Protecting Mice from H7 Avian Influenza Virus by Immunisation with a Recombinant Adenovirus Encoding Influenza A Virus Conserved Antigens

Influenza is a highly contagious disease that causes annual epidemics and occasional pandemics. Birds are believed to be the source of newly emerging pandemic strains, including highly pathogenic avian influenza viruses of the subtype H7. The aim of the study: to evaluate the ability of the recombinant human adenovirus, serotype 5, which expresses genes of influenza A highly conserved antigens (ion channel M2 and nucleoprotein NP), to provide protection to laboratory mice against infection with a lethal dose of avian influenza virus, subtype H7. To achieve this goal, it was necessary to adapt influenza A virus, subtype H7 for reproduction in the lungs of mice, to characterise it, and to use it for evaluation of the protective properties of the recombinant adenovirus. Materials and methods: avian influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) was adapted for reproduction in the lungs of mice by repeated passages. The adapted strain was sequenced and assessed using hemagglutination test, EID50 and LD50 for laboratory mice. BALB/c mice were immunised once with Ad5-tet-M2NP adenovirus intranasally, and 21 days after the immunisation they were infected with a lethal dose (5 LD50) of influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) in order to assess the protective properties of the recombinant adenovirus. The level of viral shedding from the lungs of the infected mice was evaluated by titration of the lung homogenates in MDCK cell culture on days 3 and 6 after infection. The level of specific antibodies to H7 avian influenza virus was determined by indirect enzyme immunoassay. Results: the use of Ad5-tet-M2NP adenovirus for immunisation of the mice ensured 100% survival of the animals that had disease symptoms (weight loss) after their infection with the lethal dose (5 LD50) of H7 avian influenza virus. The study demonstrated a high post-vaccination level of humoral immune response to H7 avian influenza virus. The virus titer decreased significantly by day 6 in the lungs of mice that had been immunised with Ad5-tet-M2NP compared to the control group. Conclusion: the Ad5-tetM2NP recombinant adenovirus can be used to create a candidate pandemic influenza vaccine that would protect against avian influenza viruses, subtype H7, in particular

Способ получения рекомбинантных антител, продуцируемых клеточной линией, трансдуцированной рекомбинантными аденовирусами

Objectives. To develop a technology for obtaining recombinant antibodies in a suspension culture of human HEK293 cells using transduction with recombinant adenovirus serotype 5 (rAd5) carrying genes expressing heavy and light chains of antibodies on the example of two broadspectrum anti-influenza antibodies 27F3 and CR9114.Methods. Ad5-27F3-H, Ad5-CR9114-H, and Ad5-27F3-L recombinant adenoviruses carrying the 27F3 antibody heavy chain gene, CR9114 antibody heavy chain gene, and 27F3 light chain gene, respectively, were generated using the AdEasy™ Adenoviral vector system. To accumulate preparative amounts of recombinant r27F3 and rCR9114 antibodies, the HEK293 suspension cell line was transduced with recombinant adenoviruses carrying genes for heavy and light chains of antibodies. The cells were cultured in a wave-type bioreactor. Chromatography was used to purify recombinant antibodies from the culture medium. After analyzing the molecular weights of purified antibodies using protein electrophoresis, their ability to interact with influenza A and B viruses was analyzed using the Western blot technique, while their ability to neutralize influenza A and B viruses was evaluated using the virus neutralization assay.Results. A method for the accumulation and purification of recombinant r27F3 and CR9114 antibodies from the culture medium of a suspension culture of human cells following transduction with its recombinant adenoviruses carrying the genes for heavy and light chains of these antibodies was developed. The ability of the r27F3 antibody to interact with and neutralize influenza A viruses of group 1 (except influenza A virus subtype H2) and group 2 was shown. The ability of the rCR9114 antibody to interact with influenza A viruses of group 1 and influenza B viruses, as well as to neutralize influenza A viruses of group 1, was demonstrated.Conclusions. A technology for obtaining recombinant antibodies in a suspension culture of HEK293 cells using transduction with recombinant adenoviruses carrying genes expressing heavy and light chains of antibodies was developed along with a confirmation of their specificity.Цели. Разработать технологию получения рекомбинантных антител в суспензионной культуре клеток человека HEK293 с помощью трансдукции рекомбинантными аденовирусами человека пятого серотипа, несущими гены, экспрессирующие тяжелые и легкие цепи антител, на примере двух противогриппозных антител широкого спектра действия 27F3 и CR9114.Методы. Рекомбинантные аденовирусы Ad5-27F3-H, Ad5-CR9114-H и Ad5-27F3-L, несущие ген тяжелой цепи антитела 27F3, ген тяжелой цепи антитела CR9114 и ген легкой цепи 27F3, были получены с помощью набора AdEasy™ Adenoviral vector system. Для накопления препаративных количеств рекомбинантных антител r27F3 и rCR9114 суспензионную клеточную линию HEK293 трансдуцировали рекомбинантными аденовирусами, несущими гены тяжелых и легких цепей антител, и культивировали клетки в биореакторе волнового типа. Рекомбинантные антитела очищали из культуральной жидкости хроматографическим методом. Молекулярную массу полученных антител анализировали с помощью белкового электрофореза, их способность взаимодействовать с вирусами гриппа А и В методом вестерн-блот анализа, а способность нейтрализовать вирусы гриппа А и В с помощью реакции вирус-нейтрализации.Результаты. Отработана методика накопления и очистки рекомбинантных антител r27F3 и CR9114 из культуральной жидкости суспензионной культуры клеток человека после трансдукции ее рекомбинантными аденовирусами, несущими гены тяжелых и легких цепей этих антител. Показана способность антитела r27F3 взаимодействовать с вирусами гриппа А подгруппы 1 (кроме вируса грипп А субтипа H2) и подгруппы 2 и нейтрализовать их. Показана способность антитела rCR9114 взаимодействовать с вирусами гриппа А подгруппы 1 и вирусами гриппа В, а также нейтрализовать вирусы гриппа А подгруппы 1.Выводы. Отработана технология получения рекомбинантных антител в суспензионной культуре клеток HEK293 с помощью трансдукции рекомбинантными аденовирусами, несущими гены, экспрессирующие тяжелые и легкие цепи антител, и показана их специфичность

Post-COVID immunopatology syndrome: characteristics of phenotypical changes in the immune system in post-COVID patients

This study examines the long-term effects of SARS-CoV-2 infection on immune status. Given the prolonged and profound immune dysregulation observed during acute SARS-CoV-2 infection, it remains to be determined whether these changes translate into subsequent immune system dysfunction in recovering individuals. In this sense, the aim of the study was to study the parameters of the immune system in patients who had undergone SARS-CoV-2 infection. 150 patients who underwent SARS-CoV-2 infection were examined according to 96 parameters using flow cytometry. A complete blood count was performed using a Medonic device (Sweden); ELISA method determined the levels of general and specific IgM, IgG, IgA, compliment fragments (JSC Vector-Best, Russia). The activity of the phagocytes was studied according to the generally accepted method. The study found that at least four phenotypes of immune system disorders are detected in patients. The first two phenotypes are related to the impairment of innate immune system factors and are associated with a decrease in the number of CD46+ and NK cells. It has been observed that a decrease in CD46+ persists for a long time in a significant number of recovered patients, highlighted by the impaired expression of this marker in various subpopulations of lymphocytes. The decrease in the level of natural killers was accompanied by a compensatory increase in the number of T lymphocytes, mainly due to T helpers and TNK lymphocytes, and the growth of total memory B cells. Two other identified phenotypes are characterized by damage to acquired immune response factors and are associated with damage to B cells and T cytotoxic cells. The relationship of such disorders with damage to hematopoiesis erythrocyte and platelet sprouts, which contribute to the appearance of hypoxia and possible violation of the blood coagulation system, has been shown. Therefore, the results obtained indicate a long-term pronounced damage to the immune system in postCOVID patients that requires immunocorrection of these disorders

A Bioinformatics Classifier and Database for Heme-Copper Oxygen Reductases

Background: Heme-copper oxygen reductases (HCOs) are the last enzymatic complexes of most aerobic respiratory chains, reducing dioxygen to water and translocating up to four protons across the inner mitochondrial membrane (eukaryotes) or cytoplasmatic membrane (prokaryotes). The number of completely sequenced genomes is expanding exponentially, and concomitantly, the number and taxonomic distribution of HCO sequences. These enzymes were initially classified into three different types being this classification recently challenged. Methodology:We reanalyzed the classification scheme and developed a new bioinformatics classifier for the HCO and Nitric oxide reductases (NOR), which we benchmark against a manually derived gold standard sequence set. It is able to classify any given sequence of subunit I from HCO and NOR with a global recall and precision both of 99.8%. We use this tool to classify this protein family in 552 completely sequenced genomes. Conclusions: We concluded that the new and broader data set supports three functional and evolutionary groups of HCOs. Homology between NORs and HCOs is shown and NORs closest relationship with C Type HCOs demonstrated. We established and made available a classification web tool and an integrated Heme-Copper Oxygen reductase and NOR protein database (www.evocell.org/hco)

Защита мышей от заражения вирусом гриппа птиц субтипа H7 с помощью иммунизации рекомбинантным аденовирусом, кодирующим консервативные антигены вируса гриппа А

Influenza is a highly contagious disease that causes annual epidemics and occasional pandemics. Birds are believed to be the source of newly emerging pandemic strains, including highly pathogenic avian influenza viruses of the subtype H7. The aim of the study: to evaluate the ability of the recombinant human adenovirus, serotype 5, which expresses genes of influenza A highly conserved antigens (ion channel M2 and nucleoprotein NP), to provide protection to laboratory mice against infection with a lethal dose of avian influenza virus, subtype H7. To achieve this goal, it was necessary to adapt influenza A virus, subtype H7 for reproduction in the lungs of mice, to characterise it, and to use it for evaluation of the protective properties of the recombinant adenovirus. Materials and methods: avian influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) was adapted for reproduction in the lungs of mice by repeated passages. The adapted strain was sequenced and assessed using hemagglutination test, EID50 and LD50 for laboratory mice. BALB/c mice were immunised once with Ad5-tet-M2NP adenovirus intranasally, and 21 days after the immunisation they were infected with a lethal dose (5 LD50) of influenza virus A/Chicken/NJ/294508-12/2004 (H7N2) in order to assess the protective properties of the recombinant adenovirus. The level of viral shedding from the lungs of the infected mice was evaluated by titration of the lung homogenates in MDCK cell culture on days 3 and 6 after infection. The level of specific antibodies to H7 avian influenza virus was determined by indirect enzyme immunoassay. Results: the use of Ad5-tet-M2NP adenovirus for immunisation of the mice ensured 100% survival of the animals that had disease symptoms (weight loss) after their infection with the lethal dose (5 LD50) of H7 avian influenza virus. The study demonstrated a high post-vaccination level of humoral immune response to H7 avian influenza virus. The virus titer decreased significantly by day 6 in the lungs of mice that had been immunised with Ad5-tet-M2NP compared to the control group. Conclusion: the Ad5-tetM2NP recombinant adenovirus can be used to create a candidate pandemic influenza vaccine that would protect against avian influenza viruses, subtype H7, in particular.Грипп – высококонтагиозное заболевание, вызывающее ежегодные эпидемии и через неравные интервалы времени – пандемии. Источником вновь возникающих пандемичных штаммов, как правило, являются птицы, а наибольшее беспокойство в настоящее время вызывают высокопатогенные вирусы гриппа птиц субтипа H7. Цель работы: оценить способность рекомбинантного аденовируса человека пятого серотипа, экспрессирующего гены высококонсервативных антигенов вируса гриппа А (ионного канала М2 и нуклеопротеина NP), обеспечивать защиту от заражения лабораторных мышей летальной дозой вируса гриппа птиц субтипа H7. Для достижения цели необходимо было адаптировать для размножения в легких мышей вирус гриппа А субтипа Н7, охарактеризовать и с его помощью оценить защитные свойства рекомбинантного аденовируса. Материалы и методы: вирус гриппа птиц A/Chicken/NJ/294508-12/2004 (H7N2) был адаптирован для размножения в легких мышей путем многократного пассирования. Этот штамм был секвенирован и охарактеризован в реакции гемагглютинации, установлены его ЭИД50 и ЛД50 для лабораторных мышей. Для изучения защитных свойств рекомбинантного аденовируса мыши линии BALB/c были иммунизированы аденовирусом Ad5-tet-M2NP однократно интраназально и через 21 сутки после иммунизации заражены летальной дозой (5 ЛД50) вируса гриппа птиц A/Chicken/NJ/294508-12/2004 (H7N2). Уровень вирусовыделения из легких мышей был оценен на 3 и 6 сутки после заражения с помощью титрования гомогенатов легких на культуре клеток MDCK. Уровень специфических антител к вирусу гриппа птиц субтипа Н7 определяли методом непрямого иммуноферментного анализа. Результаты: иммунизация мышей аденовирусом Ad5-tet-M2NP при наличии симптомов заболевания (снижение массы тела) обеспечила 100% выживаемость животных после заражения летальной дозой (5 ЛД50) вируса гриппа птиц субтипа H7. Продемонстрирован высокий поствакцинальный уровень гуморального иммунного ответа к вирусу гриппа птиц субтипа H7. Показано, что в легких мышей из группы, иммунизированной Ad5-tet-M2NP, уже к 6 суткам наблюдалось существенное снижение титра вируса гриппа птиц субтипа H7 по сравнению с контрольной группой. Заключение: рекомбинантный аденовирус Ad5-tet-M2NP может быть использован для создания потенциальной пандемичной противогриппозной вакцины, в том числе и от вирусов гриппа птиц субтипа H7

Ferroelectric Langmuir-Blodgett films showing bistable switching

For the first time switchable ferroelectric Langmuir-Blodgett films are prepared and investigated. The films with a regular multilayered structure are prepared from the ferroelectric copolymer of vinylidene fluoride with trifluoroethylene P(VDF-TrFE). The films with the thickness of 150 Å  show a phase transition of the first order and a bistable switching of the remanent polarization. Films thinner than 100 Å  show only monostable switching