"Human endogenous retroviruses"

BACKGROUND: Bipolar disorder (BD) and schizophrenia (SZ) are the two main mental disorders with unknown etiology that significantly impact individuals' quality of life. The potential pro-inflammatory role in their pathogenesis is postulated and Human Endogenous Retrovirus W (HERV-W) is an emerging candidate to modulate this pathogenic finding. HERVs, ancient retroviruses in the human genome, may play roles in inflammation and disease pathogenesis. Despite HERVs' involvement in autoimmune diseases, their influence on mental disorders remains underexplored...

The function of CD5 protein in T cells is well documented, but regulation of its surface-level expression has yet to be fully understood. However, variation in its surface expression is associated with various immunopathological conditions and haematological malignancies. Briefly, expression of an alternate exon E1B of a human endogenous retroviruses (HERV) origin directly downregulates the conventional transcript variant (E1A), as its expression leads to the retention of the resultant protein at the intracellular level (cCD5)...

Objective: Human endogenous retrovirus-H long terminal repeat associating 2 (HHLA2) is a new immune checkpoint in the B7 family, and the value of HHLA2 in small cell lung cancer (SCLC) is unknown. Methods: We retrospectively detected HHLA2 expression by immunohistochemistry in SCLC patients. Moreover, plasma biomarkers of SCLC were detected retrospectively. Results: Seventy-four percent of SCLC patients exhibited HHLA2 expression. HHLA2 staining was localised within the nucleus of SCLC cells, while no staining was detected in normal lung tissue specimens...

Human endogenous retroviruses (HERVs) are derived from the infection and integration of exogenetic retroviruses. HERVs account for 8% of human genome, and the majority of HERVs are solitary LTRs (solo-LTRs) due to homologous recombination. Multiple findings have showed that solo-LTRs could provide an enormous reservoir of transcriptional regulatory sequences involved in diverse biological processes, especially carcinogenesis and cancer development. The link between solo-LTRs and human diseases still remains poorly understood...

The role of extracellular vesicles (EVs), including retroviral-like particles (RVLPs), in pathogenic processes is currently a subject of active investigation. Several studies have identified mechanistic links between the increased presence of EVs and the process of senescence. A recent study reveals that the reverse transcribed complementary DNA (cDNA) of a human endogenous retroviral sequence can activate the innate immune system and result in tissue damage and/or the spread of cellular senescence to distant tissues...

BACKGROUND: Epstein barr virus (EBV) infection of B cells is now understood to be one of the triggering events for the development of Multiple Sclerosis (MS), a progressive immune-mediated disease of the central nervous system. EBV infection is also linked to expression of human endogenous retroviruses (HERVs) of the HERV-W group, a further risk factor for the development of MS. Ocrelizumab is a high-potency disease-modifying treatment (DMT) for MS, which depletes B cells by targeting CD20...

Low copy numbers (CNs) of C4 genes are associated with systemic autoimmune disorders and affects autoantibody diversity and disease subgroups. The primary objective of this study was to characterize diversity of complement (C4) and C4-Human Endogenous Retrovirus (HERV) gene copy numbers in SLE. We also sought to assess the association of C4 and C4-HERV CNs with serum complement levels, autoantibodies, disease phenotypes and activity. Finally, we checked the association of C4 and HERV CNs with specific HLA alleles...

Hepatocellular carcinoma (HCC) stands as one of the most malignant tumors characterized by poor prognosis and high mortality rates. Emerging evidence underscores the crucial role of the B7 protein family in various cancers, including HCC. However, the involvement of the human endogenous retrovirus H long-terminal repeat-associated protein 2 (HHLA2, or B7-H5) in HCC remains unclear. Immunohistochemistry was employed to assess the differential expression of HHLA2 between HCC and normal liver tissues...

Immunotherapy aimed at inhibiting the negative co-stimulatory molecule programmed cell death receptor-1 has limited effectiveness, with clinical response rates remaining below 10%-15%. Therefore, new immune checkpoints need to be explored. Our study focused on human endogenous retrovirus H long terminal repeat-associating protein 2 (HHLA2), a highly glycosylated member of the B7 family that is widely expressed in colorectal cancer. HHLA2 expression negatively correlates with the prognosis of colorectal cancer...

Human endogenous retrovirus sequences (HERVs) constitute up to 8% of the human genome, yet not all HERVs remain silent passengers within our genomes. Some HERVs, especially the HERV type K (HERV-K), have been found to be frequently transactivated in a variety of inflammatory diseases and human cancers. Np9, a 9-kDa HERV-K encoded protein, has been reported as an oncoprotein and found present in a variety of tumors and transformed cells. In the current study, we for the first time reported that ectopic expression of Np9 protein was able to induce DNA damage response from host cells especially through upregulation of γH2AX...

Human endogenous retroviruses (HERVs) constitute approximately 8% of the human genome and have long been regarded as silent passengers within our genomes. However, the reactivation of HERVs has been increasingly linked to a range of human diseases, particularly the HERV-K (HML-2) family. Many studies are dedicated to elucidating the potential role of HERV-K in pathogenicity. While the underlying mechanisms require further investigation, targeting HERV-K transactivation emerges as a promising avenue for treating human diseases, including cancer, autoimmune disorders, neurodegenerative conditions, and infectious diseases...

Endogenous retroviruses (ERVs) are frequently reactivated in mammalian placenta. It has been proposed that ERVs contribute to shaping the gene regulatory network of mammalian trophoblasts, dominantly acting as species- and placental-specific enhancers. However, whether and how ERVs control human trophoblast development through alternative pathways remains poorly understood. Besides the well-recognized function of human endogenous retrovirus-H (HERVH) in maintaining pluripotency of early human epiblast, here we present a unique role of HERVH on trophoblast lineage development...

INTRODUCTION: The etiology of multiple sclerosis (MS) remains unknown. Pathogenesis likely relies on a complex interaction between multiple environmental, genetic, and behavioral risk factors. However, a growing body of literature supports the role of a preceding Epstein Barr Virus (EBV) infection in the majority of cases. AREAS COVERED: In this narrative review, we summarize the latest findings regarding the potential role of EBV as a predisposing event inducing new onset of MS...

BACKGROUND: Human endogenous retrovirus (HERV)-K is a type of retrovirus that is present in the human genome, and its expression is usually silenced in healthy tissues. The precise mechanism by which HERV-K env influences cancer stemness is not fully understood, but it has been suggested that HERV-K env may activate various signaling pathways that promote stemness traits in cancer cells. OBJECTIVE: To establish the connection between HERV-K env expression and cancer stemness in ovarian cancer cells, we carried out correlation analyses between HERV-K env and the cancer stem cell (CSC) marker known as the cluster of differentiation 133 (CD133) gene in SKOV3 ovarian cancer cells...

While infection with high-risk human papillomavirus (HPV) types is necessary for cervical cancer (CC) development, it is not enough, and other risk factors are required. Several studies have reported the activation of HERV-K in different cancers; however, the investigation of HERV-K expression levels in CC is scarce. In this study, it was hypothesized that activation of HERV-K could play an essential role in CC development. In this order, the expression levels of HERV-K Env, Np9, and Rec transcripts were investigated on 147 normal to CC uterine cervical tissues using quantitative real-time PCR...

PURPOSE: Investigation of undiagnosed cases of infectious neurological diseases, especially in the paediatric population, remains a challenge. This study aimed to enhance understanding of viruses in CSF from children with clinically diagnosed meningitis and/or encephalitis (M/ME) of unknown aetiology using shotgun sequencing enhanced by hybrid capture (HCSS). METHODS: A single-centre prospective study was conducted at Sant Joan de Déu University Hospital, Barcelona, involving 40 M/ME episodes of unknown aetiology, recruited from May 2021 to July 2022...

Introduction Breast cancer is the most common cancer and the leading cause of cancer death in women. Recent research indicates that human endogenous retroviruses (HERVs) may be linked to carcinogenesis, but the data remain controversial. Methods HERVs´ expression was evaluated to show the differences between breast cancer and control samples, and their associations with clinicopathological parameters. Gene expression of 12 HERVs, i.e. ERVE-4, ERVW-1, ERVFRD-1, ERVV-1, ERV3-1, ERVH48-1, ERVMER34-1, ERVK7, ERVK13-1, ERVK11-1, ERVK3-1 and HCP5 was analyzed by qPCR and/or TCGA datasets for breast cancer...

PURPOSE: Human endogenous retroviruses (HERVs) are ubiquitous genomic sequences. Normally dormant HERVs, undergo reactivation by environmental factors. This deregulation of HERVs' transcriptional equilibrium correlates with medical conditions such as multiple sclerosis (MS). Here we sought to explore whether exposing the U-87 MG astrocytoma cells to traumatic injury deregulates the expression of HERV-W family member ERVW-1 encoding syncytin-1. We also examined the expression of FURIN gene that is crucial in syncytin-1 synthesis...

Interindividual variability in drug response is a major problem in the prescription of pharmacological treatments. The therapeutic effect of drugs can be influenced by human genes. Pharmacogenomic guidelines for individualization of treatment have been validated and used for conventional dosage forms. However, drugs can often target non-specific areas and produce both desired and undesired pharmacological effects. The use of nanoparticles, liposomes, or other available forms for drug formulation could help to overcome the latter problem...

Human endogenous retroviruses (HERVs) are the result of retroviral infections acquired millions of years ago; nowadays, they compose around 8% of human DNA. Multiple mechanisms have been employed for endogenous retroviral deactivation, rendering replication and retrotransposition defective, while some of them have been co-opted to serve host evolutionary advantages. A pleiad of mechanisms retains the delicate balance of HERV expression in modern humans. Thus, epigenetic modifications, such as DNA and histone methylation, acetylation, deamination, chromatin remodeling, and even post-transcriptional control are recruited...