Vaccination and diabetes mellitus type 1 in children

Influence of vaccination on the risk of developing diabetes mellitus type 1 (DM1) has been studied by different researchers for several decades. In rodents, vaccination can prevent development of DM1. This review summarises existing literature and discusses the results of a 2016 meta-analysis, pertaining to vaccination and DM1. No vaccines appear to increase the risk of DM1. Additional investigations are needed to determine if vaccines can be considered protective against DM1. Patients with DM1 are at increased risk of morbidities from controllable infections. Children with DM1 should receive regularly-scheduled vaccinations; choice of vaccines and inoculation with non-regular vaccines should be determined on an individual basis. We present basic principles surrounding vaccination in patients with DM1 and analyse the role of the paediatric endocrinologist in increasing vaccination uptake in children with DM1

Molecular identification of Newcastle disease virus isolated on the poultry farm of the Moscow Oblast in summer of 2022

In August 2022, a sudden death in backyard chickens was reported in the Moscow Oblast (urban district Chernogolovka, settlement Starki). As a result, within just a few days 45 chickens on this farm died or fell ill with the following signs – gray mucus discharge from nostrils and beak, coughing, gasping and rales. On day 1–3 after the onset of symptoms, the chicken died. The Newcastle disease virus, which is a representative of the Paramyxoviruses family, was isolated from the dead poultry. We determined the nucleotide sequences of fragments in F gene (encodes the fusion surface protein) and in NP gene (encodes the nucleocapsid protein). The motif of 109SGGRRQKRFIG119 proteolysis site, typical for the velogenic pathotype, was determined for the F gene, and a phylogenetic analysis was carried out to demonstrate that the isolate belonged to Subgenotype VII, Class II of the subfamily Avulavirinae. The Basic Local Alignment Search Tool revealed that they are most genetically related with isolates from Iran. It was found that the average death time of developing chicken embryos, infected with a minimum infectious dose, was 52 hours, which is typical for the velogenic pathotype. The virus caused 100% death in six-week-old chickens after oral infection and 100% death in all contact chickens, including those kept in cages at a distance, which proves the high level of pathogenicity and contagiousness of the recovered isolate and its ability to transmit both via fecal-oral and aerosols–borne routes. No death cases were reported in mice after intranasal infection with high doses

Examining immune arms in mice immunized with site-specific influenza virus mutants

Site-specific mutants as candidates for live influenza vaccines were resulted from directly introducing into the genome of the pathogenic influenza virus A/WSN/33 (H1N1) strain ts mutations derived from the genes encoding the polymerase complex proteins from some cold-adapted strains serving as attenuation donor. Here we present the data of a comparative study examining immune system arms in mice immunized intranasally with influenza virus mutants and classical cold-adapted reassortant obtained by crossing cold-adapted strain Donor A/Krasnodar/101/35/59 (H2N2) with strain A/WSN/33 (H1N1) bearing surface antigens (hemagglutinin and neuraminidase) similar to mutants. Immunophenotyping mononuclear leukocytes from immunized mice indicated at moderate suppressive effect after using site-specific mutant and the HA reassortant viruses on some immune cell subsets. All viruses in immunized mice resulted in activation of certain lymphocyte subsets including MHC II-positive cells, CD45+/CD19+ B lymphocytes and natural killer cells (CD16/32+/CD3–). Timescale and magnitude of activation markedly differed for each cell subsets. Mice immunized with mutants M26 and U2 peaked with count of CD16/32+/CD3– expressing cells on day 2 after the second immunization compared with control (p < 0.05) that may suggest about an important role for NK cells in activating immune response. In contrast, no significant changes were observed during the study in percentage of CD4+/CD25+/Fox P3 regulatory T cells, CD4+ T helpers and CD8+ cytotoxic cells, except for a sharply decreased count of activated CD4+/CD25+ cells (4-fold) on day 7 after immunization with mutant virus M26. Moreover, mutants U2 and M26 more moderately increased percentage of TLR2- and TLR4-positive cells. The viruses studied ambiguously affected count of TLR9-expressing cells in immunized animals. All viruses increased phagocytic activity in monocytes, but not neutrophils. Despite the moderate activation of innate and adaptive immunity arms, site-specific mutants more profoundly affected humoral reactions inducing increased antibody titers, so that immunogenicity of mutant viruses was higher than that of the cold-adapted reassortant. Thus, the findings hold a promise of using site-specific mutants as live influenza vaccines

Comparative study of the biological properties of influenza А virus mutants obtained by site-specific mutagenesis and the live influenza reassortant vaccine variant

The aim of study was to carry out comparative investigation of biological properties of site-specific mutants of Influenza A virus and variant of live cold-adapted (CA) influenza reassortant vaccine. Materials and methods. The genetic stability of site-specific mutants (SSM) of the A/WSN/33 (H1N1) strain with ts (temperature sensitive)-mutations in polymerase genes was studied using a stress-test in MadinDarby Canine Kidney (MDCK) culture. A comparative study of immunogenicity of U2 and M26 mutants with the high genetic stability and the CA-reassortant with similar surface proteins was carried out. The increase in the antibody titer was investigated using enzyme-linked immunosorbent assay and the reaction of delayed hemagglutination. Ability of the studied viruses to induce type 1 interferon in A549 cells was determined using real-time polymerase chain reaction (real-time PCR). Results. It was shown that U2 and M26 mutants, which have 3 ts-mutations or more in polymerase genes have high genetic stability. It was found that U2 and M26 mutants induced a higher antibody titers than the CA reassortant in mice following the intranasal immunization. The ability of site-specific mutants and CA reassortant to induce type 1 interferon was also investigated. Mutants U2 and M26 increased the level of interferon to a greater extent than the CA-reassortant. Conclusion. The data obtained indicate that SSM U2 and M26 with 3 ts-mutations or more in the genome have a significant level of genetic stability. Mutants U2 and M26 have a higher immunogenicity and a higher ability to induce interferon in comparison with the CA reassortant. These facts allow us to conclude that SSM of the influenza virus with a set of mutations in polymerase genes can be considered as promising candidates for live influenza vaccines

Нокдаун клеточных генов FLT4, Nup98 и Nup205 как супрессор вирусной активности гриппа А/WSN/33 (H1N1) в культуре клеток А549

Objectives. To evaluate the effect of cellular genes FLT4, Nup98, and Nup205 on the reproduction of the influenza A virus in A549 human lung cancer cell line.Methods. The work was carried out using the equipment of the center for collective use of the I.I. Mechnikov Research Institute of Vaccines and Sera (Russia). The virus-containing fluid was collected within three days from the moment of transfection and infection and the intensity of viral reproduction was assessed by viral titration and hemagglutination reaction. The viral RNA concentration was determined by real-time reverse-transcription polymerase chain reaction (RT-PCR). To calculate statistically significant differences between groups, the nonparametric Mann–Whitney test was used.Results. In cells treated with small interfering RNAs (siRNAs) targeted at FLT4, Nup98, and Nup205 genes, a significant decrease in their expression and indicators of viral reproduction (virus titer, hemagglutinating activity, viral RNA concentration) was observed at a multiplicity of infection (MOI) = 0.1. Additionally, it was found that a decrease in the expression of target genes using siRNA does not lead to a significant decrease in cell survival. The viral titer in cells treated with siRNA FLT4.2, Nup98.1, and Nup205 on the first day was lower by an average of 1.0 lg, and on the second and third days, by 2.2–2.3 lg, compared to cells treated with nonspecific siRNA. During real-time RT-PCR, a significant decrease in the concentration of viral RNA was observed with siRNA Nup98.1 (up to 190 times) and Nup205 (up to 30 times) on the first day, 26 and 29 times on the second day, and 6 and 30 times on the third day, respectively. For FLT4.2 siRNA, the number of viral RNA copies decreased by 23, 18, and 16 times on the first, second, and third days. Similar results were obtained when determining the hemagglutinating activity of the virus. The hemagglutinating activity on the third day most strongly decreased in cells treated with siRNA Nup205 and FLT4.2 (16 times). In cells treated with siRNA FLT4.1, Nup98.1, and Nup98.2, hemagglutinating activity decreased by 8 times.Conclusions. In the present study, three cellular genes (FLT4, Nup98, and Nup205) were identified—the decrease in the expression of which effectively suppresses viral reproduction— and the original siRNA sequences were obtained. The results obtained are important for creating therapeutic and prophylactic medication, whose action is based on the RNA interference mechanism.Цели. Оценка влияния подавления экспрессии клеточных генов FLT4, Nup98 и Nup205 на динамику репродукции вируса гриппа А в культуре легочных клеток человека А549.Методы. Работа выполнена с использованием оборудования центра коллективного пользования Научно-исследовательского института вакцин и сывороток им И.И. Мечникова (Россия). Вируссодержащую жидкость отбирали в течение трех дней с момента трансфекции и заражения и оценивали интенсивность вирусной репродукции методами титрования по цитопатическому действию и в реакции гемагглютинации. Концентрацию вирусной РНК определяли методом полимеразной цепной реакции (ПЦР) в реальном времени с обратной транскрипцией (ОТ-ПЦР-РВ). Для вычисления статистически значимых различий между группами использовали непараметрический критерий Манна–Уитни.Результаты. В клетках, обработанных малыми интерферирующими РНК (миРНК) к генам FLT4, Nup98 и Nup205, отмечалось достоверное подавление экспрессии целевых генов и показателей вирусной репродукции (титр вируса, гемагглютинирующая активность, концентрация вирусной РНК) при коэффициенте множественности заражения, равном 0.1. Дополнительно было установлено, что подавление экспрессии целевых генов с помощью миРНК не приводит к значительному снижению выживаемости клеток. Вирусный титр в клетках, обработанных миРНК FLT4.2, Nup98.1 и Nup205, на первые сутки был меньше в среднем на 1.0 lg, а на вторые и третьи – на 2.2–2.3 lg, по сравнению с клетками, обработанными неспецифической миРНК. При проведении ОТ-ПЦР-РВ отмечено достоверное уменьшение концентрации вирусной РНК с миРНК Nup98.1 (до 190 раз) и Nup205 (до 30 раз) на первые сутки, в 26 и в 29 раз на вторые и в 6 и 30 раз на третьи сутки, соответственно. Для миРНК FLT4.2 количество копий вирусной РНК уменьшилось в 23, 18 и 16 раз на первые, вторые и третьи сутки. Схожие результаты были получены при определении гемагглютинирующей активности вируса. Наиболее сильно, в 16 раз, гемагглютинирующая активность на третьи сутки снизилась в клетках, обработанных миРНК Nup205 и FLT4.2. В клетках, обработанных миРНК FLT4.1, Nup98.1 и Nup98.2, гемагглютинирующая активность уменьшилась в 8 раз.Выводы. В ходе исследования были выявлены три клеточных гена (FLT4, Nup98 и Nup205), подавление экспрессии которых позволяет эффективно уменьшить вирусную репродукцию, а также получены оригинальные последовательности миРНК. Полученные результаты имеют важное значение для создания терапевтических и профилактических препаратов, чье действие основано на механизме РНК-интерференции

Determination of cold-adapted influenza virus (Orthomyxoviridae: <i>Alphainfluenzavirus</i>) polymerase activity by the minigenome method with a fluorescent protein

Introduction. Polymerase proteins PB1 and PB2 determine the cold-adapted phenotype of the influenza virus A/Krasnodar/101/35/59 (H2N2), as was shown earlier. Objective. The development of the reporter construct to determine the activity of viral polymerase at 33 and 37 °C using the minigenome method. Materials and methods. Co-transfection of Cos-1 cells with pHW2000 plasmids expressing viral polymerase proteins PB1, PB2, PA, NP (minigenome) and reporter construct. Results. Based on segment 8, two reporter constructs were created that contain a direct or inverted NS1-GFP-NS2 sequence for the expression of NS2 and NS1 proteins translationally fused with green fluorescent protein (GFP), which allowed the evaluation the transcriptional and/or replicative activity of viral polymerase. Conclusion. Polymerase of virus A/Krasnodar/101/35/59 (H2N2) has higher replicative and transcriptional activity at 33 °C than at 37 °C. Its transcriptional activity is more temperature-dependent than its replicative activity. The replicative and transcriptional activity of polymerase A/Puerto Rico/8/34 virus (H1N1, Mount Sinai variant) have no significant differences and do not depend on temperature

Effect of virulent and vaccine variants of influenza virus on the immunophenotype of dendritic cells generated from murine bone marrow

The aim of this study was to generate dendritic cells from the bone marrow of mice (DC) in vitro and to assess the effect of virulent and attenuated variants of influenza virus on the maturation of DCs. Granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) were used in combination, to induce differentiation of mouse bone marrow (BM) mononucleocytes into DCs. On the 5th day, distinct variants of influenza virus were added to the cell culture, and the cells were additionally incubated for 2 days. The morphological characteristics of DCs, immunophenotype of DCs and expression of some Toll-like receptors were evaluated. On the 5th day of incubation. the DCs acquired typical morphological characteristics. DCs were large in size with an eccentrically located nucleous, often irregular in shape, with numerous processes. On the 7th day of incubation with influenza virus variants, their cytoplasm was somewhat denser. DCs acquired more processes, necessary for intercellular contacts. Expression levels of CD11c, a specific marker of BM-derived DCs, and of co-stimulatory molecules such as CD40, CD80, CD86, and MHC-II were elevated in mature DCs. Virulent versus attenuated strains of the influenza virus induced special variants of DCs differentiation, with respect to expression rates of differentiation markers, as well as expression of Toll-like receptors and costimulatory molecules. Conclusions. The in vitro cultured murine mononucleocytes derived from bone marrow can produce a large number of n-DCs, that can mature in the presence of different variants.During evolution of the DC immunophenotype treated with variant influenza viruses, we have found distinct signs of immunosuppression.The attenuated U-2 and M-26 influenza variants obtained by site-specific mutagenesis upon development of DCs immunophenotype, exhibited a decreased immunosuppressive activity and were not inferior to the cold-adapted (CA) reassortant for the most positions, but exceeded it in some instances. These studies can help to assess the criteria for evaluation the efficiency of in vitro developed influenza vaccines

Менингококковая инфекция у детей в период 2012–2021 гг. Основные итоги ретроспективного многоцентрового исследования, проблемы сегодняшнего дня

The heavy burden of meningococcal infection is associated not only with life-threatening complications in the acute period and high mortality in invasive forms of the disease, but also with severe consequences in survivors, who are not recorded in our country.The aim of study: to analyze clinical manifestations, complications of the acute period and outcomes of invasive forms of meningococcal disease in children in various regions of the Russian Federation.Materials and methods: an analysis of data from 1327 inpatient medical records of children with an invasive meningococcal infection from 14 regional centers of the Russian Federation for 2012-2021 was carried out (28.3% of cases of the disease in children in the represented federal districts).Results: it was found that young children predominated among the patients – the median was 27.4 (10.7-70.4) months. Complications of the acute period, often combined, were observed in 47.6% of cases. The development of septic shock was noted in 30.4%, Waterhouse-Friderichsen syndrome in 6.6%, carditis in 2.9%, cerebral edema in 15.7%, arthritis in 1.4% of cases; the formation of hydrocephalus, subdural effusion, sensorineural hearing loss in 1.8%, 0.6%, 1% of children, respectively. The presence of soft tissue necrosis requiring surgical intervention was noted in 3.5% of cases. Mortality rate was 10.1%. At the time of discharge from the hospital, 30% of children had complications associated with meningococcal infection: organ dysfunction/ failure in 13.2% of patients (severe in 1.3%), cerebral insufficiency in 19.6%; severe psycho-neurological deficits, sensorineural hearing loss, problems associated with the need for orthopedic/surgical interventions accounted for 0.7%, 0.6% and 0.8%, respectively.Conclusion. Considering the epidemiological features of meningococcal infection – the risk of a sharp increase in morbidity in short periods of time, the life-threatening nature of the disease itself, it is necessary to remain alert to these risks and take all possible measures to prevent the disease using all available means, the most effective of which is vaccine prevention.Тяжелое бремя менингококковой инфекции связано не только с жизнеугрожающими осложнениями острого периода и высокой летальностью при генерализованных формах заболевания, но и с тяжелыми последствиями у выживших, учет которых в нашей стране не ведется.Цель: проведение анализа клинических проявлений, осложнений острого периода и исходов генерализованных форм менингококковой инфекции у детей в различных регионах Российской Федерации.Материалы и методы: проведен анализ данных 1327 медицинских карт (форма 003/у) детей с генерализованной формой менингококковой инфекции из 14 региональных центров Российской Федерации за 2012– 2021 гг. (28,3% случаев заболевания у детей в представляемых федеральных округах).Результаты: установлено, что среди больных преобладали дети раннего возраста – медиана составила 27,4 (10,7–70,4) месяцев. Осложнения, часто сочетанные, в остром периоде заболевания наблюдались в 47,6% случаев: септический шок в 30,4%, синдром Уотерхауза – Фридериксена в 6,6%, кардит в 2,9%, отек головного мозга в 15,7%, артриты в 1,4%, гидроцефалия в 1,8%, сенсоневральная тугоухость в 1%, субдуральный выпот в 0,6% случаев. Наличие некрозов мягких тканей, требовавших хирургического вмешательства, отмечено в 3,5% случаев. Летальность составила 10,1%. На момент выписки из стационара у 30% детей выявлялись осложнения, в том числе выраженная органная дисфункция в 1,3%, грубый психоневрологический дефицит, сенсоневральная тугоухость; осложнения, требующие проведения ортопедических/хирургических вмешательств, составили 0,7%, 0,6% и 0,8% соответственно.Анализ полученных данных позволил вскрыть существующие проблемы, касающиеся клинической и этиологической диагностики заболевания, возможностей выявления осложнений острого периода и учета последствий генерализованных форм менингококковой инфекции.Заключение. Учитывая эпидемиологические особенности менингококковой инфекции (риск резкого подъема заболеваемости в короткие временные промежутки, жизнеугрожающий характер самого заболевания), необходимо сохранять настороженность в отношении данных рисков и предпринимать все возможные меры для профилактики заболевания с использованием всех доступных средств, наиболее эффективным из которых является вакцинопрофилактика