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The transcription profile of Tax-3 is more similar to Tax-1 than Tax-2: insights into HTLV-3 potential leukemogenic properties.

Chevalier SA, Durand S, Dasgupta A, Radonovich M, Cimarelli A, Brady JN, Mahieux R, Pise-Masison CA - PLoS ONE (2012)

Bottom Line: These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation.The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation.In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo.

View Article: PubMed Central - PubMed

Affiliation: Virus Tumor Biology Section, Laboratory of Cellular Oncology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America. sebastien.chevalier@ens-lyon.fr

ABSTRACT
Human T-cell Lymphotropic Viruses type 1 (HTLV-1) is the etiological agent of Adult T-cell Leukemia/Lymphoma. Although associated with lymphocytosis, HTLV-2 infection is not associated with any malignant hematological disease. Similarly, no infection-related symptom has been detected in HTLV-3-infected individuals studied so far. Differences in individual Tax transcriptional activity might account for these distinct physiopathological outcomes. Tax-1 and Tax-3 possess a PDZ binding motif in their sequence. Interestingly, this motif, which is critical for Tax-1 transforming activity, is absent from Tax-2. We used the DNA microarray technology to analyze and compare the global gene expression profiles of different T- and non T-cell types expressing Tax-1, Tax-2 or Tax-3 viral transactivators. In a T-cell line, this analysis allowed us to identify 48 genes whose expression is commonly affected by all Tax proteins and are hence characteristic of the HTLV infection, independently of the virus type. Importantly, we also identified a subset of genes (n = 70) which are specifically up-regulated by Tax-1 and Tax-3, while Tax-1 and Tax-2 shared only 1 gene and Tax-2 and Tax-3 shared 8 genes. These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation. Analysis of the molecular interactions existing between those Tax-1/Tax-3 deregulated genes then allowed us to highlight biological networks of genes characteristic of HTLV-1 and HTLV-3 infection. The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation. In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo.

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Expression of the Lenti-Flag-Tax lentiviruses.(A) Schematic representation of the Lenti-IRES-GFP and Lenti-Flag-Tax constructs. (B) Western blot analyses were performed on 70 µg of cellular extracts from MOLT4 cells transduced for 72 h by Lenti-IRES-GFP, Lenti-Flag-Tax-1, Lenti-Flag-Tax-2 or Lenti-Flag-Tax-3 lentiviruses, as indicated. Membranes were probed with anti-Flag-M2 or anti-β-actin antibody (Sigma). (C) 293 T cells were transduced by Lenti-IRES-GFP or Lenti-Flag-Tax lentiviruses for 72 h. Pictures of live cells were taken using Nikon eclipse TS 100 microscope (magnification x10).
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pone-0041003-g001: Expression of the Lenti-Flag-Tax lentiviruses.(A) Schematic representation of the Lenti-IRES-GFP and Lenti-Flag-Tax constructs. (B) Western blot analyses were performed on 70 µg of cellular extracts from MOLT4 cells transduced for 72 h by Lenti-IRES-GFP, Lenti-Flag-Tax-1, Lenti-Flag-Tax-2 or Lenti-Flag-Tax-3 lentiviruses, as indicated. Membranes were probed with anti-Flag-M2 or anti-β-actin antibody (Sigma). (C) 293 T cells were transduced by Lenti-IRES-GFP or Lenti-Flag-Tax lentiviruses for 72 h. Pictures of live cells were taken using Nikon eclipse TS 100 microscope (magnification x10).

Mentions: Since T-cells are the primary targets of HTLV infection in vivo and transfection of T -cells is inefficient, we introduced Tax-1, -2 or -3 sequences into the multi-cloning site of pSDM101 lentiviral vector (Dasgupta unpublished data). This vector contains the “medium” expression promoter EF1A and an IRES-GFP allowing discrimination of transduced versus non-transduced cells. Because an antibody able to detect all three Tax proteins is not available, an N-terminal Flag tag was added to the Tax sequence (Figure 1A). A T-cell line, MOLT4, and a non T-cell line 293 T, were selected to identify subset of genes deregulated independently of the cell type selected.


The transcription profile of Tax-3 is more similar to Tax-1 than Tax-2: insights into HTLV-3 potential leukemogenic properties.

Chevalier SA, Durand S, Dasgupta A, Radonovich M, Cimarelli A, Brady JN, Mahieux R, Pise-Masison CA - PLoS ONE (2012)

Expression of the Lenti-Flag-Tax lentiviruses.(A) Schematic representation of the Lenti-IRES-GFP and Lenti-Flag-Tax constructs. (B) Western blot analyses were performed on 70 µg of cellular extracts from MOLT4 cells transduced for 72 h by Lenti-IRES-GFP, Lenti-Flag-Tax-1, Lenti-Flag-Tax-2 or Lenti-Flag-Tax-3 lentiviruses, as indicated. Membranes were probed with anti-Flag-M2 or anti-β-actin antibody (Sigma). (C) 293 T cells were transduced by Lenti-IRES-GFP or Lenti-Flag-Tax lentiviruses for 72 h. Pictures of live cells were taken using Nikon eclipse TS 100 microscope (magnification x10).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3401231&req=5

pone-0041003-g001: Expression of the Lenti-Flag-Tax lentiviruses.(A) Schematic representation of the Lenti-IRES-GFP and Lenti-Flag-Tax constructs. (B) Western blot analyses were performed on 70 µg of cellular extracts from MOLT4 cells transduced for 72 h by Lenti-IRES-GFP, Lenti-Flag-Tax-1, Lenti-Flag-Tax-2 or Lenti-Flag-Tax-3 lentiviruses, as indicated. Membranes were probed with anti-Flag-M2 or anti-β-actin antibody (Sigma). (C) 293 T cells were transduced by Lenti-IRES-GFP or Lenti-Flag-Tax lentiviruses for 72 h. Pictures of live cells were taken using Nikon eclipse TS 100 microscope (magnification x10).
Mentions: Since T-cells are the primary targets of HTLV infection in vivo and transfection of T -cells is inefficient, we introduced Tax-1, -2 or -3 sequences into the multi-cloning site of pSDM101 lentiviral vector (Dasgupta unpublished data). This vector contains the “medium” expression promoter EF1A and an IRES-GFP allowing discrimination of transduced versus non-transduced cells. Because an antibody able to detect all three Tax proteins is not available, an N-terminal Flag tag was added to the Tax sequence (Figure 1A). A T-cell line, MOLT4, and a non T-cell line 293 T, were selected to identify subset of genes deregulated independently of the cell type selected.

Bottom Line: These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation.The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation.In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo.

View Article: PubMed Central - PubMed

Affiliation: Virus Tumor Biology Section, Laboratory of Cellular Oncology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America. sebastien.chevalier@ens-lyon.fr

ABSTRACT
Human T-cell Lymphotropic Viruses type 1 (HTLV-1) is the etiological agent of Adult T-cell Leukemia/Lymphoma. Although associated with lymphocytosis, HTLV-2 infection is not associated with any malignant hematological disease. Similarly, no infection-related symptom has been detected in HTLV-3-infected individuals studied so far. Differences in individual Tax transcriptional activity might account for these distinct physiopathological outcomes. Tax-1 and Tax-3 possess a PDZ binding motif in their sequence. Interestingly, this motif, which is critical for Tax-1 transforming activity, is absent from Tax-2. We used the DNA microarray technology to analyze and compare the global gene expression profiles of different T- and non T-cell types expressing Tax-1, Tax-2 or Tax-3 viral transactivators. In a T-cell line, this analysis allowed us to identify 48 genes whose expression is commonly affected by all Tax proteins and are hence characteristic of the HTLV infection, independently of the virus type. Importantly, we also identified a subset of genes (n = 70) which are specifically up-regulated by Tax-1 and Tax-3, while Tax-1 and Tax-2 shared only 1 gene and Tax-2 and Tax-3 shared 8 genes. These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation. Analysis of the molecular interactions existing between those Tax-1/Tax-3 deregulated genes then allowed us to highlight biological networks of genes characteristic of HTLV-1 and HTLV-3 infection. The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation. In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo.

Show MeSH
Related in: MedlinePlus