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Cells May 2024Cancer immunotherapy is a rapidly developing field of medicine that aims to use the host's immune mechanisms to inhibit and eliminate cancer cells. Antibodies targeting... (Review)
Review
Cancer immunotherapy is a rapidly developing field of medicine that aims to use the host's immune mechanisms to inhibit and eliminate cancer cells. Antibodies targeting CTLA-4, PD-1, and its ligand PD-L1 are used in various cancer therapies. However, the most thoroughly researched pathway targeting PD-1/PD-L1 has many limitations, and multiple malignancies resist its effects. Human endogenous retrovirus-H Long repeat-associating 2 (HHLA2, known as B7H5/B7H7/B7y) is the youngest known molecule from the B7 family. HHLA2/TMIGD2/KIRD3DL3 is one of the critical pathways in modulating the immune response. Recent studies have demonstrated that HHLA2 has a double effect in modulating the immune system. The connection of HHLA2 with TMIGD2 induces T cell growth and cytokine production via an AKT-dependent signaling cascade. On the other hand, the binding of HHLA2 and KIR3DL3 leads to the inhibition of T cells and mediates tumor resistance against NK cells. This review aimed to summarize novel information about HHLA2, focusing on immunological mechanisms and clinical features of the HHLA2/KIR3DL3/TMIGD2 pathway in the context of potential strategies for malignancy treatment.
Topics: Humans; Neoplasms; Immunotherapy; B7 Antigens; Animals; Signal Transduction; Immunoglobulins
PubMed: 38786018
DOI: 10.3390/cells13100794 -
Nature Communications May 2024Human endogenous retroviruses (HERVs) are repetitive elements previously implicated in major psychiatric conditions, but their role in aetiology remains unclear. Here,...
Human endogenous retroviruses (HERVs) are repetitive elements previously implicated in major psychiatric conditions, but their role in aetiology remains unclear. Here, we perform specialised transcriptome-wide association studies that consider HERV expression quantified to precise genomic locations, using RNA sequencing and genetic data from 792 post-mortem brain samples. In Europeans, we identify 1238 HERVs with expression regulated in cis, of which 26 represent expression signals associated with psychiatric disorders, with ten being conditionally independent from neighbouring expression signals. Of these, five are additionally significant in fine-mapping analyses and thus are considered high confidence risk HERVs. These include two HERV expression signatures specific to schizophrenia risk, one shared between schizophrenia and bipolar disorder, and one specific to major depressive disorder. No robust signatures are identified for autism spectrum conditions or attention deficit hyperactivity disorder in Europeans, or for any psychiatric trait in other ancestries, although this is likely a result of relatively limited statistical power. Ultimately, our study highlights extensive HERV expression and regulation in the adult cortex, including in association with psychiatric disorder risk, therefore providing a rationale for exploring neurological HERV expression in complex neuropsychiatric traits.
Topics: Humans; Endogenous Retroviruses; Schizophrenia; Genome-Wide Association Study; Bipolar Disorder; Transcriptome; Risk Factors; Depressive Disorder, Major; Mental Disorders; Brain; Female; Male; Genetic Predisposition to Disease; Attention Deficit Disorder with Hyperactivity; Adult
PubMed: 38778015
DOI: 10.1038/s41467-024-48153-z -
World Journal of Surgical Oncology May 2024Human endogenous retrovirus subfamily H long terminal repeat associating protein 2, (HHLA2), a member of B7 family, exhibits heightened expression in various malignant...
BACKGROUND
Human endogenous retrovirus subfamily H long terminal repeat associating protein 2, (HHLA2), a member of B7 family, exhibits heightened expression in various malignant tumors. However, the exact functions of HHLA2 in pancreatic cancer (PC) remain incompletely elucidated.
METHODS
We initially conducted an analysis of the B7 family members' expression pattern in pancreatic tumor samples and adjacent normal tissues using The Cancer Genome Atlas (TCGA) database. Subsequently, immunohistochemistry, RT-qPCR and western blot methods were used to assess HHLA2 expression levels in PC tissues and cell lines. Furthermore, after silencing HHLA2 in PC cell lines, cell migration and proliferation of PC cells were detected by wound healing and CCK-8 assays, and cell invasion of PC cells was detected by transwell assays. We also investigated the regulation of epithelial-mesenchymal transition (EMT) markers and levels of EGFR, MEK, ERK1/2, mTOR and AKT via western blot analysis. Finally, the correlation between HHLA2 expression and immune infiltration was further explored.
RESULTS
Silencing of HHLA2 resulted in the inhibition of PC cell proliferation, migration and invasion, potentially through the suppression of the EGFR/MAPK/ERK and mTOR/AKT signaling pathway. Additionally, silencing HHLA2 led to the inhibition of M2-type polarization of tumor associated macrophages (TAMs).
CONCLUSION
The knockdown of HHLA2 was observed to inhibit the migration and invasion of PC cells through the regulation of the EMT process and EGFR/MAPK/ERK and mTOR/AKT pathway. Furthermore, silencing HHLA2 was found to modulate M2 polarization of TAMs. These finding suggest that HHLA2 could be a promising therapeutic target for Pancreatic cancer.
Topics: Humans; Pancreatic Neoplasms; TOR Serine-Threonine Kinases; ErbB Receptors; Cell Proliferation; Proto-Oncogene Proteins c-akt; Cell Movement; Epithelial-Mesenchymal Transition; Disease Progression; Prognosis; Macrophages; Tumor Cells, Cultured; Signal Transduction; Male; Biomarkers, Tumor; MAP Kinase Signaling System; Apoptosis; THP-1 Cells; Gene Expression Regulation, Neoplastic; Female; Immunoglobulins
PubMed: 38762741
DOI: 10.1186/s12957-024-03409-2 -
Nature Communications May 2024TAR DNA-binding protein 43 (TDP-43) proteinopathy in brain cells is the hallmark of amyotrophic lateral sclerosis (ALS) but its cause remains elusive....
TAR DNA-binding protein 43 (TDP-43) proteinopathy in brain cells is the hallmark of amyotrophic lateral sclerosis (ALS) but its cause remains elusive. Asparaginase-like-1 protein (ASRGL1) cleaves isoaspartates, which alter protein folding and susceptibility to proteolysis. ASRGL1 gene harbors a copy of the human endogenous retrovirus HML-2, whose overexpression contributes to ALS pathogenesis. Here we show that ASRGL1 expression was diminished in ALS brain samples by RNA sequencing, immunohistochemistry, and western blotting. TDP-43 and ASRGL1 colocalized in neurons but, in the absence of ASRGL1, TDP-43 aggregated in the cytoplasm. TDP-43 was found to be prone to isoaspartate formation and a substrate for ASRGL1. ASRGL1 silencing triggered accumulation of misfolded, fragmented, phosphorylated and mislocalized TDP-43 in cultured neurons and motor cortex of female mice. Overexpression of ASRGL1 restored neuronal viability. Overexpression of HML-2 led to ASRGL1 silencing. Loss of ASRGL1 leading to TDP-43 aggregation may be a critical mechanism in ALS pathophysiology.
Topics: Amyotrophic Lateral Sclerosis; Animals; Humans; DNA-Binding Proteins; Mice; Female; TDP-43 Proteinopathies; Neurons; Brain; Male; Motor Cortex
PubMed: 38755145
DOI: 10.1038/s41467-024-48488-7 -
PloS One 2024Human Endogenous Retroviruses (HERVs) are fossil viruses that composes 8% of the human genome and plays several important roles in human physiology, including muscle...
BACKGROUND
Human Endogenous Retroviruses (HERVs) are fossil viruses that composes 8% of the human genome and plays several important roles in human physiology, including muscle repair/myogenesis. It is believed that inflammation may also regulate HERV expression, and therefore may contribute in the muscle repair, especially after training exercise. Hence, this study aimed to assess the level of HERVs expression and inflammation profile in practitioners' resistance exercises after an acute strength training session.
METHODS
Healthy volunteers were separated in regular practitioners of resistance exercise training group (REG, n = 27) and non-trained individuals (Control Group, n = 20). All individuals performed a strength exercise section. Blood samples were collected before the exercise (T0) and 45 minutes after the training session (T1). HERV-K (HML1-10) and W were relatively quantified, cytokine concentration and circulating microparticles were assessed.
RESULTS
REG presented higher level of HERV-W expression (~2.5 fold change) than CG at T1 (p<0.01). No difference was observed in the levels of HERV-K expression between the groups as well as the time points. Higher serum TNF-α and IL-10 levels were verified post-training session in REG and CG (p<0.01), and in REG was found a positive correlation between the levels of TNF-α at T1 and IL-10 at T0 (p = 0.01). Finally, a lower endothelial microparticle percentage was observed in REG at T1 than in T0 (p = 0.04).
CONCLUSION
REG individuals exhibited a significant upregulation of HERV-W and modulation of inflammatory markers when compared to CG. This combined effect could potentially support the process of skeletal muscle repair in the exercised individuals.
Topics: Humans; Endogenous Retroviruses; Resistance Training; Biomarkers; Male; Adult; Inflammation; Female; Young Adult; Tumor Necrosis Factor-alpha; Exercise; Interleukin-10
PubMed: 38753716
DOI: 10.1371/journal.pone.0303798 -
Genome Biology May 2024Genomic regions that remain poorly understood, often referred to as the dark genome, contain a variety of functionally relevant and biologically informative features....
BACKGROUND
Genomic regions that remain poorly understood, often referred to as the dark genome, contain a variety of functionally relevant and biologically informative features. These include endogenous viral elements (EVEs)-virus-derived sequences that can dramatically impact host biology and serve as a virus fossil record. In this study, we introduce a database-integrated genome screening (DIGS) approach to investigate the dark genome in silico, focusing on EVEs found within vertebrate genomes.
RESULTS
Using DIGS on 874 vertebrate genomes, we uncover approximately 1.1 million EVE sequences, with over 99% originating from endogenous retroviruses or transposable elements that contain EVE DNA. We show that the remaining 6038 sequences represent over a thousand distinct horizontal gene transfer events across 10 virus families, including some that have not previously been reported as EVEs. We explore the genomic and phylogenetic characteristics of non-retroviral EVEs and determine their rates of acquisition during vertebrate evolution. Our study uncovers novel virus diversity, broadens knowledge of virus distribution among vertebrate hosts, and provides new insights into the ecology and evolution of vertebrate viruses.
CONCLUSIONS
We comprehensively catalog and analyze EVEs within 874 vertebrate genomes, shedding light on the distribution, diversity, and long-term evolution of viruses and reveal their extensive impact on vertebrate genome evolution. Our results demonstrate the power of linking a relational database management system to a similarity search-based screening pipeline for in silico exploration of the dark genome.
Topics: Animals; Vertebrates; Genome; Fossils; Phylogeny; Evolution, Molecular; Humans; Gene Transfer, Horizontal; Viruses; Genomics; Endogenous Retroviruses; DNA Transposable Elements
PubMed: 38741126
DOI: 10.1186/s13059-024-03258-y -
IScience May 2024We previously reported that loss of function of TYW1 led to cerebral palsy with severe intellectual disability through reduced neural proliferation. However, whether...
We previously reported that loss of function of TYW1 led to cerebral palsy with severe intellectual disability through reduced neural proliferation. However, whether TYW1 loss affects neural differentiation is unknown. In this study, we first demonstrated that TYW1 loss blocked the formation of OHyW in tRNA and therefore affected the translation efficiency of UUU codon. Using the brain organoid model, we showed impaired neuron differentiation when TYW1 was depleted. Interestingly, retrotransposons were differentially regulated in hESCs (human embryonic stem cells). In particular, one kind of human-specific endogenous retrovirus-K (HERVK/HML2), whose reactivation impaired human neurodevelopment, was significantly up-regulated in hESCs. Consistently, a UUU codon-enriched protein, SMARCAD1, which was a key factor in controlling endogenous retroviruses, was reduced. Taken together, TYW1 loss leads to up-regulation of HERVK in hESCs by down-regulated SMARCAD1, thus impairing neuron differentiation.
PubMed: 38706838
DOI: 10.1016/j.isci.2024.109748 -
The New Microbiologica May 2024The shortage of organs for human transplantation is a topic of extreme interest, and xenotransplantation with porcine organs has been recognized as a promising solution....
The shortage of organs for human transplantation is a topic of extreme interest, and xenotransplantation with porcine organs has been recognized as a promising solution. However, the potential spillover linked to infectious agents present in pigs remains a concern. Among these, Pig Endogenous Retroviruses (PERVs), whose proviral DNAs are integrated in the genome of all pig breeds, represent an extremely important biological risk. This study aims to evaluate PERVs distribution in several swine cell lines and samples of domestic and feral pigs. Moreover, the capacity of PERVs to infect human and non-human primate cells and to integrate in the cellular genome was tested by Real-Time PCR and by Reverse Transcriptase assay. Results indicated a widespread diffusion of PERVs both in cell lines and samples analysed: the viral genome was found in all the established cell lines, in 40% of the primary cell lines and in 60% of the tissue samples tested. The assays indicated that the virus can be transmitted from porcine to human cells: in the specific case, infected NSK and NPTr cells allow passage to human 293 and MRC-5 cells with active production of the virus demonstrable via PCR and RT assay. In light of these aspects and also the lack of studies on PERVs, it appears clear that there are still many questions to be clarified, also by means of future studies, before xenotransplantation can be considered microbiologically safe.
Topics: Animals; Endogenous Retroviruses; Swine; Humans; Cell Line; Retroviridae Infections
PubMed: 38700882
DOI: No ID Found -
Theriogenology Jul 2024Syncytins are endogenous retroviral envelope proteins which induce the fusion of membranes. A human representative of this group, endogenous retrovirus group W member 1...
Syncytins are endogenous retroviral envelope proteins which induce the fusion of membranes. A human representative of this group, endogenous retrovirus group W member 1 envelope (ERVW-1) or syncytin-1 is present in trophoblast-derived extracellular vesicles and supports the incorporation of these extracellular vesicles into recipient cells. During pregnancy, placenta-derived extracellular vesicles participate in feto-maternal communication. Bovine fetal binucleate trophoblast cells express the syncytin, bovine endogenous retroviral envelope protein K1 (BERV-K1). These cells release extracellular vesicles into the maternal stroma, but it is unclear whether BERV-K1 is included in these extracellular vesicles. Here, extracellular vesicles were isolated from bovine placental tissue using collagenase digestion, ultracentrifugation, and size exclusion chromatography. They were characterized with transmission electron microscopy, nanoparticle tracking analysis, immunoblotting and mass spectrometry. Immunohistochemistry and immunoelectron microscopy were used to localize BERV-K1 within the bovine placental tissue. The isolated extracellular vesicles range between 50 and 300 nm, carrying multiple extracellular vesicle biomarkers. Proteomic analysis and immunoelectron microscopy confirmed BERV-K1 presence on the isolated extracellular vesicles. Further, BERV-K1 was localized on intraluminal vesicles in secretory granules of binucleate trophoblast cells. The presence of BERV-K1 on bovine placental extracellular vesicles suggests their role in feto-maternal communication and potential involvement of BERV-K1 in uptake of extracellular vesicles by target cells.
Topics: Animals; Female; Extracellular Vesicles; Pregnancy Proteins; Cattle; Pregnancy; Placenta; Gene Products, env; Trophoblasts
PubMed: 38678697
DOI: 10.1016/j.theriogenology.2024.04.012 -
EBioMedicine May 2024Endogenous retroelements (EREs), including human endogenous retroviruses (HERVs) and long interspersed nuclear elements (LINEs), comprise almost half of the human...
BACKGROUND
Endogenous retroelements (EREs), including human endogenous retroviruses (HERVs) and long interspersed nuclear elements (LINEs), comprise almost half of the human genome. Our previous studies of the interferome in the gut suggest potential mechanisms regarding how IFNb may drive HIV-1 gut pathogenesis. As ERE activity is suggested to partake in type 1 immune responses and is incredibly sensitive to viral infections, we sought to elucidate underlying interactions between ERE expression and gut dynamics in people living with HIV-1 (PLWH).
METHODS
ERE expression profiles from bulk RNA sequencing of colon biopsies and PBMC were compared between a cohort of PLWH not on antiretroviral therapy (ART) and uninfected controls.
FINDINGS
59 EREs were differentially expressed in the colon of PLWH when compared to uninfected controls (padj <0.05 and FC ≤ -1 or ≥ 1) [Wald's Test]. Of these 59, 12 EREs were downregulated in PLWH and 47 were upregulated. Colon expression of the ERE loci LTR19_12p13.31 and L1FLnI_1q23.1s showed significant correlations with certain gut immune cell subset frequencies in the colon. Furthermore L1FLnI_1q23.1s showed a significant upregulation in peripheral blood mononuclear cells (PBMCs) of PLWH when compared to uninfected controls suggesting a common mechanism of differential ERE expression in the colon and PBMC.
INTERPRETATION
ERE activity has been largely understudied in genomic characterizations of human pathologies. We show that the activity of certain EREs in the colon of PLWH is deregulated, supporting our hypotheses that their underlying activity could function as (bio)markers and potential mediators of pathogenesis in HIV-1 reservoirs.
FUNDING
US NIH grants NCI CA260691 (DFN) and NIAID UM1AI164559 (DFN).
Topics: Humans; HIV Infections; HIV-1; Endogenous Retroviruses; Male; Female; Leukocytes, Mononuclear; Adult; Middle Aged; Colon; Long Interspersed Nucleotide Elements; Retroelements; Gene Expression Profiling; Gene Expression Regulation; Gastrointestinal Microbiome
PubMed: 38677181
DOI: 10.1016/j.ebiom.2024.105133