RESUMEN
Coxsackievirus A21 (CVA21) is a naturally occurring RNA virus that, in preclinical studies and clinical trials, has demonstrated promising potential in treating a range of malignancies. Other oncolytic viruses, such as adenovirus, vesicular stomatitis virus, herpesvirus, and vaccinia virus, all can be engineered to carry one or more transgenes for various purposes, including immune modulation, virus attenuation, and induction of apoptosis of tumor cells. However, it remained unknown whether CVA21 can express therapeutic or immunomodulatory payloads due to its small size and high mutation rate. Using reverse genetics techniques, we demonstrated that a transgene encoding a truncated green fluorescent protein (GFP) of up to 141 amino acids (aa) can be successfully carried in the 5' end of the coding region. Furthermore, a chimeric virus carrying an eel fluorescent protein, UnaG (139 aa), was also made and shown to be stable, and it maintained efficient tumor cell-killing activity. Similar to other oncolytic viruses, the likelihood of delivering CVA21 by the intravenous route is low due to issues like blood absorption, neutralizing antibodies, and liver clearance. To address this problem, we designed the CVA21 cDNA under the control of a weak RNA polymerase II promoter, and subsequently, a stable cell pool in 293T cells was made by integrating the resulting CVA21 cDNA into the cell genome. We showed that the cells are viable and able to persistently generate rCVA21 de novo. The carrier cell approach described here may pave the way to designing new cell therapy strategies by arming with oncolytic viruses. IMPORTANCE As a naturally occurring virus, coxsackievirus A21 is a promising oncolytic virotherapy modality. In this study, we first used reverse genetics to determine whether A21 can stably carry transgenes and found that it could express up to 141 amino acids of foreign GFP. The chimeric virus carrying another fluorescent eel protein UnaG (139 amino acids) gene also appeared to be stable over at least 7 passages. Our results provided guidance on how to select and engineer therapeutic payloads for future A21 anticancer research. Second, the challenges of delivering oncolytic viruses by the intravenous route hamper the broader use of oncolytic viruses in the clinic. Here, we used A21 to show that cells could be engineered to stably carry and persistently release the virus by harboring the viral cDNA in the genome. The approach we presented here may pave a new way for oncolytic virus administration using cells as carriers.
Asunto(s)
Enterovirus Humano A , Virus Oncolíticos , Aminoácidos/genética , Línea Celular Tumoral , ADN Complementario , Enterovirus Humano A/genética , Viroterapia Oncolítica/métodos , Virus Oncolíticos/genética , TransgenesRESUMEN
Antibody-drug conjugates (ADCs) have garnered worldwide attention for disease treatment, as they possess high target specificity, a long half-life, and outstanding potency to kill or modulate the functions of targets. FDA approval of multiple ADCs for cancer therapy has generated a strong desire for novel conjugation strategies with high biocompatibility and controllable bioproperties. Herein, we present a bisecting glycan-bridged conjugation strategy that enables site-specific conjugation without the need for the oligosaccharide synthesis and genetic engineering of antibodies. Application of this method is demonstrated by conjugation of anti-HER2 human and mouse IgGs with a cytotoxic drug, monomethyl auristatin E. The glycan bridge showed outstanding stability, and the resulting ADCs eliminated HER2-expressing cancer cells effectively. Moreover, our strategy preserves the feasibility of glycan structure remodeling to fine-tune the immunogenicity and pharmacokinetic properties of ADCs through glycoengineering.
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Anticuerpos , Inmunoconjugados , Humanos , Animales , Ratones , Inmunoconjugados/uso terapéutico , Ingeniería Genética , Semivida , PolisacáridosRESUMEN
Cytokine release syndrome (CRS) is a serious and potentially life-threatening complication typically associated with biological drug products. Pre-clinical testing in vitro and in vivo studies using non-human primates had failed to reliably predict CRS. To determine if bone marrow-thymus-liver (BLT) humanized mice with a fully engrafted human immune system or a CD34-humanized mouse model could predict CRS, we tested an anti-CD28 monoclonal antibody (mAb) similar to TGN1412. This TGN1412 analogue (TGN1412A) was initially tested in vitro and found to produce significant dose-dependent increases in cytokine production. For in vivo studies, adalimumab, an anti-tumor necrosis factor-alpha antibody known not to cause CRS, served as a negative control. We evaluated immune cell activation and cytokine expression in three independent experiments. In BLT humanized mice, significant increases in levels of human cytokines were identified in animals treated with anti-CD28 mAb. As expected, CD28+ cell detection was strongly reduced in the anti-CD28 treated group. Increased T cell activation was also observed. The control group did not show reductions in CD28+ T-cells and did not experience increased cytokine levels. Responses by CD34-humanized mice showed no significant differences between adalimumab and anti-CD28 treatment at doses used to test BLT-humanized mice. These results suggest that the TGN1412A produces similar results in vitro to the original TGN1412 monoclonal antibody. The BLT immune humanized mice but not the CD34 humanized mice produce both robust and specific cytokine responses and may represent a pre-clinical model to identify CRS.
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Anticuerpos Monoclonales Humanizados/toxicidad , Antígenos CD28/antagonistas & inhibidores , Síndrome de Liberación de Citoquinas/etiología , Citocinas/sangre , Linfocitos T/efectos de los fármacos , Animales , Antígenos CD34/inmunología , Antígenos CD28/sangre , Antígenos CD28/inmunología , Células Cultivadas , Síndrome de Liberación de Citoquinas/sangre , Síndrome de Liberación de Citoquinas/inmunología , Citocinas/inmunología , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Trasplante de Hígado , Ratones Endogámicos NOD , Ratones SCID , Medición de Riesgo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Timo/embriología , Timo/trasplanteRESUMEN
Drosophila melanogaster is one of the most well studied genetic model organisms; nonetheless, its genome still contains unannotated coding and non-coding genes, transcripts, exons and RNA editing sites. Full discovery and annotation are pre-requisites for understanding how the regulation of transcription, splicing and RNA editing directs the development of this complex organism. Here we used RNA-Seq, tiling microarrays and cDNA sequencing to explore the transcriptome in 30 distinct developmental stages. We identified 111,195 new elements, including thousands of genes, coding and non-coding transcripts, exons, splicing and editing events, and inferred protein isoforms that previously eluded discovery using established experimental, prediction and conservation-based approaches. These data substantially expand the number of known transcribed elements in the Drosophila genome and provide a high-resolution view of transcriptome dynamics throughout development.
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Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/genética , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica/genética , Transcripción Genética/genética , Empalme Alternativo/genética , Animales , Secuencia de Bases , Proteínas de Drosophila/genética , Drosophila melanogaster/embriología , Exones/genética , Femenino , Genes de Insecto/genética , Genoma de los Insectos/genética , Masculino , MicroARNs/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Isoformas de Proteínas/genética , Edición de ARN/genética , ARN Mensajero/análisis , ARN Mensajero/genética , ARN Pequeño no Traducido/análisis , ARN Pequeño no Traducido/genética , Análisis de Secuencia , Caracteres SexualesRESUMEN
Drosophila melanogaster cell lines are important resources for cell biologists. Here, we catalog the expression of exons, genes, and unannotated transcriptional signals for 25 lines. Unannotated transcription is substantial (typically 19% of euchromatic signal). Conservatively, we identify 1405 novel transcribed regions; 684 of these appear to be new exons of neighboring, often distant, genes. Sixty-four percent of genes are expressed detectably in at least one line, but only 21% are detected in all lines. Each cell line expresses, on average, 5885 genes, including a common set of 3109. Expression levels vary over several orders of magnitude. Major signaling pathways are well represented: most differentiation pathways are "off" and survival/growth pathways "on." Roughly 50% of the genes expressed by each line are not part of the common set, and these show considerable individuality. Thirty-one percent are expressed at a higher level in at least one cell line than in any single developmental stage, suggesting that each line is enriched for genes characteristic of small sets of cells. Most remarkable is that imaginal disc-derived lines can generally be assigned, on the basis of expression, to small territories within developing discs. These mappings reveal unexpected stability of even fine-grained spatial determination. No two cell lines show identical transcription factor expression. We conclude that each line has retained features of an individual founder cell superimposed on a common "cell line" gene expression pattern.
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Drosophila melanogaster/genética , Variación Genética , Transcripción Genética , Animales , Línea Celular , Análisis por Conglomerados , Exones , Femenino , Perfilación de la Expresión Génica , Masculino , Datos de Secuencia Molecular , Transducción de Señal/genética , Factores de Transcripción/genéticaRESUMEN
miRNAs are â¼22-nt RNAs that bind to the Argonaute family of proteins and have important regulatory roles in plants and animals. Here, we show that miRNAs exhibit targeting activity in cells when delivered as single strands that are 5'-phosphorylated and that contain 2'-fluoro ribose modifications. Length preferences, chemical modification sensitivity, and genome-wide seed-based targeting all suggest that this activity is Ago-based. Activity could be enhanced by annealing of segmented passenger strands containing non-nucleic acid spacers. Furthermore, screening of randomly generated sequences identified pyrimidine rich 3' cassette sequences that increased single strand activity. These results provide an initial step in the development of single-stranded miRNA mimics for therapeutic use.
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ADN de Cadena Simple/síntesis química , MicroARNs/química , Imitación Molecular , Secuencia de Bases , Clonación Molecular , ADN de Cadena Simple/química , Fluoruros/síntesis química , Fluoruros/química , Técnicas de Silenciamiento del Gen/instrumentación , Técnicas de Silenciamiento del Gen/métodos , Células HCT116 , Ensayos Analíticos de Alto Rendimiento , Humanos , Análisis por Micromatrices , Imitación Molecular/fisiología , Datos de Secuencia Molecular , Fosforilación , Ribosa/síntesis química , Ribosa/química , TransfecciónRESUMEN
While RNAi has traditionally relied on RNA duplexes, early evaluation of siRNAs demonstrated activity of the guide strand in the absence of the passenger strand. However, these single strands lacked the activity of duplex RNAs. Here, we report the systematic use of chemical modifications to optimize single-strand RNA (ssRNA)-mediated mRNA knockdown. We identify that 2'F ribose modifications coupled with 5'-end phosphorylation vastly improves ssRNA activity both in vitro and in vivo. The impact of specific chemical modifications on ssRNA activity implies an Ago-mediated mechanism but the hallmark mRNA cleavage sites were not observed which suggests ssRNA may operate through a mechanism beyond conventional Ago2 slicer activity. While currently less potent than duplex siRNAs, with additional chemical optimization and alternative routes of delivery, chemically modified ssRNAs could represent a powerful RNAi platform.
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Interferencia de ARN , ARN Pequeño no Traducido/química , Animales , Proteínas Argonautas/metabolismo , Línea Celular , Ratones , Ratones Endogámicos C57BL , Fosforilación , ARN Mensajero/metabolismo , ARN Interferente Pequeño/química , ARN Pequeño no Traducido/metabolismoRESUMEN
Toll-like receptors 7 and 8 are involved in modulating the adaptive and innate immune responses, and their activation has shown promise as a therapeutic strategy in the field of immuno-oncology. While systemic exposure to TLR7/8 agonists can result in poor tolerance, combination therapies and targeted delivery through antibody-drug conjugates (ADCs) can help mitigate adverse effects. Described herein is the identification of a novel and potent series of pyrazolopyrimidine-based TLR7/8 agonists with tunable receptor selectivity. Representative agonists from this series were successfully able to induce the production of various proinflammatory cytokines and chemokines from human peripheral blood mononuclear cells. Anti-HER2-25 and anti-HER2-26 ADCs made from this class of payloads demonstrated mechanism-based activation of TLR7/8 in a THP1/N87 coculture system.
RESUMEN
LAG3 and PD1 are both immunomodulatory receptor that act by inhibiting activation of T cells, producing a more immunosuppressive environment. Even with the recent clinical success of PD1 and LAG3 co-blockade, signal transduction downstream of LAG3 remains largely unknown. We have leveraged an engineered Jurkat (T cell) and Raji (APC) co-culture system to assess simultaneous blockade of PD1 and LAG3 pathways using antibodies. RNA-Seq analysis of cell pellets individually treated with LAG3 or PD1 antibodies revealed modest immune activation however, 5-fold more genes were upregulated upon combination treatment. There were increases in costimulatory genes like CD28, CD5, CD6 as well as intracellular signaling molecules like LCP2 and ITK. Given the role of ERK in immune activation of T cells, pERK levels of Jurkat cells in the assay were evaluated. A very modest activation of pERK was observed with anti-LAG3 compared to anti-PD1 but a combination treatment resulted in prolonged ERK phosphorylation. Treatment of Jurkat cells with a commercial phosphatase inhibitor NSC87877 which can impact many phosphatases resulted in immune activation, measured by increased IL2 levels, only in the presence of LAG3. When NSC87877 was combined with the PD1 antibody, it could phenocopy combination benefit of PD1 and LAG3 blocking antibodies. CD28 has a recognized role in PD1 signaling but the impact on LAG3 signaling remains unknown. CD28 knockout in Jurkat cells affected overall IL-2 response of both LAG3 and PD1 antibody treatment but still retained combination benefit. Taken together this reductionist system highlights differences in downstream effects of LAG3 and PD1 blockade and we believe that the assay may have further utility to dissect convergence of both signaling pathways and augment studies in primary cells.
Asunto(s)
Anticuerpos , Antígenos CD28 , Humanos , Antígenos CD28/genética , Células Jurkat , Anticuerpos Bloqueadores , FenotipoRESUMEN
Targeted immune agonist (TIA) comprising a TLR7 agonist conjugated to tumor-targeting antibodies have been shown to induce potent anti-tumor responses in various preclinical models. However, the clinical proof-of-concept of a TIA has been hampered by systemic dose-limiting immune-related toxicities, including rapid induction of anti-drug antibodies in patients. We have developed ELISPOT-based assay to measure activation of antibody-secreting cells (ASCs), intended to simulate the interaction between TIA and peripheral B cells as a tool to pre-clinically de-risk tumor target-independent peripheral B-cell activation by TIA. This method has proven to be robust and has fast turn-around time to evaluate the induction of spontaneous B-cell activation by TIA in a tumor target- and FcγR-independent manner. This novel ASC assay platform may serve as a preclinical tool to de-risk TIAs that can potentially induce immune-related adverse effects in the clinic.
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Neoplasias , Receptor Toll-Like 7 , Humanos , Adyuvantes Inmunológicos , Anticuerpos , Activación de LinfocitosRESUMEN
Small interfering RNAs (siRNAs) are short, double-stranded RNAs that use the endogenous RNAi pathway to mediate gene silencing. Phosphorylation facilitates loading of a siRNA into the Ago2 complex and subsequent cleavage of the target mRNA. In this study, 2', 3' seco nucleoside modifications, which contain an acylic ribose ring and are commonly called unlocked nucleic acids (UNAs), were evaluated at all positions along the guide strand of a siRNA targeting apolipoprotein B (ApoB). UNA modifications at positions 1, 2 and 3 were detrimental to siRNA activity. UNAs at positions 1 and 2 prevented phosphorylation by Clp1 kinase, abrogated binding to Ago2, and impaired Ago2-mediated cleavage of the mRNA target. The addition of a 5'-terminal phosphate to siRNA containing a position 1 UNA restored ApoB mRNA silencing, Ago2 binding, and Ago2 mediated cleavage activity. Position 1 UNA modified siRNA containing a 5'-terminal phosphate exhibited a partial restoration of siRNA silencing activity in vivo. These data reveal the complexity of interpreting the effects of chemical modification on siRNA activity, and exemplify the importance of using multiple biochemical, cell-based and in vivo assays to rationally design chemically modified siRNA destined for therapeutic use.
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Nucleósidos/química , Interferencia de ARN , ARN Interferente Pequeño/química , Animales , Apolipoproteínas B/genética , Línea Celular , Factor 2 Eucariótico de Iniciación/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Proteínas Nucleares/metabolismo , Fosforilación , Fosfotransferasas/metabolismo , ARN Interferente Pequeño/metabolismo , Termodinámica , Factores de Transcripción/metabolismo , ARN Pequeño no TraducidoRESUMEN
Immune stimulation is a significant hurdle in the development of effective and safe RNA interference therapeutics. Here, we address this problem in the context of a mimic of microRNA-122 by employing novel nucleobase and known 2'-ribose modifications. The nucleobase modifications are analogues of adenosine and guanosine that contain cyclopentyl and propyl minor-groove projections. Via a site-by-site chemical modification analysis, we identify several immunostimulatory 'hot spots' within the miRNA guide strand at which single base modifications significantly reduce immune stimulation. A duplex containing one base modification on each strand proved to be most effective in preventing immune stimulation.
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Materiales Biomiméticos/efectos adversos , Materiales Biomiméticos/química , Sistema Inmunológico/efectos de los fármacos , MicroARNs/genética , ARN Bicatenario/efectos adversos , ARN Bicatenario/química , Ribosa/química , Animales , Secuencia de Bases , Materiales Biomiméticos/síntesis química , Línea Celular Tumoral , Citocinas/metabolismo , Técnicas de Silenciamiento del Gen , Sistema Inmunológico/metabolismo , Ratones , ARN Bicatenario/síntesis química , ARN Bicatenario/genéticaRESUMEN
Immunomodulatory therapeutics such as monoclonal antibodies (mAb) carry an inherent risk of undesired immune reactions. One such risk is cytokine release syndrome (CRS), a rapid systemic inflammatory response characterized by the secretion of pro-inflammatory cytokines from immune cells. It is crucial for patient safety to correctly identify potential risk of CRS prior to first-in-human dose administration. For this purpose, a variety of in vitro cytokine release assays (CRA) are routinely used as part of the preclinical safety assessment of novel therapeutic mAbs. One of the challenges for the development and comparison of CRA performance is the lack of availability of standard positive and negative control mAbs for use in assay qualification. To address this issue, the National Institute for Biological Standards and Control (NIBSC) developed a reference panel of lyophilised mAbs known to induce CRS in the clinic: human anti-CD52, mouse anti-CD3 and human superagonistic (SA) anti-CD28 mAb manufactured according to the respective published sequences of Campath-1H® (alemtuzumab, IgG1) , Orthoclone OKT-3® (muromonab, IgG2a) and TGN1412 (theralizumab, IgG4), as well as three isotype matched negative controls (human IgG1, mouse IgG2a and human IgG4, respectively). The relative capacity of these control mAbs to stimulate the release of IFN-γ, IL-2, TNF-α and IL-6 in vitro was evaluated in eleven laboratories in an international collaborative study mediated through the HESI Immuno-safety Technical Committee Cytokine Release Assay Working Group. Participants tested the NIBSC mAbs in a variety of CRA platforms established at each institution. This paper presents the results from the centralised cytokine quantification on all the plasma/supernatants corresponding to the stimulation of immune cells in the different CRA platforms by a single concentration of each mAb. Each positive control mAb induced significant cytokine release in most of the tested CRA platforms. There was a high inter-laboratory variability in the levels of cytokines produced, but similar patterns of response were observed across laboratories that replicated the cytokine release patterns previously published for the respective clinical therapeutic mAbs. Therefore, the positive and negative mAbs are suitable as a reference panel for the qualification and validation of CRAs, comparison of different CRA platforms (e.g. solid vs aqueous phase), and intra- and inter-laboratory comparison of CRA performance. Thus, the use of this panel of positive and negative control mAbs will increase the confidence in the robustness of a CRA platform to identify a potential CRS risk for novel immunomodulatory therapeutic candidates.
RESUMEN
The programmed cell death 1 (PD-1) pathway represents a major immune checkpoint, which may be engaged by cells in the tumor microenvironment to overcome active T-cell immune surveillance. Pembrolizumab (Keytruda®, MK-3475) is a potent and highly selective humanized mAb of the IgG4/kappa isotype designed to directly block the interaction between PD-1 and its ligands, PD-L1 and PD-L2. This blockade enhances the functional activity of T cells to facilitate tumor regression and ultimately immune rejection. Pembrolizumab binds to human and cynomolgus monkey PD-1 with picomolar affinity and blocks the binding of human and cynomolgus monkey PD-1 to PD-L1 and PD-L2 with comparable potency. Pembrolizumab binds both the C'D and FG loops of PD-1. Pembrolizumab overcomes human and cynomolgus monkey PD-L1-mediated immune suppression in T-cell cultures by enhancing IL2 production following staphylococcal enterotoxin B stimulation of healthy donor and cancer patient cells, and IFNγ production in human primary tumor histoculture. Ex vivo and in vitro studies with human and primate T cells show that pembrolizumab enhances antigen-specific T-cell IFNγ and IL2 production. Pembrolizumab does not mediate FcR or complement-driven effector function against PD-1-expressing cells. Pembrolizumab displays dose-dependent clearance and half-life in cynomolgus monkey pharmacokinetic and toxicokinetic studies typical for human IgG4 antibodies. In nonhuman primate toxicology studies, no findings of toxicologic significance were observed. The preclinical data for pembrolizumab are consistent with the clinical anticancer activity and safety that has been demonstrated in human clinical trials.
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Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/farmacocinética , Leucocitos Mononucleares/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Linfocitos T/efectos de los fármacos , Animales , Antineoplásicos Inmunológicos/farmacocinética , Antineoplásicos Inmunológicos/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/inmunología , Antígeno B7-H1/metabolismo , Femenino , Humanos , Inhibidores de Puntos de Control Inmunológico/farmacocinética , Inhibidores de Puntos de Control Inmunológico/farmacología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/patología , Macaca fascicularis , Ratones , Ratones Endogámicos BALB C , Neoplasias/inmunología , Neoplasias/patología , Proteína 2 Ligando de Muerte Celular Programada 1/antagonistas & inhibidores , Proteína 2 Ligando de Muerte Celular Programada 1/inmunología , Proteína 2 Ligando de Muerte Celular Programada 1/metabolismo , Receptor de Muerte Celular Programada 1/inmunología , Linfocitos T/inmunología , Linfocitos T/patología , Distribución Tisular , Pruebas de ToxicidadRESUMEN
LAG3 is an important regulator of T cell homeostasis and studies in mouse tumor models have demonstrated that simultaneously antagonizing LAG3 and PD1 can augment tumor-specific T cell responses and induce tumor rejection. The combined use of LAG3 antagonist antibodies with established anti-PD1 therapies is currently being evaluated in human clinical trials. A functional assay for human LAG3 was developed by co-culture of a Jurkat T-cell lymphoma line overexpressing LAG3 with a Raji B-cell lymphoma line in the presence of staphylococcal enterotoxins. Reversal of LAG3 repression was measured as an increase in IL-2 production or NFAT activation in response to treatment with MK-4280, an anti-human LAG3 antagonist antibody. Changes in cytokines, chemokines, and other mRNA transcripts were in agreement with published in vitro and in vivo models for LAG3 biology which highlights the physiological relevance of the Jurkat functional assay. Additional engineering of PD1 and PDL1 components into the LAG3 assay resulted in a bi-functional assay that is capable of inducing a 10-fold response to individual antibodies blocking either PD1 or LAG3. Importantly, when MK-4280 and pembrolizumab were combined to block both pathways, a synergistic 50-fold increase in response was observed.
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Anticuerpos Bloqueadores/análisis , Antígenos CD/inmunología , Ingeniería Celular , Receptor de Muerte Celular Programada 1/inmunología , Transducción de Señal/inmunología , Anticuerpos Bloqueadores/inmunología , Antígenos CD/genética , Citometría de Flujo , Perfilación de la Expresión Génica , Humanos , Células Jurkat , Receptor de Muerte Celular Programada 1/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Transducción de Señal/genética , Linfocitos T/inmunología , Células Tumorales Cultivadas , Proteína del Gen 3 de Activación de LinfocitosRESUMEN
GITR is a T-cell costimulatory receptor that enhances cellular and humoral immunity. The agonist anti-mouse GITR antibody DTA-1 has demonstrated efficacy in murine models of cancer primarily by attenuation of Treg-mediated immune suppression, but the translatability to human GITR biology has not been fully explored. Here, we report the potential utility of MK-4166, a humanized GITR mAb selected to bind to an epitope analogous to the DTA-1 epitope, which enhances the proliferation of both naïve and tumor-infiltrating T lymphocytes (TIL). We also investigated the role of GITR agonism in human antitumor immune responses and report here the preclinical characterization and toxicity assessment of MK-4166, which is currently being evaluated in a phase I clinical study. Expression of human GITR was comparable with that of mouse GITR in tumor-infiltrating Tregs despite being drastically lower in other human TILs and in many human peripheral blood populations. MK-4166 decreased induction and suppressive effects of Tregsin vitro In human TIL cultures, MK-4166 induced phosphorylation of NFκB and increased expression of dual specificity phosphatase 6 (DUSP6), indicating that MK-4166 activated downstream NFκB and Erk signaling pathways. Furthermore, MK-4166 downregulated FOXP3 mRNA in human tumor infiltrating Tregs, suggesting that, in addition to enhancing the activation of TILs, MK-4166 may attenuate the Treg-mediated suppressive tumor microenvironment. Cancer Res; 77(16); 4378-88. ©2017 AACR.
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Anticuerpos/farmacología , Proteína Relacionada con TNFR Inducida por Glucocorticoide/inmunología , Linfocitos T Reguladores/inmunología , Animales , Anticuerpos/inmunología , Línea Celular Tumoral , Femenino , Proteína Relacionada con TNFR Inducida por Glucocorticoide/agonistas , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Microambiente TumoralRESUMEN
Cancer develops through the successive accumulation and selection of genetic and epigenetic alterations, enabling cells to survive, replicate and evade homeostatic control mechanisms such as apoptosis and antiproliferative signals. This transformation process, however, may create vulnerabilities since the accumulation of mutations can expose synthetic lethal gene interactions and oncogene-driven cellular reprogramming ('addiction'), giving rise to new therapeutic avenues. With the completion of the human genome project, it is anticipated that the identification and characterization of genetic networks that regulate cell growth, differentiation, apoptosis and transformation will be fundamental to decoding the complexity of these processes, and ultimately, cancer itself. Genomic methodologies, such as large-scale mRNA profiling using microarrays, have already begun to reveal the molecular basis of cancer heterogeneity and the clinical behavior of tumors. The combination of traditional cell culture techniques with high-throughput screening approaches has given rise to new cellular-genomics methodologies that enable the simultaneous interrogation of thousands of genes in live cells, facilitating true functional profiling of biological processes. Among these, RNA interference (RNAi) has the potential to enable rapid genome-wide loss-of-function (LOF) screens in mammalian systems, which until recently has been the sole domain of lower organisms. Here, we present a broad overview of this maturing technology and explore how, within current technical constraints, large-scale LOF use of RNAi can be exploited to uncover the molecular basis of cancer--from the genetics of synthetic lethality and oncogene-dependent cellular addiction to the acquisition of cancer-associated cellular phenotypes.
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Neoplasias/genética , Oncogenes , Interferencia de ARN/fisiología , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Neoplasias/metabolismoRESUMEN
Cytochrome P450s have generally been acknowledged as broadly tuned detoxifying enzymes. However, emerging evidence argues P450s have an integral role in cell signaling and developmental processes, via their metabolism of retinoic acid, arachidonic acid, steroids, and other cellular ligands. To study the morphogenesis of Drosophila sensory organs, we examined mutants with impaired mechanosensation and discovered one, nompH, encodes the cytochrome P450 CYP303a1. We now report the characterization of nompH, a mutant defective in the function of peripheral chemo- and mechanoreceptor cells, and demonstrate CYP303a1 is essential for the development and structure of external sensory organs which mediate the reception of vital mechanosensory and chemosensory stimuli. Notably this P450 is expressed only in sensory bristles, localizing in the apical region of the socket cell. The wide diversity of the P450 family and the growing number of P450s with developmental phenotypes suggests the exquisite tissue and subcellular specificity of CYP303a1 illustrates an important aspect of P450 function; namely, a strategy to process critical developmental signals in a tissue- and cell-specific manner.
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Sistema Enzimático del Citocromo P-450/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/enzimología , Drosophila/crecimiento & desarrollo , Órganos de los Sentidos/enzimología , Órganos de los Sentidos/crecimiento & desarrollo , Secuencia de Aminoácidos , Animales , Animales Modificados Genéticamente , Células Quimiorreceptoras/enzimología , Células Quimiorreceptoras/crecimiento & desarrollo , Sistema Enzimático del Citocromo P-450/genética , Drosophila/genética , Proteínas de Drosophila/genética , Genes de Insecto , Mecanorreceptores/enzimología , Mecanorreceptores/crecimiento & desarrollo , Mecanotransducción Celular , Datos de Secuencia Molecular , MutaciónRESUMEN
The immune stimulation induced by short interfering RNAs (siRNAs) has been reported to be quieted or abrogated by methoxy or fluoro modifications of the 2' position of the ribose sugar. However, variables such as the type of modification, nucleotide preference, and strand bias have not been systematically evaluated. Here, we report the results of a screen of several modified siRNAs via a human peripheral blood monocyte cytokine induction assay. Unlike corresponding modifications of guanosine, cytidine, or uridine, 2'-fluoro modification of adenosine significantly reduced cytokine induction while retaining siRNA knockdown activity. The results of this study suggest adenosine as an optimal target for modification.
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Adenosina/química , ARN Interferente Pequeño/inmunología , Citocinas/biosíntesis , Citocinas/sangre , Ensayo de Inmunoadsorción Enzimática , Humanos , ARN Interferente Pequeño/química , beta-Galactosidasa/metabolismoRESUMEN
Endogenous and exogenous short interfering RNAs (siRNAs) require a 5'-phosphate for loading into Ago2 and cleavage of the target mRNA. We applied a synthetic 5'-phosphate to siRNA guide strands to evaluate if phosphorylation in vivo is rate limiting for maximal siRNA knockdown and duration. We report, for the first time, an in vivo evaluation of siRNAs with a synthetic 5'-phosphate compared to their unphosphorylated versions. siRNAs that contained a 5'-phosphate had the same activity in vivo compared with unphosphorylated siRNAs, indicating phosphorylation of an siRNA is not a rate limiting step in vivo.