24 research outputs found
Retained NK cell phenotype and functionality in non-alcoholic fatty liver disease
Non-alcoholic fatty liver disease (NAFLD), and the progressive stage non-alcoholic steatohepatitis (NASH), is the predominant cause of chronic liver disease globally. As part of the complex pathogenesis, natural killer (NK) cells have been implicated in the development of liver inflammation in experimental murine models of NASH. However, there is a lack of knowledge on how NK cells are affected in humans with this disease. Here, we explored the presence of disease-specific changes within circulating and tissue-resident NK cell populations, as well as within other major immune cell subsets, in patients with liver biopsy-confirmed NAFLD. Using 18-color-flow cytometry, substantial changes were observed in certain myeloid populations in patients as compared to controls. NK cell numbers, on the other hand, were not altered. Furthermore, only minor differences in expression of activating and inhibitory NK cell receptors were noted, with the exception of an increased expression of NKG2D on NK cells from patients with NASH. NK cell differentiation remained constant, and NK cells from these patients retain their ability to respond adequately upon stimulation. Instead, considerable alterations were observed between liver, adipose tissue, and peripheral blood NK cells, independently of disease status. Taken together, these results increase our understanding of the importance of the local microenvironment in shaping the NK cell compartment and stress the need for further studies exploring how NASH affects intrahepatic NK cells in humans.publishedVersio
Robust T Cell Immunity in Convalescent Individuals with Asymptomatic or Mild COVID-19
SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19.Fil: Sekine, Takuya. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Perez Potti, AndrĂ©. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Rivera Ballesteros, Olga. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: StrĂ„lin, Kristoffer. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Gorin, Jean Baptiste. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Olsson, Annika. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Llewellyn Lacey, Sian. University Hospital of Wales; Reino UnidoFil: Kamal, Habiba. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Bogdanovic, Gordana. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Muschiol, Sandra. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Wullimann, David J.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Kammann, Tobias. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: EmgĂ„rd, Johanna. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Parrot, Tiphaine. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Folkesson, Elin. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Rooyackers, Olav. Karolinska Huddinge Hospital. Karolinska Institutet; Suecia. Karolinska University Hospital; SueciaFil: Eriksson, Lars I.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Henter, Jan Inge. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Sönnerborg, Anders. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Allander, Tobias. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Albert, Jan. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Nielsen, Morten. Technical University of Denmark; Dinamarca. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de Investigaciones BiotecnolĂłgicas. Universidad Nacional de San MartĂn. Instituto de Investigaciones BiotecnolĂłgicas; ArgentinaFil: Klingstrom, Jonas. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Gredmark Russ, Sara. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Björkström, Niklas K.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Sandberg, Johan K.. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Price, David A.. Cardiff University School of Medicine; Reino UnidoFil: Ljunggren, Hans Gustaf. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Aleman, Soo. Karolinska Huddinge Hospital. Karolinska Institutet; SueciaFil: Buggert, Marcus. Karolinska Huddinge Hospital. Karolinska Institutet; Sueci
Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19
SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19
Regression methods in multidimensional prediction and estimation
In regression with near collinear explanatory variables, the least squares predictor has large variance. Ordinary least squares regression (OLSR) often leads to unrealistic regression coefficients. Several regularized regression methods have been proposed as alternatives. Well-known are principal components regression (PCR), ridge regression (RR) and continuum regression (CR). The latter two involve a continuous metaparameter, offering additional flexibility. For a univariate response variable, CR incorporates OLSR, PLSR, and PCR as special cases, for special values of the metaparameter. CR is also closely related to RR. However, CR can in fact yield regressors that vary discontinuously with the metaparameter. Thus, the relation between CR and RR is not always one-to-one. We develop a new class of regression methods, LSRR, essentially the same as CR, but without discontinuities, and prove that any optimization principle will yield a regressor proportional to a RR, provided only that the principle implies maximizing some function of the regressor's sample correlation coefficient and its sample variance. For a multivariate response vector we demonstrate that a number of well-established regression methods are related, in that they are special cases of basically one general procedure. We try a more general method based on this procedure, with two meta-parameters. In a simulation study we compare this method to ridge regression, multivariate PLSR and repeated univariate PLSR. For most types of data studied, all methods do approximately equally well. There are cases where RR and LSRR yield larger errors than the other methods, and we conclude that one-factor methods are not adequate for situations where more than one latent variable are needed to describe the data. Among those based on latent variables, none of the methods tried is superior to the others in any obvious way
OmstÀllning till ett hÄllbart transport- och mobilitetssystem med mÀnniskan i centrum
Den globala uppvĂ€rmningen Ă€r vĂ„r tids stora utmaÂning. FN:s klimatpanels, IPCC:s, första rapport publicerades 1990. Det Ă€r alltsĂ„ över 30 Ă„r sedan forskarÂsamhĂ€llet konstaterade att en snabb klimatförĂ€ndring sker. Ny forskning har sedan dess visat att redan vid 1,5 graders global uppvĂ€rmning finns uppenbara risÂker för sĂ„vĂ€l mĂ€nniskors som djurs och naturs milÂjöer. Det ledde till att en stor majoritet av vĂ€rldens lĂ€nder skrev under Parisöverenskommelsen vid FN:s klimatmöte, COP 21, 2015. Parisöverenskommelsen anger att vĂ€rldens lĂ€nder ska vidta Ă„tgĂ€rder som leder till att den globala medeltemperaturhöjningen hĂ„lls lĂ„ngt under 2 grader och helst begrĂ€nsas till under 1,5 grader. Trots att det Ă€r vetenskapligt belagt och allmĂ€nt accepterat att de utslĂ€pp mĂ€nniskan orsakat Ă€r den helt överskuggande orsaken till globala uppÂvĂ€rmningen, sĂ„ saknas de nödvĂ€ndiga Ă„tgĂ€rderna för att minska utslĂ€ppen av vĂ€xthusgaser. Den globala temperaturhöjningen Ă€r nu 1,1 grader jĂ€mfört med förindustriell tid. Det Ă€r mot denna bakgrund Klimatriksdagen tar fram ett förslag till klimatpolitiska insatser dĂ€r utgĂ„ngsÂpunkten Ă€r Sveriges Ă„taganden enligt ParisöverensÂkommelsen. Koldioxidbudgeten, som gĂ€llde för SveriÂge 2020 utifrĂ„n dessa förutsĂ€ttningar, visar att senast 2035 tar budgeten slut. Denna rapport om Mobilitet och transport Ă€r en friÂstĂ„ende rapport och samtidigt ett underlag till KliÂmatriksdagens samlade KlimatomstĂ€llningsplan. Inrikes transporter orsakar ungefĂ€r en tredjedel av de territoriella utslĂ€ppen, inkluderas utslĂ€ppen frĂ„n brĂ€nslen som lagras i Sverige, bunkrade brĂ€nslen, för utrikes flyg och sjöfart hela 40 procent. TransportÂsektorn karaktĂ€riseras av mĂ„nga kopplingar till andra sektorer och Ă€r beroende av ett stort antal aktörer. UtÂbyggnad av transportinfrastrukturen tar lĂ„ng tid och krĂ€ver stora investeringar. OmstĂ€llningen till en kliÂmatneutral transportsektor inom loppet av ett drygt decennium krĂ€ver dĂ€rför kraftfulla och snabbt insatta Ă„tgĂ€rder. För analysen och valet av Ă„tgĂ€rder har en mĂ„lbild för en utslĂ€ppsfri transportsektor Ă„r 2035 varit vĂ€gledanÂde. Genom att sĂ€tta denna i relation till situationen idag har ett antal alternativa scenarier med olika uppÂsĂ€ttningar Ă„tgĂ€rder tagits fram â en metodik benĂ€mnd back-casting. UtslĂ€ppsbanor för dessa alternativ illustrerar hur minskningen av utslĂ€pp kan komma att fördelas tidsmĂ€ssigt. För analyser av hur och nĂ€r olika Ă„tgĂ€rder bör sĂ€ttas in har Ă€ven dynamisk modellering och simulering anvĂ€nts. Vi hĂ€vdar i rapporten att synen pĂ„ transporter och transportplanering mĂ„ste Ă€ndras i grunden. MĂ€nniskors behov och förhĂ„llanden, hög tillgĂ€nglighet och lĂ„g resursbelastning bör vara ledstjĂ€rnor och transÂportplaneringen inordnas i övrig samhĂ€llsplaneringen. Ett klimatvĂ€nligt mobilitetsmönster behöver skapas. MĂ€nniskors acceptans och engagemang kommer att vara helt avgörande för att omstĂ€llningen ska lyckas. Föreslagna Ă„tgĂ€rderna ska ses i ljuset av de Ă„tagÂanden som Sverige gjort och den koldioxidbudget som följer av dessa. Vissa förslag kan framstĂ„ som mindre populĂ€ra och dĂ€rför svĂ„ra att genomföra. ĂndĂ„ Ă€r de inte tillrĂ€ckliga. Detta gĂ€ller speciellt flyg men ocksĂ„ persontrafik pĂ„ vĂ€g och sjöfart. Efter hand behöver de föreslagna Ă„tgĂ€rderna kompletteras och skĂ€rpas för att transportsektorns utslĂ€pp ska rymmas inom ramen för gĂ€llande koldioxidbudget. Rapporten ger inledningsvis en sammanfattning av slutsatser och förslag i rapporten, följt av vad som mĂ„ste ha uppnĂ„tts av klimatomstĂ€llningen mĂ„lĂ„ret 2035. Vad har hĂ€nt och genomförts under Ă„ren fram till dess? Vanligtvis utgĂ„r framtidsbeskrivningar frĂ„n situationen idag för att dĂ€rifrĂ„n blicka framĂ„t i tiden. Detta lĂ„ser dock lĂ€tt tanken vid rĂ„dande förutsĂ€ttningÂar. KlimatomstĂ€llningen kommer emellertid att krĂ€va sĂ„ genomgripande förĂ€ndringar att dagens tankesĂ€tt, rutiner och lagbundenheter mĂ„ste överges och ersĂ€tÂtas med nya ordningar och kreativa lösningar. De delar, som beskriver föreslagna Ă„tgĂ€rder, Ă€r skrivÂna utifrĂ„n vad som gĂ€ller idag. De ska beslutas nu och genomföras skyndsamt för att nödvĂ€ndiga förĂ€ndringÂar ska kunna ske i tid. Under resans gĂ„ng kommer omÂprövningar att ske, nya förutsĂ€ttningar att gĂ€lla och nya möjligheter att dyka upp. Antalet Ă„tgĂ€rder och de mĂ„nga sambanden och kopplingarna dem emellan som krĂ€vs för att fĂ„ önskad effekt visar komplexiteten i omstĂ€llningen. ĂvervĂ€ganden och slutsatser i korthet Det korta tidsperspektivet â omstĂ€llningen till ett klimatvĂ€nligt mobilitetsmönster ska ske pĂ„ ett drygt decennium â medför krav pĂ„ beslut och genomförande av kraftfulla och snabbt insatta Ă„tgĂ€rder. Ett helt nytt synsĂ€tt, ett systemperspektiv, anlĂ€ggs pĂ„ mobilitet, transporter och deras roll i samhĂ€lÂlet. Utbud och Ă„tgĂ€rder inom olika transportslag samordnas och understöds i relation till samhĂ€llsnytta som tillgĂ€nglighet, rĂ€ttvisa, minskad klimatÂpĂ„verkan, hĂ€lsa, lokal miljö och biologisk mĂ„ngfald. Först nĂ€r utformningen av transportsektorn utgĂ„r frĂ„n dessa mĂ„l, med hĂ€nsyn till den tillgĂ€ngliga koldioxidbudgeten och överger dagens prognosstyrÂda och snĂ€va infrastrukturplanering inleds sektorns klimatomstĂ€llning pĂ„ allvar. Digitalt system för dynamiska och differentierade priser pĂ„ anvĂ€ndningen av vĂ€ginfrastrukturen â dyÂnamiska och differentierade vĂ€gavgifter â samordÂnat med utbud och biljettsystem i kollektivtrafik pĂ„verkar trafikvolymer, val av transportsĂ€tt och skapar lĂ„ngsiktig finansiering för kollektivtrafiken. De offentliga insatserna finansieras ur en gemensam kassa. Insatser för minskade trafikvolymer pĂ„ vĂ€g komÂbineras med Ă„tgĂ€rder för ökad gĂ„ng-, cykel-och kollektivtrafik samt en snabb elektrifiering av motorfordonen. Omfattande investeringar görs inom jĂ€rnvĂ€g, kollekÂtivtrafik, laddinfrastruktur och bredband. Dessa genomförs mycket snabbt för att bidra med positiva klimateffekter fram till 2035. Transportsektorns totala utslĂ€pp av biogen och fosÂsil koldioxid Ă€r av en storleksordning som innebĂ€r att de praktiskt inte kan reduceras ner till netto noll med tillgĂ€ngliga Ă„tgĂ€rder fram till 2035. Koldioxidbudgeten för mobilitets-och transportÂsektorn bryts ner pĂ„ regional nivĂ„ dĂ€r klimatomÂstĂ€llningen drivs pĂ„ under ledning av lĂ€nsstyrelserÂna, i samverkan med berörda parter och med statliga stimulanspengar.The global warming is the greatest challenge of our time. The first report by the UN climate panel, IPCC, was published 1990. Thus, it is more than 30 years since the research community concluded that a rapid climate change is ongoing. Since then new research has shown that already at 1.5 degrees global warming there are definite risks for environments needed by both humans, animals, and nature. This motivated a large majority of the worldâs countries to sign the Paris Agreement at the UN climate conference, COP 21, in 2015. The Paris Agreement states that the countries of the World shall take action to keep the global average temperature increase far below 2.0 degrees and preferably below 1.5 degrees. Despite the fact that it is scientifically shown and generally accepted that human caused emissions is the completely dominating cause of the global warming, the necessary actions to reduce emissions are still missing. The average global temperature increase is now 1.1 degrees Celsius compared to pre-industrial times.     With this as background, the Swedish Climate Parliament (an NGO, www.klimatriksdagen.se) develops a set of proposals for climate policy actions based on Swedenâs commitments according to the Paris Agreement. The CO2 emission budget for Sweden 2020 according to these assumptions show that the Swedish emission budget will be used up latest 2035. This report about mobility and transport is an independent report and at the same time input to the Climate Parliamentâs comprehensive climate-based transition plan. Domestic transport causes about a third of Swedenâs territorial emission. If we also include emissions from fuels stored in Sweden, bunkered fuels for aircraft and ships, Swedenâs emissions related to transport amounts to about 40 percent. The transport sector is characterized by many interactions to other sectors and requires large investments. The transition to a climate neutral neutral transport section within slightly more than a decade therefore requires powerful and rapidly executed actions.     The goal of an emission free transport sector for Sweden 2035 has been guiding the analysis and choice of actions. By putting this in relation to the situation of today, a number of alternative scenarios with different sets of actions to reach this goal have been developed. This methodology is called back-casting. Emission trajectories for these scenarios illustrate how emission reductions can be distributed over time. Moreover, dynamic system modeling and simulation has also been employed regarding analysis of how and when different actions should be executed. In this report we claim that the view of transport and transport planning must be fundamentally changed. Human needs and conditions, high availability, and low resource usage should be long term goals and the transport planning should be included in the general societal planning. A climate friendly mobility pattern must be created. Peopleâs acceptance and engagement will be absolutely crucial for the success of the sustainability transition.   The proposed actions should be viewed in view of the commitments that Sweden has done and the CO2 budget for Sweden that becomes the consequence. Certain proposals may appear to be less popular and therefore difficult to implement. Nonetheless, even these are not enough. This is true especially for air traffic but also for person transport on road and at sea. Over time the proposed actions need to be extended and applied more strictly in order for the CO2 budget of the transport sector to be accommodated within the applicable CO2 budget. The introductory part of the report first presents a summary of the conclusions and proposals of the report, followed by the goals that need to be reached at the target year 2035. What will happen and which actions have been realized until the year 2035? Usually visions of the future starts at the current situation today and projects current trends forward in time. This has the drawback that the current situation and trends may lock thinking and prevent necessary actions. However, the climate induced transition will need such large and comprehensive changes that parts of todayâs thinking, methodology and tradition have to be abandoned and replaced by new methods and creative solutions. The parts of the report that describe proposed actions are written based on what is applicable today. They should be decided on and executed very soon in order that necessary changes should happen in time. During this process re-evaluation of policies and solutions will need to be done continuously. New conditions and new possibilities will appear. The many solutions and actions and the connections and inter-relations between those that must be fulfilled to get the desired results indicate the complexity of the climate sustainability transition. Considerations and conclusions summarized: The short time available â since the transition to a climate friendly mobility and transport system needs to take place during a little bit more than a decade â results in requirements on decisions and implementation of powerful and rapidly implemented measures. A fundamentally new point of view, a system perspective, is applied to mobility, transport, and their roles in society. Availability and measures related to different modes of transportation will be coordinated and supported in relation to societal benefits such as availability, equity, reduced climate impact, health, local environment, and biodiversity. The climate related transformation of the transport sector will be seriously begun only if these goals are used as guidance, in relation to available carbon dioxide budgets, abandoning todaysâ forecast driven and short term oriented infra structure planning. A digital system for dynamic and differentiated prices on usage of road infra structure â dynamic and differentiated road fees â coordinated with supply and a comprehensive public transport ticket system will influence traffic volumes, choice of transport mode, and create long term financing of public transport. The public investments will be financed from a general governmental fund. Measures for reduced road traffic volumes are combined with actions to stimulate increased mobility on foot, via bicycle, or public transport, and a rapid electrification of motor vehicles. Large scale investments are done within the railway system, public transport, charge infrastructure and broadband. These should be implemented very rapidly to contribute to reduced climate emissions until 2035. The total emissions from the transport sector, including both biogenic and fossil carbon dioxide, are at a such a large order of magnitude that they cannot be completely eliminated to net zero until 2035 using practically available measures. The national carbon dioxide budget for mobility and transport is regionalized at a level where the climate transition can be effectively coordinated in collaboration with affected parties and with support from governmental investment funds
Human hantavirus infection elicits pronounced redistribution of mononuclear phagocytes in peripheral blood and airways
Hantaviruses infect humans via inhalation of virus-contaminated rodent excreta. Infection can cause severe disease with up to 40% mortality depending on the viral strain. The virus primarily targets the vascular endothelium without direct cytopathic effects. Instead, exaggerated immune responses may inadvertently contribute to disease development. Mononuclear phagocytes (MNPs), including monocytes and dendritic cells (DCs), orchestrate the adaptive immune responses. Since hantaviruses are transmitted via inhalation, studying immunological events in the airways is of importance to understand the processes leading to immunopathogenesis. Here, we studied 17 patients infected with Puumala virus that causes a mild form of hemorrhagic fever with renal syndrome (HFRS). Bronchial biopsies as well as longitudinal blood draws were obtained from the patients. During the acute stage of disease, a significant influx of MNPs expressing HLA-DR, CD11c or CD123 was detected in the patients' bronchial tissue. In parallel, absolute numbers of MNPs were dramatically reduced in peripheral blood, coinciding with viremia. Expression of CCR7 on the remaining MNPs in blood suggested migration to peripheral and/or lymphoid tissues. Numbers of MNPs in blood subsequently normalized during the convalescent phase of the disease when viral RNA was no longer detectable in plasma. Finally, we exposed blood MNPs in vitro to Puumala virus, and demonstrated an induction of CCR7 expression on MNPs. In conclusion, the present study shows a marked redistribution of blood MNPs to the airways during acute hantavirus disease, a process that may underlie the local immune activation and contribute to immunopathogenesis in hantavirus-infected patients
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SARS-CoV-2 vaccination enhances the effector qualities of spike-specific T cells induced by COVID-19.
T cells are critical for immune protection against severe COVID-19, but it has remained unclear whether repeated exposure to SARS-CoV-2 antigens delivered in the context of vaccination fuels T cell exhaustion or reshapes T cell functionality. Here, we sampled convalescent donors with a history of mild or severe COVID-19 before and after SARS-CoV-2 vaccination to profile the functional spectrum of hybrid T cell immunity. Using combined single-cell technologies and high-dimensional flow cytometry, we found that the frequencies and functional capabilities of spike-specific CD4+ and CD8+ T cells in previously infected individuals were enhanced by vaccination, despite concomitant increases in the expression of inhibitory receptors such as PD-1 and TIM3. In contrast, CD4+ and CD8+ T cells targeting non-spike proteins remained functionally static and waned over time, and only minimal effects were observed in healthy vaccinated donors experiencing breakthrough infections with SARS-CoV-2. Moreover, hybrid immunity was characterized by elevated expression of IFN-Îł, which was linked with clonotype specificity in the CD8+ T cell lineage. Collectively, these findings identify a molecular hallmark of hybrid immunity and suggest that vaccination after infection is associated with cumulative immunological benefits over time, potentially conferring enhanced protection against subsequent episodes of COVID-19
SARS-CoV-2 vaccination enhances the effector qualities of spike-specific T cells induced by COVID-19
T cells are critical for immune protection against severe COVID-19, but it has remained unclear whether repeated exposure to SARS-CoV-2 antigens delivered in the context of vaccination fuels T cell exhaustion or reshapes T cell functionality. Here, we sampled convalescent donors with a history of mild or severe COVID-19 before and after SARS-CoV-2 vaccination to profile the functional spectrum of hybrid T cell immunity. Using combined single-cell technologies and high-dimensional flow cytometry, we found that the frequencies and functional capabilities of spike-specific CD4+ and CD8+ T cells in previously infected individuals were enhanced by vaccination, despite concomitant increases in the expression of inhibitory receptors such as PD-1 and TIM3. In contrast, CD4+ and CD8+ T cells targeting non-spike proteins remained functionally static and waned over time, and only minimal effects were observed in healthy vaccinated donors experiencing breakthrough infections with SARS-CoV-2. Moreover, hybrid immunity was characterized by elevated expression of IFN-Îł, which was linked with clonotype specificity in the CD8+ T cell lineage. Collectively, these findings identify a molecular hallmark of hybrid immunity and suggest that vaccination after infection is associated with cumulative immunological benefits over time, potentially conferring enhanced protection against subsequent episodes of COVID-19
Susceptibility of classical monocytes and CD1c<sup>+</sup> MDCs to PUUV <i>in vitro</i>.
<p>(<b>A</b>) Human CM (top panel, green) and CD1c<sup>+</sup> MDCs (bottom panel, coral) were isolated from peripheral blood of healthy volunteers. Flow cytometry dot plots show live, HLA-DR<sup>+</sup> CD11c<sup>+</sup> CD14<sup>+</sup> CD16<sup>-</sup> monocytes or live, CD11c<sup>+</sup> CD1c<sup>+</sup> MDCs. Numbers in gate depict the frequency of cells out of total live cells. One representative donor of six is shown. Cells were left unexposed, exposed to PUUV or UV-inactivated PUUV for 2 h at an MOI of 7.5. Cells were washed and subsequently incubated for 12â60 h. (<b>B</b>) Immunofluorescence staining with patient serum on CM (left panel) and CD1c<sup>+</sup> MDCs (right panel) on uninfected and PUUV-infected cells 40 h after infection indicates detectable viral antigen (green). Cells were counterstained with DAPI (gray) and also stained for HLA-DR (blue). Scale bar, 10 ÎŒm. (<b>C</b>) Bar graphs summarize the mean±SD of PUUV<sup>+</sup> CM (left panel, n = 3) or CD1c<sup>+</sup> MDCs (n = 3). n.d., not detectable. (<b>D</b>) Relative expression of PUUV RNA was measured in CM and CD1c<sup>+</sup> MDCs (n = 2) after 60 h of infection. Bar graphs show 2<sup>-ÎCt</sup> values relative to the housekeeping gene <i>ÎČ-Actin</i>. (<b>E</b>) Viability of cells was assessed by flow cytometry based on a LIVE/DEAD dye. Graphs show mean±SD viability of CM (top panel, n = 4) or CD1c<sup>+</sup> MDC (bottom panel, n = 6). (<b>F</b>) Histograms indicate changes in expression of CCR2, CCR4, CCR6 and CD86 in cells exposed to PUUV (ocean blue) compared to unexposed (black line) from one representative donor of CM (n = 4) and CD1c<sup>+</sup> MDCs (n = 6). Fluorescence minus one (FMO) controls are shown in gray. <b>(G</b>) Bar graphs summarize the MFI±SD of CCR2, CCR4, CCR6 and CD86 (n = 4â6) in cells left unexposed (white), exposed to PUUV (ocean blue) or UV PUUV (patterned ocean blue). <b>(H</b>) Flow cytometry dot plots show changes in CCR7 in cells exposed to PUUV or unexposed. Numbers in gate depict the frequency of CCR7<sup>+</sup> cells out of total CM (n = 4) or CD1c<sup>+</sup> MDC (n = 6). (<b>I</b>) Bar graphs summarize the MFI±SD of CCR7 (n = 4â6). Statistical differences were assessed using paired <i>t</i>-test: * <i>p</i><0.05, n.s. not significant.</p
Upregulation of CCR7 on MNPs in blood of HFRS patients during acute infection.
<p>(<b>A</b>) Representative flow cytometry plots showing CCR7 expression on CD1c<sup>+</sup> MDCs from one representative UC and one HFRS patient are shown. (<b>B</b>) Mean±SD frequencies of CCR7<sup>+</sup> CMs (green), IM (red), NCM (blue), CD1c<sup>+</sup> MDCs (coral), CD141<sup>+</sup> MDCs (maroon) and PDCs (teal) were quantified in longitudinal samples from HFRS patients in comparison to UC. (<b>C</b>) Histograms indicate upregulation of CD70 on CM, and upregulation of CD86 and CD70 on CD1c<sup>+</sup> MDCs of a HFRS patient during the acute phase. (<b>D</b>) Bar graphs summarize the MFI±SD of CD70 and CD86 in CCR7<sup>+</sup> and CCR7<sup>-</sup> CM and CD1c<sup>+</sup> MDCs. Differences in proportion of CCR7<sup>+</sup> cells were assessed using logistic regression; * <i>p</i><0.05, ** <i>p</i><0.01, *** <i>p</i><0.001, n.s. not significant.</p