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Scientific Reports May 2024The Bovine Leukemia Virus (BLV) Envelope (Env) glycoprotein complex is instrumental in viral infectivity and shapes the host's immune response. This study presents the...
The Bovine Leukemia Virus (BLV) Envelope (Env) glycoprotein complex is instrumental in viral infectivity and shapes the host's immune response. This study presents the production and characterization of a soluble furin-mutated BLV Env ectodomain (sBLV-EnvFm) expressed in a stable S2 insect cell line. We purified a 63 kDa soluble protein, corresponding to the monomeric sBLV-EnvFm, which predominantly presented oligomannose and paucimannose N-glycans, with a high content of core fucose structures. Our results demonstrate that our recombinant protein can be recognized from specific antibodies in BLV infected cattle, suggesting its potential as a powerful diagnostic tool. Moreover, the robust humoral immune response it elicited in mice shows its potential contribution to the development of subunit-based vaccines against BLV.
Topics: Animals; Leukemia Virus, Bovine; Cattle; Recombinant Proteins; Mice; Viral Envelope Proteins; Antibodies, Viral; Enzootic Bovine Leukosis; Cell Line; Gene Products, env
PubMed: 38806566
DOI: 10.1038/s41598-024-62811-8 -
International Journal of Molecular... Nov 2023Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the...
Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the reasons why cell-free HTLV-1 infection is poor remain unknown. In this study, we found that the retrovirus pseudotyped with HTLV-1 viral envelope glycoprotein (Env) was infectious when human immunodeficiency virus type 1 (HIV-1) was used to produce the virus. We found that the incorporation of HTLV-1 Env into virus-like particles (VLPs) was low when HTLV-1 Gag was used to produce VLPs, whereas VLPs produced using HIV-1 Gag efficiently incorporated HTLV-1 Env. The production of VLPs using Gag chimeras between HTLV-1 and HIV-1 Gag and deletion mutants of HIV-1 Gag showed that the p6 domain of HIV-1 Gag was responsible for the efficient incorporation of HTLV-1 Env into the VLPs. Further mutagenic analyses of the p6 domain of HIV-1 Gag revealed that the PTAP motif in the p6 domain of HIV-1 Gag facilitates the incorporation of HTLV-1 Env into VLPs. Since the PTAP motif is known to interact with tumor susceptibility gene 101 (TSG101) during the budding process, we evaluated the effect of TSG101 knockdown on the incorporation of HTLV-1 Env into VLPs. We found that TSG101 knockdown suppressed the incorporation of HTLV-1 Env into VLPs and decreased the infectivity of cell-free HIV-1 pseudotyped with HTLV-1 Env. Our results suggest that the interaction of TSG101 with the PTAP motif of the retroviral L domain is involved not only in the budding process but also in the efficient incorporation of HTLV-1 Env into the cell-free virus.
Topics: Humans; Amino Acid Motifs; Gene Products, gag; Human T-lymphotropic virus 1; Virion; HIV-1; Gene Products, env
PubMed: 38003710
DOI: 10.3390/ijms242216520 -
Frontiers in Public Health 2024Human T Lymphotropic Virus type 1 (HTLV-1) is a neglected retrovirus associated with many clinical disorders, most notably Adult T-cell Leukemia/Lymphoma and... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Human T Lymphotropic Virus type 1 (HTLV-1) is a neglected retrovirus associated with many clinical disorders, most notably Adult T-cell Leukemia/Lymphoma and HTLV-1-Associated Myelopathy (HAM). Found in endemic clusters across the world, high prevalence has been reported in minoritized groups who suffer from health inequities. This study investigates the association between HTLV-1 prevalence and the following socioeconomic determinants of health: education, income, and employment, which are markers of health inequity.
METHODS
A systematic review was conducted by searching the following databases: Ovid/Medline, Embase, Global Health Database, Web of Science, LILACS and SciELO. Primary studies in English, Spanish and Portuguese mentioning HTLV-1 and one of education, income and/or employment were included. A random-effects meta-analysis was performed, and odds ratios (OR) were calculated to determine the association between these socioeconomic determinants of health and HTLV-1 prevalence.
RESULTS
42 studies were included. The likelihood of having HTLV-1 was higher in individuals with less than completed primary education compared to those who completed primary education (OR 1.86 [95% CI 1.34-2.57]; < 0.01). This may be because individuals with low education have reduced access to and understanding of health information, thus increasing the prevalence of risk factors associated with HTLV-1 infection. No other determinants were found to be statistically significant.
CONCLUSION
Fewer years of schooling are associated with increased likelihood of contracting HTLV-1. Therefore, health promotion materials and public health policies regarding HTLV-1 must consider those with lower educational levels to effectively reduce disease transmission.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=335004, identifier (CRD42022335004).
Topics: Humans; Adult; Human T-lymphotropic virus 1; HTLV-I Infections; Paraparesis, Tropical Spastic; Risk Factors; Socioeconomic Factors
PubMed: 38327581
DOI: 10.3389/fpubh.2024.1298308 -
PloS One 2024Human T-cell leukemia virus type I (HTLV-I) is an oncogenic virus whose infection can cause diverse diseases, most notably adult T-cell leukemia/lymphoma (ATL or ATLL),...
Human T-cell leukemia virus type I (HTLV-I) is an oncogenic virus whose infection can cause diverse diseases, most notably adult T-cell leukemia/lymphoma (ATL or ATLL), an aggressive and fatal malignancy of CD4 T cells. The oncogenic ability of HTLV-I is mostly attributed to the viral transcriptional transactivator Tax. Tax alone is sufficient to induce specific tumors in mice depending on the promotor used to drive Tax expression, thereby being used to understand HTLV-I tumorigenesis and model the tumor types developed in Tax transgenic mice. Tax exerts its oncogenic role predominantly by activating the cellular transcription factor NF-κB. Here, we report that genetic deletion of NF-κB1, the prototypic member of the NF-κB family, promotes adrenal medullary tumors but suppresses neurofibromas in mice with transgenic Tax driven by the HTLV-I Long Terminal Repeat (LTR) promoter. The adrenal tumors are derived from macrophages. Neoplastic macrophages also infiltrate the spleen and lymph nodes, causing splenomegaly and lymphadenopathy in mice. Nevertheless, the findings could be human relevant, because macrophages are important target cells of HTLV-I infection and serve as a virus reservoir in vivo. Moreover, the spleen, lymph nodes and adrenal glands are the most common sites of tumor cell infiltration in HTLV-I-infected patients. These data provide new mechanistic insights into the complex interaction between Tax and NF-κB, therefore improving our understanding of HTLV-I oncogenic pathogenesis. They also expand our knowledge and establish a new animal model of macrophage neoplasms and adrenal tumors.
Topics: Animals; Humans; Mice; Adrenal Gland Neoplasms; Gene Products, tax; Human T-lymphotropic virus 1; Macrophages; Mice, Transgenic; NF-kappa B p50 Subunit; Terminal Repeat Sequences
PubMed: 38722890
DOI: 10.1371/journal.pone.0303138 -
Epidemiologia E Servicos de Saude :... Sep 2023
Topics: Humans; Female; Brazil; Breast Feeding; Deltaretrovirus Infections
PubMed: 37729266
DOI: 10.1590/S2237-96222023000200025 -
Virology Journal Jan 2024The human T-lymphotropic virus type 1 (HTLV-1) infects millions of people globally and is endemic to various resource-limited regions. Infections persist for life and...
The human T-lymphotropic virus type 1 (HTLV-1) infects millions of people globally and is endemic to various resource-limited regions. Infections persist for life and are associated with increased susceptibility to opportunistic infections and severe diseases including adult T cell leukemia/lymphoma and HTLV-1-associated myelopathy-tropical spastic paraparesis. No HTLV-1-specific anti-retrovirals have been developed and it is unclear whether existing anti-retrovirals developed for treatment of human immunodeficiency virus (HIV) have efficacy against HTLV-1. To understand the structural basis for therapeutic binding, homology modelling and machine learning were used to develop a structural model of the HTLV-1 reverse transcriptase. With this, molecular docking experiments using a panel of FDA-approved inhibitors of viral reverse transcriptases to assess their capacity for binding, and in turn, inhibition. Importantly, nucleoside/nucleotide reverse transcriptase inhibitor but not non-nucleoside reverse transcriptase inhibitors were predicted to bind the HTLV-1 reverse transcriptase, with similar affinity to HIV-1 reverse transcriptase. By strengthening the rationale for clinical testing of therapies such as tenofovir alafenamide, zidovudine, lamivudine, and azvudine for treatment of HTLV-1, this study has demonstrated the power of in silico structural biology approaches in drug design and therapeutic testing.
Topics: Adult; Humans; Human T-lymphotropic virus 1; Nucleotides; Reverse Transcriptase Inhibitors; Molecular Docking Simulation; Paraparesis, Tropical Spastic
PubMed: 38200531
DOI: 10.1186/s12985-024-02288-z -
Pharmaceuticals (Basel, Switzerland) Jun 2024With an estimated 10 million people infected, the deltaretrovirus human T-cell lymphotropic virus type 1 (HTLV-1) is the second most prevalent pathogenic retrovirus in...
With an estimated 10 million people infected, the deltaretrovirus human T-cell lymphotropic virus type 1 (HTLV-1) is the second most prevalent pathogenic retrovirus in humans after HIV-1. Like HIV-1, HTLV-1 overwhelmingly persists in a host via a reservoir of latently infected CD4 T cells. Although most patients are asymptomatic, HTLV-1-associated pathologies are often debilitating and include adult T-cell leukaemia/lymphoma (ATLL), which presents in mature adulthood and is associated with poor prognosis with short overall survival despite treatment. Curiously, the strongest indicator for the development of ATLL is the acquisition of HTLV-1 through breastfeeding. There are no therapeutic or preventative regimens for HTLV-1. However, antiretrovirals (ARVs), which target the essential retrovirus enzymes, have been developed for and transformed HIV therapy. As the architectures of retroviral enzyme active sites are highly conserved, some HIV-specific compounds are active against HTLV-1. Here, we expand on our work, which showed that integrase strand transfer inhibitors (INSTIs) and some nucleoside reverse transcriptase inhibitors (NRTIs) block HTLV-1 transmission in cell culture. Specifically, we find that dolutegravir, the INSTI currently recommended as the basis of all new combination antiretroviral therapy prescriptions, and the latest prodrug formula of the NRTI tenofovir, tenofovir alafenamide, also potently inhibit HTLV-1 infection. Our results, if replicated in a clinical setting, could see transmission rates of HTLV-1 and future caseloads of HTLV-1-associated pathologies like ATLL dramatically cut via the simple repurposing of already widely available HIV pills in HTLV-1 endemic areas. Considering our findings with the old medical saying "it is better to prevent than cure", we highly recommend the inclusion of INSTIs and tenofovir prodrugs in upcoming HTLV-1 clinical trials as potential prophylactics.
PubMed: 38931397
DOI: 10.3390/ph17060730 -
Internal Medicine (Tokyo, Japan) Nov 2023Objective A T-SPOT.TB can yield indeterminate results under two test observation conditions: a high response to the nil in negative control wells (high nil-control) or a...
Objective A T-SPOT.TB can yield indeterminate results under two test observation conditions: a high response to the nil in negative control wells (high nil-control) or a low response to the mitogen in positive control wells (low mitogen-control). The most strongly influential factors for these indeterminate results, however, have yet to be identified. Methods From June 1, 2015, to June 30, 2021, we conducted a 1:1 matched case-control, retrospective study. Patients Patients who underwent a T-SPOT.TB test at Chiba University Hospital. Results The study included 5,956 participants. Indeterminate results were found in 63 participants (1.1%), including high nil-control in 37 and low mitogen-control in 26. Human T-cell leukemia virus type 1 (HTLV-1) positivity was the only influencing factor associated with high nil-control (adjusted odds ratio=98.5, 95% confidence interval: 6.59-1,480). Conclusion Regarding the indeterminate results, all HTLV-1 positive participants had a high nil response and no low mitogen response. It was suspected that abnormally produced interferon γ caused a nonspecific reaction to the negative control well, resulting in a high nil response. Low mitogen-control, conversely, did not appear to have any statistically significant influential factors.
Topics: Humans; Case-Control Studies; Retrospective Studies; Mitogens; Interferon-gamma; Human T-lymphotropic virus 1; Tuberculin Test; Interferon-gamma Release Tests
PubMed: 37005270
DOI: 10.2169/internalmedicine.1006-22 -
American Journal of Veterinary Research Apr 2024The objective of this study was to determine the seroprevalence of reproductive and infectious diseases in tropical cattle in the Tambopata and Tahuamanu Provinces in...
OBJECTIVE
The objective of this study was to determine the seroprevalence of reproductive and infectious diseases in tropical cattle in the Tambopata and Tahuamanu Provinces in the department of Madre de Dios, Peru.
SAMPLE
156 bovines from 7 cattle farms were sampled. These farms used exclusive grazing for food and natural mating for reproduction and did not have sanitary or vaccination programs.
METHODS
The serum of blood samples was subjected to ELISA with commercial kits for the detection of antibodies against Neospora caninum, Mycobacterium avium subsp paratuberculosis (MAP), Leptospira interrogans, pestivirus bovine viral diarrhea virus-1, retrovirus bovine leukemia virus (BLV), orbivirus bluetongue virus (BTV), and herpesvirus bovine herpes virus-1 (BHV). The data were analyzed by means of association tests with χ2 (P < .05) and Spearman rank correlation (P < .05) in the SPSS v.15.0 software (IBM Corp).
RESULTS
A low prevalence of antibodies to L interrogans, N caninum, M avium subsp paratuberculosis, bovine viral diarrhea virus-1 was found, but it was high to BTV, BLV, and BHV (100%, 53.85%, and 72.44%, respectively). The presence of BLV and BHV was higher in the Las Piedras District, bovines less than 5 years old, and cattle with breed characteristics of zebu and crossbred (P < .01). In addition, there was a significant correlation between both infections, showing 83.3% of BLV positivity that were also BHV positive (P < .01).
CLINICAL RELEVANCE
The high prevalence of antibodies to BTV, BHV, and BLV could be due to livestock management practices, direct contact with infected animals, and variation of the presence of vectors and natural reservoirs in the context of climate change in the tropics.
Topics: Cattle; Animals; Paratuberculosis; Cattle Diseases; Enzootic Bovine Leukosis; Bovine Virus Diarrhea-Mucosal Disease; Peru; Seroepidemiologic Studies; Diarrhea Viruses, Bovine Viral; Antibodies, Viral; Antibodies, Bacterial; Communicable Diseases; Reproduction; Diarrhea Virus 1, Bovine Viral; Leukemia Virus, Bovine; Diarrhea
PubMed: 38335721
DOI: 10.2460/ajvr.23.08.0177 -
Viruses Feb 2024To mediate intercellular communication, cells produce extracellular vesicles (EVs). These EVs transport many biomolecules such as proteins, nucleic acids, and lipids...
To mediate intercellular communication, cells produce extracellular vesicles (EVs). These EVs transport many biomolecules such as proteins, nucleic acids, and lipids between cells and regulate pathophysiological actions in the recipient cell. However, EVs and virus particles produced from virus-infected cells are of similar size and specific gravity; therefore, the separation and purification of these two particles is often controversial. When analyzing the physiological functions of EVs from virus-infected cells, the presence or absence of virus particle contamination must always be verified. The human T-cell leukemia virus type 1 (HTLV-1)-infected cell line, MT-2, produces EVs and virus particles. Here, we validated a method for purifying EVs from MT-2 cell culture supernatants while avoiding HTLV-1 viral particle contamination. EV fractions were collected using a combination of immunoprecipitation with Tim-4, which binds to phosphatidylserine, and polymer precipitation. The HTLV-1 viral envelope protein, gp46, was not detected in the EV fraction. Proteomic analysis revealed that EV-constituted proteins were predominant in this EV fraction. Furthermore, the EVs were found to contain the HTLV-1 viral genome. The proposed method can purify EVs while avoiding virus particle contamination and is expected to contribute to future research on EVs derived from HTLV-1-infected cells.
Topics: Humans; Human T-lymphotropic virus 1; Proteomics; Proteins; Leukemia, T-Cell; Virion; Extracellular Vesicles
PubMed: 38400025
DOI: 10.3390/v16020249