| 1. |
- Dumanski, Jan P., et al.
(författare)
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Immune cells lacking Y chromosome show dysregulation of autosomal gene expression
- 2021
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Ingår i: Cellular and Molecular Life Sciences (CMLS). - : Springer. - 1420-682X .- 1420-9071. ; 78:8, s. 4019-4033
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer’s disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a “genetic wasteland”, and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.
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| 2. |
- Frisan, Teresa, 1967-, et al.
(författare)
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A bacterial genotoxin causes virus reactivation and genomic instability in Epstein-Barr virus infected epithelial cells pointing to a role of co-infection in viral oncogenesis
- 2019
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Ingår i: International Journal of Cancer. - : John Wiley & Sons. - 0020-7136 .- 1097-0215. ; 144:1, s. 98-109
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Tidskriftsartikel (refereegranskat)abstract
- We have addressed the role of bacterial co-infection in viral oncogenesis using as model Epstein-Barr virus (EBV), a human herpesvirus that causes lymphoid malignancies and epithelial cancers. Infection of EBV carrying epithelial cells with the common oral pathogenic Gram-negative bacterium Aggregatibacter actinomycetemcomitans (Aa) triggered reactivation of the productive virus cycle. Using isogenic Aa strains that differ in the production of the cytolethal distending toxin (CDT) and purified catalytically active or inactive toxin, we found that the CDT acts via induction of DNA double strand breaks and activation of the Ataxia Telangectasia Mutated (ATM) kinase. Exposure of EBV-negative epithelial cells to the virus in the presence of sub-lethal doses of CDT was accompanied by the accumulation of latently infected cells exhibiting multiple signs of genomic instability. These findings illustrate a scenario where co-infection with certain bacterial species may favor the establishment of a microenvironment conducive to the EBV-induced malignant transformation of epithelial cells.
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| 3. |
- Iorio Di, C T, et al.
(författare)
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Cross-border flow of health information: is 'privacy by design' enough? Privacy performance assessment in EUBIROD.
- 2013
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Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 23:2, s. 247-53
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Tidskriftsartikel (refereegranskat)abstract
- Background: The EUBIROD project aims to perform a cross-border flow of diabetes information across 19 European countries using the BIRO information system, which embeds privacy principles and data protection mechanisms in its architecture (privacy by design). A specific task of EUBIROD was to investigate the variability in the implementation of the EU Data Protection Directive (DPD) across participating centres. Methods: Compliance with privacy requirements was assessed by means of a specific questionnaire administered to all participating diabetes registers. Items included relevant issues e.g. patient consent, accountability of data custodian, communication (openness) and complaint procedures (challenging compliance), authority to disclose, accuracy, access and use of personal information, and anonymization. The identification of an ad hoc scoring system and statistical software allowed an overall quali-quantitative analysis and independent evaluation of questionnaire responses, automated through a dedicated IT platform (‘privacy performance assessment’). Results: A total of 18 diabetes registers from different countries completed the survey. Over 50% of the registers recorded a maximum score for accountability, openness, anonymization and challenging compliance. Low average values were found for disclosure and disposition, access, consent, use of personal information and accuracy. A high heterogeneity was found for anonymization, consent, accuracy and access. Conclusions: The novel method of privacy performance assessment realized in EUBIROD may improve the respect of privacy in each data source, reduce overall variability in the implementation of privacy principles and favour a sound and legitimate cross-border exchange of high quality data across Europe.
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| 4. |
- Kis, Loránd L., et al.
(författare)
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The STAT6 signaling pathway activated by the cytokines IL-4 and IL-13 induces expression of the Epstein-Barr virus-encoded protein LMP-1 in absence of EBNA-2 : implications for the type II EBV latent gene expression in Hodgkin lymphoma
- 2011
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 117:1, s. 165-174
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Tidskriftsartikel (refereegranskat)abstract
- In line with the B-lymphotropic nature of EBV, the virus is present in several types of B cell lymphomas. EBV expresses a different set of latent genes in the associated tumors, such as EBNA-1 and LMPs (type II latency) in the classical Hodgkin lymphomas (cHL). We have previously reported that exposure of the in vitro EBV-converted, HL-derived cell line KMH2-EBV to CD40-ligand and IL-4 induced the expression of LMP-1. Here we show that exposure to IL-4 or IL-13 alone induced LMP-1 in the absence of EBNA-2. The induction of LMP-1 by IL-4 and IL-13 was mediated by the signal transducer STAT6 and a newly defined high-affinity STAT6-binding site in the LMP-1 promoter. IL-4 induced LMP-1 also in Burkitt lymphoma-derived lines and in tonsillar B cells infected with the EBNA-2-deficient EBV strain P3HR-1. Furthermore, co-culture of EBV-carrying BL cells with activated CD4(+) T cells resulted in the induction of LMP-1 in the absence of EBNA-2. As the Hodgkin/Reed-Sternberg are known to secrete IL-13, to have constitutively activated STAT6, and to be closely surrounded by CD4+ T cells, these mechanisms may be involved in the expression of LMP-1 in the EBV-positive cHLs.
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| 5. |
- Li, Jinlin, et al.
(författare)
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The Epstein-Barr virus deubiquitinating enzyme BPLF1 regulates the activity of topoisomerase II during productive infection
- 2021
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Ingår i: PLoS Pathogens. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 17:9
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Tidskriftsartikel (refereegranskat)abstract
- Topoisomerases are essential for the replication of herpesviruses but the mechanisms by which the viruses hijack the cellular enzymes are largely unknown. We found that topoisomerase-II (TOP2) is a substrate of the Epstein-Barr virus (EBV) ubiquitin deconjugase BPLF1. BPLF1 co-immunoprecipitated and deubiquitinated TOP2, and stabilized SUMOylated TOP2 trapped in cleavage complexes (TOP2cc), which halted the DNA damage response to TOP2-induced double strand DNA breaks and promoted cell survival. Induction of the productive virus cycle in epithelial and lymphoid cell line carrying recombinant EBV encoding the active enzyme was accompanied by TOP2 deubiquitination, accumulation of TOP2ccs and resistance to Etoposide toxicity. The protective effect of BPLF1 was dependent on the expression of tyrosyl-DNA phosphodiesterase 2 (TDP2) that releases DNA-trapped TOP2 and promotes error-free DNA repair. These findings highlight a previously unrecognized function of BPLF1 in supporting a non-proteolytic pathway for TOP2cc debulking that favors cell survival and virus production.
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| 6. |
- Malyukova, Alena, et al.
(författare)
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Combination of tyrosine kinase inhibitors and the MCL1 inhibitor S63845 exerts synergistic antitumorigenic effects on CML cells
- 2021
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Ingår i: Cell Death and Disease. - : Springer Nature. - 2041-4889 .- 2041-4889. ; 12:10
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Tidskriftsartikel (refereegranskat)abstract
- Tyrosine kinase inhibitor (TKI) treatment has dramatically improved the survival of chronic myeloid leukemia (CML) patients, but measurable residual disease typically persists. To more effectively eradicate leukemia cells, simultaneous targeting of BCR-ABL1 and additional CML-related survival proteins has been proposed. Notably, several highly specific myeloid cell leukemia 1 (MCL1) inhibitors have recently entered clinical trials for various hematologic malignancies, although not for CML, reflecting the insensitivity of CML cell lines to single MCL1 inhibition. Here, we show that combining TKI (imatinib, nilotinib, dasatinib, or asciminib) treatment with the small-molecule MCL1 inhibitor S63845 exerted strong synergistic antiviability and proapoptotic effects on CML lines and CD34+ stem/progenitor cells isolated from untreated CML patients in chronic phase. Using wild-type BCR-ABL1-harboring CML lines and their T315I-mutated sublines (generated by CRISPR/Cas9-mediated homologous recombination), we prove that the synergistic proapoptotic effect of the drug combination depended on TKI-mediated BCR-ABL1 inhibition, but not on TKI-related off-target mechanisms. Moreover, we demonstrate that colony formation of CML but not normal hematopoietic stem/progenitor cells became markedly reduced upon combination treatment compared to imatinib monotherapy. Our results suggest that dual targeting of MCL1 and BCR-ABL1 activity may efficiently eradicate residual CML cells without affecting normal hematopoietic stem/progenitors.
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| 7. |
- Nagy, Noemi
(författare)
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Expression and function of the small immune adaptor protein SAP
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Epstein-Barr virus (EBV) carrier state is widespread in humans. Primary infection can cause infectious mononucleosis (IM) that presents with variable clinical severity, but almost always subsides. For 50% of boys with a rare hereditary immunodeficiency, X-linked lymphoproliferative disease (XLP), primary infection with E13V has a fatal course. In addition, XLP patients have elevated (200 times) risk for development of lymphomas. The underlying cause of the syndrome is lack of the function of a protein SAP, due to mutations of the encoding gene named also DSHP or SH2DIA. SAP binds to a group of cell surface proteins belonging to the SLAM-family. We found an increase of SAP in T and NK cells after their activation. This correlated well with the inadequacy of cell mediated immune functions in the affected individuals, indicating the importance of SAP. SAP was absent in B cells infected with EBV and in the established lymphoblastoid cell lines (LCL), in SAC+IL-2 or CD40L+IL-4 activated B cells. EBV carrying - but not EBV negative - Burkitt lymphoma (BL) lines with the Type I EBV expression pattern were SAP positive. The type III lines had no SAP. The difference between the EBV negative BLs and the group I EBV positive lines is the first marker that distinguishes these 2 groups. Our results suggest that CD40 ligation can be the physiological signal for SAP down-regulation in B cells. We have also detected SAP in 5 EBV negative cell lines derived from Hodgkin's disease. In the continuation of our studies we focused our attention on the high incidence of lymphoma development in the XLP patients. Since lymphomas appear with high frequency even in EBV negative XLP patients, we considered that in addition to the immunological defect, the absence of SAP may lead to an intrinsic B cell dysfunction. This could possibly affect apoptosis/cell cycle control/DNA repair. We identified SAP as one of the targets of p53. We used a temperature sensitive p53 system and a panel of cell lines with endogenous wt p53. With the help of chromatin immunoprecipitation assay (ChIP) we have proven the functionality of one of the 2 possible p53 binding sites. DNA damage induced by ã-irradiation, induced SAP expression in primary T cells. Induction of SAP by p53 was tissue specific. Our results suggest that SAP contributes to the execution of some p53 functions. We have introduced SAP by retroviral transduction to various cell lines and found that SAP elevated the sensitivity of cells to DNA damage. This was established by cell survival and colony formation assays. We also showed that the proportion of apoptotic cells was higher in the SAP positive populations. Thus SAP has a pro-apoptotic role. We found that in activated T cells the SAP level is increased in the late phase of activation. The high levels of SAP showed a negative correlation with cell proliferation. Furthermore, clones of the T-ALL cell line with low and high SAP expression showed that the latter are more prone to activation induced cell death. Altogether, we have shown that absence of SAP function modifies cell proliferation / cell survival and by this we have introduced a new dimension to SAP and to XLP. Loss of this function can contribute to the maintenance of over-activated, proliferating T cells in the fatal IM and also to the development of lymphomas.
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| 8. |
- Nagy, Noemi, et al.
(författare)
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The apoptosis modulating role of SAP (SLAM associated protein) contributes to the symptomatology of the X linked lymphoproliferative disease
- 2009
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Ingår i: Cell Cycle. - : Landes Bioscience. - 1538-4101 .- 1551-4005. ; 8:19, s. 3086-3090
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Tidskriftsartikel (refereegranskat)abstract
- Deletion or mutation of the SH2D1A gene located at Xq25 is responsible for the development of the X-linked lymphoproliferative disease, XLP. Primary infection of the affected individuals with EBV leads to fulminant and often fatal infectious mononucleosis, FIM. Moreover, they run a 200 fold elevated risk for lymphoma development. Due to the critical role of the immune response for the outcome of EBV infection and the detection of EBV genomes in several malignancies, XLP studies have been mainly focused on the immunological aspects. The involvement of SAP in the apoptotic machinery provides a further aspect in the complex syndrome of XLP. Functional impairment of SAP leads to defective apoptotic responses. Activation induced apoptosis plays a pivotal role in the termination of the lymphocyte proliferation in IM. This mechanism is inefficient in XLP patients. In addition, in the absence of SAP, lymphoma development may be promoted by the illegitimate survival of lymphocytes with damaged DNA that would be normally eliminated by apoptosis.
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| 9. |
- Nagy, Noémi, et al.
(författare)
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The proapoptotic function of SAP provides a clue to the clinical picture of X-linked lymphoproliferative disease
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:29, s. 11966-11971
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Tidskriftsartikel (refereegranskat)abstract
- Deletion or mutation of the SAP gene is associated with the X-linked lymphoproliferative disease (XLP) that is characterized by extreme sensitivity to Epstein-Barr virus (EBV). Primary infection of the affected individuals leads to serious, sometimes fatal infectious mononucleosis (IM) and proneness to lymphoma. Our present results revealed a proapoptotic function of SAP by which it contributes to the maintenance of T-cell homeostasis and to the elimination of potentially dangerous DNA-damaged cells. Therefore, the loss of this function could be responsible for the uncontrolled T-cell proliferation in fatal IM and for the generation of lymphomas. We show now the role of SAP in apoptosis in T and B lymphocyte-derived lines. Among the clones of T-ALL line, the ones with higher SAP levels succumbed more promptly to activation induced cell death (AICD). Importantly, introduction of SAP expression into lymphoblastoid cell lines (LCL) established from XLP patients led to elevated apoptotic response to DNA damage. Similar results were obtained in the osteosarcoma line, Saos-2. We have shown that the anti-apoptotic protein VCP (valosin-containing protein) binds to SAP, suggesting that it could be instrumental in the enhanced apoptotic response modulated by SAP.
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| 10. |
- Nasi, Aikaterini, et al.
(författare)
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Dendritic cell response to HIV-1 is controlled by differentiation programs in the cells and strain-specific properties of the virus
- 2017
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 8:MAR
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCs) are potent antigen-presenting cells that might play contradictory roles during HIV-1 infection, contributing not only to antiviral immunity but also to viral dissemination and immune evasion. Although DCs are characterized by enormous functional diversity, it has not been analyzed how differentially programmed DCs interact with HIV-1. We have previously described the reprogramming of DC development by endogenously produced lactic acid that accumulated in a cell culture density-dependent manner and provided a long-lasting anti-inflammatory signal to the cells. By exploiting this mechanism, we generated immunostimulatory DCs characterized by the production of TH1 polarizing and inflammatory mediators or, alternatively, suppressed DCs that produce IL-10 upon activation, and we tested the interaction of these DC types with different HIV-1 strains. Cytokine patterns were monitored in HIV-1-exposed DC cultures. Our results showed that DCs receiving suppressive developmental program strongly upregulated their capacity to produce the TH1 polarizing cytokine IL-12 and the inflammatory chemokines CCL2 and CCL7 upon interaction with HIV-1 strains IIIB and SF162. On the contrary, HIV-1 abolished cytokine production in the more inflammatory DC types. Preincubation of the cells with the HIV-1 proteins gp120 and Nef could inhibit IL-12 production irrespectively of the tested DC types, whereas MyD88- and TRIF-dependent signals stimulated IL-12 production in the suppressed DC type only. Rewiring of DC cytokines did not require DC infections or ligation of the HIV-1 receptor CD209. A third HIV-1 strain, BaL, could not modulate DC cytokines in a similar manner indicating that individual HIV-1 strains can differ in their capacity to influence DCs. Our results demonstrated that HIV-1 could not induce definite and invariable modulatory programs in DCs. Instead, interaction with the virus triggered different responses in different DC types. Thus, the outcome of DC-HIV-1 interactions might be highly variable, shaped by endogenous features of the cells and diversity of the virus.
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