Pub Date : 2022-11-01DOI: 10.3389/fviro.2022.971293
J. J. McAllister, Satinder Dahiya, R. Berman, Mackenzie E. Collins, M. Nonnemacher, T. Burdo, B. Wigdahl
Human immunodeficiency virus type 1 (HIV-1) transcription in cells of the monocyte-macrophage lineage is regulated by interactions between the HIV-1 long terminal repeat (LTR) and a variety of host cell and viral proteins. Binding of the Sp family of transcription factors (TFs) to the G/C box array of the LTR governs both basal as well as activated LTR-directed transcriptional activity. The effect of monocytic differentiation on Sp factor binding and transactivation was examined with respect to the HIV-1 LTR. The binding of Sp1, full-length Sp3 and truncated Sp3 to a high affinity HIV-1 Sp element was specifically investigated and results showed that Sp1 binding increased relative to the binding of the sum of full-length and truncated Sp3 binding following chemically-induced monocytic differentiation in monoblastic (U-937, THP-1) and myelomonocytic (HL-60) cells. In addition, Sp binding ratios from PMA-induced cell lines were shown to more closely approximate those derived from primary monocyte-derived macrophages (MDMs) than did ratios derived from uninduced cell lines. The altered Sp binding phenotype associated with changes in the transcriptional activation mediated by the HIV-1 G/C box array. Additionally, analysis of post-translational modifications on Sp1 and Sp3 revealed a loss of phosphorylation on serine and threonine residues with chemically-induced differentiation indicating that the activity of Sp factors is additionally regulated at the level of post-translational modifications (PTMs).
{"title":"Altered recruitment of Sp isoforms to HIV-1 long terminal repeat between differentiated monoblastic cell lines and primary monocyte-derived macrophages","authors":"J. J. McAllister, Satinder Dahiya, R. Berman, Mackenzie E. Collins, M. Nonnemacher, T. Burdo, B. Wigdahl","doi":"10.3389/fviro.2022.971293","DOIUrl":"https://doi.org/10.3389/fviro.2022.971293","url":null,"abstract":"Human immunodeficiency virus type 1 (HIV-1) transcription in cells of the monocyte-macrophage lineage is regulated by interactions between the HIV-1 long terminal repeat (LTR) and a variety of host cell and viral proteins. Binding of the Sp family of transcription factors (TFs) to the G/C box array of the LTR governs both basal as well as activated LTR-directed transcriptional activity. The effect of monocytic differentiation on Sp factor binding and transactivation was examined with respect to the HIV-1 LTR. The binding of Sp1, full-length Sp3 and truncated Sp3 to a high affinity HIV-1 Sp element was specifically investigated and results showed that Sp1 binding increased relative to the binding of the sum of full-length and truncated Sp3 binding following chemically-induced monocytic differentiation in monoblastic (U-937, THP-1) and myelomonocytic (HL-60) cells. In addition, Sp binding ratios from PMA-induced cell lines were shown to more closely approximate those derived from primary monocyte-derived macrophages (MDMs) than did ratios derived from uninduced cell lines. The altered Sp binding phenotype associated with changes in the transcriptional activation mediated by the HIV-1 G/C box array. Additionally, analysis of post-translational modifications on Sp1 and Sp3 revealed a loss of phosphorylation on serine and threonine residues with chemically-induced differentiation indicating that the activity of Sp factors is additionally regulated at the level of post-translational modifications (PTMs).","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45273382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-06DOI: 10.3389/fviro.2022.994843
Leila Issmail, C. Möser, Christian Jäger, Basma Altattan, D. Ramsbeck, M. Kleinschmidt, Mirko Buchholz, David Smith, T. Grunwald
Human respiratory syncytial virus (RSV) is the primary cause of acute lower respiratory tract infections in children and the elderly worldwide, for which neither a vaccine nor an effective therapy is approved. The entry of RSV into the host cell is mediated by stepwise structural changes in the surface RSV fusion (RSV-F) glycoprotein. Recent progress in structural and functional studies of RSV-F glycoprotein revealed conformation-dependent neutralizing epitopes which have become attractive targets for vaccine and therapeutic development. As RSV-F is present on viral surface in a trimeric form, a trivalent binding interaction between a candidate fusion inhibitor and the respective epitopes on each of the three monomers is expected to prevent viral infection at higher potency than a monovalent or bivalent inhibitor. Here we demonstrate a novel RSV entry inhibitory approach by implementing a trimeric DNA nanostructure as a template to display up to three linear peptide moieties that simultaneously target an epitope on the surface of the prefusion RSV-F protein. In order to design synthetic binding peptides that can be coupled to the DNA nanostructure, the prefusion RSV-F-specific monoclonal antibody (D25) was selected. Complementarity-determining region 3 (CDR3) derived peptides underwent truncation and alanine-scanning mutagenesis analysis, followed by systematic sequence modifications using non-canonical amino acids. The most effective peptide candidate was used as a binding moiety to functionalize the DNA nanostructure. The designed DNA-peptide construct was able to block RSV infection on cells more efficiently than the monomeric peptides, however a more moderate reduction of viral load was observed in the lungs of infected mice upon intranasal application, likely due to dissociation or absorption of the underlying DNA structure by cells in the lungs. Taken together, our results point towards the inhibitory potential of a novel trimeric DNA-peptide based approach against RSV and open the possibility to apply this platform to target other viral infections.
{"title":"Prefusion-specific antibody-derived peptides trivalently presented on DNA-nanoscaffolds as an innovative strategy against RSV entry","authors":"Leila Issmail, C. Möser, Christian Jäger, Basma Altattan, D. Ramsbeck, M. Kleinschmidt, Mirko Buchholz, David Smith, T. Grunwald","doi":"10.3389/fviro.2022.994843","DOIUrl":"https://doi.org/10.3389/fviro.2022.994843","url":null,"abstract":"Human respiratory syncytial virus (RSV) is the primary cause of acute lower respiratory tract infections in children and the elderly worldwide, for which neither a vaccine nor an effective therapy is approved. The entry of RSV into the host cell is mediated by stepwise structural changes in the surface RSV fusion (RSV-F) glycoprotein. Recent progress in structural and functional studies of RSV-F glycoprotein revealed conformation-dependent neutralizing epitopes which have become attractive targets for vaccine and therapeutic development. As RSV-F is present on viral surface in a trimeric form, a trivalent binding interaction between a candidate fusion inhibitor and the respective epitopes on each of the three monomers is expected to prevent viral infection at higher potency than a monovalent or bivalent inhibitor. Here we demonstrate a novel RSV entry inhibitory approach by implementing a trimeric DNA nanostructure as a template to display up to three linear peptide moieties that simultaneously target an epitope on the surface of the prefusion RSV-F protein. In order to design synthetic binding peptides that can be coupled to the DNA nanostructure, the prefusion RSV-F-specific monoclonal antibody (D25) was selected. Complementarity-determining region 3 (CDR3) derived peptides underwent truncation and alanine-scanning mutagenesis analysis, followed by systematic sequence modifications using non-canonical amino acids. The most effective peptide candidate was used as a binding moiety to functionalize the DNA nanostructure. The designed DNA-peptide construct was able to block RSV infection on cells more efficiently than the monomeric peptides, however a more moderate reduction of viral load was observed in the lungs of infected mice upon intranasal application, likely due to dissociation or absorption of the underlying DNA structure by cells in the lungs. Taken together, our results point towards the inhibitory potential of a novel trimeric DNA-peptide based approach against RSV and open the possibility to apply this platform to target other viral infections.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91395031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-29DOI: 10.3389/fviro.2022.999929
Yukina Uemura, Ayaka Ohashi, M. Yoshimori, Miwako Nishio, T. Hirakawa, N. Shimizu, Naomi Wada, K. Imadome, A. Arai
Systemic chronic active Epstein-Barr virus infection (sCAEBV) is an intractable disease that present activated EBV-infected T- or NK-cells and their clonal proliferation. When inflammatory symptoms persist and proceed, a lethal complication of hemophagocytic lymphohistiocytosis (HLH) develops, but its biomarker to represent the pathophysiology and an effective agent to cure have not been developed as of today. It is known that interferon-γ (IFN-γ) level in the peripheral blood increases in HLH correlatedly with the disease condition and that antagonistic anti-IFN-γ antibody is effective against HLH. We examined the plasma level of IFN-γ to investigate its role in the disease condition of sCAEBV. sCAEBV was diagnosed based on the criteria conforming to the definition of sCAEBV in the WHO classification issued in 2017. As it was previously reported, disease activity was defined as the condition positive for any one of the followings: fever, liver dysfunction, progressive skin lesions, vasculitis, and uveitis. Eighteen sCAEBV patients were examined. Their plasma IFN-γ levels were significantly higher than those of healthy donors. The levels in sCAEBV patients with disease activity were higher than those without disease activity. The mRNA expression of IFNG was detected in EBV-infected cells of all patients. We also detected a correlation between plasma IFN-γ levels and mRNA levels of EBV-infected cells in peripheral blood mononuclear cells. These results suggest that EBV-infected cells produce IFN-γ in sCAEBV. Although the difference was not significant, the patients whose plasma IFN-γ levels at diagnosis were higher than 40 pg/mL tended to result in poorer survival than those with lower levels. We concluded that plasma IFN-γ is a potential biomarker that indicates disease activity of sCAEBV. Further study shall confirm its significance.
{"title":"Plasma interferon-γ concentration: a potential biomarker of disease activity of systemic chronic active Epstein-Barr virus infection","authors":"Yukina Uemura, Ayaka Ohashi, M. Yoshimori, Miwako Nishio, T. Hirakawa, N. Shimizu, Naomi Wada, K. Imadome, A. Arai","doi":"10.3389/fviro.2022.999929","DOIUrl":"https://doi.org/10.3389/fviro.2022.999929","url":null,"abstract":"Systemic chronic active Epstein-Barr virus infection (sCAEBV) is an intractable disease that present activated EBV-infected T- or NK-cells and their clonal proliferation. When inflammatory symptoms persist and proceed, a lethal complication of hemophagocytic lymphohistiocytosis (HLH) develops, but its biomarker to represent the pathophysiology and an effective agent to cure have not been developed as of today. It is known that interferon-γ (IFN-γ) level in the peripheral blood increases in HLH correlatedly with the disease condition and that antagonistic anti-IFN-γ antibody is effective against HLH. We examined the plasma level of IFN-γ to investigate its role in the disease condition of sCAEBV. sCAEBV was diagnosed based on the criteria conforming to the definition of sCAEBV in the WHO classification issued in 2017. As it was previously reported, disease activity was defined as the condition positive for any one of the followings: fever, liver dysfunction, progressive skin lesions, vasculitis, and uveitis. Eighteen sCAEBV patients were examined. Their plasma IFN-γ levels were significantly higher than those of healthy donors. The levels in sCAEBV patients with disease activity were higher than those without disease activity. The mRNA expression of IFNG was detected in EBV-infected cells of all patients. We also detected a correlation between plasma IFN-γ levels and mRNA levels of EBV-infected cells in peripheral blood mononuclear cells. These results suggest that EBV-infected cells produce IFN-γ in sCAEBV. Although the difference was not significant, the patients whose plasma IFN-γ levels at diagnosis were higher than 40 pg/mL tended to result in poorer survival than those with lower levels. We concluded that plasma IFN-γ is a potential biomarker that indicates disease activity of sCAEBV. Further study shall confirm its significance.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49314960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-23DOI: 10.3389/fviro.2022.972156
Samuel Narvey, Alex Vandenakker, Megan Rempel, R. Douville
Retroviral proteases are essential enzymes for viral replication and drive changes within the cellular proteome. While several studies have demonstrated that protease (PR) enzymes from exogenous retroviruses cleave cellular proteins and modulate cellular signaling, the impact of PRs encoded by endogenous retroviruses within the human genome has been largely overlooked. One human symbiont called Endogenous retrovirus-K (ERVK) is pathologically associated with both neurological disease and cancers. Using a computational biology approach, we sought to characterize the ERVK PR interactome. The ERVK PR protein sequence was analyzed using the Eukaryotic Linear Motif (ELM) database and results compared to ELMs of other betaretroviral PRs and similar endogenated viral PRs. A list of putative ERVK PR cellular protein interactors was curated from the ELM list and submitted for STRING analysis to generate an ERVK PR interactome. Reactome analysis was used to identify key pathways potentially influenced by ERVK PR. Network analysis postulated that ERVK PR interacts at the apex of several ubiquitination pathways, as well as has a role in the DNA damage response, gene regulation, and intracellular trafficking. Among retroviral PRs, a predicted interaction with proliferating cell nuclear antigen (PCNA) was unique to ERVK PR. The most prominent disease-associated pathways identified were viral carcinogenesis and neurodegeneration. This strengthens the role of ERVK PR in these pathologies by putatively driving alterations in cellular signaling cascades via select protein-protein interactions.
{"title":"Predicted cellular interactors of the endogenous retrovirus-K protease enzyme","authors":"Samuel Narvey, Alex Vandenakker, Megan Rempel, R. Douville","doi":"10.3389/fviro.2022.972156","DOIUrl":"https://doi.org/10.3389/fviro.2022.972156","url":null,"abstract":"Retroviral proteases are essential enzymes for viral replication and drive changes within the cellular proteome. While several studies have demonstrated that protease (PR) enzymes from exogenous retroviruses cleave cellular proteins and modulate cellular signaling, the impact of PRs encoded by endogenous retroviruses within the human genome has been largely overlooked. One human symbiont called Endogenous retrovirus-K (ERVK) is pathologically associated with both neurological disease and cancers. Using a computational biology approach, we sought to characterize the ERVK PR interactome. The ERVK PR protein sequence was analyzed using the Eukaryotic Linear Motif (ELM) database and results compared to ELMs of other betaretroviral PRs and similar endogenated viral PRs. A list of putative ERVK PR cellular protein interactors was curated from the ELM list and submitted for STRING analysis to generate an ERVK PR interactome. Reactome analysis was used to identify key pathways potentially influenced by ERVK PR. Network analysis postulated that ERVK PR interacts at the apex of several ubiquitination pathways, as well as has a role in the DNA damage response, gene regulation, and intracellular trafficking. Among retroviral PRs, a predicted interaction with proliferating cell nuclear antigen (PCNA) was unique to ERVK PR. The most prominent disease-associated pathways identified were viral carcinogenesis and neurodegeneration. This strengthens the role of ERVK PR in these pathologies by putatively driving alterations in cellular signaling cascades via select protein-protein interactions.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41320394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-23DOI: 10.3389/fviro.2022.972452
E. Barnea, N. Di Simone, S. Hayrabedyan, K. Todorova, A. Inversetti, G. Vento, S. Costa
Prenatal infections that have been exhaustively studied help frame the current Severe Acute Respiratory Syndrome related coronavirus-2 (SARS-CoV-2) pandemic, with the caveat that asymptomatic SARS-CoV-2 infected patients are not tested, while those symptomatic are delivered and/or treated with drug(s) available on-site. Thus, management and therapy are still heterogeneous. SARS-CoV-2 induced respiratory infection remains mostly local, unless severe, which lessens transplacental vertical transmission (VT). Vaccination prior to or during pregnancy significantly changes the prognosis for both the mother and newborn. The virus spread to the fetus can be binding to ACE2 and TMPRSS2 protein receptors. A recent study demonstrated ACE2 and TMPRSS2 fetal expression in the intestine from the second trimester. Most placental infections are subclinical unless severe villitis and apoptosis are observed. The placenta is rarely tested, and it is highly probable that most are positive for the virus, requiring sophisticated diagnostics to document. Other VT modalities, such as vaginal, rectal or through amniotic fluid contamination, are very rare. Therefore, vaginal delivery is preferable when clinically feasible. It has not yet been determined whether the placenta is a shield or if it transmits infection, while, on the other hand, recent data support fetal resilience, which is plausible due to the major difference between the placental and fetal rates of infection: only 3%–5% of documentable VT compared with up to 100% expected placental exposure to viremia. Newborn Polymerase Chain Reaction (PCR) from nasal swab is more practical as an option for VT diagnosis compared to ocular or anal swab, with low yield. The maternal infection leads to antiviral IgG production of 100% in severe cases, which is transferred to the fetus and breast milk. Postpartum-documenting VT is difficult since horizontal viral transmission may be common and minimized by mother/staff/family-preventive measures. Breastfeeding is safe and encouraged because, beyond nutrition, it promotes protective antibody transfer and maternal bonding. Lessons learned from other Betacorona viruses (SARS-CoV and Middle East Respiratory Syndrome related coronavirus [MERS-CoV]) virulence are relevant since mutations can increase or decrease vulnerability. Overall, data support fetal/newborn resilience against SARS-CoV-2 VT. However, viremia monitoring by sensitive tests and assessment for delayed sequelae shown in adults is necessary.
{"title":"SARS-CoV-2 vertical transmission supports innate fetal protection: A narrative review","authors":"E. Barnea, N. Di Simone, S. Hayrabedyan, K. Todorova, A. Inversetti, G. Vento, S. Costa","doi":"10.3389/fviro.2022.972452","DOIUrl":"https://doi.org/10.3389/fviro.2022.972452","url":null,"abstract":"Prenatal infections that have been exhaustively studied help frame the current Severe Acute Respiratory Syndrome related coronavirus-2 (SARS-CoV-2) pandemic, with the caveat that asymptomatic SARS-CoV-2 infected patients are not tested, while those symptomatic are delivered and/or treated with drug(s) available on-site. Thus, management and therapy are still heterogeneous. SARS-CoV-2 induced respiratory infection remains mostly local, unless severe, which lessens transplacental vertical transmission (VT). Vaccination prior to or during pregnancy significantly changes the prognosis for both the mother and newborn. The virus spread to the fetus can be binding to ACE2 and TMPRSS2 protein receptors. A recent study demonstrated ACE2 and TMPRSS2 fetal expression in the intestine from the second trimester. Most placental infections are subclinical unless severe villitis and apoptosis are observed. The placenta is rarely tested, and it is highly probable that most are positive for the virus, requiring sophisticated diagnostics to document. Other VT modalities, such as vaginal, rectal or through amniotic fluid contamination, are very rare. Therefore, vaginal delivery is preferable when clinically feasible. It has not yet been determined whether the placenta is a shield or if it transmits infection, while, on the other hand, recent data support fetal resilience, which is plausible due to the major difference between the placental and fetal rates of infection: only 3%–5% of documentable VT compared with up to 100% expected placental exposure to viremia. Newborn Polymerase Chain Reaction (PCR) from nasal swab is more practical as an option for VT diagnosis compared to ocular or anal swab, with low yield. The maternal infection leads to antiviral IgG production of 100% in severe cases, which is transferred to the fetus and breast milk. Postpartum-documenting VT is difficult since horizontal viral transmission may be common and minimized by mother/staff/family-preventive measures. Breastfeeding is safe and encouraged because, beyond nutrition, it promotes protective antibody transfer and maternal bonding. Lessons learned from other Betacorona viruses (SARS-CoV and Middle East Respiratory Syndrome related coronavirus [MERS-CoV]) virulence are relevant since mutations can increase or decrease vulnerability. Overall, data support fetal/newborn resilience against SARS-CoV-2 VT. However, viremia monitoring by sensitive tests and assessment for delayed sequelae shown in adults is necessary.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43537658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.3389/fviro.2022.994842
T. Koma, N. Doi, A. Suzuki, Kentaro Nagamatsu, Takeshi Yasui, K. Yasutomo, A. Adachi, T. Minamikawa, Masako Nomaguchi
Deep ultraviolet light (UV) is useful for the disinfection of microorganisms, including bacteria and viruses. Although genome damage by UV has been widely accepted, the adverse effects of UV on the activity and/or function of viral proteins including the envelope components are poorly documented. Worthy of note, the observed unfavorable UV-effects for viruses are only insufficiently analyzed in association with the reduction in viral infectivity. In this study, we aimed to clarify which component of virions affected by UV significantly correlates with the loss of viral infectivity using HIV-1 as a model for single-stranded RNA enveloped viruses. Using our UV irradiation apparatus at three wavelengths (265, 280, and 300 nm), we first quantitatively determined the UV power density and irradiation period of each wavelength required for a reduction in infectivity. A heat-treated sample as a control drastically reduced the virion-associated reverse transcriptase (RT) activity and Gag-p24 level. The UV-irradiated samples at the three wavelengths, completely lacking viral infectivity, showed p24 levels similar to those without irradiation. While the virion-associated RT activity was gradually decreased in a wavelength and power density dependent manner, this reduction did not explain the loss of viral infectivity by UV. Remarkably, virological assays revealed that the entry efficiency of the UV-irradiated virus samples at the three wavelengths is comparable to those without irradiation. Importantly, this result shows that, even the virions exposed to UV of various wavelengths at the lethal level, still maintain the function of their envelope composed of a host lipid bilayer and viral proteins. In sharp contrast, UV-induced genome damage shown by semiquantitative RT-PCR correlated well with the reduction in viral infectivity, indicating that it is a major determinant for virus inactivation by UV. The degree of damage was found to be distinct among the regions analyzed. This was probably due to the different nucleotide sequences in those genomic regions amplified by PCR. Our data clearly demonstrate a principal mechanism for viral inactivation by UV and provide information contributing to the improvement of UV-based disinfection technology for microorganisms.
{"title":"Major target for UV-induced complete loss of HIV-1 infectivity: A model study of single-stranded RNA enveloped viruses","authors":"T. Koma, N. Doi, A. Suzuki, Kentaro Nagamatsu, Takeshi Yasui, K. Yasutomo, A. Adachi, T. Minamikawa, Masako Nomaguchi","doi":"10.3389/fviro.2022.994842","DOIUrl":"https://doi.org/10.3389/fviro.2022.994842","url":null,"abstract":"Deep ultraviolet light (UV) is useful for the disinfection of microorganisms, including bacteria and viruses. Although genome damage by UV has been widely accepted, the adverse effects of UV on the activity and/or function of viral proteins including the envelope components are poorly documented. Worthy of note, the observed unfavorable UV-effects for viruses are only insufficiently analyzed in association with the reduction in viral infectivity. In this study, we aimed to clarify which component of virions affected by UV significantly correlates with the loss of viral infectivity using HIV-1 as a model for single-stranded RNA enveloped viruses. Using our UV irradiation apparatus at three wavelengths (265, 280, and 300 nm), we first quantitatively determined the UV power density and irradiation period of each wavelength required for a reduction in infectivity. A heat-treated sample as a control drastically reduced the virion-associated reverse transcriptase (RT) activity and Gag-p24 level. The UV-irradiated samples at the three wavelengths, completely lacking viral infectivity, showed p24 levels similar to those without irradiation. While the virion-associated RT activity was gradually decreased in a wavelength and power density dependent manner, this reduction did not explain the loss of viral infectivity by UV. Remarkably, virological assays revealed that the entry efficiency of the UV-irradiated virus samples at the three wavelengths is comparable to those without irradiation. Importantly, this result shows that, even the virions exposed to UV of various wavelengths at the lethal level, still maintain the function of their envelope composed of a host lipid bilayer and viral proteins. In sharp contrast, UV-induced genome damage shown by semiquantitative RT-PCR correlated well with the reduction in viral infectivity, indicating that it is a major determinant for virus inactivation by UV. The degree of damage was found to be distinct among the regions analyzed. This was probably due to the different nucleotide sequences in those genomic regions amplified by PCR. Our data clearly demonstrate a principal mechanism for viral inactivation by UV and provide information contributing to the improvement of UV-based disinfection technology for microorganisms.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48108053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-20DOI: 10.3389/fviro.2022.994057
A. Butković, Rubén González
Viruses are highly evolvable biological entities capable of wreaking havoc on our society. Therefore, a better understanding of virus evolution is important for two main reasons: (i) it will lead to better management of current diseases and prevention of future ones, and (ii) it will contribute to a better understanding of evolutionary processes and their dynamics. In order to understand the evolution of viruses as a whole, it is necessary to consider different elements that shape virus evolution. In this review, we give a general overview of the most relevant factors that determine the evolution of plant viruses. We will focus on mutation rates, epistasis, robustness, recombination, genome organization, virus-host interactions, transmission, community interactions and abiotic factors. Since this review gives a summarized overview of the most important factors in virus evolution it can be a useful starting material for anyone interested in approaching (plant) virus evolution.
{"title":"A brief view of factors that affect plant virus evolution","authors":"A. Butković, Rubén González","doi":"10.3389/fviro.2022.994057","DOIUrl":"https://doi.org/10.3389/fviro.2022.994057","url":null,"abstract":"Viruses are highly evolvable biological entities capable of wreaking havoc on our society. Therefore, a better understanding of virus evolution is important for two main reasons: (i) it will lead to better management of current diseases and prevention of future ones, and (ii) it will contribute to a better understanding of evolutionary processes and their dynamics. In order to understand the evolution of viruses as a whole, it is necessary to consider different elements that shape virus evolution. In this review, we give a general overview of the most relevant factors that determine the evolution of plant viruses. We will focus on mutation rates, epistasis, robustness, recombination, genome organization, virus-host interactions, transmission, community interactions and abiotic factors. Since this review gives a summarized overview of the most important factors in virus evolution it can be a useful starting material for anyone interested in approaching (plant) virus evolution.","PeriodicalId":73114,"journal":{"name":"Frontiers in virology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42023092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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