Targeted integration of human herpesvirus 6 in the p arm of chromosome 17 of human peripheral blood mononuclear cells in vivo

ABSTRACT Human endogenous retroviruses (HERVs) and mammalian apparent long terminal repeat (LTR) retrotransposons (MaLRs) are retroviral sequences that integrated into germ line cells millions of years ago. Transcripts of these LTR retrotransposons are present in several tissues, and their expression is modulated in pathological conditions, although their function remains often far from being understood. Here, we focused on the HERV/MaLR expression and modulation in a scenario of immune system activation. We used a public data set of human peripheral blood mononuclear cells (PBMCs) RNA-Seq from 15 healthy participants to a clinical trial before and after exposure to lipopolysaccharide (LPS), for which we established an RNA-Seq workflow for the identification of expressed and modulated cellular genes and LTR retrotransposon elements. IMPORTANCE We described the HERV and MaLR transcriptome in PBMCs, finding that about 8.4% of the LTR retrotransposon loci were expressed and identifying the betaretrovirus-like HERVs as those with the highest percentage of expressed loci. We found 4,607 HERV and MaLR loci that were modulated as a result of in vivo stimulation with LPS. The HERV-H group showed the highest number of differentially expressed most intact proviruses. We characterized the HERV and MaLR loci as differentially expressed, checking their genomic context of insertion and observing a general colocalization with genes that are involved and modulated in the immune response, as a consequence of LPS stimulation. The analyses of HERV and MaLR expression and modulation show that these LTR retrotransposons are expressed in PBMCs and regulated in inflammatory settings. The similar regulation of HERVs/MaLRs and genes after LPS stimulation suggests possible interactions of LTR retrotransposons and the immune host response.

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Simvastatin Suppresses Interleukin Iβ Release in Human Peripheral Blood Mononuclear Cells Stimulated With Cholesterol Crystals

Journal of Cardiovascular Pharmacology and Therapeutics ◽

10.1177/1074248418776261 ◽

2018 ◽

Vol 23 (6) ◽

pp. 509-517 ◽

Cited By ~ 10

Author(s):

Anna J. Boland ◽

Nisha Gangadharan ◽

Pierce Kavanagh ◽

Linda Hemeryck ◽

Jennifer Kieran ◽

...

Keyword(s):

Cardiovascular Disease ◽

Peripheral Blood Mononuclear Cells ◽

Nlrp3 Inflammasome ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Human Peripheral Blood ◽

Peripheral Blood Mononuclear ◽

Blood Mononuclear Cells

Statins are mainstream therapy in the treatment and prevention of cardiovascular disease through inhibitory effects on cholesterol synthesis. However, statins’ beneficial effects in cardiovascular disease may also be attributable to their role as anti-inflammatory mediators. Here, we investigated the effects of simvastatin treatment on expression levels of interleukin (IL) 1β in both patient with hyperlipidemia and healthy human peripheral blood mononuclear cells (PBMCs) using cholesterol crystals (CC), a cardiovascular pathogenic stimulus for activation of the NOD-like receptor pyrin domain–containing protein 3 (NLRP3) inflammasome. Cholesterol crystal-induced NLRP3 inflammasome activation was used to trigger maturation and release of IL-1β in PBMCs. Specifically, isolated PBMCs from patients with hyperlipidemia at baseline and following 8 weeks of in vivo treatment with simvastatin (10-20 mg) daily were stimulated with lipopolysaccharide (LPS; 100 ng/mL) for 3 hours to induce proIL-Iβ expression followed by CC (2 mg/mL) stimulation for further 18 hours to activate the NLRP3 inflammasome complex to induce maturation/activation of IL-1β. Peripheral blood mononuclear cells were also isolated from healthy donors and stimulated in vitro with simvastatin (50, 25, 5, and 2 µmol/L) prior to stimulation with LPS and CC as described above. The effects of simvastatin treatment on levels of IL-1β expression were determined by enzyme-linked immunosorbent assay and western blot. Both in vitro and in vivo treatments with simvastatin led to a significant reduction in the levels of expression of IL-1β in response to stimulation with CC. Simvastatin inhibits the expression and activation of IL-1β induced by CC in PBMCs, which may contribute to its protective role in patients with cardiovascular disease.

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Neopterin suppresses the activity of tryptophan-degrading enzyme indoleamine 2,3-dioxygenase in human peripheral blood mononuclear cells

Pteridines ◽

10.1515/pterid-2013-0037 ◽

2013 ◽

Vol 24 (3) ◽

pp. 237-243

Author(s):

Sebastian Schroecksnadel ◽

Elena-Sophia Ledjeff ◽

Johanna Gostner ◽

Christiana Winkler ◽

Katharina Kurz ◽

...

Keyword(s):

Peripheral Blood Mononuclear Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Human Peripheral Blood ◽

Peripheral Blood Mononuclear ◽

Indoleamine 2,3 Dioxygenase ◽

Blood Mononuclear Cells ◽

Ifn Γ

AbstractIn vitro, large amounts of neopterin are released from human monocyte-derived macrophages and dendritic cells primarily upon stimulation with Th1-type cytokine interferon-γ (IFN-γ). IFN-γ also induces the enzyme indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan (TRP) to form kynurenine (KYN). IDO-mediated TRP catabolism is very effective in suppressing the proliferation of T lymphocytes as well as of pathogens in vitro and in vivo. In this study, we investigated whether exogenously added neopterin may influence IDO activity in resting and in stimulated peripheral blood mononuclear cells (PBMC). PBMC were isolated from healthy donors, and neopterin was added in a concentration range from 0.01 to 50 μmol/L. After 30 min, PBMC were stimulated or not with 10 μg/mL of mitogen phytohemagglutinin (PHA). After 48 h, culture supernatants were collected, KYN and TRP concentrations were measured by high-performance liquid chromatography, and the ratio of KYN vs. TRP was calculated as an estimate of IDO activity. Spontaneous as well as PHA-induced TRP breakdown was suppressed by exogenously added neopterin in a dose-dependent way; the lowest active concentration of neopterin was <100 nmol/L. As neopterin concentrations in the nanomolar range are commonly observed in patients suffering from infections, sepsis, or uremia, our results suggest that neopterin formation might also serve as a feedback mechanism to slow down TRP degradation in vivo.

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Presence of human herpesvirus 6 variants A and B in saliva and peripheral blood mononuclear cells of healthy adults.

Journal of Clinical Microbiology ◽

10.1128/jcm.34.12.3223-3225.1996 ◽

1996 ◽

Vol 34 (12) ◽

pp. 3223-3225 ◽

Cited By ~ 34

Author(s):

S W Aberle ◽

C W Mandl ◽

C Kunz ◽

T Popow-Kraupp

Keyword(s):

Peripheral Blood Mononuclear Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Human Herpesvirus ◽

Healthy Adults ◽

Human Herpesvirus 6 ◽

Peripheral Blood Mononuclear ◽

Blood Mononuclear Cells ◽

Herpesvirus 6

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RNA-seq transcriptome analysis reveals LTR-retrotransposons modulation in Human Peripheral Blood Mononuclear Cells (PBMCs) after in vivo Lipopolysaccharides (LPS) injection

10.1101/2019.12.20.884494 ◽

2019 ◽

Author(s):

Maria Paola Pisano ◽

Olivier Tabone ◽

Maxime Bodinier ◽

Nicole Grandi ◽

Julien Textoris ◽

...

Keyword(s):

Peripheral Blood Mononuclear Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Human Peripheral Blood ◽

Differentially Expressed ◽

Ltr Retrotransposons ◽

Rna Seq ◽

Peripheral Blood Mononuclear ◽

Blood Mononuclear Cells

AbstractHuman Endogenous Retroviruses (HERVs) and Mammalian apparent LTR-retrotransposons (MaLRs) are retroviral sequences that integrated into the germline cells millions year ago. Transcripts of these LTR-retrotransposons are present in several tissues, and their expression is modulated in pathological conditions, although their function remains often far from being understood. In this work, we focused on the HERVs/MaLRs expression and modulation in a scenario of immune system activation. We used a public dataset of Human Peripheral Blood Mononuclear Cells (PBMCs) RNA-seq from 15 healthy participants to a clinical trial before and after the exposure to Lipopolysaccharide (LPS), for which we established an RNA-seq workflow for the identification of expressed and modulated cellular genes and LTR-retrotransposon elements.ImportanceWe described the HERV and MaLR transcriptome in PBMCs, finding that about 8.4 % of the LTR-retrotransposons loci were expressed, and identifying the betaretrovirus-like HERVs as those with the highest percentage of expressed loci. We found 4,607 HERVs and MaLRs loci that were modulated as a result of in vivo stimulation with LPS. The HERV-H group showed the highest number of differentially expressed most intact proviruses. We characterized the HERV and MaLR loci differentially expressed checking their genomic context of insertion and, interestingly, we found a general co-localization with genes that are involved and modulated in the immune response, as consequence of LPS stimulation. The analyses of HERVs and MaLRs expression and modulation show that this LTR-retrotransposons are expressed in PBMCs and regulated in inflammatory settings. The similar regulation of HERVs/MaLRs and genes after LPS stimulation suggests possible interactions of LTR-retrotransposons and the immune host response.

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