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MOTIVATION: Reliable label-free methods are needed for detecting and profiling apoptotic events in time-lapse cell-cell interaction assays. Prior studies relied on fluorescent markers of apoptosis, e.g. Annexin-V, that provide an inconsistent and late indication of apoptotic onset for human melanoma cells. Our motivation is to improve the detection of apoptosis by directly detecting apoptotic bodies in a label-free manner. RESULTS: Our trained ResNet50 network identified nanowells containing apoptotic bodies with 92% accuracy and predicted the onset of apoptosis with an error of one frame (5 min/frame). Our apoptotic body segmentation yielded an IoU accuracy of 75%, allowing associative identification of apoptotic cells. Our method detected apoptosis events, 70% of which were not detected by Annexin-V staining. AVAILABILITY AND IMPLEMENTATION: Open-source code and sample data provided at https://github.com/kwu14victor/ApoBDproject.
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Vesículas Extracelulares , Redes Neurales de la Computación , Humanos , Microscopía por Video , Imagen de Lapso de Tiempo/métodos , AnexinasRESUMEN
BACKGROUND: The mechanism by which immune cells regulate metastasis is unclear. Understanding the role of immune cells in metastasis will guide the development of treatments improving patient survival. METHODS: We used syngeneic orthotopic mouse tumour models (wild-type, NOD/scid and Nude), employed knockout (CD8 and CD4) models and administered CXCL4. Tumours and lungs were analysed for cancer cells by bioluminescence, and circulating tumour cells were isolated from blood. Immunohistochemistry on the mouse tumours was performed to confirm cell type, and on a tissue microarray with 180 TNBCs for human relevance. TCGA data from over 10,000 patients were analysed as well. RESULTS: We reveal that intratumoral immune infiltration differs between metastatic and non-metastatic tumours. The non-metastatic tumours harbour high levels of CD8+ T cells and low levels of platelets, which is reverse in metastatic tumours. During tumour progression, platelets and CXCL4 induce differentiation of monocytes into myeloid-derived suppressor cells (MDSCs), which inhibit CD8+ T-cell function. TCGA pan-cancer data confirmed that CD8lowPlatelethigh patients have a significantly lower survival probability compared to CD8highPlateletlow. CONCLUSIONS: CD8+ T cells inhibit metastasis. When the balance between CD8+ T cells and platelets is disrupted, platelets produce CXCL4, which induces MDSCs thereby inhibiting the CD8+ T-cell function.
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Neoplasias de la Mama/inmunología , Antígenos CD4/genética , Antígenos CD8/genética , Linfocitos T CD8-positivos/trasplante , Neoplasias Pulmonares/prevención & control , Neoplasias Pulmonares/secundario , Factor Plaquetario 4/metabolismo , Animales , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Linfocitos T CD8-positivos/metabolismo , Línea Celular Tumoral , Femenino , Técnicas de Inactivación de Genes , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos NOD , Ratones Desnudos , Células Supresoras de Origen Mieloide/inmunología , Células Neoplásicas Circulantes/inmunología , Factor Plaquetario 4/administración & dosificación , Factor Plaquetario 4/farmacología , Análisis de Supervivencia , Trasplante Isogénico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
MOTIVATION: Automated profiling of cell-cell interactions from high-throughput time-lapse imaging microscopy data of cells in nanowell grids (TIMING) has led to fundamental insights into cell-cell interactions in immunotherapy. This application note aims to enable widespread adoption of TIMING by (i) enabling the computations to occur on a desktop computer with a graphical processing unit instead of a server; (ii) enabling image acquisition and analysis to occur in the laboratory avoiding network data transfers to/from a server and (iii) providing a comprehensive graphical user interface. RESULTS: On a desktop computer, TIMING 2.0 takes 5 s/block/image frame, four times faster than our previous method on the same computer, and twice as fast as our previous method (TIMING) running on a Dell PowerEdge server. The cell segmentation accuracy (f-number = 0.993) is superior to our previous method (f-number = 0.821). A graphical user interface provides the ability to inspect the video analysis results, make corrective edits efficiently (one-click editing of an entire nanowell video sequence in 5-10 s) and display a summary of the cell killing efficacy measurements. AVAILABILITY AND IMPLEMENTATION: Open source Python software (GPL v3 license), instruction manual, sample data and sample results are included with the Supplement (https://github.com/RoysamLab/TIMING2). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Comunicación Celular , Microscopía , Análisis de la Célula Individual , Programas Informáticos , Imagen de Lapso de Tiempo , Gráficos por Computador , Interfaz Usuario-ComputadorRESUMEN
BACKGROUND: The p38 MAPK is constitutively activated in B-NHL cell lines and regulates chemoresistance. Accordingly, we hypothesized that activated p38 MAPK may be associated with the in vivo unresponsiveness to chemotherapy in B-NHL patients. METHODS: Tissue microarrays generated from eighty untreated patients with Diffused Large B Cell Lymphoma (DLBCL) were examined by immunohistochemistry for the expression of p38 and phospho p38 (p-p38) MAPK. In addition, both Bcl-2 and NF-κB expressions were determined. Kaplan Meier analysis was assessed. RESULTS: Tumor tissues expressed p38 MAPK (82 %) and p-p38 MAPK (30 %). Both p38 and p-p38 MAPK expressions correlated with the high score performance status. A significant correlation was found between the expression p-p38 and poor response to CHOP. The five year median follow-up FFS was 81 % for p38(-) and 34 % for p38(+) and for OS was 83 % for p38(-) and 47 % for p38(+). The p-p38(+) tissues expressed Bcl-2 and 90 % of p-p38(-) where Bcl-2(-). The coexpression of p-p38 and Bcl-2 correlated with pool EFS and OS. There was no correlation between the expression of p-p38 and the expression of NF-κB. CONCLUSION: The findings revealed, for the first time, that a subset of patients with DLBCL and whose tumors expressed high p-p38 MAPK responded poorly to CHOP therapy and had poor EFS and OS. The expression of p38, p-p38, Bcl2 and the ABC subtype are significant risk factors both p38 and p-p38 expressions remain independent prognostic factors.
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Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Proteínas Quinasas p38 Activadas por Mitógenos/biosíntesis , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ciclofosfamida/administración & dosificación , Supervivencia sin Enfermedad , Doxorrubicina/administración & dosificación , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Estimación de Kaplan-Meier , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , FN-kappa B/genética , Prednisona/administración & dosificación , Pronóstico , Proteínas Proto-Oncogénicas c-bcl-2/genética , Análisis de Matrices Tisulares , Vincristina/administración & dosificación , Proteínas Quinasas p38 Activadas por Mitógenos/genéticaRESUMEN
Although glutamine addiction in cancer cells is extensively reported, there is controversy on the impact of glutamine metabolism on the immune cells within the tumor microenvironment (TME). To address the role of extracellular glutamine, we enzymatically depleted circulating glutamine using PEGylated Helicobacter pylori gamma-glutamyl transferase (PEG-GGT) in syngeneic mouse models of breast and colon cancers. PEG-GGT treatment inhibits growth of cancer cells in vitro, but in vivo it increases myeloid-derived suppressor cells (MDSCs) and has no significant impact on tumor growth. By deriving a glutamine depletion signature, we analyze diverse human cancers within the TCGA and illustrate that glutamine depletion is not associated with favorable clinical outcomes and correlates with accumulation of MDSC. Broadly, our results help clarify the integrated impact of glutamine depletion within the TME and advance PEG-GGT as an enzymatic tool for the systemic and selective depletion (no asparaginase activity) of circulating glutamine in live animals.
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Respiratory viral infections cause morbidity and mortality worldwide. Despite the success of vaccines, vaccination efficacy is weakened by the rapid emergence of viral variants with immunoevasive properties. The development of an off-the-shelf, effective, and safe therapy against respiratory viral infections is thus desirable. Here, we develop NanoSTING, a nanoparticle formulation of the endogenous STING agonist, 2'-3' cGAMP, to function as an immune activator and demonstrate its safety in mice and rats. A single intranasal dose of NanoSTING protects against pathogenic strains of SARS-CoV-2 (alpha and delta VOC) in hamsters. In transmission experiments, NanoSTING reduces the transmission of SARS-CoV-2 Omicron VOC to naïve hamsters. NanoSTING also protects against oseltamivir-sensitive and oseltamivir-resistant strains of influenza in mice. Mechanistically, NanoSTING upregulates locoregional interferon-dependent and interferon-independent pathways in mice, hamsters, as well as non-human primates. Our results thus implicate NanoSTING as a broad-spectrum immune activator for controlling respiratory virus infection.
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Administración Intranasal , Nanopartículas , SARS-CoV-2 , Animales , Nanopartículas/química , Nanopartículas/administración & dosificación , Ratones , Cricetinae , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/inmunología , Modelos Animales de Enfermedad , Humanos , Proteínas de la Membrana/agonistas , Proteínas de la Membrana/metabolismo , Femenino , Nucleótidos Cíclicos/farmacología , Ratas , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/virología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/tratamiento farmacológico , Masculino , Antivirales/farmacología , Antivirales/administración & dosificación , Ratones Endogámicos C57BLRESUMEN
Immunization programs against SARS-CoV-2 with commercial intramuscular vaccines prevent disease but are less efficient in preventing infections. Mucosal vaccines can provide improved protection against transmission, ideally for different variants of concern (VOCs) and related sarbecoviruses. Here, we report a multi-antigen, intranasal vaccine, NanoSTING-SN (NanoSTING-Spike-Nucleocapsid), eliminates virus replication in both the lungs and the nostrils upon challenge with the pathogenic SARS-CoV-2 Delta VOC. We further demonstrate that NanoSTING-SN prevents transmission of the SARS-CoV-2 Omicron VOC (BA.5) to vaccine-naïve hamsters. To evaluate protection against other sarbecoviruses, we immunized mice with NanoSTING-SN. We showed that immunization affords protection against SARS-CoV, leading to protection from weight loss and 100% survival in mice. In non-human primates, animals immunized with NanoSTING-SN show durable serum IgG responses (6 months) and nasal wash IgA responses cross-reactive to SARS-CoV-2 (XBB1.5), SARS-CoV and MERS-CoV antigens. These observations have two implications: (1) mucosal multi-antigen vaccines present a pathway to reducing transmission of respiratory viruses, and (2) eliciting immunity against multiple antigens can be advantageous in engineering pan-sarbecovirus vaccines.
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Administración Intranasal , Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Animales , SARS-CoV-2/inmunología , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/transmisión , COVID-19/virología , Ratones , Cricetinae , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Femenino , Ratones Endogámicos BALB C , Humanos , Mesocricetus , Antígenos Virales/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangreRESUMEN
Chimeric antigen receptor (CAR) T cells used for the treatment of B cell malignancies can identify T cell subsets with superior clinical activity. Here, using infusion products of individuals with large B cell lymphoma, we integrated functional profiling using timelapse imaging microscopy in nanowell grids with subcellular profiling and single-cell RNA sequencing to identify a signature of multifunctional CD8+ T cells (CD8-fit T cells). CD8-fit T cells are capable of migration and serial killing and harbor balanced mitochondrial and lysosomal volumes. Using independent datasets, we validate that CD8-fit T cells (1) are present premanufacture and are associated with clinical responses in individuals treated with axicabtagene ciloleucel, (2) longitudinally persist in individuals after treatment with CAR T cells and (3) are tumor migrating cytolytic cells capable of intratumoral expansion in solid tumors. Our results demonstrate the power of multimodal integration of single-cell functional assessments for the discovery and application of CD8-fit T cells as a T cell subset with optimal fitness in cell therapy.
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Linfocitos T CD8-positivos , Inmunoterapia Adoptiva , Linfoma de Células B Grandes Difuso , Receptores Quiméricos de Antígenos , Análisis de la Célula Individual , Humanos , Linfoma de Células B Grandes Difuso/inmunología , Linfoma de Células B Grandes Difuso/terapia , Análisis de la Célula Individual/métodos , Inmunoterapia Adoptiva/métodos , Linfocitos T CD8-positivos/inmunología , Receptores Quiméricos de Antígenos/inmunología , Subgrupos de Linfocitos T/inmunología , Productos BiológicosRESUMEN
Extracellular vesicles (EVs) regulate the tumor microenvironment by facilitating transport of biomolecules. Despite extensive investigation, heterogeneity in EV secretion among cancer cells and the mechanisms that support EV secretion are not well characterized. We developed an integrated method to identify individual cells with differences in EV secretion and performed linked single-cell RNA-sequencing on cloned single cells from the metastatic breast cancer cells. Differential gene expression analyses identified a four-gene signature of breast cancer EV secretion: HSP90AA1, HSPH1, EIF5, and DIAPH3. We functionally validated this gene signature by testing it across cell lines with different metastatic potential in vitro. Analysis of the TCGA and METABRIC datasets showed that this signature is associated with poor survival, invasive breast cancer types, and poor CD8+ T cell infiltration in human tumors. We anticipate that our method for directly identifying the molecular determinants of EV secretion will have broad applications across cell types and diseases.
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Extracellular vesicles (EVs) mediate communication in health and disease. Conventional assays are limited in profiling EVs secreted from large populations of cells and cannot map EV secretion onto individual cells and their functional profiles. We developed a high-throughput single-cell technique that enabled the mapping of dynamics of EV secretion. By utilizing breast cancer cell lines, we established that EV secretion is heterogeneous at the single-cell level and that non-metastatic cancer cells can secrete specific subsets of EVs. Single-cell RNA sequencing confirmed that pathways related to EV secretion were enriched in the non-metastatic cells compared with metastatic cells. We established isogenic clonal cell lines from non-metastatic cells with differing propensities for CD81+CD63+EV secretion and showed for the first time that specificity in EV secretion is an inheritable property preserved during cell division. Combined in vitro and animal studies with these cell lines suggested that CD81+CD63+EV secretion can impede tumor formation. In human non-metastatic breast tumors, tumors enriched in signatures of CD81+CD63+EV have a better prognosis, higher immune cytolytic activity, and enrichment of pro-inflammatory macrophages compared with tumors with low CD81+CD63+EVs signatures. Our single-cell methodology enables the direct integration of EV secretion with multiple cellular functions and enables new insights into cell/disease biology.
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Despite remarkable progress in the development and authorization of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is a need to validate vaccine platforms for broader application. The current intramuscular vaccines are designed to elicit systemic immunity without conferring mucosal immunity in the nasal compartment, which is the first barrier that SARS-CoV-2 virus breaches before dissemination to the lung. We report the development of an intranasal subunit vaccine that uses lyophilized spike protein and liposomal STING agonist as an adjuvant. This vaccine induces systemic neutralizing antibodies, IgA in the lung and nasal compartments, and T-cell responses in the lung of mice. Single-cell RNA sequencing confirmed the coordinated activation of T/B-cell responses in a germinal center-like manner within the nasal-associated lymphoid tissues, confirming its role as an inductive site to enable durable immunity. The ability to elicit immunity in the respiratory tract can prevent the establishment of infection in individuals and prevent disease transmission.
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Chimeric antigen receptor (CAR) T-cells targeting CD19 demonstrate remarkable efficacy in treating B-lineage acute lymphoblastic leukemia (BL-ALL), yet up to 39% of treated patients relapse with CD19(-) disease. We report that CD19(-) escape is associated with downregulation, but preservation, of targetable expression of CD20 and CD22. Accordingly, we reasoned that broadening the spectrum of CD19CAR T-cells to include both CD20 and CD22 would enable them to target CD19(-) escape BL-ALL while preserving their upfront efficacy. We created a CD19/20/22-targeting CAR T-cell by coexpressing individual CAR molecules on a single T-cell using one tricistronic transgene. CD19/20/22CAR T-cells killed CD19(-) blasts from patients who relapsed after CD19CAR T-cell therapy and CRISPR/Cas9 CD19 knockout primary BL-ALL both in vitro and in an animal model, while CD19CAR T-cells were ineffective. At the subcellular level, CD19/20/22CAR T-cells formed dense immune synapses with target cells that mediated effective cytolytic complex formation, were efficient serial killers in single-cell tracking studies, and were as efficacious as CD19CAR T-cells against primary CD19(+) disease. In conclusion, independent of CD19 expression, CD19/20/22CAR T-cells could be used as salvage or front-line CAR therapy for patients with recalcitrant disease.
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Antígenos CD19/inmunología , Inmunoterapia Adoptiva , Leucemia de Células B/inmunología , Leucemia de Células B/metabolismo , Receptores de Antígenos de Linfocitos T/inmunología , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Animales , Antígenos CD19/química , Antígenos de Neoplasias , Biomarcadores , Línea Celular Tumoral , Citocinas/metabolismo , Citotoxicidad Inmunológica , Modelos Animales de Enfermedad , Expresión Génica , Humanos , Inmunoterapia Adoptiva/métodos , Leucemia de Células B/genética , Leucemia de Células B/terapia , Ratones Transgénicos , Unión Proteica , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores Quiméricos de Antígenos/genética , Receptores Quiméricos de Antígenos/metabolismo , Relación Estructura-Actividad , Transducción Genética , Transgenes , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A safe and durable vaccine is urgently needed to tackle the COVID19 pandemic that has infected >15 million people and caused >620,000 deaths worldwide. As with other respiratory pathogens, the nasal compartment is the first barrier that needs to be breached by the SARS-CoV-2 virus before dissemination to the lung. Despite progress at remarkable speed, current intramuscular vaccines are designed to elicit systemic immunity without conferring mucosal immunity. We report the development of an intranasal subunit vaccine that contains the trimeric or monomeric spike protein and liposomal STING agonist as adjuvant. This vaccine induces systemic neutralizing antibodies, mucosal IgA responses in the lung and nasal compartments, and T-cell responses in the lung of mice. Single-cell RNA-sequencing confirmed the concomitant activation of T and B cell responses in a germinal center-like manner within the nasal-associated lymphoid tissues (NALT), confirming its role as an inductive site that can lead to long-lasting immunity. The ability to elicit immunity in the respiratory tract has can prevent the initial establishment of infection in individuals and prevent disease transmission across humans.
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Transgenic coexpression of a class I-restricted tumor antigen-specific T cell receptor (TCR) and CD8αß (TCR8) redirects antigen specificity of CD4+ T cells. Reinforcement of biophysical properties and early TCR signaling explain how redirected CD4+ T cells recognize target cells, but the transcriptional basis for their acquired antitumor function remains elusive. We, therefore, interrogated redirected human CD4+ and CD8+ T cells by single-cell RNA sequencing and characterized them experimentally in bulk and single-cell assays and a mouse xenograft model. TCR8 expression enhanced CD8+ T cell function and preserved less differentiated CD4+ and CD8+ T cells after tumor challenge. TCR8+CD4+ T cells were most potent by activating multiple transcriptional programs associated with enhanced antitumor function. We found sustained activation of cytotoxicity, costimulation, oxidative phosphorylation- and proliferation-related genes, and simultaneously reduced differentiation and exhaustion. Our study identifies molecular features of TCR8 expression that can guide the development of enhanced immunotherapies.
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Linfocitos T CD8-positivos , Neoplasias , Animales , Linfocitos T CD4-Positivos , Antígenos CD8 , Humanos , Ratones , Neoplasias/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , TranscriptomaRESUMEN
Natural killer (NK) cells are a highly heterogeneous population of innate lymphocytes that constitute our first line of defense against several types of tumors and microbial infections. Understanding the heterogeneity of these lymphocytes requires the ability to integrate their underlying phenotype with dynamic functional behaviors. We have developed and validated a single-cell methodology that integrates cellular phenotyping and dynamic cytokine secretion based on nanowell arrays and bead-based molecular biosensors. We demonstrate the robust passivation of the polydimethylsiloxane (PDMS)-based nanowells arrays with polyethylene glycol (PEG) and validated our assay by comparison to enzyme-linked immunospot (ELISPOT) assays. We used numerical simulations to optimize the molecular density of antibodies on the surface of the beads as a function of the capture efficiency of cytokines within an open-well system. Analysis of hundreds of individual human peripheral blood NK cells profiled ex vivo revealed that CD56dimCD16+ NK cells are immediate secretors of interferon gamma (IFN-γ) upon activation by phorbol 12-myristate 13-acetate (PMA) and ionomycin (< 3 h), and that there was no evidence of cooperation between NK cells leading to either synergistic activation or faster IFN-γ secretion. Furthermore, we observed that both the amount and rate of IFN-γ secretion from individual NK cells were donor-dependent. Collectively, these results establish our methodology as an investigational tool for combining phenotyping and real-time protein secretion of individual cells in a high-throughput manner.
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Citocinas/metabolismo , Inmunofenotipificación , Células Asesinas Naturales/inmunología , Antígeno CD56/inmunología , Dimetilpolisiloxanos , Ensayo de Inmunoadsorción Enzimática , Proteínas Ligadas a GPI/inmunología , Humanos , Células Asesinas Naturales/efectos de los fármacos , Receptores de IgG/inmunología , Análisis de la Célula Individual , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Galiximab (anti-CD80 monoclonal antibody) is a primatized (human IgG1 constant regions and cynomologus macaque variable regions) monoclonal antibody that is currently in clinical trials. Galiximab inhibits tumor cell proliferation through possibly cell signaling-mediated effects. Thus, we hypothesized that galiximab may signal the tumor cells and modify intracellular survival/antiapoptotic pathways such as the NF-κB pathway. This hypothesis was tested using various CD80(+) Burkitt B-NHL (non-Hodgkin lymphomas) cell lines as models. Treatment of B-NHL cells with galiximab (25-100 µg/mL) resulted in significant inhibition of NF-κB activity and its target resistant factors such as YY1, Snail, and Bcl-2/Bcl-XL. Treatment of B-NHL cells with galiximab sensitized the tumor cells to both cis-diamminedichloroplatinum(II) (CDDP)- and TRAIL-induced apoptosis. The important roles of YY1- and Snail-induced inhibition by galiximab in the sensitization to CCDP and TRAIL were corroborated following transfection of Raji cells with YY1 or Snail short interfering RNA. The transfected cells were shown to become sensitive to both CCDP- and TRAIL-induced apoptosis in the absence of galiximab. Furthermore, knockdown of YY1 or Snail inhibited Bcl-XL. The involvement of Bcl-XL inhibition in sensitization was corroborated by the use of the pan-Bcl-2 inhibitor 2MAM-3 whereby the treated cells were sensitive to both CDDP- and TRAIL-induced apoptosis. These findings show that galiximab inhibits the NF-κB/Snail/YY1/Bcl-XL circuit that regulates drug resistance in B-NHL and in combination with cytotoxic drugs results in apoptosis. The findings also support the therapeutic application of the combination of galiximab and cytotoxic drugs in the treatment of drug-resistant CD80-positive B-cell malignancies.
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Anticuerpos Monoclonales/farmacología , Apoptosis/efectos de los fármacos , FN-kappa B/metabolismo , Factores de Transcripción/metabolismo , Factor de Transcripción YY1/metabolismo , Proteína bcl-X/metabolismo , Anticuerpos Monoclonales/inmunología , Antígenos CD20/inmunología , Antígenos CD20/metabolismo , Antineoplásicos/farmacología , Western Blotting , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cisplatino/farmacología , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos/efectos de los fármacos , Sinergismo Farmacológico , Humanos , Linfoma de Células B/genética , Linfoma de Células B/metabolismo , Linfoma de Células B/patología , Interferencia de ARN , Transducción de Señal/efectos de los fármacos , Factores de Transcripción de la Familia Snail , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Factores de Transcripción/genética , Factor de Transcripción YY1/genética , Proteína bcl-X/antagonistas & inhibidoresRESUMEN
Rituximab (anti-CD20 mAb) mediates antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and apoptosis in B-NHL cells. The contribution of other host-mediated cytotoxic effects has not been examined. The expression of death-inducing ligands (e.g. TRAIL) by host effector cells may contribute to the mechanism of tumor cell destruction in vivo by rituximab-mediated sensitization of resistant B-cell non-Hodgkin lymphoma (B-NHL) cells. We have examined the sensitizing activity of rituximab on B-NHL cell lines resistant to TRAIL (as model) and natural killer (NK)-induced apoptosis. Treatment of TRAIL-resistant B-NHL cell lines with rituximab sensitized the cells to TRAIL apoptosis and synergy was achieved via activation of the type II mitochondrial pathway for apoptosis. Further, rituximab (Fab')(2)-treated tumor cells were killed by purified peripheral blood-derived NK cells via TRAIL. Treatment of B-NHL cells with rituximab inhibited both YY1 DNA-binding activity and expression. Rituximab-mediated sensitization to TRAIL apoptosis was due, in large part, to rituximab-mediated inhibition of the transcription factor Yin Yang 1 (YY1). The direct role of YY1 in TRAIL sensitization by rituximab was shown in cells transfected with YY1 siRNA, and such cells mimicked rituximab and became sensitive to TRAIL-induced apoptosis. These data suggest that, in vivo, host effector cells expressing TRAIL may contribute to rituximab-mediated depletion of B-NHL cells.
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Anticuerpos Monoclonales de Origen Murino/uso terapéutico , Apoptosis/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Linfoma de Células B/metabolismo , Linfoma de Células B/prevención & control , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Western Blotting , Proliferación Celular/efectos de los fármacos , Sinergismo Farmacológico , Ensayo de Cambio de Movilidad Electroforética , Citometría de Flujo , Humanos , Técnicas para Inmunoenzimas , Linfoma de Células B/patología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , ARN Interferente Pequeño/genética , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF , Proteínas Recombinantes , Rituximab , Células Tumorales Cultivadas , Factor de Transcripción YY1/antagonistas & inhibidores , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismoRESUMEN
The pan Bcl-2 family antagonist Obatoclax (GX15-070), currently in clinical trials, was shown to sensitize TRAIL-resistant tumors to TRAIL-mediated apoptosis via the release of Bak and Bim from Mcl-1 or Bcl-2/Bcl-XL complexes or by the activation of Bax, though other mechanisms were not examined. Herein, we hypothesize that Obatoclax-mediated sensitization to TRAIL apoptosis may also result from alterations of the apoptotic pathways. The TRAIL-resistant B-cell line Ramos was used as a model for investigation. Treatment of Ramos cells with Obatoclax significantly inhibited the expression of several members of the Bcl-2 family, dissociated Bak from Mcl-1 and inhibited the NFκB activity. Cells treated with Mcl-1 siRNA were sensitized to TRAIL apoptosis. We examined whether the sensitization of Ramos to TRAIL by Obatoclax resulted from signaling of the DR4 and/or DR5. Transfection with DR5 siRNA, but not with DR4 siRNA, sensitized the cells to apoptosis following treatment with Obatoclax and TRAIL. The signaling via DR5 correlated with Obatoclax-induced inhibition of the DR5 repressor Yin Yang 1 (YY1). Transfection with YY1 siRNA sensitized the cells to TRAIL apoptosis following treatment with Obatoclax and TRAIL. Overall, the present findings reveal a new mechanism of Obatoclax-induced sensitization to TRAIL apoptosis and the involvement of the inhibition of NFκB activity and downstream Mcl-1 and YY1 expressions and activities.
Asunto(s)
Apoptosis/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Pirroles/farmacología , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Factor de Transcripción YY1/metabolismo , Linfocitos B/efectos de los fármacos , Linfocitos B/metabolismo , Línea Celular , Resistencia a Antineoplásicos , Humanos , Indoles , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , FN-kappa B/antagonistas & inhibidores , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Interferencia de ARN , ARN Interferente Pequeño , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/genética , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Factor de Transcripción YY1/genéticaRESUMEN
Treatment of patients with relapsed or refractory low grade follicular B-NHL lymphoma with rituximab (chimeric anti-CD20 mAb) has resulted in approximately 50% response rate. The mechanism underlying the failure of rituximab to affect the remaining 50% of the patients is not clear, though their tumors express CD20. The in vivo effector functions of rituximab include ADCC, CDC and seldom apoptosis. In addition, we have reported that rituximab signals the cells and inhibits several intracellular cell survival pathways that are responsible for the immuno and chemo-sensitizing effects of rituximab on resistant B-NHL cell lines. The objective of this study was to develop novel and fully humanized anti-CD20 monoclonal antibodies with enhanced effector functions and molecular signaling that may potentiate their therapeutic efficacy. Novel humanized anti-CD20 monoclonal antibodies were derived from a chimerized form of murine anti-CD20 1K11791, shown to exert a more potent ADCC, CDC and apoptotic activities compared to rituximab. A representative humanized monoclonal antibody, BM-ca was used to examine its biological effect and molecular signaling using Ramos B-NHL cell line as a model. The studies were also performed in parallel with rituximab treatment for comparison. Ramos cells were treated with various concentrations of BM-ca monoclonal antibody. Inhibition of cell proliferation was observed in a concentration-dependent manner, suggesting cell signal perturbations must have occurred. Compared to untreated cells, treatment with BM-ca inhibited both the constitutively activated NF-kappaB and p38 MAPK pathways, as assessed by inhibition of both phospho-p65 and phospho-IkappaBalpha and phospho-p38, respectively, but not the unphosphorylated forms. BM-ca significantly induced the expression of the metastasis suppressor and immune surveillance cancer gene product, Raf-1 kinase inhibitor protein (RKIP). These alterations resulted in inhibition of anti-apoptotic gene products and sensitized Ramos cells to apoptosis by CDDP. In comparison with rituximab, BM-ca showed qualitative and quantitative differences in the above analyses. These findings demonstrate that BM-ca triggers CD20 expressing B-NHL cells resulting in a significant alteration of several gene products that regulate cell growth and chemoresistance.