scholarly journals One by One – Insights into Complex Immune Responses through Functional Single-cell Analysis

2020 ◽  
Vol 74 (9) ◽  
pp. 716-723
Author(s):  
Klaus Eyer

Immune responses are highly dynamic and complex. The successful completion thereof involves and needs many different cells from the immune system, and requires their specific interactions and functions. Individual cells are the functional units within any immune response, and their varying frequencies and degrees of activity shape and define the response. The state, activation and ultimately functionality of immune cells displays high dynamic heterogeneity. Hence, there is a need for quantitative high-throughput systems that allow for a dynamic and functional single-cell phenotyping, linking function to the individual cells. In this regard, my research group focuses on developing and applying technologies and analytical strategies that allow us to measure, describe and exploit functionality within the immune system, resolved down to the individual, primary cell, to study novel and unique research questions. While doing ex vivo measurements, we are aiming to understand the functionalities of the extracted cells in vivo , within the context of our applied disturbance – vaccination, infection or malignant transformation.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David S. Fischer ◽  
Meshal Ansari ◽  
Karolin I. Wagner ◽  
Sebastian Jarosch ◽  
Yiqi Huang ◽  
...  

AbstractThe in vivo phenotypic profile of T cells reactive to severe acute respiratory syndrome (SARS)-CoV-2 antigens remains poorly understood. Conventional methods to detect antigen-reactive T cells require in vitro antigenic re-stimulation or highly individualized peptide-human leukocyte antigen (pHLA) multimers. Here, we use single-cell RNA sequencing to identify and profile SARS-CoV-2-reactive T cells from Coronavirus Disease 2019 (COVID-19) patients. To do so, we induce transcriptional shifts by antigenic stimulation in vitro and take advantage of natural T cell receptor (TCR) sequences of clonally expanded T cells as barcodes for ‘reverse phenotyping’. This allows identification of SARS-CoV-2-reactive TCRs and reveals phenotypic effects introduced by antigen-specific stimulation. We characterize transcriptional signatures of currently and previously activated SARS-CoV-2-reactive T cells, and show correspondence with phenotypes of T cells from the respiratory tract of patients with severe disease in the presence or absence of virus in independent cohorts. Reverse phenotyping is a powerful tool to provide an integrated insight into cellular states of SARS-CoV-2-reactive T cells across tissues and activation states.


2000 ◽  
Vol 164 (6) ◽  
pp. 3047-3055 ◽  
Author(s):  
Dragana Jankovic ◽  
Marika C. Kullberg ◽  
Nancy Noben-Trauth ◽  
Patricia Caspar ◽  
William E. Paul ◽  
...  

2016 ◽  
Vol 22 ◽  
pp. S59-S60
Author(s):  
Alan Simmons ◽  
Amrita Banerjee ◽  
Eliot McKinley ◽  
Cherieʼ Scurrah ◽  
Jeffrey Franklin ◽  
...  

2021 ◽  
Vol 22 ◽  
Author(s):  
Jizong Jiang

Abstract: Vaccination with small antigens, such as proteins, peptides, or nucleic acids, is used to activate the immune system and trigger the protective immune responses against a pathogen. Currently, nanovaccines are undergoing development instead of conventional vaccines. The size of nanovaccines is in the range of 10–500 nm, which enables them to be readily taken up by cells and exhibit improved safety profiles. However, low-level immune responses, as the removal of redundant pathogens, trigger counter-effective activation of the immune system invalidly and present a challenging obstacle to antigen recognition and its uptake via antigen-presenting cells (APCs). In addition, toxicity can be substantial. To overcome these problems, a variety of cell-penetrating peptide (CPP)-mediated vaccine delivery systems based on nanotechnology have been proposed, most of which are designed to improve the stability of antigens in vivo and their delivery into immune cells. CPPs are particularly attractive components of antigen delivery. Thus, the unique translocation property of CPPs ensures that they remain an attractive carrier with the capacity to deliver cargo in an efficient manner for the application of drugs, gene transfer, protein, and DNA/RNA vaccination delivery. CPP-mediated nanovaccines can enhance antigen uptake, processing, and presentation by APCs, which are the fundamental steps in initiating an immune response. This review describes the different types of CPP-based nanovaccines delivery strategies.


2022 ◽  
Author(s):  
Michael Valente ◽  
Nils Collinet ◽  
Thien-Phong Vu Manh ◽  
Karima Naciri ◽  
Gilles Bessou ◽  
...  

Plasmacytoid dendritic cells (pDC) were identified about 20 years ago, based on their unique ability to rapidly produce copious amounts of all subsets of type I and type III interferon (IFN-I/III) upon virus sensing, while being refractory to infection. Yet, the identity and physiological functions of pDC are still a matter of debate, in a large part due to their lack of specific expression of any single cell surface marker or gene that would allow to track them in tissues and to target them in vivo with high specificity and penetrance. Indeed, recent studies showed that previous methods that were used to identify or deplete pDC also targeted other cell types, including pDC-like cells and transitional DC (tDC) that were proposed to be responsible for all the antigen presentation ability previously attributed to steady state pDC. Hence, improving our understanding of the nature and in vivo choreography of pDC physiological functions requires the development of novel tools to unambiguously identify and track these cells, including in comparison to pDC-like cells and tDC. Here, we report successful generation of a pDC-reporter mouse model, by using an intersectional genetic strategy based on the unique co-expression of Siglech and Pacsin1 in pDC. This pDC-Tomato mouse strain allows specific ex vivo and in situ detection of pDC. Breeding them with Zbtb46GFP mice allowed side-by-side purification and transcriptional profiling by single cell RNA sequencing of bona fide pDC, pDC-like cells and tDC, in comparison to type 1 and 2 conventional DC (cDC1 and cDC2), both at steady state and during a viral infection, revealing diverging activation patterns of pDC-like cells and tDC. Finally, by breeding pDC-Tomato mice with Ifnb1EYFP mice, we determined the choreography of pDC recruitment to the micro-anatomical sites of viral replication in the spleen, with initially similar but later divergent behaviors of the pDC that engaged or not into IFN-I production. Our novel pDC-Tomato mouse model, and newly identified gene modules specific to combinations of DC types and activations states, will constitute valuable resources for a deeper understanding of the functional division of labor between DC types and its molecular regulation at homeostasis and during viral infections.


2020 ◽  
Vol 6 (10) ◽  
pp. 206-233
Author(s):  
S. Bulgakova ◽  
N. Romanchuk

The availability of innovative technologies, such as next-generation sequencing and correlated bioinformatics tools, allows deeper investigation of the cross-network relationships between the microbiota and human immune responses. Immune homeostasis is the balance between immunological tolerance and inflammatory immune responses — a key feature in the outcome of health or disease. A healthy microbiota is the qualitative and quantitative ratio of diverse microbes of individual organs and systems, maintaining the biochemical, metabolic and immune equilibrium of the macroorganism necessary to preserve human health. The studies of P. I. Romanchuk found that the microbiota is a key element potentially capable of influencing antigen functions to induce a protective immune response and the ability of the immune system to adequately respond to antigenic stimulation (vaccine efficacy) by acting as an immunological modulator as well as a natural vaccine adjuvant. The mechanisms underlying the crosstalk between the gut microbiota and the immune system play a crucial role, especially at an early age (early gut microbiota forms immunological functions). New interactions, along with other genetic and environmental factors, lead to a certain composition and richness of the microbiota, which can diversify the individual response to vaccinations. Variations in microbial communities may explain the geographical effectiveness of vaccination. Modern technologies for quantifying the specific and functional characteristics of the microbiota of the gastrointestinal tract, along with fundamental and new concepts in the field of immunology, have revealed numerous ways in which the interaction of the host and microbiota proceeds favorably, neutrally or unfavorably. The gut microbiota has a strong influence on the shape and quality of the immune system, respectively, the immune system determines the composition and localization of the microbiota. Thus, a healthy microbiota directly modulates intestinal and systemic immune homeostasis. The new managed healthy biomicrobiota and personalized functional and balanced nutrition of the “brain and microbiota” is a patient's long-term medical program that allows the combined use of nutritional epigenetics and pharmacepigenetics, and most importantly, an increase in the protective mechanisms of immunity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Laura S. Peterson ◽  
Julien Hedou ◽  
Edward A. Ganio ◽  
Ina A. Stelzer ◽  
Dorien Feyaerts ◽  
...  

Although most causes of death and morbidity in premature infants are related to immune maladaptation, the premature immune system remains poorly understood. We provide a comprehensive single-cell depiction of the neonatal immune system at birth across the spectrum of viable gestational age (GA), ranging from 25 weeks to term. A mass cytometry immunoassay interrogated all major immune cell subsets, including signaling activity and responsiveness to stimulation. An elastic net model described the relationship between GA and immunome (R=0.85, p=8.75e-14), and unsupervised clustering highlighted previously unrecognized GA-dependent immune dynamics, including decreasing basal MAP-kinase/NFκB signaling in antigen presenting cells; increasing responsiveness of cytotoxic lymphocytes to interferon-α; and decreasing frequency of regulatory and invariant T cells, including NKT-like cells and CD8+CD161+ T cells. Knowledge gained from the analysis of the neonatal immune landscape across GA provides a mechanistic framework to understand the unique susceptibility of preterm infants to both hyper-inflammatory diseases and infections.


Author(s):  
Claudia Matteucci ◽  
Antonella Minutolo ◽  
Emanuela Balestrieri ◽  
Vita Petrone ◽  
Marialaura Fanelli ◽  
...  

Abstract COVID-19 is characterized by immune-mediated lung injury and complex alterations of the immune system, such as lymphopenia and cytokine storm, that have been associated with adverse outcomes underlining a fundamental role of host response in SARS-CoV-2 infection and the pathogenesis of the disease. Thymosin alpha 1 (Tα1) is one of the molecules used in the management of COVID-19, since it is known to restore the homeostasis of the immune system during infections and cancer. Here we captured the interconnected biological processes regulated by Tα1 in CD8+ T cells under inflammatory conditions. Genes associated with cytokine signaling and production were found up-regulated in blood cells from COVID-19 patients and the ex-vivo treatment with Tα1 mitigated cytokines expression and inhibited lymphocytes activation in CD8+ T cell subset specifically, suggesting the potential role of Tα1 in modulating the immune response homeostasis and the cytokine storm in vivo.


2013 ◽  
Vol 21 (1) ◽  
pp. 242-250 ◽  
Author(s):  
Elisabeth Schültke ◽  
Ralf Menk ◽  
Bernd Pinzer ◽  
Alberto Astolfo ◽  
Marco Stampanoni ◽  
...  

Gold nanoparticles are excellent intracellular markers in X-ray imaging. Having shown previously the suitability of gold nanoparticles to detect small groups of cells with the synchrotron-based computed tomography (CT) technique bothex vivoandin vivo, it is now demonstrated that even single-cell resolution can be obtained in the brain at leastex vivo. Working in a small animal model of malignant brain tumour, the image quality obtained with different imaging modalities was compared. To generate the brain tumour, 1 × 105C6 glioma cells were loaded with gold nanoparticles and implanted in the right cerebral hemisphere of an adult rat. Raw data were acquired with absorption X-ray CT followed by a local tomography technique based on synchrotron X-ray absorption yielding single-cell resolution. The reconstructed synchrotron X-ray images were compared with images obtained by small animal magnetic resonance imaging. The presence of gold nanoparticles in the tumour tissue was verified in histological sections.


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