The Human Cell Atlas is a large international collaborative effort to map all cell types of the human body. Single-cell RNA sequencing can generate high-quality data for the delivery of such an ...atlas. However, delays between fresh sample collection and processing may lead to poor data and difficulties in experimental design.
This study assesses the effect of cold storage on fresh healthy spleen, esophagus, and lung from ≥ 5 donors over 72 h. We collect 240,000 high-quality single-cell transcriptomes with detailed cell type annotations and whole genome sequences of donors, enabling future eQTL studies. Our data provide a valuable resource for the study of these 3 organs and will allow cross-organ comparison of cell types. We see little effect of cold ischemic time on cell yield, total number of reads per cell, and other quality control metrics in any of the tissues within the first 24 h. However, we observe a decrease in the proportions of lung T cells at 72 h, higher percentage of mitochondrial reads, and increased contamination by background ambient RNA reads in the 72-h samples in the spleen, which is cell type specific.
In conclusion, we present robust protocols for tissue preservation for up to 24 h prior to scRNA-seq analysis. This greatly facilitates the logistics of sample collection for Human Cell Atlas or clinical studies since it increases the time frames for sample processing.
There has been increasing interest in the role played by B cells, plasma cells and their associated antibody in the immune response to an allograft, driven by the need to undertake ...antibody‐incompatible transplantation and evidence suggesting that B cells play a role in acute cellular rejection and in acute and chronic antibody‐mediated rejection. A number of immunosuppressive agents have emerged which target B cells, plasma cells and/or antibody, for example, the B cell‐depleting CD20 antibody rituximab. This review describes recent developments in the use of such agents, our understanding of the role of B cells in alloimmunity and the application of this knowledge toward novel therapies in transplantation. It also considers the evidence to date suggesting that B cells may act as regulators of an alloimmune response. Thus, future attempts to target B cells will need to address the problem of how to inhibit effector B cells, while enhancing those with regulatory capacity.
This article reviews recent advances in the field of B cell biology, including data suggesting a regulatory role for B cells, and discusses the potential implications for therapeutic strategies in transplantation.
IgG antibodies cause inflammation and organ damage in autoimmune diseases such as systemic lupus erythematosus (SLE). We investigated the metabolic profile of macrophages isolated from inflamed ...tissues in immune complex (IC)-associated diseases, including SLE and rheumatoid arthritis, and following IgG Fcγ receptor cross-linking. We found that human and mouse macrophages undergo a switch to glycolysis in response to IgG IC stimulation, mirroring macrophage metabolic changes in inflamed tissue in vivo. This metabolic reprogramming was required to generate a number of proinflammatory mediators, including IL-1β, and was dependent on mTOR and hypoxia-inducible factor (HIF)1α. Inhibition of glycolysis, or genetic depletion of HIF1α, attenuated IgG IC-induced activation of macrophages in vitro, including primary human kidney macrophages. In vivo, glycolysis inhibition led to a reduction in kidney macrophage IL-1β and reduced neutrophil recruitment in a murine model of antibody-mediated nephritis. Together, our data reveal the molecular mechanisms underpinning FcγR-mediated metabolic reprogramming in macrophages and suggest a therapeutic strategy for autoantibody-induced inflammation, including lupus nephritis.
Despite their crucial role in health and disease, our knowledge of immune cells within human tissues remains limited. We surveyed the immune compartment of 16 tissues from 12 adult donors by ...single-cell RNA sequencing and VDJ sequencing generating a dataset of ~360,000 cells. To systematically resolve immune cell heterogeneity across tissues, we developed CellTypist, a machine learning tool for rapid and precise cell type annotation. Using this approach, combined with detailed curation, we determined the tissue distribution of finely phenotyped immune cell types, revealing hitherto unappreciated tissue-specific features and clonal architecture of T and B cells. Our multitissue approach lays the foundation for identifying highly resolved immune cell types by leveraging a common reference dataset, tissue-integrated expression analysis, and antigen receptor sequencing.
Immune cell dysfunction within the tumor microenvironment (TME) undermines the control of cancer progression. Established tumors contain phenotypically distinct, tumor-specific natural killer (NK) ...cells; however, the temporal dynamics, mechanistic underpinning and functional significance of the NK cell compartment remains incompletely understood. Here, we use photo-labeling, combined with longitudinal transcriptomic and cellular analyses, to interrogate the fate of intratumoral NK cells. We reveal that NK cells rapidly lose effector functions and adopt a distinct phenotypic state with features associated with tissue residency. NK cell depletion from established tumors did not alter tumor growth, indicating that intratumoral NK cells cease to actively contribute to anti-tumor responses. IL-15 administration prevented loss of function and improved tumor control, generating intratumoral NK cells with both tissue-residency characteristics and enhanced effector function. Collectively, our data reveals the fate of NK cells after recruitment into tumors and provides insight into how their function may be revived.
Donor‐specific HLA alloantibodies may cause acute and chronic antibody‐mediated rejection (AMR) and significantly compromise allograft survival. The clinical relevance of antibodies directed against ...some HLA class II antigens, particularly HLA‐DP, is less clear with conflicting reports on their pathogenicity. We report two patients with high levels of pretransplant donor‐specific HLA‐DP antibodies who subsequently developed recurrent acute AMR and graft failure. In both cases, there were no other donor‐specific HLA alloantibodies, suggesting that the HLA‐DP‐specific antibodies may be directly pathogenic.
The authors present two case reports in which isolated donor‐specific HLA‐DP antibodies were associated with recurrent antibody‐mediated rejection and allograft loss following renal transplantation.
Pancreatic allograft thrombosis (PAT) remains the leading cause of nonimmunologic graft failure. Here, we propose a new computed tomography (CT) grading system of PAT to identify risk factors for ...allograft loss and outline a management algorithm by retrospective review of consecutive pancreatic transplantations between 2009 and 2014. Triple‐phase CT scans were graded independently by 2 radiologists as grade 0, no thrombosis; grade 1, peripheral thrombosis; grade 2, intermediate non‐occlusive thrombosis; and grade 3, central occlusive thrombosis. Twenty‐four (23.3%) of 103 recipients were diagnosed with PAT (including grade 1). Three (2.9%) grafts were lost due to portal vein thrombosis. On multivariate analysis, pancreas after simultaneous pancreas–kidney transplantation/solitary pancreatic transplantation, acute rejection, and CT findings of peripancreatic edema and/or inflammatory change were significant risk factors for PAT. Retrospective review of CT scans revealed more grade 1 and 2 thromboses than were initially reported. There was no significant difference in graft or patient survival, postoperative stay, or morbidity of recipients with grade 1 or 2 thrombosis who were or were not anticoagulated. Our data suggest that therapeutic anticoagulation is not necessary for grade 1 and 2 arterial and grade 1 venous thrombosis. The proposed grading system can assist clinicians in decision‐making and provide standardized reporting for future studies.
The Cambridge Pancreatic Allograft Thrombosis grading system may be used to standardize reports of thrombosis, identify patients who would benefit from therapeutic anticoagulation, provide prognostic information, and allow better comparison of reports from different centers for improved understanding and management of this common condition.
The author comments on a randomized controlled trial by van den Hoogen et al (page 407) in which a single dose of rituximab at the time of transplantation was associated with a lower frequency of T ...cell‐mediated rejection in patients with a previous transplant or with panel reactive antibodies of >6%.
B cell modulation in transplantation Clatworthy, M. R.
Clinical and experimental immunology,
December 2014, 2014-Dec, 20141201, Letnik:
178, Številka:
S1
Journal Article
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