Novel multiparameter correlates of \u3cem\u3eCoxiella burnetii\u3c/em\u3e infection and vaccination identified by longitudinal deep immune profiling

Q-fever is a flu-like illness caused by Coxiella burnetii (Cb), a highly infectious intracellular bacterium. There is an unmet need for a safe and effective vaccine for Q-fever. Correlates of immune protection to Cb infection are limited. We proposed that analysis by longitudinal high dimensional immune (HDI) profiling using mass cytometry combined with other measures of vaccination and protection could be used to identify novel correlates of effective vaccination and control of Cb infection. Using a vaccine-challenge model in HLA-DR transgenic mice, we demonstrated significant alterations in circulating T-cell and innate immune populations that distinguished vaccinated from naïve mice within 10 days, and persisted until at least 35 days post-vaccination. Following challenge, vaccinated mice exhibited reduced bacterial burden and splenomegaly, along with distinct effector T-cell and monocyte profiles. Correlation of HDI data to serological and pathological measurements was performed. Our data indicate a Th1-biased response to Cb, consistent with previous reports, and identify Ly6C, CD73, and T-bet expression in T-cell, NK-cell, and monocytic populations as distinguishing features between vaccinated and naïve mice. This study refines the understanding of the integrated immune response to Cb vaccine and challenge, which can inform the assessment of candidate vaccines for Cb

Promiscuous \u3cem\u3eCoxiella burnetii\u3c/em\u3e CD4 Epitope Clusters Associated With Human Recall Responses Are Candidates for a Novel T-Cell Targeted Multi-Epitope Q Fever Vaccine

Coxiella burnetii, the causative agent of Q fever, is a Gram-negative intracellular bacterium transmitted via aerosol. Regulatory approval of the Australian whole-cell vaccine Q-VAX® in the US and Europe is hindered by reactogenicity in previously exposed individuals. The aim of this study was to identify and rationally select C. burnetii epitopes for design of a safe, effective, and less reactogenic T-cell targeted human Q fever vaccine. Immunoinformatic methods were used to predict 65 HLA class I epitopes and 50 promiscuous HLA class II C. burnetii epitope clusters, which are conserved across strains of C. burnetii. HLA binding assays confirmed 89% of class I and 75% of class II predictions, and 11 HLA class II epitopes elicited IFNγ responses following heterologous DNA/DNA/peptide/peptide prime-boost immunizations of HLA-DR3 transgenic mice. Human immune responses to the predicted epitopes were characterized in individuals naturally exposed to C. burnetii during the 2007–2010 Dutch Q fever outbreak. Subjects were divided into three groups: controls with no immunological evidence of previous infection and individuals with responses to heat-killed C. burnetii in a whole blood IFNγ release assay (IGRA) who remained asymptomatic or who experienced clinical Q fever during the outbreak. Recall responses to C. burnetii epitopes were assessed by cultured IFNγ ELISpot. While HLA class I epitope responses were sparse in this cohort, we identified 21 HLA class II epitopes that recalled T-cell IFNγ responses in 10–28% of IGRA+ subjects. IGRA+ individuals with past asymptomatic and symptomatic C. burnetii infection showed a comparable response pattern and cumulative peptide response which correlated with IGRA responses. None of the peptides elicited reactogenicity in a C. burnetii exposure-primed guinea pig model. These data demonstrate that a substantial proportion of immunoinformatically identified HLA class II epitopes show long-lived immunoreactivity in naturally infected individuals, making them desirable candidates for a novel human multi-epitope Q fever vaccine

Cytometry profiling of ex vivo recall responses to Coxiella burnetii in previously naturally exposed individuals reveals long-term changes in both adaptive and innate immune cellular compartments

IntroductionQ fever, caused by the intracellular bacterium Coxiella burnetii, is considered an occupational and biodefense hazard and can result in debilitating long-term complications. While natural infection and vaccination induce humoral and cellular immune responses, the exact nature of cellular immune responses to C. burnetii is incompletely understood. The current study seeks to investigate more deeply the nature of long-term cellular recall responses in naturally exposed individuals by both cytokine release assessment and cytometry profiling.MethodsIndividuals exposed during the 2007-2010 Dutch Q fever outbreak were grouped in 2015, based on a C. burnetii-specific IFNγ release assay (IGRA), serological status, and self-reported clinical symptoms during initial infection, into asymptomatic IGRA-negative/seronegative controls, and three IGRA-positive groups (seronegative/asymptomatic; seropositive/asymptomatic and seropositive/symptomatic). Recall responses following in vitro re-stimulation with heat-inactivated C. burnetii in whole blood, were assessed in 2016/2017 by cytokine release assays (n=55) and flow cytometry (n=36), and in blood mononuclear cells by mass cytometry (n=36).ResultsCytokine release analysis showed significantly elevated IL-2 responses in all seropositive individuals and elevated IL-1β responses in those recovered from symptomatic infection. Comparative flow cytometry analysis revealed significantly increased IFNγ, TNFα and IL-2 recall responses by CD4 T cells and higher IL-6 production by monocytes from symptomatic, IGRA-positive/seropositive individuals compared to controls. Mass cytometry profiling and unsupervised clustering analysis confirmed recall responses in seropositive individuals by two activated CD4 T cell subsets, one characterized by a strong Th1 cytokine profile (IFNγ+IL-2+TNFα+), and identified C. burnetii-specific activation of CD8 T cells in all IGRA-positive groups. Remarkably, increased C. burnetii-specific responses in IGRA-positive individuals were also observed in three innate cell subpopulations: one characterized by an IFNγ+IL-2+TNFα+ Th1 cytokine profile and lack of canonical marker expression, and two IL-1β-, IL-6- and IL-8-producing CD14+ monocyte subsets that could be the drivers of elevated secretion of innate cytokines in pre-exposed individuals.DiscussionThese data highlight that there are long-term increased responses to C. burnetii in both adaptive and innate cellular compartments, the latter being indicative of trained immunity. These findings warrant future studies into the protective role of these innate responses and may inform future Q fever vaccine design

R5-SHIV Induces Multiple Defects in T Cell Function during Early Infection of Rhesus Macaques Including Accumulation of T Reg Cells in Lymph Nodes

Background: HIV-1 is a pathogen that T cell responses fail to control. HIV-1gp120 is the surface viral envelope glycoprotein that interacts with CD4 T cells and mediates entry. HIV-1gp120 has been implicated in immune dysregulatory functions that may limit anti-HIV antigen-specific T cell responses. We hypothesized that in the context of early SHIV infection, immune dysregulation of antigen-specific T-effector cell and regulatory functions would be detectable and that these would be associated or correlated with measurable concentrations of HIV-1gp120 in lymphoid tissues. Methods: Rhesus macaques were intravaginally inoculated with a Clade C CCR5-tropic simian-human immunodeficiency virus, SHIV-1157ipd3N4. HIV-1gp120 levels, antigen-specificity, levels of apoptosis/anergy and frequency and function of Tregs were examined in lymph node and blood derived T cells at 5 and 12 weeks post inoculation. Results/Conclusions: We observed reduced responses to Gag in CD4 and gp120 in CD8 lymph node-derived T cells compared to the peripheral blood at 5 weeks post-inoculation. Reduced antigen-specific responses were associated with higher levels of PD-1 on lymph node-derived CD4 T cells as compared to peripheral blood and uninfected lymph node-derived CD4 T cells. Lymph nodes contained increased numbers of Tregs as compared to peripheral blood, which positively correlated with gp120 levels; T regulatory cell depletion restored CD8 T cell responses to Gag but not to gp120. HIV gp120 was also able to induce T regulatory cell chemotaxis in a dose-dependent, CCR5-mediated manner. These studies contribute to our broader understanding of the ways in which HIV-1 dysregulates T cell function and localization during early infection

Характеристики процесса сгорания двигателя 2Ч 7,2/6 с добавками до 65 % синтез-газа к бензину

Характеристики процесса сгорания двигателя 2Ч 7,2/6 с добавками до 65 % синтез-газа к бензину = Characteristics of the 2 cylinder 4-stroke engine 7,2/6 with additives to 65% of synthesis gas to gasoline / Б. Г. Тимошевский, М. Р. Ткач, А. С. Познанский, А. С. Митрофанов, А. Ю. Проскурин // Двигатели внутреннего сгорания. – 2015. – № 1. – С. 33–37.Представлені результати досліджень роботи двигуна 2Ч 7,2/6 з іскровим запалюванням та зовнішнім сумішоутворенням при роботі на бензині з добавками синтез-газу. Отримано індикаторні діаграми при роботі по навантажувальної характеристиці при добавках синтез-газу – 25–64 %. Запропоновано залежності для визначення значень показника згоряння m і тривалості згоряння φz при коефіцієнті надлишку повітря 1,1...1,22.The results of the performance of 2 cylinder 4–stroke engine 7,2/6 with spark ignition and external mixture formation at work on gasoline with synthesis gas additives are presented. Indicator diagrams during the working on loading characteristic with addition of synthesis gas – 25–64 % were obtained. Dependences for determination of the combustion rate values of m and length of combustion φz when excess air ratio of 1.1...1.22 were offered.Представлены результаты исследований работы двигателя 2Ч 7,2/6 с искровым зажиганием и внешним смесеобразованием при работе на бензине с добавками синтез-газа. Получены индикаторные диаграммы при работе по нагрузочной характеристике при добавках синтез-газа – 25–64 %. Предложены зависимости для определения значений показателя сгорания m и продолжительности сгорания φz при коэффициенте избытка воздуха 1,1...1,22

Эффективность энергетической установки на базе двигателя 1Ч 7,5/6 с термохимической утилизацией теплоты отходящих газов

Эффективность энергетической установки на базе двигателя 1Ч 7,5/6 с термохимической утилизацией теплоты отходящих газов = Efficiency of power plant based on 1 cylinder 4-stroke engine 7,5/6 with thermochemical heat utilization of exhaust gases / Б. Г. Тимошевский, М. Р. Ткач, А. Ю. Проскурин, А. С. Митрофанов, А. С. Познанский // Двигатели внутреннего сгорания. – 2015. – № 2. – С. 30–34.Представлені результати чисельних досліджень параметрів роботи енергетичної установки на базі поршневого двигуна 1Ч 7,5/6 з термохімічною утилізацією теплоти відпрацьованих газів. Визначено параметри роботи двигуна залежно від режиму навантаження при роботі по навантажувальній характеристиці на етанолі і синтез-газах, отриманих з реакції розкладання і паровою конверсією. Встановлено, що для ДВЗ 1Ч 7,5/6, що працює на етанолі застосування ТХУ теплоти відпрацьованих газів ефективно при конверсії етанолу з реакції розкладання. Зниження витрати етанолу досягається при ступенях конверсії – 95...100 % і становить 6...26 г/(кВт∙год) (1,0...5,4 %). Визначено, що раціональний температурний напір на вході в термохімічний реактор лежить в діапазоні 20…160 °С. Частка теплоти відпрацьованих газів, яку необхідно утилізувати змінюється в межах 38…44 %.The numerical studies results of power plant parameters on reciprocating 1 cylinder 4-stroke engine with dimension of 7,5/6 and thermochemical heat recovery system of exhaust gases are presented. The parameters of the engine as a function of load conditions during operation by loading characteristic were defined. Engine was running on ethanol and synthesis gases produced by the decomposition reaction and steam reforming. It is found that for reciprocating 1 cylinder 4-stroke engine with dimension of 7,5/6 with ethanol use TCU waste heat efficiently in the conversion of ethanol decomposition reaction. Reducing consumption of ethanol is achieved at a level of conversion – 95...100 % and is 6...26 g/(kW∙ h) (1...5.4 %). It was determined that a rational temperature difference at the inlet of the thermochemical reactor lies in the range 20…160 ° C. Ratio of exhaust gases heat, which must be recycled varies in the range 38…44 %.Представлены результаты численных исследований параметров работы энергетической установки на базе поршневого двигателя 1Ч 7,5/6 с термохимической утилизацией теплоты отходящих газов. Определены параметры работы двигателя в зависимости от режима нагрузки при работе по нагрузочной характеристике на этаноле и синтез-газах, полученных по реакции разложения и паровой конверсией. Установлено, что для ДВС 1Ч 7,5/6, работающего на этаноле применение ТХУ теплоты отходящих газов эффективно при конверсии этанола по реакции разложения. Снижение расхода этанола достигается при степенях конверсии – 95…100 % и составляет 6…26 г/(кВт∙ч) (1,0…5,4 %). Определено, что рациональный температурный напор на входе в термохимический реактор лежит в диапазоне 20…160 °С. Доля теплоты отходящих газов, которую необходимо утилизировать, изменяется в пределах 38…44 %

Повышение эффективности двигателя 4Ч 8,4/9,1 путем добавки синтез-газа к бензину

Повышение эффективности двигателя 4Ч 8,4/9,1 путем добавки синтез-газа к бензину = Improving the efficiency of the 4 cylinder 4-stroke engine 8.4/9.1 with additives synthesis gas to gasoline / М. Р. Ткач, Б. Г. Тимошевский, А. С. Познанский, А. С. Митрофанов, А. Ю. Проскурин // Авиационно-космическая техника и технология. – 2016. – № 7 (134). – С. 134–138.Представлені результати роботи двигуна 4Ч 8,4/9,1 з іскровим запалюванням та зовнішнім сумішоутворенням при роботі на бензині з добавками синтез-газу. Отримано залежності зміни параметрів робочого циклу двигуна, що працює за навантажувальною характеристикою при величині добавки синтез-газу до бензину 25…65 %. При використанні добавок синтез-газу 65 % зниження індикаторної потужності стано вить 20 %, при цьому також знижується і питома індикаторний витрата палива. Встановлено, що добавка синтез-газу до бензину зменшує загальну тривалість згоряння суміші і покращує екологічні показники роботи двигуна.Presented the results of operation of the 4 cylinder 4-stroke engine 8.4/9.1 with spark ignition and external mixture formation on petrol with additives of synthesis gas. The dependences of change of the engine operating cycle parameters, working under the loading characteristic at the value of the additive synthesis gas to gasoline of 25…65 %. When using the additives of the synthesis gas 65 % reduction in power display is 20 %, while also dropping indicator and the specific fuel consumption. It is found that the addition of synthesis gas to gasoline reduces the overall duration of the combustion mixture and improves the environmental performance of the engine.Представлены результаты работы двигателя 4Ч 8,4/9,1 с искровым зажиганием и внешним смесеобразованием при работе на бензине с добавками синтез-газа. Получены зависимости изменения параметров рабочего цикла двигателя, работающего по нагрузочной характеристике при величине добавки синтез-газа к бензину 25…65 %. При использовании добавок синтез-газа 65 % снижение индикаторной мощности составляет 20 %, при этом также снижается и удельный индикаторный расход топлива. Установлено, что добавка синтез-газа к бензину уменьшает общую продолжительность сгорания смеси и улучшает экологические показатели работы двигателя