor fas/metabolismo
13.
J Immunol ; 178(12): 7756-66, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17548613

RESUMO

HLA-A2-restricted CTL responses to immunodominant HIV-1 epitopes do not appear to be very effective in the control of viral replication in vivo. In this study, we studied human CD8+ T cell responses to the subdominant HLA-A2-restricted epitope TV9 (Gag p24(19-27), TLNAWVKVV) to explore the possibility of increasing its immune recognition. We confirmed in a cohort of 313 patients, infected by clade B or clade C viruses, that TV9 is rarely recognized. Of interest, the functional sensitivity of the TV9 response can be relatively high. The potential T cell repertoires for TV9 and the characteristics of constituent clonotypes were assessed by ex vivo priming of circulating CD8+ T cells from healthy seronegative donors. TV9-specific CTLs capable of suppressing viral replication in vitro were readily generated, suggesting that the cognate T cell repertoire is not limiting. However, these cultures contained multiple discrete populations with a range of binding avidities for the TV9 tetramer and correspondingly distinct functional dependencies on the CD8 coreceptor. The lack of dominant clonotypes was not affected by the stage of maturation of the priming dendritic cells. Cultures primed by dendritic cells transduced to present endogenous TV9 were also incapable of clonal maturation. Thus, a diffuse TCR repertoire appeared to be an intrinsic characteristic of TV9-specific responses. These data indicate that subdominance is not a function of poor immunogenicity, cognate TCR repertoire availability, or the potential avidity properties thereof, but rather suggest that useful responses to this epitope are suppressed by competing CD8+ T cell populations during HIV-1 infection.


Assuntos
Produtos do Gene gag/imunologia , HIV-1/imunologia , Antígeno HLA-A2/imunologia , Epitopos Imunodominantes/imunologia , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Reações Cruzadas , Células Dendríticas/imunologia , Humanos , Receptores de Antígenos de Linfócitos T/imunologia
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