CD4+ T cell activation distinguishes response to anti-PD-L1+anti-CTLA4 therapy from anti-PD-L1 monotherapy.

Cancer patients often receive a combination of antibodies targeting programmed death-ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen-4 (CTLA4). We conducted a window-of-opportunity study in head and neck squamous cell carcinoma (HNSCC) to examine the contribution of anti-CTLA4 to anti-PD-L1 therapy. Single-cell profiling of on- versus pre-treatment biopsies identified T cell expansion as an early response marker. In tumors, anti-PD-L1 triggered the expansion of mostly CD8+ T cells, whereas combination therapy expanded both CD4+ and CD8+ T cells. Such CD4+ T cells exhibited an activated T helper 1 (Th1) phenotype. CD4+ and CD8+ T cells co-localized with and were surrounded by dendritic cells expressing T cell homing factors or antibody-producing plasma cells. T cell receptor tracing suggests that anti-CTLA4, but not anti-PD-L1, triggers the trafficking of CD4+ naive/central-memory T cells from tumor-draining lymph nodes (tdLNs), via blood, to the tumor wherein T cells acquire a Th1 phenotype. Thus, CD4+ T cell activation and recruitment from tdLNs are hallmarks of early response to anti-PD-L1 plus anti-CTLA4 in HNSCC.

Functional filter for whole-genome sequencing data identifies HHT and stress-associated non-coding SMAD4 polyadenylation site variants >5 kb from coding DNA.

Despite whole-genome sequencing (WGS), many cases of single-gene disorders remain unsolved, impeding diagnosis and preventative care for people whose disease-causing variants escape detection. Since early WGS data analytic steps prioritize protein-coding sequences, to simultaneously prioritize variants in non-coding regions rich in transcribed and critical regulatory sequences, we developed GROFFFY, an analytic tool that integrates coordinates for regions with experimental evidence of functionality. Applied to WGS data from solved and unsolved hereditary hemorrhagic telangiectasia (HHT) recruits to the 100,000 Genomes Project, GROFFFY-based filtration reduced the mean number of variants/DNA from 4,867,167 to 21,486, without deleting disease-causal variants. In three unsolved cases (two related), GROFFFY identified ultra-rare deletions within the 3' untranslated region (UTR) of the tumor suppressor SMAD4, where germline loss-of-function alleles cause combined HHT and colonic polyposis (MIM: 175050). Sited >5.4 kb distal to coding DNA, the deletions did not modify or generate microRNA binding sites, but instead disrupted the sequence context of the final cleavage and polyadenylation site necessary for protein production: By iFoldRNA, an AAUAAA-adjacent 16-nucleotide deletion brought the cleavage site into inaccessible neighboring secondary structures, while a 4-nucleotide deletion unfolded the downstream RNA polymerase II roadblock. SMAD4 RNA expression differed to control-derived RNA from resting and cycloheximide-stressed peripheral blood mononuclear cells. Patterns predicted the mutational site for an unrelated HHT/polyposis-affected individual, where a complex insertion was subsequently identified. In conclusion, we describe a functional rare variant type that impacts regulatory systems based on RNA polyadenylation. Extension of coding sequence-focused gene panels is required to capture these variants.

Hsa-miR-134-5p predicts cardiovascular risk in circulating mononuclear cells and improves angiogenic action of senescent endothelial progenitor cells.

This research explores the role of microRNA in senescence of human endothelial progenitor cells (EPCs) induced by replication. Hsa-miR-134-5p was found up-regulated in senescent EPCs where overexpression improved angiogenic activity. Hsa-miR-134-5p, which targeted transforming growth factor ß-activated kinase 1-binding protein 1 (TAB1) gene, down-regulated TAB1 protein, and inhibited phosphorylation of p38 mitogen-activated protein kinase (p38) in hsa-miR-134-5p-overexpressed senescent EPCs. Treatment with siRNA specific to TAB1 (TAB1si) down-regulated TAB1 protein and subsequently inhibited p38 activation in senescent EPCs. Treatment with TAB1si and p38 inhibitor, respectively, showed angiogenic improvement. In parallel, transforming growth factor Beta 1 (TGF-ß1) was down-regulated in hsa-miR-134-5p-overexpressed senescent EPCs and addition of TGF-ß1 suppressed the angiogenic improvement. Analysis of peripheral blood mononuclear cells (PBMCs) disclosed expression levels of hsa-miR-134-5p altered in adult life, reaching a peak before 65 years, and then falling in advanced age. Calculation of the Framingham risk score showed the score inversely correlates with the hsa-miR-134-5p expression level. In summary, hsa-miR-134-5p is involved in the regulation of senescence-related change of angiogenic activity via TAB1-p38 signalling and via TGF-ß1 reduction. Hsa-miR-134-5p has a potential cellular rejuvenation effect in human senescent EPCs. Detection of human PBMC-derived hsa-miR-134-5p predicts cardiovascular risk.

Aerobic glycolysis of bronchial epithelial cells rewires Mycoplasma pneumoniae pneumonia and promotes bacterial elimination.

The immune response to Mycoplasma pneumoniae infection plays a key role in clinical symptoms. Previous investigations focused on the pro-inflammatory effects of leukocytes and the pivotal role of epithelial cell metabolic status in finely modulating the inflammatory response have been neglected. Herein, we examined how glycolysis in airway epithelial cells is affected by M. pneumoniae infection in an in vitro model. Additionally, we investigated the contribution of ATP to pulmonary inflammation. Metabolic analysis revealed a marked metabolic shift in bronchial epithelial cells during M. pneumoniae infection, characterized by increased glucose uptake, enhanced aerobic glycolysis, and augmented ATP synthesis. Notably, these metabolic alterations are orchestrated by adaptor proteins, MyD88 and TRAM. The resulting synthesized ATP is released into the extracellular milieu via vesicular exocytosis and pannexin protein channels, leading to a substantial increase in extracellular ATP levels. The conditioned medium supernatant from M. pneumoniae-infected epithelial cells enhances the secretion of both interleukin (IL)-1ß and IL-18 by peripheral blood mononuclear cells, partially mediated by the P2X7 purine receptor (P2X7R). In vivo experiments confirm that addition of a conditioned medium exacerbates pulmonary inflammation, which can be attenuated by pre-treatment with a P2X7R inhibitor. Collectively, these findings highlight the significance of airway epithelial aerobic glycolysis in enhancing the pulmonary inflammatory response and aiding pathogen clearance.

A unique human cord blood CD8+CD45RA+CD27+CD161+ T-cell subset identified by flow cytometric data analysis using Seurat.

Advances in single-cell level analytical techniques, especially cytometric approaches, have led to profound innovation in biomedical research, particularly in the field of clinical immunology. This has resulted in an expansion of high-dimensional data, posing great challenges for comprehensive and unbiased analysis. Conventional manual analysis is thus becoming untenable to handle these challenges. Furthermore, most newly developed computational methods lack flexibility and interoperability, hampering their accessibility and usability. Here, we adapted Seurat, an R package originally developed for single-cell RNA sequencing (scRNA-seq) analysis, for high-dimensional flow cytometric data analysis. Based on a 20-marker antibody panel and analyses of T-cell profiles in both adult blood and cord blood (CB), we showcased the robust capacity of Seurat in flow cytometric data analysis, which was further validated by Spectre, another high-dimensional cytometric data analysis package, and conventional manual analysis. Importantly, we identified a unique CD8+ T-cell population defined as CD8+CD45RA+CD27+CD161+ T cell that was predominantly present in CB. We characterised its IFN-γ-producing and potential cytotoxic properties using flow cytometry experiments and scRNA-seq analysis from a published dataset. Collectively, we identified a unique human CB CD8+CD45RA+CD27+CD161+ T-cell subset and demonstrated that Seurat, a widely used package for scRNA-seq analysis, possesses great potential to be repurposed for cytometric data analysis. This facilitates an unbiased and thorough interpretation of complicated high-dimensional data using a single analytical pipeline and opens a novel avenue for data-driven investigation in clinical immunology.

Atypical memory B cells increase in the peripheral blood of patients with breast cancer regardless of lymph node involvement.

BACKGROUND: Breast cancer is the most common cancer in females. The immune system has a crucial role in the fight against cancer. B and T cells, the two main components of the adaptive immunity, are critical players that specifically target tumor cells. However, B cells, in contrast to T cells, and their role in cancer inhibition or progression is less investigated. Accordingly, in this study, we assessed and compared the frequency of naïve and different subsets of memory B cells in the peripheral blood of patients with breast cancer and healthy women. RESULTS: We found no significant differences in the frequencies of peripheral CD19+ B cells between the patients and controls. However, there was a significant decrease in the frequency of CD19+IgM+ B cells in patients compared to the control group (P=0.030). Moreover, the patients exhibited higher percentages of atypical memory B cells (CD19+CD27‒IgM‒, P=0.006) and a non-significant increasing trend in switched memory B cells (CD19+CD27+IgM‒, P=0.074). Further analysis revealed a higher frequency of atypical memory B cells (aMBCs) in the peripheral blood of patients without lymph node involvement as well as those with a tumor size greater than 2cm or with estrogen receptor (ER) negative/progesterone receptor (PR) negative tumors, compared with controls (P=0.030, P=0.040, P=0.031 and P=0.054, respectively). CONCLUSION: Atypical memory B cells (CD19+CD27‒IgM‒) showed a significant increase in the peripheral blood of patients with breast cancer compared to the control group. This increase seems to be associated with tumor characteristics. Nevertheless, additional research is necessary to determine the precise role of these cells during breast cancer progression.

Deep immune profiling of chronic rhinosinusitis in allergic and non-allergic cohorts using mass cytometry.

Chronic rhinosinusitis (CRS) is a persistent nasal and paranasal sinus mucosa inflammation comprising two phenotypes, namely CRS with nasal polyps (CRSwNP) and without (CRSsNP). CRSwNP can be associated with asthma and hypersensitivity to non-steroidal anti-inflammatory drug (NSAID) in a syndrome known as NSAID-exacerbated respiratory disease (N-ERD). Furthermore, CRS frequently intertwines with respiratory allergies. This study investigated levels of 33 different nasal and serum cytokines and phenotypic characteristics of peripheral blood mononuclear cells (PBMCs) within cohorts of CRS patients (n = 24), additionally examining the influence of comorbid respiratory allergies by mass cytometry. N-ERD patients showed heightened type 2 nasal cytokine levels. Mass cytometry revealed increased activated naive B cell levels in CRSwNP and N-ERD, while resting naive B cells were higher in CRSsNP. Th2a cell levels were significantly elevated in allergic subjects, but not in CRS groups. In conclusion, there are distinct immunological features in PBMCs of CRS phenotypes and allergy.

Investigating cryopreserved PBMC functionality in an antigen-induced model of sarcoidosis granuloma formation.

Sarcoidosis, a systemic inflammatory disease, poses challenges in understanding its etiology and variable clinical courses. Despite ongoing uncertainty about causative agents and genetic predisposition, granuloma formation remains its hallmark feature. To address this, we developed a validated in vitro human granuloma model using patient-derived peripheral blood mononuclear cells (PBMCs), offering a dynamic platform for studying early granuloma formation and sarcoidosis pathogenesis. However, a current limitation of this model is its dependence on freshly isolated PBMCs obtained from whole blood. While cryopreservation is a common method for long-term sample preservation, the biological effects of freezing and thawing PBMCs on granuloma formation remain unclear. This study aimed to assess the viability and functionality of cryopreserved sarcoidosis PBMCs within the granuloma model, revealing similar granulomatous responses to fresh cells and highlighting the potential of cryopreserved PBMCs as a valuable tool for studying sarcoidosis and related diseases.

High sodium, rather than high blood pressure, induces immune cell activation and renal infiltration in ovariectomized adult Wistar rats.

We used an animal model of salt-sensitive hypertension (SSH) in which ovariectomized (oVx) rats developed hypertension with high salt (HS) intake. Hypertension is accompanied by changes in the percentage of CD4+ T lymphocytes, immune CD45+ cell infiltration into renal tissue, and changes in Na+, K+- ATPase (NKA) expression in both renal tissue and peripheral blood mononuclear cells (PBMCs). To determine whether the observed changes resulted from HS intake, high blood pressure, or both, hydralazine (HDZ) was used to lower blood pressure. The oVx HS rats received two HDZ schedules either to prevent or to treat hypertension. NKA was overexpressed in the kidneys of all oVx groups and in PBMCs of oVx HS rats. This pattern was not altered with HDZ treatment. Changes in CD4+ T lymphocytes and renal infiltration of CD45+ cells were not reversed either. High salt, but not high blood pressure, induces immune cell activation and renal infiltration. Overexpressed NKA is the primary event, and HS is the perturbation to the system in this model of SSH, which resembles the postmenopausal state.

Impact on in-depth immunophenotyping of delay to peripheral blood processing.

Peripheral blood mononuclear cell (PBMC) immunophenotyping is crucial in tracking activation, disease state, and response to therapy in human subjects. Many studies require the shipping of blood from clinical sites to a laboratory for processing to PBMC, which can lead to delays that impact sample quality. We used an extensive cytometry by time-of-flight (CyTOF) immunophenotyping panel to analyze the impacts of delays to processing and distinct storage conditions on cell composition and quality of PBMC from seven adults across a range of ages, including two with rheumatoid arthritis. Two or more days of delay to processing resulted in extensive red blood cell contamination and increased variability of cell counts. While total memory and naïve B- and T-cell populations were maintained, 4-day delays reduced the frequencies of monocytes. Variation across all immune subsets increased with delays of up to 7 days in processing. Unbiased clustering analysis to define more granular subsets confirmed changes in PBMC composition, including decreases of classical and non-classical monocytes, basophils, plasmacytoid dendritic cells, and follicular helper T cells, with each subset impacted at a distinct time of delay. Expression of activation markers and chemokine receptors changed by Day 2, with differential impacts across subsets and markers. Our data support existing recommendations to process PBMC within 36 h of collection but provide guidance on appropriate immunophenotyping experiments with longer delays.

Cell-type specific molecular expression levels by restricted-dimensional cytometry.

BACKGROUND: Cytometric analysis has been commonly used to delineate distinct cell subpopulations among peripheral blood mononuclear cells by the differential expression of surface receptors. This capability has reached its apogee with high-dimensional approaches such as mass cytometry and spectral cytometry that include simultaneous assessment of 20-50 analytes. Unfortunately, this approach also engenders significant complexity with analytical and interpretational pitfalls. METHODS: Here, we demonstrate a complementary approach with restricted-dimensionality to assess cell-type specific intracellular molecular expression levels at exceptional levels of precision. The expression of five analytes was individually assessed in four mononuclear cell-types from peripheral blood. RESULTS: Distinctions in expression levels were seen between cell-types and between samples from different donor groups. Mononuclear cell-type specific molecular expression levels distinguished pregnant from nonpregnant women and G-CSF-treated from untreated persons. Additionally, the precision of our analysis was sufficient to quantify a novel relationship between two molecules-Rel A and translocator protein-by correlational analysis. CONCLUSIONS: Restricted-dimensional cytometry can provide a complementary approach to define characteristics of cell-type specific intracellular protein and phosphoantigen expression in mononuclear cells.

Inflammation induces α1-adrenoceptor expression in peripheral blood mononuclear cells of patients with complex regional pain syndrome.

Persistent regional and systemic inflammation may promote pain and hyperalgesia in complex regional pain syndrome (CRPS). In this study, we investigated whether stimulation of α1-adrenoceptors (α1-AR) on peripheral blood mononuclear cells (PBMC) might contribute to this inflammatory state. PBMC were isolated from venous blood collected from 21 CRPS patients and 21 sex and age-matched controls. Lipopolysaccharide (LPS), a bacterial toxin, was administered to cultured PBMC for 24 h to trigger inflammation. Exposure to LPS resulted in heightened gene expression of α1-AR subtype B (α1B-AR) in PBMC of CRPS patients relative to controls. Interleukin (IL)-1ß and IL-6 levels did not change when the α1-AR agonist phenylephrine was administered to naïve PBMC. However, α1-AR stimulation following LPS treatment increased IL-6 mRNA and protein levels in PBMC of patients and controls. To investigate the possible consequence of heightened IL-6 levels on immunoglobulin G antibody production, PBMC were stimulated with CD40 ligand and IL-21 to generate plasmablasts (B cells that secrete antibodies). This response was similar in patients and controls. Adding IL-6 to the cell culture medium increased plasmablast differentiation in controls and antibody production both in patients and controls. These findings suggest that the inflammatory cascade associated with elevated levels of IL-6 may generate α1B-AR expression in CRPS PBMC. A reciprocal interaction between heightened α1-AR expression in PBMC and IL-6 secretion may contribute to systemic inflammation and antibody production in CRPS.

RAGE in circulating immune cells is fundamental for hippocampal inflammation and cognitive decline in a mouse model of latent chronic inflammation.

BACKGROUND: Latent chronic inflammation has been proposed as a key mediator of multiple derangements in metabolic syndrome (MetS), which are increasingly becoming recognized as risk factors for age-related cognitive decline. However, the question remains whether latent chronic inflammation indeed induces brain inflammation and cognitive decline. METHODS: A mouse model of latent chronic inflammation was constructed by a chronic subcutaneous infusion of low dose lipopolysaccharide (LPS) for four weeks. A receptor for advanced glycation end products (RAGE) knockout mouse, a chimeric myeloid cell specific RAGE-deficient mouse established by bone marrow transplantation and a human endogenous secretory RAGE (esRAGE) overexpressing adenovirus system were utilized to examine the role of RAGE in vivo. The cognitive function was examined by a Y-maze test, and the expression level of genes was determined by quantitative RT-PCR, western blot, immunohistochemical staining, or ELISA assays. RESULTS: Latent chronic inflammation induced MetS features in C57BL/6J mice, which were associated with cognitive decline and brain inflammation characterized by microgliosis, monocyte infiltration and endothelial inflammation, without significant changes in circulating cytokines including TNF-α and IL-1ß. These changes as well as cognitive impairment were rescued in RAGE knockout mice or chimeric mice lacking RAGE in bone marrow cells. P-selectin glycoprotein ligand-1 (PSGL-1), a critical adhesion molecule, was induced in circulating mononuclear cells in latent chronic inflammation in wild-type but not RAGE knockout mice. These inflammatory changes and cognitive decline induced in the wild-type mice were ameliorated by an adenoviral increase in circulating esRAGE. Meanwhile, chimeric RAGE knockout mice possessing RAGE in myeloid cells were still resistant to cognitive decline and brain inflammation. CONCLUSIONS: These findings indicate that RAGE in inflammatory cells is necessary to mediate stimuli of latent chronic inflammation that cause brain inflammation and cognitive decline, potentially by orchestrating monocyte activation via regulation of PSGL-1 expression. Our results also suggest esRAGE-mediated inflammatory regulation as a potential therapeutic option for cognitive dysfunction in MetS with latent chronic inflammation.

Measurement of chromosomal instability and level of DNA damage in peripheral blood mononuclear cells of endometrial cancer patients.

Endometrial cancer is one of the most common invasive gynecologic malignancies in developed countries. The aim of this study was to evaluate chromosomal instability and level of DNA damage in peripheral blood mononuclear cells (PBMCs) of newly diagnosed endometrial cancer patients in relation to health status (diagnosis), age, histological grade of cancer, residence, smoking, number of pregnancies, miscarriages, and abortions. The analyzed sample consisted of 60 individuals, 30 endometrial cancer patients with an average age of 64.37 ±â€…7.08, and 30 healthy control women with an average age of 60.23 ±â€…11.55. Chromosomal instability was evaluated by the cytokinesis-block micronucleus (CBMN) assay, and the level of DNA damage by the single-cell gel electrophoresis (comet) assay in PBMCs. The average frequencies of micronuclei (MNi), nucleoplasmic bridges (NPBs) as well as nuclear buds (NBUDs) were significantly higher in cancer patients compared to controls (P < .0005). There was no difference in the nuclear division index (NDI) among the analyzed samples. The comet assay showed that the patients had a significantly increased genetic damage index (GDI) compared with controls (P < .0005). Using linear regression analysis, we found that health status (diagnosis) had the strongest influence on the MN frequency as well as GDI (P < .0005). Our results indicated that there is a high level of genetic damage in both the level of DNA and the level of chromosomes in the PBMCs of newly diagnosed patients with endometrial cancer, where the frequency and level of damage were significantly affected by health status, grade of cancer, residence, number of pregnancies, miscarriages, and abortions.

Serum long non-coding Ribonucleic Acid H19 serves as a biomarker for systemic lupus erythematosus and participates in the disease progression.

AIM: This study aimed to investigate the expression of H19 and its possible molecular mechanism in systemic lupus erythematosus (SLE). METHODS: The expression of H19 and miR-19b in serum and peripheral blood mononuclear cells (PBMCs) were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic value of serum H19 in SLE. Pearson correlation coefficient was used to analyze the correlation between serum levels of H19 and miR-19b. Flow cytometry and Cell counting kit-8 (CCK-8) assay were performed to detect cell apoptosis and viability. The levels of pro-inflammatory and anti-inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Luciferase reporter gene assay was conducted to verify the interaction between H19 and miR-19b. RESULTS: The expression of H19 and miR-19b in SLE group were up-regulated and down-regulated, respectively. Serum H19 has certain clinical diagnostic value in SLE. In in vitro studies, overexpression of H19 can significantly inhibit the viability of PBMCs and promote apoptosis and inflammatory response of PBMCs by interacting with miR-19b. CONCLUSIONS: The expression of H19 is upregulated in patients with SLE and plays a role in cell function and inflammation by targeting miR-19b in PBMCs, which may be one of the pathological mechanisms of SLE.

Variants of NLRP3 Protein in Haemonchus contortus Infected Sheep: Impact on Immune Cell Responsiveness to LPS In Vitro.

Pathogen recognition is an essential component to achieve the desired outcome of host protection. Nod-like receptor pyrin containing domain 3 (NLRP3) is a cytoplasmic pattern recognition receptor (PRR) with a wide array of agonists, such as PAMPs, DAMPs, ATP, bacterial product and viral products. Stimulation of the NLRP3 inflammasome results in proteolytic activation of IL-1ß and IL-18, cell pyroptosis and classically, the induction of proinflammatory responses. St. Croix (STC) sheep have resistance traits exhibiting the appropriate T-helper type 2 immune response ensuing protection during helminth parasitic infection whereas parasite-susceptible Suffolk (SUF) sheep have an impaired response resulting in parasite establishment and adverse symptoms. The objective of these experiments was to determine if NLRP3 protein in H. contortus-infected SUF sheep was defective using the classical activation pathway of NLRP3 inflammasome. Peripheral blood mononuclear cells (PBMCs) derived from H. contortus-infected STC and SUF sheep were isolated from whole blood and treated (MCC950 treatment for 2 h followed by LPS treatment for 3 h, 1400 W treatment for 2 h followed by LPS treatment for 3 h, LPS treatment for 3 h or culture media for 3 h). qPCR analysis of LPS-stimulated PBMC revealed an upregulation in inflammatory associated genes IL-1ß, TLR4, TNFα and NFκB (p < 0.0001) in STC PBMC and downregulation in IFNγ, IL-6 and iNOS for SUF PBMC. Pharmacological inhibition of iNOS in SUF PBMC resulted in an upregulation in the expression of IFNγ. These preliminary data begin to discover a relationship between NLRP3 activation and TLR4 signalling in PBMC of STC and SUF sheep.

BRAF-V600E mutations in plasma and peripheral blood mononuclear cells correlate with prognosis of pediatric Langerhans cell histiocytosis treated with first-line therapy.

BACKGROUND: The clinical relevance of BRAF-V600E alleles in peripheral blood mononuclear cells (PBMCs) and the prognostic impact of the mutants in cell-free (cf) and PBMC DNAs of Langerhans cell histiocytosis (LCH) have not been fully clarified in pediatric LCH. METHODS: We retrospectively determined the levels of BRAF-V600E mutation in paired plasma and PBMC samples at the time of diagnosis of LCH. Subsequently, we performed a separate or combined analysis of the clinical and prognostic impact of the mutants. RESULTS: We assessed BRAF-V600E mutation in peripheral blood from 94 patients of childhood LCH. Our data showed that cfBRAF-V600E was related to young age, multiple-system (MS) disease, involvements of organs with high risk, increased risk of relapse, and worse progression-free survival (PFS) of patients. We also observed that the presence of BRAF-V600E in PBMCs at baseline was significantly associated with MS LCH with risk organ involvement, younger age, and disease progression or relapse. The coexisting of plasma(+)/PBMC(+) identified 36.2% of the patients with the worst outcome, and the hazard ratio was more significant than either of the two alone or neither, indicating that combined analysis of the mutation in plasma and PBMCs was more accurate to predict relapse than evaluation of either one. CONCLUSIONS: Concurrent assessment of BRAF-V600E mutation in plasma and PBMCs significantly impacted the prognosis of children with LCH. Further prospective studies with larger cohorts need to validate the results of this study.

Longitudinal dynamic single-cell mass cytometry analysis of peripheral blood mononuclear cells in COVID-19 patients within 6 months after viral RNA clearance.

This study investigates the longitudinal dynamic changes in immune cells in COVID-19 patients over an extended period after recovery, as well as the interplay between immune cells and antibodies. Leveraging single-cell mass spectrometry, we selected six COVID-19 patients and four healthy controls, dissecting the evolving landscape within six months post-viral RNA clearance, alongside the levels of anti-spike protein antibodies. The T cell immunophenotype ascertained via single-cell mass spectrometry underwent validation through flow cytometry in 37 samples. Our findings illuminate that CD8 + T cells, gamma-delta (gd) T cells, and NK cells witnessed an increase, in contrast to the reduction observed in monocytes, B cells, and double-negative T (DNT) cells over time. The proportion of monocytes remained significantly elevated in COVID-19 patients compared to controls even after six-month. Subpopulation-wise, an upsurge manifested within various T effector memory subsets, CD45RA + T effector memory, gdT, and NK cells, whereas declines marked the populations of DNT, naive and memory B cells, and classical as well as non-classical monocytes. Noteworthy associations surfaced between DNT, gdT, CD4 + T, NK cells, and the anti-S antibody titer. This study reveals the changes in peripheral blood mononuclear cells of COVID-19 patients within 6 months after viral RNA clearance and sheds light on the interactions between immune cells and antibodies. The findings from this research contribute to a better understanding of immune transformations during the recovery from COVID-19 and offer guidance for protective measures against reinfection in the context of viral variants.

Altered Transcriptome Response in PBMCs of Czech Adults Linked to Multiple PFAS Exposure: B Cell Development as a Target of PFAS Immunotoxicity.

While the immunomodulation effects of per- and polyfluoroalkyl substances (PFASs) are described on the level of clinical signs in epidemiological studies (e.g., suppressed antibody response after vaccination), the underlying mechanism has still not been fully elucidated. To reveal mechanisms of PFAS exposure on immunity, we investigated the genome-wide transcriptomic changes of peripheral blood mononuclear cells (PBMCs) responding to PFAS exposure (specifically, exposure to PFPA, PFOA, PFNA, PFDA, PFUnDA, PFHxS, and PFOS). Blood samples and the chemical load in the blood were analyzed under the cross-sectional CELSPAC: Young Adults study. The overall aim of the study was to identify sensitive gene sets and cellular pathways conserved for multiple PFAS chemicals. Transcriptome networks related to adaptive immunity were perturbed by multiple PFAS exposure (i.e., blood levels of at least four PFASs). Specifically, processes tightly connected with late B cell development, such as B cell receptor signaling, germinal center reactions, and plasma cell development, were shown to be affected. Our comprehensive transcriptome analysis identified the disruption of B cell development, specifically the impact on the maturation of antibody-secreting cells, as a potential mechanism underlying PFAS immunotoxicity.

Alpha-synuclein dynamics bridge Type-I Interferon response and SARS-CoV-2 replication in peripheral cells.

BACKGROUND: Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection. RESULTS: Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-ß, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium. CONCLUSIONS: Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.