RESUMEN
Human T-cell leukemia virus type 1 (HTLV-1) infection is linked to the development of adult T-cell leukemia/lymphoma (ATLL) and the neuroinflammatory disease, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-1 Tax oncoprotein regulates viral gene expression and persistently activates NF-κB to maintain the viability of HTLV-1-infected T cells. Here, we utilize a kinome-wide shRNA screen to identify the tyrosine kinase KDR as an essential survival factor of HTLV-1-transformed cells. Inhibition of KDR specifically induces apoptosis of Tax expressing HTLV-1-transformed cell lines and CD4 + T cells from HAM/TSP patients. Furthermore, inhibition of KDR triggers the autophagic degradation of Tax resulting in impaired NF-κB activation and diminished viral transmission in co-culture assays. Tax induces the expression of KDR, forms a complex with KDR, and is phosphorylated by KDR. These findings suggest that Tax stability is dependent on KDR activity which could be exploited as a strategy to target Tax in HTLV-1-associated diseases.
Asunto(s)
Supervivencia Celular , Productos del Gen tax , Virus Linfotrópico T Tipo 1 Humano , FN-kappa B , Paraparesia Espástica Tropical , Receptor 2 de Factores de Crecimiento Endotelial Vascular , Humanos , Productos del Gen tax/metabolismo , Productos del Gen tax/genética , Virus Linfotrópico T Tipo 1 Humano/patogenicidad , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 1 Humano/fisiología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/genética , FN-kappa B/metabolismo , Paraparesia Espástica Tropical/virología , Paraparesia Espástica Tropical/metabolismo , Apoptosis , Infecciones por HTLV-I/virología , Infecciones por HTLV-I/metabolismo , Linfocitos T CD4-Positivos/virología , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T/metabolismo , Linfocitos T/virología , Leucemia-Linfoma de Células T del Adulto/virología , Leucemia-Linfoma de Células T del Adulto/metabolismo , Leucemia-Linfoma de Células T del Adulto/genética , Leucemia-Linfoma de Células T del Adulto/patología , Fosforilación , Células HEK293RESUMEN
Human T-cell leukemia virus type 1 (HTLV-1) is the etiological agent of adult T-cell leukemia/lymphoma. The HTLV-1 Tax constitutively activates nuclear factor-κB (NF-κB) to promote the survival and transformation of HTLV-1-infected T cells. Despite extensive study of Tax, how Tax interacts with host factors to regulate NF-κB activation and HTLV-1-driven cell proliferation is not entirely clear. Here, we showed that overexpression of Poly (rC)-binding protein 1 (PCBP1) promoted Tax-mediated IκB kinase (IKK)-NF-κB signaling activation, whereas knockdown of PCBP1 attenuated Tax-dependent IKK-NF-κB activation. However, Tax activation of HTLV-1 long terminal repeat was unaffected by PCBP1. Furthermore, depletion of PCBP1 led to apoptosis and reduced proliferation of HTLV-1-transformed cells. Mechanistically, PCBP1 interacted and co-localized with Tax in the cytoplasm, and PCBP1 KH3 domain was indispensable for the interaction between PCBP1 and Tax. Moreover, PCBP1 facilitated the assembly of Tax/IKK complex. Collectively, our results demonstrated that PCBP1 may exert an essential effect in Tax/IKK complex combination and subsequent NF-κB activation, which provides a novel insight into the pathogenetic mechanisms of HTLV-1.
Asunto(s)
Proteínas de Unión al ADN , Productos del Gen tax , Ribonucleoproteínas Nucleares Heterogéneas , Virus Linfotrópico T Tipo 1 Humano , FN-kappa B , Proteínas de Unión al ARN , Humanos , Productos del Gen tax/metabolismo , FN-kappa B/metabolismo , Virus Linfotrópico T Tipo 1 Humano/fisiología , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas/genética , Transducción de Señal , Células HEK293 , Unión Proteica , Proliferación Celular , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/virología , Apoptosis , Quinasa I-kappa B/metabolismo , Interacciones Huésped-PatógenoRESUMEN
Hypoxia regulates fibroblast function by changing intracellular signaling and secretion factors, that influence the states of nearby cells. In this work, we investigated how medium (CM) from human adult dermal fibroblasts (HDFs) cultured in normoxic and hypoxic conditions affected cervical cancer (HeLa) cells. The HeLa cells showed decreased cell viability, increased apoptosis, and cell cycle arrest in response to CM from hypoxic-cultured HDFs (H-CM) compared with CM from normoxic-cultured HDFs (N-CM). Among the proteins up-regulated (>2-fold) in H-CM compared with N-CM, lymphotoxin-beta receptor (LTBR) decreased the viability of HeLa cells. Among the intracellular proteins down-regulated (>2-fold) in HeLa cells treated with H-CM compared with N-CM, the most enriched biological process GO term and KEGG pathway were protein deubiquitination and hsa05166:HTLV-I infection, respectively. In the protein−protein interaction network of intracellular proteins with altered expression (>2-fold), 1 up-regulated (TNF) and 8 down-regulated (ESR1, MCL1, TBP, CD19, LCK, PCNA, CHEK1, and POLA1) hub proteins were defined. Among the down-regulated hub proteins, the most enriched biological process GO term and KEGG pathway were leading strand elongation and hsa05166:HTLV-I infection, respectively. This study reveals that H-CM had stronger anti-cancer effects on cervical cancer cells than N-CM and induced intracellular signaling patterns related to those enhanced anti-cancer effects.
Asunto(s)
Infecciones por HTLV-I , Neoplasias del Cuello Uterino , Adulto , Células Cultivadas , Medios de Cultivo Condicionados/farmacología , Femenino , Fibroblastos/metabolismo , Infecciones por HTLV-I/metabolismo , Células HeLa , Humanos , Hipoxia/metabolismo , Neoplasias del Cuello Uterino/metabolismoRESUMEN
After integration to the human genome as a provirus, human T-cell leukemia virus type 1 (HTLV-1) utilizes host T cell gene expression machinery for viral replication. The viral RNA-binding protein, Rex, is known to transport unspliced/incompletely spliced viral mRNAs encoding viral structural proteins out of the nucleus to enhance virus particle formation. However, the detailed mechanism of how Rex avoids extra splicing of unspliced/incompletely spliced viral mRNAs and stabilizes them for effective translation is still unclear. To elucidate the underlying molecular mechanism of Rex function, we comprehensively analyzed the changes in gene expression and splicing patterns in Rex-overexpressing T cells. In addition, we identified 81 human proteins interacting with Rex, involved in transcription, splicing, translation, and mRNA quality control. In particular, Rex interacts with NONO and SFPQ, which play important roles in the regulation of transcription and splicing. Accordingly, expression profiles and splicing patterns of a wide variety of genes are significantly changed in Rex-expressing T cells. Especially, the level of vPD-L1 mRNA that lacks the part of exon 4, thus encodes soluble PD-L1 was significantly increased in Rex-expressing cells. Overall, by integrated analysis of these three datasets, we showed for the first time that Rex intervenes the host gene expression machinery throughout the pathway, probably to escort viral unstable mRNAs from transcription (start) to translation (end). Upon exerting its function, Rex may alter the expression level and splicing patterns of various genes, thus influencing the phenotype of the host cell.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Productos del Gen rex/metabolismo , Infecciones por HTLV-I/metabolismo , Virus Linfotrópico T Tipo 1 Humano/genética , Proteínas de Unión al ARN/metabolismo , Replicación Viral/genética , Antígeno B7-H1/metabolismo , Línea Celular , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/genética , Regulación Viral de la Expresión Génica , Humanos , Factor de Empalme Asociado a PTB/metabolismo , Empalme del ARN , ARN Mensajero , Proteínas de Unión al ARN/genéticaRESUMEN
Human T-cell Leukemia Virus type-1 (HTLV-1) is an oncovirus that may cause two main life-threatening diseases including a cancer type named Adult T-cell Leukemia/Lymphoma (ATLL) and a neurological and immune disturbance known as HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). However, a large number of the infected subjects remain as asymptomatic carriers (ACs). There is no comprehensive study that determines which dysregulated genes differentiate the pathogenesis routes toward ATLL or HAM/TSP. Therefore, two main algorithms including weighted gene co-expression analysis (WGCNA) and multi-class support vector machines (SVM) were utilized to find major gene players in each condition. WGCNA was used to find the highly co-regulated genes and multi-class SVM was employed to identify the most important classifier genes. The identified modules from WGCNA were validated in the external datasets. Furthermore, to find specific modules for ATLL and HAM/TSP, the non-preserved modules in another condition were found. In the next step, a model was constructed by multi-class SVM. The results revealed 467, 3249, and 716 classifiers for ACs, ATLL, and HAM/TSP, respectively. Eventually, the common genes between the WGCNA results and classifier genes resulted from multi-class SVM that also determined as differentially expressed genes, were identified. Through these step-wise analyses, PAIP1, BCAS2, COPS2, CTNNB1, FASLG, GTPBP1, HNRNPA1, RBBP6, TOP1, SLC9A1, JMY, PABPC3, and PBX1 were found as the possible critical genes involved in the progression of ATLL. Moreover, FBXO9, ZNF526, ERCC8, WDR5, and XRCC3 were identified as the conceivable major involved genes in the development of HAM/TSP. These genes can be proposed as specific biomarker candidates and therapeutic targets for each disease.
Asunto(s)
Regulación de la Expresión Génica , Marcadores Genéticos , Infecciones por HTLV-I/complicaciones , Virus Linfotrópico T Tipo 1 Humano/genética , Leucemia-Linfoma de Células T del Adulto/patología , Enfermedades del Sistema Nervioso/patología , Máquina de Vectores de Soporte , Perfilación de la Expresión Génica , Infecciones por HTLV-I/genética , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/virología , Humanos , Leucemia-Linfoma de Células T del Adulto/etiología , Leucemia-Linfoma de Células T del Adulto/metabolismo , Enfermedades del Sistema Nervioso/etiología , Enfermedades del Sistema Nervioso/metabolismoRESUMEN
The Pim family of serine/threonine kinases promote tumorigenesis by enhancing cell survival and inhibiting apoptosis. Three isoforms exist, Pim-1, -2, and -3, that are highly expressed in hematological cancers, including Pim-1 in adult T-cell leukemia (ATL). Human T-cell leukemia virus type-1 (HTLV-1) is the etiological agent of ATL, a dismal lymphoproliferative disease known as adult T-cell leukemia. The HTLV-1 virally encoded oncogene Tax promotes CD4+ T-cell transformation through disruption of DNA repair pathways and activation of survival and cellular proliferation pathways. In this study, we found Tax increases the expression of Pim-1 and Pim-3, while decreasing Pim-2 expression. Furthermore, we discovered that Pim-1, -2, and -3 bind Tax protein to reduce its expression thereby creating a feedback regulatory loop between these two oncogenes. The loss of Tax expression triggered by Pim kinases led to loss in Tax-mediated transactivation of the HTLV-1 long terminal repeat (LTR) and reductions in HTLV-1 virus replication. Because Tax is also the immunodominant cytotoxic T cell lymphocytes (CTL) target, our data suggest that Pim kinases may play an important role in immune escape of HTLV-1-infected cells. IMPORTANCE The Pim family of protein kinases have established pro-oncogenic functions. They are often upregulated in cancer; especially leukemias and lymphomas. In addition, a role for Pim kinases in control of virus expression and viral latency is important for Kaposi sarcoma-associated herpesvirus (KSHV) and human immunodeficiency virus type 1 (HIV-1). Our data demonstrate that HTLV-1 encodes viral genes that promote and maintain Pim kinase activation, which in turn may stimulate T-cell transformation and maintain ATL leukemic cell growth. HTLV-1 Tax increases expression of Pim-1 and Pim-3, while decreasing expression of Pim-2. In ATL cells, Pim expression is maintained through extended protein half-life and heat shock protection. In addition, we found that Pim kinases have a new role during HTLV-1 infection. Pim-1, -2, and -3 can subvert Tax expression and HTLV-1 virus production. This may lead to partial suppression of the host immunogenic responses to Tax and favor immune escape of HTLV-1-infected cells. Therefore, Pim kinases have not only pro-oncogenic roles but also favor persistence of the virus-infected cell.
Asunto(s)
Productos del Gen tax/metabolismo , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/virología , Interacciones Huésped-Patógeno , Virus Linfotrópico T Tipo 1 Humano/fisiología , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , Replicación Viral , Línea Celular , Susceptibilidad a Enfermedades , Regulación Viral de la Expresión Génica , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Modelos Moleculares , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Secuencias Repetidas Terminales , Factores de Transcripción/metabolismoRESUMEN
The human T-cell leukemia virus type 1 (HTLV-1)-encoded transactivator and oncoprotein Tax-1 is essential for HTLV-1 replication. We recently found that Tax-1 interacts with transcription elongation factor for RNA polymerase II 2, ELL2, which enhances Tax-1-mediated transactivation of the HTLV-1 promotor. Here, we characterize the Tax-1:ELL2 interaction and its impact on viral transactivation by confocal imaging, co-immunoprecipitation, and luciferase assays. We found that Tax-1 and ELL2 not only co-precipitate, but also co-localize in dot-like structures in the nucleus. Tax-1:ELL2 complex formation occurred independently of Tax-1 point mutations, which are crucial for post translational modifications (PTMs) of Tax-1, suggesting that these PTMs are irrelevant for Tax-1:ELL2 interaction. In contrast, Tax-1 deletion mutants lacking either N-terminal (aa 1-37) or C-terminal regions (aa 150-353) of Tax-1 were impaired in interacting with ELL2. Contrary to Tax-1, the related, non-oncogenic Tax-2B from HTLV-2B did not interact with ELL2. Finally, we found that ELL2-R1 (aa 1-353), which carries an RNA polymerase II binding domain, and ELL2-R3 (aa 515-640) are sufficient to interact with Tax-1; however, only ELL2-truncations expressing R1 could enhance Tax-1-mediated transactivation of the HTLV-1 promoter. Together, this study identifies domains in Tax-1 and ELL2 being required for Tax-1:ELL2 complex formation and for viral transactivation.
Asunto(s)
Infecciones por HTLV-I/metabolismo , Virus Linfotrópico T Tipo 1 Humano/fisiología , Transactivadores/metabolismo , Factores de Elongación Transcripcional/metabolismo , Proteínas Virales/metabolismo , Regulación Viral de la Expresión Génica , Células HEK293 , Interacciones Huésped-Patógeno , Virus Linfotrópico T Tipo 1 Humano/genética , Humanos , Proteínas Oncogénicas Virales/genética , Proteínas Oncogénicas Virales/metabolismo , Mutación Puntual , Mapas de Interacción de Proteínas , Transactivadores/genética , Activación Transcripcional , Proteínas Virales/genéticaRESUMEN
Human T-cell leukemia virus type 1 (HTLV-1) infects target cells primarily through cell-to-cell routes. Here, we provide evidence that cellular protein M-Sec plays a critical role in this process. When purified and briefly cultured, CD4+ T cells of HTLV-1 carriers, but not of HTLV-1- individuals, expressed M-Sec. The viral protein Tax was revealed to mediate M-Sec induction. Knockdown or pharmacological inhibition of M-Sec reduced viral infection in multiple co-culture conditions. Furthermore, M-Sec knockdown reduced the number of proviral copies in the tissues of a mouse model of HTLV-1 infection. Phenotypically, M-Sec knockdown or inhibition reduced not only plasma membrane protrusions and migratory activity of cells, but also large clusters of Gag, a viral structural protein required for the formation of viral particles. Taken together, these results suggest that M-Sec induced by Tax mediates an efficient cell-to-cell viral infection, which is likely due to enhanced membrane protrusions, cell migration, and the clustering of Gag.
Asunto(s)
Membrana Celular/virología , Modelos Animales de Enfermedad , Productos del Gen tax/metabolismo , Infecciones por HTLV-I/transmisión , Virus Linfotrópico T Tipo 1 Humano/fisiología , Factores de Necrosis Tumoral/metabolismo , Proteínas Estructurales Virales/metabolismo , Animales , Membrana Celular/metabolismo , Movimiento Celular , Técnicas de Cocultivo , Productos del Gen tax/genética , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/virología , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Factores de Necrosis Tumoral/genética , Proteínas Estructurales Virales/genéticaRESUMEN
Viral infections are known to hijack the transcription and translation of the host cell. However, the extent to which viral proteins coordinate these perturbations remains unclear. Here we used a model system, the human T-cell leukemia virus type 1 (HTLV-1), and systematically analyzed the transcriptome and interactome of key effectors oncoviral proteins Tax and HBZ. We showed that Tax and HBZ target distinct but also common transcription factors. Unexpectedly, we also uncovered a large set of interactions with RNA-binding proteins, including the U2 auxiliary factor large subunit (U2AF2), a key cellular regulator of pre-mRNA splicing. We discovered that Tax and HBZ perturb the splicing landscape by altering cassette exons in opposing manners, with Tax inducing exon inclusion while HBZ induces exon exclusion. Among Tax- and HBZ-dependent splicing changes, we identify events that are also altered in Adult T cell leukemia/lymphoma (ATLL) samples from two independent patient cohorts, and in well-known cancer census genes. Our interactome mapping approach, applicable to other viral oncogenes, has identified spliceosome perturbation as a novel mechanism coordinated by Tax and HBZ to reprogram the transcriptome.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Productos del Gen tax/metabolismo , Infecciones por HTLV-I/metabolismo , Leucemia-Linfoma de Células T del Adulto/virología , Proteínas de los Retroviridae/metabolismo , Células HEK293 , Infecciones por HTLV-I/etiología , Virus Linfotrópico T Tipo 1 Humano , Humanos , Células Jurkat , Empalme del ARN , ARN Mensajero , Factor de Empalme U2AF/metabolismoRESUMEN
Since the discovery of the human T-cell leukemia virus-1 (HTLV-1), cellular and animal models have provided invaluable contributions in the knowledge of viral infection, transmission and progression of HTLV-associated diseases. HTLV-1 is the causative agent of the aggressive adult T-cell leukemia/lymphoma and inflammatory diseases such as the HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). Cell models contribute to defining the role of HTLV proteins, as well as the mechanisms of cell-to-cell transmission of the virus. Otherwise, selected and engineered animal models are currently applied to recapitulate in vivo the HTLV-1 associated pathogenesis and to verify the effectiveness of viral therapy and host immune response. Here we review the current cell models for studying virus-host interaction, cellular restriction factors and cell pathway deregulation mediated by HTLV products. We recapitulate the most effective animal models applied to investigate the pathogenesis of HTLV-1-associated diseases such as transgenic and humanized mice, rabbit and monkey models. Finally, we summarize the studies on STLV and BLV, two closely related HTLV-1 viruses in animals. The most recent anticancer and HAM/TSP therapies are also discussed in view of the most reliable experimental models that may accelerate the translation from the experimental findings to effective therapies in infected patients.
Asunto(s)
Modelos Animales de Enfermedad , Infecciones por HTLV-I , Virus Linfotrópico T Tipo 1 Humano , Leucemia-Linfoma de Células T del Adulto , Animales , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/patología , Infecciones por HTLV-I/terapia , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Virus Linfotrópico T Tipo 1 Humano/patogenicidad , Humanos , Leucemia-Linfoma de Células T del Adulto/metabolismo , Leucemia-Linfoma de Células T del Adulto/patología , Leucemia-Linfoma de Células T del Adulto/terapia , Ratones , Ratones TransgénicosRESUMEN
Human T-cell leukemia virus type 1 (HTLV-1) infection of host cells is mainly mediated by interactions with the viral envelope glycoprotein surface unit (SU) and three host receptors: heparan sulfate proteoglycan, neuropilin-1 (Nrp1), and glucose transporter type 1. Residues 90-94 of SU are considered as a Nrp1 binding site, and our previous results show that an SU peptide consisting of residues 85-94 can bind directly to the Nrp1 b1 domain with a binding affinity of 7.4 µM. Therefore, the SU peptide is expected to be a good model to investigate the SU-Nrp1 interaction. Recently, the N93D mutation in the Nrp1 b1 binding region of the SU was identified in symptomatic patients with HTLV-1 infections in the Brazilian Amazon. However, it remains unclear how the SU-N93D mutation affects Nrp1 b1 binding. To elucidate the impact of the substituted Asp93 of SU on Nrp1 b1 binding, we analyzed the interaction between the SU-N93D peptide and Nrp1 b1 using isothermal titration calorimetry and nuclear magnetic resonance. The SU-N93D peptide binds directly to Nrp1 b1 with a binding affinity of 3.5 µM, which is approximately two-fold stronger than wild-type. This stronger binding is likely a result of the interaction between the substituted residue Asp93 of the N93D peptide and the four residues Trp301, Lys347, Glu348, and Thr349 of Nrp1 b1. Our results suggest that the interaction of SU Asp93 with the four residues of Nrp1 b1 renders the high affinity of the N93D mutant for Nrp1 b1 binding during HTLV-1 entry.
Asunto(s)
Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/patogenicidad , Mutación Missense , Neuropilina-1/metabolismo , Proteínas del Envoltorio Viral/metabolismo , Sitios de Unión , Productos del Gen env , Infecciones por HTLV-I/metabolismo , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Humanos , Neuropilina-1/química , Unión Proteica , Proteínas Oncogénicas de Retroviridae , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genéticaRESUMEN
The impact of HIV co-infection on the plasma immunological biomarker profile of HTLV-1 infected patients was evaluated. The plasma levels of leukotrienes and chemokines/cytokines were quantified by ELISA and Cytometric Bead Array. A total of 138 volunteers were enrolled and divided into two subgroups ("HTLV-1(+)HIV(-)" and "HTLV-1(+)(HIV(+)"), which were categorized according to the HTLV-1-associated neurological disease (AS, pHAM and HAM). Reference controls were BD and HIV mono-infected patients. HAM(+) exhibited higher CD4+ T-cell counts as compared to HIV+ mono-infected patients and lower HTLV-1 proviral load as compared to mono-infected HAM(-) patients. AS(+) exhibited higher levels of CysLT, CXCL8/IL-8 and lower levels of CCL5/RANTES as compared to AS(-). Increased levels of IL-6 and TNF with reduced levels of CXCL10/IP10 and CCL5/RANTES were observed in co-infected pHAM(+) as compared to mono-infected pHAM(-). HAM(+) patients revealed an increase in CXCL8/IL-8, CCL2/MCP-1, CXCL-10/IP-10, TNF and a decrease in IL-2 as compared to HAM(-) subgroup.
Asunto(s)
Coinfección , Infecciones por VIH/inmunología , Infecciones por VIH/metabolismo , Infecciones por HTLV-I/inmunología , Infecciones por HTLV-I/metabolismo , Interacciones Huésped-Patógeno/inmunología , Virus Linfotrópico T Tipo 1 Humano/inmunología , Adulto , Biomarcadores , Recuento de Linfocito CD4 , Estudios Transversales , Citocinas/sangre , Citocinas/metabolismo , Susceptibilidad a Enfermedades , Femenino , Infecciones por VIH/virología , Infecciones por HTLV-I/virología , Interacciones Huésped-Patógeno/genética , Humanos , Leucotrienos/metabolismo , Masculino , Persona de Mediana Edad , Carga ViralRESUMEN
Here, we have attempted to address the timing of EV and virion release from virally infected cells. Uninfected (CEM), HIV-1-infected (J1.1), and human T cell leukemia virus-1 (HTLV-1)-infected (HUT102) cells were synchronized in G0. Viral latency was reversed by increasing gene expression with the addition of serum-rich media and inducers. Supernatants and cell pellets were collected post-induction at different timepoints and assayed for extracellular vesicle (EV) and autophagy markers; and for viral proteins and RNAs. Tetraspanins and autophagy-related proteins were found to be differentially secreted in HIV-1- and HTLV-1-infected cells when compared with uninfected controls. HIV-1 proteins were present at 6 h and their production increased up to 24 h. HTLV-1 proteins peaked at 6 h and plateaued. HIV-1 and HTLV-1 RNA production correlated with viral protein expression. Nanoparticle tracking analysis (NTA) showed increase of EV concentration over time in both uninfected and infected samples. Finally, the HIV-1 supernatant from the 6-h samples was found not to be infectious; however, the virus from the 24-h samples was successfully rescued and infectious. Overall, our data indicate that EV release may occur prior to viral release from infected cells, thereby implicating a potentially significant effect of EVs on uninfected recipient cells prior to subsequent viral infection and spread.
Asunto(s)
Vesículas Extracelulares/metabolismo , Infecciones por VIH/metabolismo , Infecciones por VIH/patología , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/patología , Virión/metabolismo , Apoptosis , Biomarcadores/metabolismo , Línea Celular , Medios de Cultivo Condicionados , Citocinas/metabolismo , VIH-1/fisiología , Virus Linfotrópico T Tipo 1 Humano/fisiología , Humanos , Modelos Biológicos , Células Mieloides/metabolismo , ARN Viral/metabolismo , Linfocitos T/metabolismoRESUMEN
Adult T cell leukemia (ATL) is an aggressive malignancy secondary to chronic infection by the human T-cell leukemia virus type 1 (HTLV-1) infection. Two viral proteins, Tax and HBZ, play central roles in ATL leukemogenesis. Tax expression transforms T cells in vitro and induces ATL-like disease in mice. Tax also induces a rough eye phenotype and increases hemocyte count in Drosophila melanogaster, indicative of transformation. Among multiple functions, Tax modulates the expression of the enhancer of zeste homolog 2 (EZH2), a methyltransferase of the Polycomb Repressive Complex 2 (PRC2), leading to H3K27me3-dependent reprogramming of around half of cellular genes. HBZ is a negative regulator of Tax-mediated viral transcription. HBZ effects on epigenetic signatures are underexplored. Here, we established an hbz transgenic fly model, and demonstrated that, unlike Tax, which induces NF-κB activation and enhanced PRC2 activity creating an activation loop, HBZ neither induces transformation nor NF-κB activation in vivo. However, overexpression of Tax or HBZ increases the PRC2 activity and both proteins directly interact with PRC2 complex core components. Importantly, overexpression of HBZ in tax transgenic flies prevents Tax-induced NF-κB or PRC2 activation and totally rescues Tax-induced transformation and senescence. Our results establish the in vivo antagonistic effect of HBZ on Tax-induced transformation and cellular effects. This study helps understanding long-term HTLV-1 persistence and cellular transformation and opens perspectives for new therapeutic strategies targeting the epigenetic machinery in ATL.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Senescencia Celular , Regulación Viral de la Expresión Génica , Productos del Gen tax/metabolismo , Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/fisiología , Proteínas de los Retroviridae/metabolismo , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Drosophila melanogaster , Productos del Gen tax/genética , Infecciones por HTLV-I/genética , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/patología , Células HeLa , Humanos , Proteínas de los Retroviridae/genéticaRESUMEN
Human T-cell lymphotropic virus type 1 (HTLV-1) infects 5-10 million people worldwide and is the causative agent of adult T-cell leukemia/lymphoma (ATLL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) as well as other inflammatory diseases. A major concern is that the most majority of individuals with HTLV-1 are asymptomatic carriers and that there is limited global attention by health care officials, setting up potential conditions for increased viral spread. HTLV-1 transmission occurs primarily through sexual intercourse, blood transfusion, intravenous drug usage, and breast feeding. Currently, there is no cure for HTLV-1 infection and only limited treatment options exist, such as class I interferons (IFN) and Zidovudine (AZT), with poor prognosis. Recently, small membrane-bound structures, known as extracellular vesicles (EVs), have received increased attention due to their potential to carry viral cargo (RNA and proteins) in multiple pathogenic infections (i.e., human immunodeficiency virus type I (HIV-1), Zika virus, and HTLV-1). In the case of HTLV-1, EVs isolated from the peripheral blood and cerebral spinal fluid (CSF) of HAM/TSP patients contained the viral transactivator protein Tax. Additionally, EVs derived from HTLV-1-infected cells (HTLV-1 EVs) promote functional effects such as cell aggregation which enhance viral spread. In this review, we present current knowledge surrounding EVs and their potential role as immune-modulating agents in cancer and other infectious diseases such as HTLV-1 and HIV-1. We discuss various features of EVs that make them prime targets for possible vehicles of future diagnostics and therapies.
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Comunicación Celular , Vesículas Extracelulares/metabolismo , Infecciones por HTLV-I/virología , Interacciones Huésped-Patógeno , Virus Linfotrópico T Tipo 1 Humano/fisiología , Biomarcadores , Manejo de la Enfermedad , Infecciones por HTLV-I/complicaciones , Infecciones por HTLV-I/epidemiología , Infecciones por HTLV-I/metabolismo , Humanos , Metabolismo de los Lípidos , Estudios Seroepidemiológicos , Carga ViralRESUMEN
Human T cell leukemia virus type 1 (HTLV-1) is mainly transmitted vertically through breast milk. The rate of mother-to-child transmission (MTCT) through formula feeding, although significantly lower than through breastfeeding, is approximately 2.4%-3.6%, suggesting the possibility of alternative transmission routes. MTCT of HTLV-1 might occur through the uterus, birth canal, or placental tissues; the latter is known as transplacental transmission. Here, we found that HTLV-1 proviral DNA was present in the placental villous tissues of the fetuses of nearly half of pregnant carriers and in a small number of cord blood samples. An RNA ISH assay showed that HTLV-1-expressing cells were present in nearly all subjects with HTLV-1-positive placental villous tissues, and their frequency was significantly higher in subjects with HTLV-1-positive cord blood samples. Furthermore, placental villous trophoblasts expressed HTLV-1 receptors and showed increased susceptibility to HTLV-1 infection. In addition, HTLV-1-infected trophoblasts expressed high levels of viral antigens and promoted the de novo infection of target T cells in a humanized mouse model. In summary, during pregnancy of HTLV-1 carriers, HTLV-1 was highly expressed in placental villous tissues, and villous trophoblasts showed high HTLV-1 sensitivity, suggesting that MTCT of HTLV-1 occurs through the placenta.
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Infecciones por HTLV-I/metabolismo , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Transmisión Vertical de Enfermedad Infecciosa , Complicaciones Infecciosas del Embarazo/metabolismo , Trofoblastos/metabolismo , Adulto , Células Cultivadas , Femenino , Infecciones por HTLV-I/patología , Infecciones por HTLV-I/transmisión , Humanos , Embarazo , Complicaciones Infecciosas del Embarazo/patología , Complicaciones Infecciosas del Embarazo/virología , Trofoblastos/patología , Trofoblastos/virologíaRESUMEN
BACKGROUND: Adult T-cell leukemia lymphoma (ATLL) is a chemotherapy-resistant malignancy with a median survival of less than one year that will afflict between one hundred thousand and one million individuals worldwide who are currently infected with human T-cell leukemia virus type 1. Recurrent somatic mutations in host genes have exposed the T-cell receptor pathway through nuclear factor κB to interferon regulatory factor 4 (IRF4) as an essential driver for this malignancy. We sought to determine if IRF4 represents a therapeutic target for ATLL and to identify downstream effectors and biomarkers of IRF4 signaling in vivo. RESULTS: ATLL cell lines, particularly Tax viral oncoprotein-negative cell lines, that most closely resemble ATLL in humans, were sensitive to dose- and time-dependent inhibition by a next-generation class of IRF4 antisense oligonucleotides (ASOs) that employ constrained ethyl residues that mediate RNase H-dependent RNA degradation. ATLL cell lines were also sensitive to lenalidomide, which repressed IRF4 expression. Both ASOs and lenalidomide inhibited ATLL proliferation in vitro and in vivo. To identify biomarkers of IRF4-mediated CD4 + T-cell expansion in vivo, transcriptomic analysis identified several genes that encode key regulators of ATLL, including interleukin 2 receptor subunits α and ß, KIT ligand, cytotoxic T-lymphocyte-associated protein 4, and thymocyte selection-associated high mobility group protein TOX 2. CONCLUSIONS: These data support the pursuit of IRF4 as a therapeutic target in ATLL with the use of either ASOs or lenalidomide.
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Infecciones por HTLV-I/metabolismo , Factores Reguladores del Interferón/metabolismo , Leucemia-Linfoma de Células T del Adulto/metabolismo , Animales , Linfocitos T CD4-Positivos/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Productos del Gen tax/metabolismo , Infecciones por HTLV-I/tratamiento farmacológico , Infecciones por HTLV-I/patología , Virus Linfotrópico T Tipo 1 Humano , Humanos , Factores Reguladores del Interferón/genética , Lenalidomida/farmacología , Leucemia-Linfoma de Células T del Adulto/tratamiento farmacológico , Leucemia-Linfoma de Células T del Adulto/patología , Ratones , Oligonucleótidos Antisentido/farmacología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Tionucleótidos/farmacologíaAsunto(s)
Infecciones por HTLV-I , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Células de Reed-Sternberg , Anciano , Infecciones por HTLV-I/diagnóstico por imagen , Infecciones por HTLV-I/metabolismo , Infecciones por HTLV-I/patología , Humanos , Masculino , Células de Reed-Sternberg/metabolismo , Células de Reed-Sternberg/patología , Células de Reed-Sternberg/virologíaRESUMEN
Establishing latent infection but retaining the capability to reactivate in certain circumstance is an ingenious tactic for retroviruses to persist in vivo while evading host immune surveillance. Many evidences indicate that Human T-cell leukemia virus type 1 (HTLV-1) is not completely silent in vivo. However, signals that trigger HTLV-1 latency-reactivation switching remain poorly understood. Here, we show that aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, plays a critical role in HTLV-1 plus-strand expression. Importantly, HTLV-1 reactivation could be tunably manipulated by modulating the level of AHR ligands. Mechanistically, activated AHR binds to HTLV-1 LTR dioxin response element (DRE) site (CACGCATAT) and drives plus-strand transcription. On the other hand, persistent activation of nuclear factor kappa B (NF-κB) pathway constitutes one key prerequisite for AHR overexpression in HTLV-1 infected T-cells, setting the stage for the advent of AHR signaling. Our findings suggest that HTLV-1 might achieve its reactivation in vivo when encountering environmental, dietary, microbial and metabolic cues that induce sufficient AHR signaling.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Infecciones por HTLV-I/virología , Virus Linfotrópico T Tipo 1 Humano/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Activación Viral/fisiología , Latencia del Virus/fisiología , Línea Celular , Infecciones por HTLV-I/metabolismo , Humanos , Linfocitos T/virologíaRESUMEN
Ivermectin is a widely used drug for the treatment of various neglected tropical diseases, such as lymphatic filariasis, onchocerciasis, and strongyloidiasis among others. Despite its excellent safety profile, there are few published studies of the use of ivermectin in children, pregnant and nursing women. In the present study, we report clinical data on ivermectin concentrations in breastmilk of a woman with Strongyloides stercoralis and HTLV-I coinfection. Ivermectin levels in breastmilk ranged from 1.4 to 20.8 ng/ml, with a mean of 9.26 ng/ml after a single dose of 200 µg/kg. We estimated the possible ivermectin exposure of the infant to be 1.1 µg/kg, 0.55% of the weight-adjusted percentage of the maternal dose. This value is largely under the threshold established by the World Health Organization for safe breastfeeding. Our results bolster previous findings on the secretion of ivermectin into breastmilk in healthy volunteers. The findings from this case study do not support exclusion of lactating women or interrupting lactation to accommodate it.