scholarly journals Infection of Nonhuman Primate Cells by Pig Endogenous Retrovirus

2000 ◽  
Vol 74 (16) ◽  
pp. 7687-7690 ◽  
Author(s):  
Juergen H. Blusch ◽  
Clive Patience ◽  
Yasuhiro Takeuchi ◽  
Christian Templin ◽  
Christian Roos ◽  
...  

ABSTRACT The ongoing shortage of human donor organs for transplantation has catalyzed new interest in the application of pig organs (xenotransplantation). One of the biggest concerns about the transplantation of porcine grafts into humans is the transmission of pig endogenous retroviruses (PERV) to the recipients or even to other members of the community. Although nonhuman primate models are excellently suited to mimic clinical xenotransplantation settings, their value for risk assessment of PERV transmission at xenotransplantation is questionable since all of the primate cell lines tested so far have been found to be nonpermissive for PERV infection. Here we demonstrate that human, gorilla, and Papio hamadryas primary skin fibroblasts and also baboon B-cell lines are permissive for PERV infection. This suggests that a reevaluation of the suitability of the baboon model for risk assessment in xenotransplantation is critical at this point.

2019 ◽  
Author(s):  
Özgen Deniz ◽  
Mamataz Ahmed ◽  
Christopher D. Todd ◽  
Ana Rio-Machin ◽  
Mark A. Dawson ◽  
...  

AbstractAcute myeloid leukemia (AML) is a highly aggressive hematopoietic malignancy, defined by a series of genetic and epigenetic alterations, which result in deregulation of transcriptional networks. One understudied but important source of transcriptional regulators are transposable elements (TEs), which are widespread throughout the human genome. Aberrant usage of these sequences could therefore contribute to oncogenic transcriptional circuits. However, the regulatory influence of TEs and their links to disease pathogenesis remain unexplored in AML. Using epigenomic data from AML primary samples and leukemia cell lines, we identified six endogenous retrovirus (ERV) families with AML-associated enhancer chromatin signatures that are enriched in binding of key regulators of hematopoiesis and AML pathogenesis. Using both CRISPR-mediated locus-specific genetic editing and simultaneous epigenetic silencing of multiple ERVs, we demonstrate that ERV deregulation directly alters the expression of adjacent genes in AML. Strikingly, deletion or epigenetic silencing of an ERV-derived enhancer suppressed cell growth by inducing apoptosis in leukemia cell lines. Our work reveals that ERVs are a previously unappreciated source of AML enhancers that have the potential to play key roles in leukemogenesis. We suggest that ERV activation provides an additional layer of gene regulation in AML that may be exploited by cancer cells to help drive tumour heterogeneity and evolution.


2006 ◽  
Vol 87 (7) ◽  
pp. 2067-2071 ◽  
Author(s):  
A. Muir ◽  
A. M. L. Lever ◽  
A. Moffett

The placenta is unique amongst normal tissues in transcribing numerous different human endogenous retroviruses at high levels. In this study, RT-PCR and immunohistochemistry were used to investigate the expression of syncytin in human trophoblast. Syncytin transcripts were found in first-trimester trophoblast cells with both villous and extravillous phenotypes and also in the JAR and JEG-3 choriocarcinoma cell lines. Syncytin protein was detected in villous trophoblast and in all extravillous trophoblast subpopulations of first- and second-trimester placental tissues. It was also present in ectopic trophoblast from tubal implantations. This study confirms that syncytin is expressed widely by a variety of normal human trophoblast populations, as well as choriocarcinoma cell lines.


2011 ◽  
Vol 92 (10) ◽  
pp. 2356-2366 ◽  
Author(s):  
Sonja Haupt ◽  
Michele Tisdale ◽  
Michelle Vincendeau ◽  
Mary Anne Clements ◽  
David T. Gauthier ◽  
...  

The human genome comprises approximately 8–9 % of human endogenous retroviruses (HERVs) that are transcribed with tissue specificity. However, relatively few organs have been examined in detail for individual differences in HERV transcription pattern, nor have tissue-to-cell culture comparisons been frequently performed. Using an HERV-specific DNA microarray, a core HERV transcription profile was established for the human kidney comparing 10 tissue samples. This core represents HERV groups expressed uniformly or nearly so in non-tumour kidney tissue. The profiles obtained from non-tumour tissues were compared to 10 renal tumour tissues (renal cell carcinoma, RCC) derived from the same individuals and additionally, to 22 RCC cell lines. No RCC cell line or tumour-specific differences were observed, suggesting that HERV transcription is not altered in RCC. However, when comparing tissue transcription to cell line transcription, there were consistent differences. The differences were irrespective of cancer state and included cell lines derived from non-tumour kidney tissue, suggesting that a specific alteration of HERV transcription occurs when establishing cell lines. In contrast to previous publications, all known HERV-derived tumour antigens, including those identified in RCC, were expressed both in multiple RCC cell lines and several non-tumour tissue-derived cell lines, a result that contrasts with findings from patient samples. The results establish the core kidney transcription pattern of HERVs and reveal differences between cell culture lines and tissue samples.


1998 ◽  
Vol 72 (12) ◽  
pp. 9986-9991 ◽  
Author(s):  
Yasuhiro Takeuchi ◽  
Clive Patience ◽  
Saema Magre ◽  
Robin A. Weiss ◽  
Papia T. Banerjee ◽  
...  

ABSTRACT Recent interest in the use of porcine organs, tissues, and cells for xenotransplantation to humans has highlighted the need to characterize the properties of pig endogenous retroviruses (PERVs). Analysis of a variety of pig cells allowed us to isolate and identify three classes of infectious type C endogenous retrovirus (PERV-A, PERV-B, and PERV-C) which have distinct env genes but have highly homologous sequences in the rest of the genome. To study the properties of these env genes, expression plasmids for the three env genes were constructed and used to generate retrovirus vectors bearing corresponding Env proteins. Host range analyses by the vector transduction assay showed that PERV-A and PERV-B Envs have wider host ranges, including several human cell lines, compared with PERV-C Env, which infected only two pig cell lines and one human cell line. All PERVs could infect pig cells, indicating that the PERVs have a potential to replicate in pig transplants in immunosuppressed patients. Receptors for PERV-A and PERV-B were present on cells of some other species, including mink, rat, mouse, and dog, suggesting that such species may provide useful model systems to study infection and pathogenicity of PERV. In contrast, no vector transduction was observed on nonhuman primate cell lines, casting doubt on the utility of nonhuman primates as models for PERV zoonosis. Interference studies showed that the three PERV strains use receptors distinct from each other and from a number of other type C mammalian retroviruses.


2021 ◽  
Vol 11 ◽  
Author(s):  
Lisa Wieland ◽  
Kristina Engel ◽  
Ines Volkmer ◽  
Anna Krüger ◽  
Guido Posern ◽  
...  

Neuroblastoma (NB) is the commonest solid tumor outside the central nervous system in infancy and childhood with a unique biological heterogeneity. In patients with advanced, metastasizing neuroblastoma, treatment failure and poor prognosis is often marked by resistance to chemo- or immunotherapy. Thus, identification of robust biomarkers seems essential for understanding tumor progression and developing effective therapy. Here, we have studied the expression of human endogenous retroviruses (HERV) as potential targets in NB cell lines during stem-cell medium-induced microenvironmental change. Quantitative PCR revealed that relative expression of the HERV-K family and HERV-W1 ENV were increased in all three NB cell lines after incubation in stem-cell medium. Virus transcriptome analyses revealed the transcriptional activation of three endogenous retrovirus elements: HERV-R ENV (ERV3-1), HERV-E1 and HERV-Fc2 ENV (ERVFC1-1). Known malignancy markers in NB, e.g. proto-oncogenic MYC or MYCN were expressed highly heterogeneously in the three investigated NB cell lines with up-regulation of MYC and MYCN upon medium-induced microenvironmental change. In addition, SiMa cells exclusively showed a phenotype switching from loosely-adherent monolayers to low proliferating grape-like cellular aggregates, which was accompanied by an enhanced CD133 expression. Interestingly, the overexpression of HERV was associated with a significant elevation of immune checkpoint molecule CD200 in both quantitative PCR and RNA-seq analysis suggesting tumor escape mechanism in NB cell lines after incubation in serum-free stem cell medium.


1998 ◽  
Vol 72 (4) ◽  
pp. 2671-2676 ◽  
Author(s):  
Clive Patience ◽  
Yasuhiro Takeuchi ◽  
Francois-Loic Cosset ◽  
Robin A. Weiss

ABSTRACT Interaction of retrovirus vectors and endogenous retroviruses present in packaging cell lines and target cells may result in unwanted events, such as the formation of recombinant viruses and the mobilization of therapeutic vectors. Using sensitive reverse transcriptase PCR assays, we investigated human and murine gene therapy packaging cell lines for incorporation of endogenous retrovirus transcripts into murine leukemia virus (MLV) vector particles and, conversely, whether vector genomes are incorporated into human endogenous retrovirus (HERV) particles. VL30 endogenous retrovirus sequences were efficiently packaged in particles produced by the murine AM12 packaging system. For every seven MLV-derived β-galactosidase (β-Gal) vector genomes present in the particles, one copy of VL30 was also packaged. Although human FLY packaging cells expressed several classes of HERV transcripts (HERV-K, HuRT, type C, and RTVL-H), none was detectable in the MLV vector particles released from the cells. Nonspecific packaging of the MLV Gag-Pol expression vector transcripts was detected in the FLY virions at a low level (1 in 17,000 sequences). These findings indicate that human packaging cells produce retrovirus particles far less contaminated by endogenous viral sequences than murine packaging cells. Human teratocarcinoma cells (GH cells), which produce HERV-K particles, were transduced with an MLV-derived β-Gal vector. Although both HERV-K and RTVL-H sequences were found in association with the particles, β-Gal transcripts were not detected, indicating that HERV Gag proteins do not efficiently package MLV-based vectors.


1998 ◽  
Vol 72 (7) ◽  
pp. 6164-6168 ◽  
Author(s):  
Paul E. Kowalski ◽  
Dixie L. Mager

ABSTRACT Human endogenous retroviruses (HERVs) are repetitive, noninfectious chromosomal elements degenerated from exogenous retroviruses. The HERV-H family is composed of approximately 1,000 elements which are dispersed throughout the human genome. We have shown previously that an HERV-H element splices into a downstream locus, termed PLA2L, which has a large open reading frame (ORF) containing two domains with phospholipase A2 homology. Over half of the putative 5′ untranslated region (5′ UTR) of the resulting fusion transcript is derived from HERV-H long-terminal-repeat and internal sequences. As 5′ UTRs are known to modulate translation initiation, we tested for possible effects upon gene expression at the translation level due to the 5′ fusion with HERV-H sequences. No PLA2L protein was detected in teratocarcinoma cell lines in which PLA2L mRNA is abundantly expressed. In addition, despite a high level of transcription, no protein synthesis was detected when the full-length PLA2L cDNA was expressed in COS cells. Upon removal of the 5′-terminal HERV-H sequences, PLA2L protein was seen in transfectants. The 5′ UTR contains both small ORFs and a strong predicted RNA secondary structure, both of which have been shown to contribute to translation suppression. The HERV-H sequences, combined with a unique PLA2L 5′ UTR sequence, form a predicted RNA stem-loop that has a stability greater than that proposed to negatively affect translation. Interestingly, this stem-loop is abolished when the HERV-H sequences are removed. We hypothesize that the PLA2L 5′ HERV-H sequences function as an abnormally long and complex 5′ UTR, resulting in suppression of translation in both teratocarcinoma cell lines and full-length cDNA transfectants. This is the first known example of a endogenous retrovirus integration affecting expression of a heterologous human gene at the translational level.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 449
Author(s):  
Simin D. Rezaei ◽  
Joshua A. Hayward ◽  
Sam Norden ◽  
John Pedersen ◽  
John Mills ◽  
...  

Heightened expression of human endogenous retrovirus (HERV) sequences has been associated with a range of malignancies, including prostate cancer, suggesting that they may serve as useful diagnostic or prognostic cancer biomarkers. We analysed the expression of HERV-K (Gag and Env/Np9 regions), HERV-E 4.1 (Pol and Env regions), HERV-H (Pol) and HERV-W (Gag) sequences in prostate cancer cells lines and normal prostate epithelial cells using qRT-PCR. HERV expression was also analysed in matched malignant and benign prostate tissue samples from men with prostate cancer (n = 27, median age 65.2 years (range 47–70)) and compared to prostate cancer-free male controls (n = 11). Prostate cancer epithelial cell lines exhibited a signature of HERV RNA overexpression, with all HERVs analysed, except HERV-E Pol, showing heightened expression in at least two, but more commonly all, cell lines analysed. Analysis of primary prostate material indicated increased expression of HERV-E Pol but decreased expression of HERV-E Env in both malignant and benign regions of the prostate in men with prostate cancer as compared to those without. Expression of HERV-K Gag was significantly higher in malignant regions of the prostate in men with prostate cancer as compared to matched benign regions and prostate cancer-free men (p < 0.001 for both), with 85.2% of prostate cancers donors showing malignancy-associated upregulation of HERV-K Gag RNA. HERV-K Gag protein was detected in 12/18 (66.7%) malignant tissues using immunohistochemistry, but only 1/18 (5.6%) benign tissue sections. Heightened expression of HERV-K Gag RNA and protein appears to be a sensitive and specific biomarker of prostate malignancy in this cohort of men with prostate carcinoma, supporting its potential utility as a non-invasive, adjunct clinical biomarker.


RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1850-1861
Author(s):  
Aarzoo ◽  
Saba Naqvi ◽  
Nidhi Bharal Agarwal ◽  
Manoj P. Singh ◽  
M. Samim

The surge in vehicular activity in densely populated areas has led to an increased concentration of airborne palladium nanoparticles (PdNPs) in the environment.


Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1999
Author(s):  
Annacarmen Petrizzo ◽  
Concetta Ragone ◽  
Beatrice Cavalluzzo ◽  
Angela Mauriello ◽  
Carmen Manolio ◽  
...  

Human endogenous retroviruses (HERVs) derive from ancestral exogenous retroviruses whose genetic material has been integrated in our germline DNA. Several lines of evidence indicate that cancer immunotherapy may benefit from HERV reactivation, which can be induced either by drugs or by cellular changes occurring in tumor cells. Indeed, several studies indicate that HERV proviral DNA can be transcribed either to double-stranded RNA (dsRNA) that is sensed as a “danger signal” by pattern recognition receptors (PRRs), leading to a viral mimicry state, or to mRNA that is translated into proteins that may contribute to the landscape of tumor-specific antigens (TSAs). Alternatively, HERV reactivation is associated with the expression of long noncoding RNAs (lncRNAs). In this review, we will highlight recent findings on HERV reactivation in cancer and its implications for cancer immunotherapy.


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