scholarly journals Characterization of heterosubunit complexes formed by the R1 and R2 subunits of herpes simplex virus 1 and equine herpes virus 4 ribonucleotide reductase

2000 ◽  
Vol 347 (1) ◽  
pp. 97 ◽  
Author(s):  
Yunming SUN ◽  
Joe CONNER
2000 ◽  
Vol 347 (1) ◽  
pp. 97-104
Author(s):  
Yunming SUN ◽  
Joe CONNER

We report on the separate PCR cloning and subsequent expression and purification of the large (R1) and small (R2) subunits from equine herpes virus type 4 (EHV-4) ribonucleotide reductase. The EHV-4 R1 and R2 subunits reconstituted an active enzyme and their abilities to complement the R1 and R2 subunits from the closely related herpes simplex virus 1 (HSV-1) ribonucleotide reductase, with the use of subunit interaction and enzyme activity assays, were analysed. Both EHV-4 R1/HSV-1 R2 and HSV-1 R1/EHV-4 R2 were able to assemble heterosubunit complexes but, surprisingly, neither of these complexes was fully active in enzyme activity assays; the EHV-4 R1/HSV-1 R2 and HSV-1 R1/EHV-4 R2 enzymes had 50% and 5% of their respective wild-type activities. Site-directed mutagenesis was used to alter two non-conserved residues located within the highly conserved and functionally important C-termini of the EHV-4 and HSV-1 R1 proteins. Mutation of Pro-737 to Lys and Lys-1084 to Pro in EHV-4 and HSV-1 R1 respectively had no effects on subunit assembly. Mutation of Pro-737 to Lys in EHV-4 R1 decreased enzyme activity by 50%; replacement of Lys-1084 by Pro in HSV-1 R1 had no effect on enzyme activity. Both alterations failed to restore full enzyme activities to the heterosubunit enzymes. Therefore probably neither of these amino acids has a direct role in catalysis. However, mutation of the highly conserved Tyr-1111 to Phe in HSV-1 R1 inactivated enzyme activity without affecting subunit interaction.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bo Xu ◽  
Lei Tian ◽  
Jing Chen ◽  
Jing Wang ◽  
Rui Ma ◽  
...  

AbstractOncolytic herpes simplex virus-1 is capable of lysing tumor cells while alerting the immune system. CD47, in collaboration with SIRPα, represents an important immune checkpoint to inhibit phagocytosis by innate immune cells. Here we show locoregional control of glioblastoma by an oncolytic herpes virus expressing a full-length anti(α)-human CD47 IgG1 or IgG4 antibody. The antibodies secreted by the virus-infected glioblastoma cells block the CD47 ‘don’t eat me’ signal irrespective of the subclass; however, αCD47-IgG1 has a stronger tumor killing effect than αCD47-IgG4 due to additional antibody-dependent cellular phagocytosis by macrophages and antibody-dependent cellular cytotoxicity by NK cells. Intracranially injected αCD47-IgG1-producing virus continuously releases the respective antibody in the tumor microenvironment but not into systemic circulation; additionally, αCD47-IgG1-producing virus also improves the survival of tumor-bearing mice better than control oncolytic herpes virus combined with topical αCD47-IgG1. Results from immunocompetent mouse tumor models further confirm that macrophages, and to a lesser extent NK cells, mediate the anti-tumor cytotoxicity of antibody-producing oncolytic herpesviruses. Collectively, oncolytic herpes simplex virus-1 encoding full-length antibodies could improve immune-virotherapy for glioblastoma.


Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 463 ◽  
Author(s):  
Salvatore Crimi ◽  
Luca Fiorillo ◽  
Alberto Bianchi ◽  
Cesare D’Amico ◽  
Giulia Amoroso ◽  
...  

This manuscript aims to highlight all the clinical features of the herpes virus, with a particular focus on oral manifestations and in the maxillofacial district about Herpes Simplex Virus-1 (HSV-1) and Herpes Simplex Virus-2 (HSV-2). Oral herpes virus is a very common and often debilitating infectious disease for patients, affecting oral health and having important psychological implications. The collection of relevant data comes from the scientific databases Pubmed, Embase; initially this collection obtained an extremely high number of results, 1415. After applying the inclusion and exclusion criteria, as well as a manual screening, the results included in this review were limited to 14. The results were expressed by evaluating all the signs and symptoms that this pathology entails during the study, paying attention to the characteristics linked to the quality of life and the psychological implications. This pathology has numerous therapies, which often make the healing phase of the manifestations of this viral pathology more comfortable. The therapies currently used for the treatment of this viral infection are pharmacological, topical, systemic, or instrumental, for example with laser devices.


2019 ◽  
Vol 28 (3) ◽  
pp. 232-238
Author(s):  
C.-E. Luyt ◽  
G. Hékimian ◽  
N. Bréchot

Les réactivations à herpès simplex virus (HSV) et à cytomégalovirus (CMV) sont fréquentes chez le patient non immunodéprimé de réanimation. La réactivation HSV est localisée aux voies aériennes ; elle débute au niveau oropharyngé, progresse de façon descendante avec la contamination des voies aériennes distales et peut aboutir, chez certains malades, à une véritable bronchopneumonie herpétique. Elle est en outre associée à un pronostic défavorable. Le traitement prophylactique et préemptif des réactivations HSV ne peut pas être préconisé à l’heure actuelle. Le traitement curatif repose sur un avis d’experts, chez des malades présentant soit une charge virale élevée dans les voies aériennes distales, soit des signes cytologiques d’atteinte parenchymateuse pulmonaire sur les cellules recueillies lors du lavage bronchoalvéolaire. La réactivation CMV sanguine est fréquente et peut être isolée ou associée à une réactivation/atteinte pulmonaire et est aussi associée à un pronostic défavorable. Le traitement prophylactique de la réactivation CMV ne peut pas être préconisé, et le traitement préemptif est en cours d’évaluation. À l’heure actuelle, le traitement curatif des maladies pulmonaires à CMV repose soit sur des signes histologiques d’atteinte pulmonaire, soit sur un faisceau d’arguments clinicobiologiques évoquant une possible maladie à CMV.


Author(s):  
Т.З. Керимов ◽  
В.П. Соболев ◽  
М.А. Соболева ◽  
Н.А. Гаврилова ◽  
С.А. Борзенок

В обзоре представлено описание патофизиологических механизмов герпесвирусной инфекции. Согласно данным медицинской статистики, вирусом простого герпеса 1 типа инфицировано большинство населения планеты. В развивающихся странах данный вирус является ведущей инфекционной причиной поражения роговицы. Также вирусу простого герпеса 1 типа отводится роль одного из факторов, приводящих к отторжению трансплантата роговицы. Вышеописанные патологические явления сопряжены с перестройкой клеточных систем в ответ на вирусное воздействие. Недавние открытия в данной области обнаружили значительный вклад трансмембранных и эндосомальных Toll-подобных рецепторов во врожденный противовирусный клеточный ответ. Показано, что эндосомальные Toll-подобные рецепторы 3 типа экспрессируются в кератоцитах только после их фенотипического перехода в фибробласты. Данная трансформация обычно происходит в результате механических и патогенных воздействий на роговицу. Изменение рецепторного состава клеток в ответ на герпесвирусную инвазию вызывает выработку интерферонов 1 типа - интерферона-альфа, интерферона-бета, и синтезу провоспалительных цитокинов, что приводит к вирусной деконтаминации. This review describes pathophysiological mechanisms of herpes virus infection in cornea cells. It has been previously reported that herpes simplex virus type 1 (HSV-1) infects most of the world’s population. In developing countries, HSV-1 is the leading infectious cause of corneal damage. Also, herpes simplex virus type 1 was assigned the role of one of the factors leading to rejection of the corneal transplant. These pathological phenomena are associated with restructuring of cellular systems in response to viral exposure. Recent discoveries have revealed a significant contribution of transmembrane and endosomal Toll-like receptors to the innate antiviral cell response. It is well known that endosomal Toll-like receptors-3 are expressed in keratocytes only after their phenotypic transformation to fibroblasts. This transformation usually occurs as a result of mechanical or infectious impact on the cornea. Changes in the receptor composition of cells as a response to herpes virus invasion is the main cause of type 1 interferons (interferon-alpha and interferon-beta) production and expression of proinflammatory cytokines, which leads to viral decontamination.


2019 ◽  
Vol 4 (1) ◽  
pp. e000247 ◽  
Author(s):  
Joanna von Hofsten ◽  
Tomas Bergström ◽  
Madeleine Zetterberg

ObjectivesTo identify all patients tested positive for herpes viruses in intraocular samples between 2007 and 2016 in South-Western Sweden and evaluate which of these met the criteria of acute retinal necrosis (ARN). To compare viral load in intraocular samples and virus type with clinical outcome.Method and analysisRetrospective case series. Intraocular samples and serum were analysed with quantitative real-time PCR (qPCR) and presence of antibodies (IgG and IgM) were detected by ELISA in serum.ResultsBetween 2007 and 2016, 13 patients met the clinical criteria of ARN and were PCR-positive in aqueous or vitreous for herpes simplex virus 1 (HSV1; n=4), herpes simplex virus 2 (HSV2; n=3) and varicella zoster virus (VZV; n=6). None of the patients tested positive for cytomegalovirus (n=13) or Epstein Barr virus (n=2) met the criteria of ARN. All ARN patients had specific serum IgG and three patients exhibited virus DNA in serum. There was no correlation between high viral load and worse visual outcome. However, higher viral loads were seen in samples taken earlier in the disease process. Median age was higher (p=0.049) in VZV-ARN than for HSV-ARN patients (60.5 and 45.4 years, respectively) with a tendency of worse best corrected visual acuity at presentation (1.62 and 0.79 log MAR, respectively; p=0.079).ConclusionARN is a reactivation of alpha herpes virus and presence of herpes DNA in serum may occur. VZV-ARN are older than HSV-ARN patients. High viral load does not appear to be a predictor of worse visual outcome, but rather indicates earlier sampling.


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