BACKGROUND: Existing studies have presented limited and disparate findings on the nexus between immune cells, plasma metabolites, and metabolic dysfunction-associated steatotic liver disease (MASLD). The aim of this study was to investigate the causal relationship between immune cells and MASLD. Additionally, we aimed to identify and quantify the potential mediating role of metabolites.
METHODS: A Mendelian randomization (MR) analysis was conducted using two samples of pooled data from genome-wide association studies on MASLD that included 2568 patients and 409,613 control individuals. Additionally, a mediated MR study was employed to quantify the metabolite-mediated immune cell effects on MASLD.
RESULTS: In this study, eight immunophenotypes were linked to the risk of MASLD, and thirty-five metabolites/metabolite ratios were linked to the occurrence of MASLD. Furthermore, a total of six combinations of immunophenotypic and metabolic factors demonstrated effects on the occurrence of MASLD, although the mediating effects of metabolites were not significant.
CONCLUSIONS: Our study demonstrated that certain immunophenotypes and metabolite/metabolite ratios have independent causal relationships with MASLD. Furthermore, we identified specific metabolites/metabolite ratios that are associated with an increased risk of MASLD. However, their mediating role in the causal association between immunophenotypes and MASLD was not significant. It is important to consider immune and metabolic disorders among patients with MASLD in clinical practice.

Mounting evidence indicates that the immune response triggered by brain disorders (e.g., brain ischemia and autoimmune encephalomyelitis) occurs not only in the brain, but also in the skull. A key step toward analyzing changes in immune cell populations in both the brain and skull bone marrow after brain damage (e.g., stroke) is to obtain sufficient numbers of high-quality immune cells for downstream analyses. Here, two optimized protocols are provided for isolating immune cells from the brain and skull bone marrow. The advantages of both protocols are reflected in their simplicity, speed, and efficacy in yielding a large quantity of viable immune cells. These cells may be suitable for a range of downstream applications, such as cell sorting, flow cytometry, and transcriptomic analysis. To demonstrate the effectiveness of the protocols, immunophenotyping experiments were performed on stroke brains and normal brain skull bone marrow using flow cytometry analysis, and the results aligned with findings from published studies.

Loss of function mutations in Diaphanous related formin 1 (DIAPH1) are associated with seizures, cortical blindness, and microcephaly syndrome (SCBMS) and are recently linked to combined immunodeficiency. However, the extent of defects in T and innate lymphoid cells (ILCs) remain unexplored. Herein, we characterized the primary T, natural killer (NK) and helper ILCs of six patients carrying two novel loss of function mutation in DIAPH1 and Jurkat cells after DIAPH1 knockdown. Mutations were identified by whole exome sequencing. T-cell immunophenotyping, proliferation, migration, cytokine signaling, survival, and NK cell cytotoxicity were studied via flow cytometry-based assays, confocal microscopy, and real-time qPCR. CD4+ T cell proteome was analyzed by mass spectrometry. p.R351* and p.R322*variants led to a significant reduction in the DIAPH1 mRNA and protein levels. DIAPH1-deficient T cells showed proliferation, activation, as well as TCR-mediated signaling defects. DIAPH1-deficient PBMCs also displayed impaired transwell migration, defective STAT5 phosphorylation in response to IL-2, IL-7 and IL-15. In vitro generation/expansion of Treg cells from naïve T cells was significantly reduced. shRNA-mediated silencing of DIAPH1 in Jurkat cells reduced DIAPH1 protein level and inhibited T cell proliferation and IL-2/STAT5 axis. Additionally, NK cells from patients had diminished cytotoxic activity, function and IL-2/STAT5 axis. Lastly, DIAPH1-deficient patients\' peripheral blood contained dramatically reduced numbers of all helper ILC subsets. DIAPH1 deficiency results in major functional defects in T, NK cells and helper ILCs underlining the critical role of formin DIAPH1 in the biology of those cell subsets.

Muscle-derived mesenchymal stromal cells (mdMSCs) hold great promise in regenerative medicine due to their immunomodulatory properties, multipotent differentiation capacity and ease of collection. However, traditional in vitro expansion methods use fetal bovine serum (FBS) and have numerous limitations including ethical concerns, batch-to-batch variability, immunogenicity, xenogenic contamination and regulatory compliance issues. This study investigates the use of 10% equine platelet lysate (ePL) obtained by plasmapheresis as a substitute for FBS in the culture of mdMSCs in innovative 2D and 3D models. Using muscle microbiopsies as the primary cell source in both models showed promising results. Initial investigations indicated that small variations in heparin concentration in 2D cultures strongly influenced medium coagulation with an optimal proliferation observed at final heparin concentrations of 1.44 IU/mL. The two novel models investigated showed that expansion of mdMSCs is achievable. At the end of expansion, the 3D model revealed a higher total number of cells harvested (64.60 ± 5.32 million) compared to the 2D culture (57.20 ± 7.66 million). Trilineage differentiation assays confirmed the multipotency (osteoblasts, chondroblasts and adipocytes) of the mdMSCs generated in both models with no significant difference observed. Immunophenotyping confirmed the expression of the mesenchymal stem cell (MSC) markers CD-90 and CD-44, with low expression of CD-45 and MHCII markers for mdMSCs derived from the two models. The generated mdMSCs also had great immunomodulatory properties. Specific immunological extraction followed by enzymatic detection (SIEFED) analysis demonstrated that mdMSCs from both models inhibited myeloperoxidase (MPO) activity in a strong dose-dependent manner. Moreover, they were also able to reduce reactive oxygen species (ROS) activity, with mdMSCs from the 3D model showing significantly higher dose-dependent inhibition compared to the 2D model. These results highlighted for the first time the feasibility and efficacy of using 10% ePL for mdMSC expansion in novel 2D and 3D approaches and also that mdMSCs have strong immunomodulatory properties that can be exploited to advance the field of regenerative medicine and cell therapy instead of using FBS with all its drawbacks.

UNASSIGNED: The clinical presentation of Community-acquired pneumonia (CAP) in hospitalized patients exhibits heterogeneity. Inflammation and immune responses play significant roles in CAP development. However, research on immunophenotypes in CAP patients is limited, with few machine learning (ML) models analyzing immune indicators.
UNASSIGNED: A retrospective cohort study was conducted at Xinhua Hospital, affiliated with Shanghai Jiaotong University. Patients meeting predefined criteria were included and unsupervised clustering was used to identify phenotypes. Patients with distinct phenotypes were also compared in different outcomes. By machine learning methods, we comprehensively assess the disease severity of CAP patients.
UNASSIGNED: A total of 1156 CAP patients were included in this research. In the training cohort (n=809), we identified three immune phenotypes among patients: Phenotype A (42.0%), Phenotype B (40.2%), and Phenotype C (17.8%), with Phenotype C corresponding to more severe disease. Similar results can be observed in the validation cohort. The optimal prognostic model, SuperPC, achieved the highest average C-index of 0.859. For predicting CAP severity, the random forest model was highly accurate, with C-index of 0.998 and 0.794 in training and validation cohorts, respectively.
UNASSIGNED: CAP patients can be categorized into three distinct immune phenotypes, each with prognostic relevance. Machine learning exhibits potential in predicting mortality and disease severity in CAP patients by leveraging clinical immunological data. Further external validation studies are crucial to confirm applicability.

This panel was designed to characterize the immune cell landscape in the mouse tumor microenvironment as well as mouse lymphoid tissues (e.g., spleen). As an example, using the MC-38 mouse syngeneic tumor model, we demonstrated that we could measure the frequency and characterize the functional status of CD4 T cells, CD8 T cells, regulatory T cells, NK cells, B cells, macrophages, granulocytes, monocytes, and dendritic cells. This panel is especially useful for understanding the immune landscape in \"cold\" preclinical tumor models with very low immune cell infiltration and for investigating how therapeutic treatments may modulate the immune landscape.

Human mesenchymal stromal cells (MSCs) have gained significant interest as cell-based therapeutics for organ restoration in the field of regenerative medicine. More recently, substantial attention has been directed toward cell-free therapy, achieved through the utilization of soluble factors possessing trophic and immunomodulatory properties present in the MSC secretome. This collection of soluble factors can be found either freely in the secretome or packed within its vesicular fraction, known as extracellular vesicles (EVs). MSCs can be derived from various tissue sources, each involving different extraction methods and yielding varying cell amounts. In this study, we describe a nonenzymatic procedure for a straightforward isolation of MSCs from the fetal dermis and the adult dermis. The results demonstrate the isolation of a cell population with a uniform MSC immunophenotype from the earliest passages (approximately 90% positive for the classical MSC markers CD90, CD105, and CD73, while negative for the hematopoietic markers CD34 and CD45, as well as HLA-DR). Additionally, we describe the procedures for cell expansion, banking, and secretome collection.

BACKGROUND: Crohn\'s disease (CD) significantly affects patients\' well-being and is influenced by stress and lifestyle factors, highlighting the importance of improving quality of life in CD management. An imbalance between pro- and anti-inflammatory CD4+ T cell responses is a key factor in CD, and stress has been shown to alter the function of CD4+ T cells. Therefore, this study aimed to evaluate the effect of a mind-body medicine stress management and lifestyle modification (MBM) program on the CD4+ T cell profile in CD patients.
METHODS: Circulating CD4+ T cells from CD patients were analyzed by flow cytometry following the MBM program. Patients were randomly assigned to either a guided intervention group (IG) or a self-guided waitlist control group (CG) over a 9-month trial and compared with healthy blood donors.
RESULTS: Lifestyle intervention reduced regulatory T cell (Treg) frequencies in the blood of CD patients. Notably, we observed a significant correlation between the quality of life improvement and Treg frequencies in the IG but not in the CG. Furthermore, differential activation and expression of the gut-homing molecules G protein-coupled receptor 15 and CCR9 on circulating Tregs and CD4+ effector T cells were detected in both the IG and CG.
CONCLUSIONS: The MBM program, whether guided or self-directed, has the potential to restore the CD4+ T cell profile of CD patients to levels comparable to healthy blood donors. Lifestyle interventions may benefit CD progression, symptoms, and immunological status, but further analysis is needed to substantiate these findings and to fully understand their clinical implications. (ClinicalTrials.gov: NCT05182645).
Stress significantly impacts Crohn’s disease. Lifestyle intervention reduces circulating regulatory T cell frequencies, correlates with improved patient quality of life, holds promise for restoring circulating CD4+ T cell profiles, and improves patient care by integrating stress management.

Prior research has identified associations between immune cells and aplastic anaemia (AA); however, the causal relationships between them have not been conclusively established. A two-sample Mendelian randomisation analysis was conducted to investigate the causal link between 731 immune cell signatures and AA risk using publicly available genetic data. Four types of immune signatures, including relative cell, absolute cell (AC), median fluorescence intensities and morphological parameters, were considered sensitivity analyses were also performed to verify the robustness of the results and assess potential issues such as heterogeneity and horizontal pleiotropy. Following multiple test adjustments using the False Discovery Rate (FDR) method, no statistically significant impact of any immunophenotype on AA was observed. However, twelve immunophenotypes exhibited a significant correlation with AA without FDR correction (p of IVW < 0.01), of which eight were harmful to AA: CD127- CD8br %T cell (Treg panel), CD25 on IgD + CD38dim (B cell panel), CD38 on naive-mature B cell (B cell panel), CD39 + resting Treg % CD4 Treg (Treg panel), CD39 + secreting Treg AC (Treg panel), CD8 on CD28 + CD45RA- CD8br (Treg panel), HLA DR + NK AC (TBNK panel), Naive DN (CD4-CD8-) AC (Maturation stages of T cell panel); and four were protective to AA: CD86 on CD62L + myeloid DC (cDC panel), DC AC (cDC panel), DN (CD4-CD8-) NKT %T cell (TBNK panel), and TD CD4 + AC (Maturation stages of T cell panel). The results of this study demonstrate a close link between immune cells and AA by genetic means, thereby improving the current understanding of the interaction between immune cells and AA risk and providing guidance for future clinical research.

OBJECTIVE: Autoantibodies and autoimmune diseases after SARS-CoV-2 infection are widely reported. Given evolving variants, milder infections, and increasing population vaccination, we hypothesized that SARS-CoV-2 infection earlier in the pandemic would be associated with more autoimmune connective tissue disease (CTD) symptoms and immunologic abnormalities.
METHODS: Patients ≥18 years old with COVID-19 3/1/2020-8/15/2022 completed the CTD Screening Questionnaire and were tested for 27 autoimmune serologies, SARS-CoV-2 serologies, cell-bound complement activation products (CB-CAPs), and T and B lymphocyte immunophenotypes by flow cytometry. We assessed relationships between symptoms, serologies, and immunophenotypes in earlier (3/1/2020-1/31/2021) vs. later (2/1/2021-8/15/2022) periods, with different predominating SARS-CoV-2 viruses.
RESULTS: 57 subjects had earlier and 23 had later pandemic COVID-19. 35 % of earlier vs. 17 % of later pandemic patients had CTD symptoms (p 0.18). More patients were antinuclear antibody (ANA) positive (44 % vs. 13 %, p 0.01) and had lupus anticoagulant (11 % vs. 4 %, p 0.67). After adjustment for age, race, and sex, earlier (vs. later) COVID-19 was associated with increased ANA positivity (OR 4.60, 95%CI 1.17, 18.15). No subjects had positive CB-CAPs. T and B cell immunophenotypes and SARS-CoV-2 serologies did not differ by group. In heatmap analyses, higher autoantibody variety was seen among those with infection in the early pandemic.
CONCLUSIONS: In this sample, having COVID-19 infection in the earlier (pre-2/1/2021) vs. later pandemic was associated with more CTD symptoms, ANA positivity, and autoantibody reactivities. Earlier SARS-CoV-2 variants circulating in a less vaccinated population with less natural immunity may have been more immunogenic.