Mucosal-associated invariant T (MAIT) cells are known for their rapid effector functions and antibacterial immune protection. Here, we define the plasticity of interferon-γ (IFN-γ)-producing MAIT1 and interleukin-17A (IL-17A)-producing MAIT17 cell subsets in vivo. Whereas T-bet MAIT1 cells remained stable in all experimental settings, after adoptive transfer or acute or infection, RORγt MAIT17 cells could undergo phenotypic and functional conversion into both RORγtT-bet MAIT1/17 and RORγtT-bet MAIT1 cells.
View Article and Find Full Text PDFBackground: There are limited data assessing the spectrum of systemic sclerosis-associated pulmonary hypertension (PH).
Methods: Data for 912 systemic sclerosis patients assessed between 2000 and 2020 were retrieved from the Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre (ASPIRE) registry and classified based on 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines and multimodality investigations.
Results: Reduction in pulmonary vascular resistance (PVR) diagnostic threshold to >2WU resulted in a 19% increase in precapillary PH diagnoses.
Curr Opin Immunol
June 2024
Single-cell RNA sequencing (scRNAseq) and Variable, Diversity, Joining (VDJ) profiling have improved our understanding of B-cells. Recent scRNAseq-based approaches have led to the discovery of intermediate B-cell states, including preplasma cells and pregerminal centre B-cells, as well as unveiling protective roles for B-cells within tertiary lymphoid structures in respiratory infections and cancers. These studies have improved our understanding of transcriptional and epigenetic control of B-cell development and of atypical and memory B-cell differentiation.
View Article and Find Full Text PDFChildren in malaria-endemic regions can experience repeated Plasmodium infections over short periods of time. Effects of re-infection on multiple co-existing CD4 T cell subsets remain unresolved. Here, we examine antigen-experienced CD4 T cells during re-infection in mice, using scRNA-seq/TCR-seq and spatial transcriptomics.
View Article and Find Full Text PDFNaive CD4 T cells must differentiate in order to orchestrate immunity to Plasmodium, yet understanding of their emerging phenotypes, clonality, spatial distributions, and cellular interactions remains incomplete. Here, we observe that splenic polyclonal CD4 T cells differentiate toward T helper 1 (Th1) and T follicular helper (Tfh)-like states and exhibit rarer phenotypes not elicited among T cell receptor (TCR) transgenic counterparts. TCR clones present at higher frequencies exhibit Th1 skewing, suggesting that variation in major histocompatibility complex class II (MHC-II) interaction influences proliferation and Th1 differentiation.
View Article and Find Full Text PDFWhereas CD4 T cells conventionally mediate antitumor immunity by providing help to CD8 T cells, recent clinical studies have implied an important role for cytotoxic CD4 T cells in cancer immunity. Using an orthotopic melanoma model, we provide a detailed account of antitumoral CD4 T cell responses and their regulation by major histocompatibility complex class II (MHC II) in the skin. Intravital imaging revealed prominent interactions of CD4 T cells with tumor debris-laden MHC II host antigen-presenting cells that accumulated around tumor cell nests, although direct recognition of MHC II melanoma cells alone could also promote CD4 T cell control.
View Article and Find Full Text PDFBacterial urinary tract infections (UTIs) are both common and exhibit high recurrence rates in women. UTI healthcare costs are increasing due to the rise of multidrug-resistant (MDR) bacteria, necessitating alternative approaches for infection control. Here, we directly observed host adaptive immune responses in acute UTI.
View Article and Find Full Text PDFMaturation rates of malaria parasites within red blood cells (RBCs) can be influenced by host nutrient status and circadian rhythm; whether host inflammatory responses can also influence maturation remains less clear. Here, we observed that systemic host inflammation induced in mice by an innate immune stimulus, lipopolysaccharide (LPS), or by ongoing acute infection, slowed the progression of a single cohort of parasites from one generation of RBC to the next. Importantly, plasma from LPS-conditioned or acutely infected mice directly inhibited parasite maturation during in vitro culture, which was not rescued by supplementation, suggesting the emergence of inhibitory factors in plasma.
View Article and Find Full Text PDFLanguage is a method by which individuals express their thoughts. Each language has its own alphabet and numbers. Oral and written communication are both effective means of human interaction.
View Article and Find Full Text PDFProgrammed cell death 1 (PD1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4) suppress CD4 T cell activation and may promote latent HIV infection. By performing leukapheresis (n = 21) and lymph node biopsies (n = 8) in people with HIV on antiretroviral therapy (ART) and sorting memory CD4 T cells into subsets based on PD1/CTLA4 expression, we investigate the role of PD1 and CTLA 4 in HIV persistence. We show that double-positive (PD1CTLA4) cells in blood contain more HIV DNA compared with double-negative (PD1CTLA4) cells but still have a lower proportion of cells producing multiply spliced HIV RNA after stimulation as well as reduced upregulation of T cell activation and proliferation markers.
View Article and Find Full Text PDFSingle-cell transcriptomics (scRNA-seq) has become essential for biomedical research over the past decade, particularly in developmental biology, cancer, immunology, and neuroscience. Most commercially available scRNA-seq protocols require cells to be recovered intact and viable from tissue. This has precluded many cell types from study and largely destroys the spatial context that could otherwise inform analyses of cell identity and function.
View Article and Find Full Text PDFBackground: Artemisinin-based combination therapy (ACT) has been a mainstay for malaria prevention and treatment. However, emergence of drug resistance has incentivised development of new drugs. Defining the kinetics with which circulating parasitized red blood cells (pRBC) are lost after drug treatment, referred to as the "parasite clearance curve", has been critical for assessing drug efficacy; yet underlying mechanisms remain partly unresolved.
View Article and Find Full Text PDFThe spleen is a compartmentalized organ that serves as a blood filter and safeguard of systemic immune surveillance. Labyrinthine networks of fibroblastic stromal cells construct complex niches within the white pulp and red pulp that are important for tissue homeostasis and immune activation. However, the identity and roles of the global splenic fibroblastic stromal cells in homeostasis and immune responses are poorly defined.
View Article and Find Full Text PDFThe clinical presentation of COVID-19 is varied: from asymptomatic to severe neurological syndrome like stroke can happen. Guillain-Barré syndrome (GBS) as a manifestation of COVID-19 is not very common. GBS is an acute immune-mediated polyradiculoneuropathy that usually occurs following previous exposure to infection.
View Article and Find Full Text PDFObjectives: This study assessed the protective effect of calcium dobesilate against contrast-induced nephropathy (CIN) after coronary angiography (CAG) or percutaneous coronary intervention (PCI) in patients with diabetes and chronic kidney disease (CKD).
Methods: A total of 130 patients with diabetes and CKD estimated glomerular filtration rate: 30-90 mL/min/1.73m2 were enrolled and included in the analysis.
Pulmonary hypertension (PH) commonly affects patients with systemic sclerosis (SSc) and is associated with significant morbidity and increased mortality. PH is a heterogenous condition and several different forms can be associated with SSc, including pulmonary arterial hypertension (PAH) resulting from a pulmonary arterial vasculopathy, PH due to left heart disease and PH due to interstitial lung disease. The incidence of pulmonary veno-occlusive disease is also increased.
View Article and Find Full Text PDFMucosal-associated Invariant T (MAIT) cells are recognized for their antibacterial functions. The protective capacity of MAIT cells has been demonstrated in murine models of local infection, including in the lungs. Here we show that during systemic infection of mice with Francisella tularensis live vaccine strain results in evident MAIT cell expansion in the liver, lungs, kidney and spleen and peripheral blood.
View Article and Find Full Text PDFRaynaud's phenomenon (RP) is a common vasospastic condition which affects ~5% of the general population. The majority of individuals have primary RP; however, Raynaud's can also occur secondary to a broad range of underlying medical conditions and drug therapies. RP is a cardinal feature in patients with systemic sclerosis and is often the earliest symptom of the disease.
View Article and Find Full Text PDFThe dynamics of CD4 T cell memory development remain to be examined at genome scale. In malaria-endemic regions, antimalarial chemoprevention protects long after its cessation and associates with effects on CD4 T cells. We applied single-cell RNA sequencing and computational modelling to track memory development during Plasmodium infection and treatment.
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