Human Adipose Tissue-Derived Mesenchymal Stem Cells Abrogate Plasmablast Formation and Induce Regulatory B Cells Independently of T Helper Cells

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Precision and linearity targets for validation of an IFNγ ELISPOT, cytokine flow cytometry, and tetramer assay using CMV peptides

<p>Abstract</p> <p>Background</p> <p>Single-cell assays of immune function are increasingly used to monitor T cell responses in immunotherapy clinical trials. Standardization and validation of such assays are therefore important to interpretation of the clinical trial data. Here we assess the levels of intra-assay, inter-assay, and inter-operator precision, as well as linearity, of CD8+ T cell IFNγ-based ELISPOT and cytokine flow cytometry (CFC), as well as tetramer assays.</p> <p>Results</p> <p>Precision was measured in cryopreserved PBMC with a low, medium, or high response level to a CMV pp65 peptide or peptide mixture. Intra-assay precision was assessed using 6 replicates per assay; inter-assay precision was assessed by performing 8 assays on different days; and inter-operator precision was assessed using 3 different operators working on the same day. Percent CV values ranged from 4% to 133% depending upon the assay and response level. Linearity was measured by diluting PBMC from a high responder into PBMC from a non-responder, and yielded R²values from 0.85 to 0.99 depending upon the assay and antigen.</p> <p>Conclusion</p> <p>These data provide target values for precision and linearity of single-cell assays for those wishing to validate these assays in their own laboratories. They also allow for comparison of the precision and linearity of ELISPOT, CFC, and tetramer across a range of response levels. There was a trend toward tetramer assays showing the highest precision, followed closely by CFC, and then ELISPOT; while all three assays had similar linearity. These findings are contingent upon the use of optimized protocols for each assay.</p

Impact of cryopreservation on tetramer, cytokine flow cytometry, and ELISPOT

BACKGROUND: Cryopreservation of PBMC and/or overnight shipping of samples are required for many clinical trials, despite their potentially adverse effects upon immune monitoring assays such as MHC-peptide tetramer staining, cytokine flow cytometry (CFC), and ELISPOT. In this study, we compared the performance of these assays on leukapheresed PBMC shipped overnight in medium versus cryopreserved PBMC from matched donors. RESULTS: Using CMV pp65 peptide pool stimulation or pp65 HLA-A2 tetramer staining, there was significant correlation between shipped and cryopreserved samples for each assay (p ≤ 0.001). The differences in response magnitude between cryopreserved and shipped PBMC specimens were not significant for most antigens and assays. There was significant correlation between CFC and ELISPOT assay using pp65 peptide pool stimulation, in both shipped and cryopreserved samples (p ≤ 0.001). Strong correlation was observed between CFC (using HLA-A2-restricted pp65 peptide stimulation) and tetramer staining (p < 0.001). Roughly similar sensitivity and specificity were observed between the three assays and between shipped and cryopreserved samples for each assay. CONCLUSION: We conclude that all three assays show concordant results on shipped versus cryopreserved specimens, when using a peptide-based readout. The assays are also concordant with each other in pair wise comparisons using equivalent antigen systems

A “Crossomics” Study Analysing Variability of Different Components in Peripheral Blood of Healthy Caucasoid Individuals

Background: Different immunotherapy approaches for the treatment of cancer and autoimmune diseases are being developed and tested in clinical studies worldwide. Their resulting complex experimental data should be properly evaluated, therefore reliable normal healthy control baseline values are indispensable. Methodology/Principal Findings: To assess intra- and inter-individual variability of various biomarkers, peripheral blood of 16 age and gender equilibrated healthy volunteers was sampled on 3 different days within a period of one month. Complex "crossomics'' analyses of plasma metabolite profiles, antibody concentrations and lymphocyte subset counts as well as whole genome expression profiling in CD4(+)T and NK cells were performed. Some of the observed age, gender and BMI dependences are in agreement with the existing knowledge, like negative correlation between sex hormone levels and age or BMI related increase in lipids and soluble sugars. Thus we can assume that the distribution of all 39.743 analysed markers is well representing the normal Caucasoid population. All lymphocyte subsets, 20% of metabolites and less than 10% of genes, were identified as highly variable in our dataset. Conclusions/Significance: Our study shows that the intra- individual variability was at least two-fold lower compared to the inter-individual one at all investigated levels, showing the importance of personalised medicine approach from yet another perspective

UNITY : a low-field magnetic resonance neuroimaging initiative to characterize neurodevelopment in low and middle-income settings

DATA AVAILABILITY : Data collected as part of the UNITY network will be made available to researchers from the academic communities at varying levels of granularity depending on site-specific IRB approvals. For some sites, full access to individual raw and processed data will be provided, whilst for others, owing to national policies (e.g., those located in India) may only be able to provide de-identified composite values (e.g., regional volumes, mean relaxometry measures, etc.). The Bill & Melinda Gates Foundation is committed to open access and broad data availability as permitted.Measures of physical growth, such as weight and height have long been the predominant outcomes for monitoring child health and evaluating interventional outcomes in public health studies, including those that may impact neurodevelopment. While physical growth generally reflects overall health and nutritional status, it lacks sensitivity and specificity to brain growth and developing cognitive skills and abilities. Psychometric tools, e.g., the Bayley Scales of Infant and Toddler Development, may afford more direct assessment of cognitive development but they require language translation, cultural adaptation, and population norming. Further, they are not always reliable predictors of future outcomes when assessed within the first 12–18 months of a child’s life. Neuroimaging may provide more objective, sensitive, and predictive measures of neurodevelopment but tools such as magnetic resonance (MR) imaging are not readily available in many low and middle-income countries (LMICs). MRI systems that operate at lower magnetic fields (< 100mT) may offer increased accessibility, but their use for global health studies remains nascent. The UNITY project is envisaged as a global partnership to advance neuroimaging in global health studies. Here we describe the UNITY project, its goals, methods, operating procedures, and expected outcomes in characterizing neurodevelopment in sub-Saharan Africa and South Asia.The Bill & Melinda Gates Foundation, the NIHR Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, and through a Wellcome Trust Investigator Award and a Wellcome Trust Strategic Award.https://www.elsevier.com/locate/dcnhj2024Biochemistry, Genetics and Microbiology (BGM)ImmunologyPaediatrics and Child HealthRadiologySDG-03:Good heatlh and well-beingSDG-17:Partnerships for the goal

Safety and efficacy of a kaolin-impregnated hemostatic gauze in cardiac surgery: A randomized trialCentral MessagePerspective

Objective: A kaolin-based nonresorbable hemostatic gauze, QuikClot Control+, has demonstrated effective hemostasis and safety when used for severe/life-threatening (grade 3/4) internal organ space bleeding. We evaluated the efficacy and safety of this gauze for mild to moderate (grade 1-2) bleeding in cardiac surgery compared with control gauze. Methods: This was a randomized, controlled, single-blinded study of patients who underwent cardiac surgery between June 2020 and September 2021 across 7 sites with 231 subjects randomized 2:1 to QuikClot Control+ or control. The primary efficacy end point was hemostasis rate (ie, subjects achieving grade 0 bleed) through up to 10 minutes of bleeding site application, assessed using a semiquantitative validated bleeding severity scale tool. The secondary efficacy end point was the proportion of subjects achieving hemostasis at 5 and 10 minutes. Adverse events, assessed up to 30 days postsurgery, were compared between arms. Results: The predominant procedure was coronary artery bypass grafting, and 69.7% and 29.4% were sternal edge and surgical site (suture line)/other bleeds, respectively. Of the QuikClot Control+ subjects, 121 of 153 (79.1%) achieved hemostasis within 5 minutes, compared with 45 of 78 (58.4%) controls (P < .001). At 10 minutes, 137 of 153 patients (89.8%) achieved hemostasis compared with 52 of 78 controls (68.4%) (P < .001). At 5 and 10 minutes, hemostasis was achieved in 20.7% and 21.4% more QuikClot Control+ subjects, respectively, compared with controls (P < .001). There were no significant differences in safety or adverse events between treatment arms. Conclusions: QuikClot Control+ demonstrated superior performance in achieving hemostasis for mild to moderate cardiac surgery bleeding compared with control gauze. The proportion of subjects achieving hemostasis was more than 20% higher in QuikClot Control+ subjects at both timepoints compared with controls, with no significant difference in safety outcomes