Epigenetic quantification of immunosenescent CD8+ TEMRA cells in human blood

Triclocarban disrupts the activation and differentiation of human CD8+ T cells by suppressing the vitamin D receptor signaling

Triclocarban (TCC) is a widely applied environmental endocrine-disrupting chemical (EDC). Similar to most of EDCs, TCC potentially damages the immunity of various species. However, whether and how TCC impacts the adaptive immunity in mammals has yet to be determined. Herein, we discovered that TCC disrupts the activation and differentiation of CD8+ T cells in primary human peripheral blood samples, purified CD8+ T cells, and in mice in vivo. Mechanistically, TCC might block the activation of the vitamin D receptor (VDR) and reduce the synthesis of cholesterol, a precursor of vitamin D, resulting in inhibition of VDR signaling due to the suppression of both its ligand and the receptor itself by TCC. Our findings elucidate the hazard and potential mechanisms of TCC in mammalian adaptive immunity and highlighted VDR as a potential therapeutic target for the immunodeficiency caused by TCC.

An epigenetic human cytomegalovirus infection score predicts viremia risk in seropositive lung transplant recipients

Cytomegalovirus (CMV) infection and reactivation in solid organ transplant (SOT) recipients increases the risk of viremia, graft failure and death. Clinical studies of CMV serostatus indicate that donor positive recipient negative (D+/R-) patients have greater viremia risk than D-/R-. The majority of patients are R+ having intermediate serologic risk. To characterize the long-term impact of CMV infection and assess viremia risk, we sought to measure the effects of CMV on the recipient immune epigenome. Specifically, we profiled DNA methylation in 156 individuals before lung or kidney transplant. We found that the methylome of CMV positive SOT recipients is hyper-methylated at loci associated with neural development and Polycomb group (PcG) protein binding, and hypo-methylated at regions critical for the maturation of lymphocytes. In addition, we developed a machine learning-based model to predict the recipient CMV serostatus after correcting for cell type composition and ancestry. This CMV episcore measured at baseline in R+ individual stratifies viremia risk accurately in the lung transplant cohort, and along with serostatus the CMV episcore could be a potential biomarker for identifying R+ patients at high viremia risk.

Memory inflation: Beyond the acute phase of viral infection

Memory inflation is confirmed as the most commonly dysregulation of host immunity with antigen-independent manner in mammals after viral infection. By generating large numbers of effector/memory and terminal differentiated effector memory CD8+ T cells with diminished naïve subsets, memory inflation is believed to play critical roles in connecting the viral infection and the onset of multiple diseases. Here, we reviewed the current understanding of memory inflated CD8+ T cells in their distinct phenotypic features that different from exhausted subsets; the intrinsic and extrinsic roles in regulating the formation of memory inflation; and the key proteins in maintaining the expansion and proliferation of inflationary populations. More importantly, based on the evidences from both clinic and animal models, we summarized the potential mechanisms of memory inflation to trigger autoimmune neuropathies, such as Guillain-Barré syndrome and multiple sclerosis; the correlations of memory inflation between tumorigenesis and resistance of tumour immunotherapies; as well as the effects of memory inflation to facilitate vascular disease progression. To sum up, better understanding of memory inflation could provide us an opportunity to beyond the acute phase of viral infection, and shed a light on the long-term influences of CD8+ T cell heterogeneity in dampen host immune homeostasis.

Expanding the diagnostic toolbox for complex genetic immune disorders

Laboratory-based immunology evaluation is essential to the diagnostic workup of patients with complex immune disorders, and is as essential, if not more so, depending on the context, as genetic testing, because it enables identification of aberrant pathways amenable to therapeutic intervention and clarifies variants of uncertain significance. There have been considerable advances in techniques and instrumentation in the clinical laboratory in the past 2 decades, although there are still "miles to go." One of the goals of the clinical laboratory is to ensure advanced diagnostic testing is widely accessible to physicians and thus patients, through reference laboratories, particularly in the context of academic medical centers. This ensures a greater likelihood of translating research discoveries into the diagnostic laboratory, on the basis of patient care needs rather than a sole emphasis on commercial utility. However, these advances are under threat from burdensome regulatory oversight that can compromise, at best, and curtail, at worst, the ability to rapidly diagnose rare immune disorders and ensure delivery of precision medicine. This review discusses the clinical utility of diagnostic immunology tools, beyond cellular immunophenotyping of lymphocyte subsets, which can be used in conjunction with clinical and other laboratory data for diagnosis as well as monitoring of therapeutic response in patients with genetic immunologic diseases.

LTβR deficiency causes lymph node aplasia and impaired B cell differentiation

Secondary lymphoid organs (SLOs) provide the confined microenvironment required for stromal cells to interact with immune cells to initiate adaptive immune responses resulting in B cell differentiation. Here, we studied three patients from two families with functional hyposplenism, absence of tonsils, and complete lymph node aplasia, leading to recurrent bacterial and viral infections. We identified biallelic loss-of-function mutations in LTBR, encoding the lymphotoxin beta receptor (LTβR), primarily expressed on stromal cells. Patients with LTβR deficiency had hypogammaglobulinemia, diminished memory B cells, regulatory and follicular T helper cells, and dysregulated expression of several tumor necrosis factor family members. B cell differentiation in an ex vivo coculture system was intact, implying that the observed B cell defects were not intrinsic in nature and instead resulted from LTβR-dependent stromal cell interaction signaling critical for SLO formation. Collectively, we define a human inborn error of immunity caused primarily by a stromal defect affecting the development and function of SLOs.

Memory T Cells Subpopulations in a Cohort of COVID-19 Vaccinated or Recovered Subjects

Following viral infection, antigen-restricted T lymphocytes are activated and recognize infected cells to eliminate them. A subset of T cells differentiates into memory lymphocytes able to counteract viral rechallenge in a faster and enhanced way. SARS-CoV-2 can escape immune responses leading to a poor clinical outcome. Immune escape can be associated with the failure of the development of T cell memory compartments. The aim of this study is to characterize the T memory subsets and to test the immune response against class I- and II-restricted immunodominant epitopes shared by ancestral and SARS-CoV-2 variants strains. T memory subsets and recognition of SARS-CoV-2S Spike-specific epitopes were analyzed by flow cytometry on 14 fully vaccinated healthy donors (HDV) and 18 COVID-19 recovered patients (CD). The results obtained showed that CD8+ T naïve subset numbers decreased in association with a significant increase of the effector memory T cell subset whereas there was a small increase in the percentage of SARS-CoV-2 antigen-restricted T clones in both CD4+ and CD8+ subset in the CD compared to HDV sample. Collectively, these features may reflect a broader cytotoxic T cell repertoire stimulated by the virus during the natural infection compared to the spike-restricted response activated during vaccination.

Artificial antigen-presenting cell system reveals CD28's role in modulating T cell functions during human immunodeficiency virus infection

T cell immune dysfunction is a prominent feature of chronic HIV infection. To evaluate non-specific dysfunction, a method involving both generic activation and T cell receptor (TCR) stimulation is necessary. We created a tunable artificial antigen-presenting cell (aAPC) system. This system consists of lipid bilayers on cytometry-compatible silica microbeads (5 μm). When only anti-CD3 is incorporated, T cell activation is limited. Introducing anti-CD28 agonists significantly elevates the cytokine expression and upregulation of activation-induced markers. CD28 co-stimulation modulates the response profile, preferentially promoting IL-2 expression relative to other cytokines. aAPCs-stimulated CD4+ and CD8+ T cells from untreated HIV-infected individuals exhibit altered effector functions and diminished CD28 dependence. These functions are skewed toward TNFα, IFNγ and CD107a, with reduced IL-2. Antiretroviral therapy partially normalizes this distorted profile in CD4+ T cells, but not in CD8+ T cells. Our findings show T cell intrinsic biases that may contribute to persistent systemic T cell dysfunction associated with HIV pathogenesis.

Predominance of CD137+ And TNF-α Expressing CD8+ Central Memory T Cells in Mild COVID-19 Recovered Patients Upon SARS-CoV-2 Re-Exposure

INTRODUCTION

Memory CD8+ T cells are essential for long-term immune protection in viral infections, including COVID-19.

METHODS

This study examined the responses of CD8+ TEM, TEMRA, and TCM subsets from unvaccinated individuals who had recovered from mild and severe COVID-19 by flow cytometry.

RESULTS AND DISCUSSION

The peptides triggered a higher frequency of CD8+ TCM cells in the recovered mild group. CD8+ TCM and TEM cells showed heterogeneity in CD137 expression between evaluated groups. In addition, a predominance of CD137 expression in naïve CD8+ T cells, TCM, and TEM was observed in the mild recovered group when stimulated with peptides. Furthermore, CD8+ TCM and TEM cell subsets from mild recovered volunteers had higher TNF-α expression. In contrast, the expression partner of IFN-γ, IL-10, and IL-17 indicated an antiviral signature by CD8+ TEMRA cells. These findings underscore the distinct functional capabilities of each memory T cell subset in individuals who have recovered from COVID-19 upon re-exposure to SARS-CoV-2 antigens.

CD8 positive T-cells decrease neurogenesis and induce anxiety-like behaviour following hepatitis B vaccination

Mounting evidence indicates the involvement of peripheral immunity in the regulation of brain function, influencing aspects such as neuronal development, emotion, and cognitive abilities. Previous studies from our laboratory have revealed that neonatal hepatitis B vaccination can downregulate hippocampal neurogenesis, synaptic plasticity and spatial learning memory. In the current post-epidemic era characterized by universal vaccination, understanding the impact of acquired immunity on neuronal function and neuropsychiatric disorders, along with exploring potential underlying mechanisms, becomes imperative. We employed hepatitis B vaccine-induced CD3 positive T cells in immunodeficient mice to investigate the key mechanisms through which T cell subsets modulate hippocampal neurogenesis and anxiety-like behaviours. Our data revealed that mice receiving hepatitis B vaccine-induced T cells exhibited heightened anxiety and decreased hippocampal cell proliferation compared to those receiving phosphate-buffered saline-T cells or wild-type mice. Importantly, these changes were predominantly mediated by infiltrated CD8+ T cells into the brain, rather than CD4+ T cells. Transcriptome profiling of CD8+ T cells unveiled that C-X-C motif chemokine receptor 6 positive (CXCR6+) CD8+ T cells were recruited into the brain through microglial and astrocyte-derived C-X-C motif chemokine ligand 16 (CXCL16). This recruitment process impaired neurogenesis and induced anxiety-like behaviour via tumour necrosis factor-α-dependent mechanisms. Our findings highlight the role of glial cell derived CXCL16 in mediating the recruitment of CXCR6+CD8+ T cell subsets into the brain. This mechanism represents a potential avenue for modulating hippocampal neurogenesis and emotion-related behaviours after hepatitis B vaccination.

Plasma proteomic signature of neonates in the context of placental histological chorioamnionitis

BACKGROUND

Placental histological chorioamnionitis (HCA) is recognised as a significant risk factor for various adverse neonatal outcomes. This study aims to explore if the inflammatory protein levels in neonates were associated with HCA.

METHODS

All women with singleton births from February 2020 to November 2022 were selected and divided into three groups based on maternal placental pathology results: the HCA-stage 1 group (n=24), the HCA-stage 2 group (n=16) and the control group (n=17). Olink Target 96 Inflammation Panel was used to detect the levels of 92 inflammation-related proteins in the plasma of newborns from all three groups within 24 hours after birth. We compared the protein profiles through differential protein expression analysis.

RESULTS

A total of six inflammation-related proteins exhibited significant differences between the HCA-stage 1 and the control group. Specifically, TRANCE and CST5 were significantly upregulated (p=0.006, p=0.025, respectively), whereas the expression of IFN-gamma, CXCL9, CXCL10 and CCL19 was significantly downregulated (p=0.040, p=0.046, p=0.007, p=0.006, respectively). HCA-stage 2 newborns had significantly elevated levels of CD5 and CD6 and decreased IFN-gamma, CXCL10 and CCL19 in comparison to controls. These differential proteins were significantly enriched in positive regulation of cytokine activity, leucocyte chemotaxis and positive regulation of T-cell activation pathway-related Gene Ontology terms. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that viral protein interaction with cytokine and cytokine receptor, interleukin-17/NF-kappa B/toll-like receptor/chemokine signalling pathway, and cytokine-cytokine receptor interaction exhibited significant differences. Spearman analysis demonstrated a significant positive connection between the levels of CD6 and CD5 proteins, not only in neonatal leucocytes but also in maternal leucocytes. Additionally, CD6 was found to be associated with neonatal birth weight.

CONCLUSIONS

In conclusion, placental histological changes associated with chorioamnionitis appear to influence the expression of inflammatory proteins in offspring. Notably, CD6 and CD5 proteins may potentially contribute to the pathogenesis of HCA-related neonatal diseases.

An in-depth understanding of the role and mechanisms of T cells in immune organ aging and age-related diseases

T cells play a critical and irreplaceable role in maintaining overall health. However, their functions undergo alterations as individuals age. It is of utmost importance to comprehend the specific characteristics of T-cell aging, as this knowledge is crucial for gaining deeper insights into the pathogenesis of aging-related diseases and developing effective therapeutic strategies. In this review, we have thoroughly examined the existing studies on the characteristics of immune organ aging. Furthermore, we elucidated the changes and potential mechanisms that occur in T cells during the aging process. Additionally, we have discussed the latest research advancements pertaining to T-cell aging-related diseases. These findings provide a fresh perspective for the study of T cells in the context of aging.

Impact and potential value of immunosenescence on solid gastrointestinal tumors

Solid gastrointestinal tumors often respond poorly to immunotherapy for the complex tumor microenvironment (TME), which is exacerbated by immune system alterations. Immunosenescence is the process of increased diversification of immune genes due to aging and other factors, leading to a decrease in the recognition function of the immune system. This process involves immune organs, immune cells, and the senescence-associated secretory phenotype (SASP). The most fundamental change is DNA damage, resulting in TME remodeling. The main manifestations are worsening inflammation, increased immunosuppressive SASP production, decreased immune cell antitumor activity, and the accumulation of tumor-associated fibroblasts and myeloid-derived suppressor cells, making antitumor therapy less effective. Senotherapy strategies to remove senescent cells and block key senescence processes can have synergistic effects with other treatments. This review focuses on immunoenescence and its impact on the solid TME. We characterize the immunosenescent TME and discuss future directions for antitumor therapies targeting senescence.

CD28-CD57+ T cells from head and neck cancer patients produce high levels of cytotoxic granules and type II interferon but are not senescent

T lymphocytes expressing CD57 and lacking costimulatory receptors CD27/CD28 have been reported to accumulate with aging, chronic infection, and cancer. These cells are described as senescent, with inability to proliferate but enhanced cytolytic and cytokine-producing capacity. However, robust functional studies on these cells taken directly from cancer patients are lacking. We isolated these T cells and their CD27/28+ counterparts from blood and tumor samples of 50 patients with previously untreated head and neck cancer. Functional studies confirmed that these cells have enhanced ability to degranulate and produce IFN-γ. They also retain the ability to proliferate, thus are not senescent. These data suggest that CD27/28-CD57+ CD8+ T cells are a subset of highly differentiated, CD45RA+ effector memory (TEMRA) cells with retained proliferative capacity. Patients with > 34% of these cells among CD8+ T cells in the blood had a higher rate of locoregional disease relapse, suggesting these cells may have prognostic significance.

Terminally differentiated effector memory T cells associate with cognitive and AD-related biomarkers in an aging-based community cohort

BACKGROUND AND PURPOSE

The immune response changes during aging and the progression of Alzheimer's disease (AD) and related dementia (ADRD). Terminally differentiated effector memory T cells (called TEMRA) are important during aging and AD due to their cytotoxic phenotype and association with cognitive decline. However, it is not clear if the changes seen in TEMRAs are specific to AD-related cognitive decline specifically or are more generally correlated with cognitive decline. This study aimed to examine whether TEMRAs are associated with cognition and plasma biomarkers of AD, neurodegeneration, and neuroinflammation in a community-based cohort of older adults.

METHODS

Study participants from a University of Kentucky Alzheimer's Disease Research Center (UK-ADRC) community-based cohort of aging and dementia were used to test our hypothesis. There were 84 participants, 44 women and 40 men. Participants underwent physical examination, neurological examination, medical history, cognitive testing, and blood collection to determine plasma biomarker levels (Aβ42/Aβ40 ratio, total tau, Neurofilament Light chain (Nf-L), Glial Fibrillary Acidic Protein (GFAP)) and to isolate peripheral blood mononuclear cells (PBMCs). Flow cytometry was used to analyze PBMCs from study participants for effector and memory T cell populations, including CD4+ and CD8+ central memory T cells (TCM), Naïve T cells, effector memory T cells (TEM), and effector memory CD45RA+ T cells (TEMRA) immune cell markers.

RESULTS

CD8+ TEMRAs were positively correlated with Nf-L and GFAP. We found no significant difference in CD8+ TEMRAs based on cognitive scores and no associations between CD8+ TEMRAs and AD-related biomarkers. CD4+ TEMRAs were associated with cognitive impairment on the MMSE. Gender was not associated with TEMRAs, but it did show an association with other T cell populations.

CONCLUSION

These findings suggest that the accumulation of CD8+ TEMRAs may be a response to neuronal injury (Nf-L) and neuroinflammation (GFAP) during aging or the progression of AD and ADRD. As our findings in a community-based cohort were not clinically-defined AD participants but included all ADRDs, this suggests that TEMRAs may be associated with changes in systemic immune T cell subsets associated with the onset of pathology.

Differential peripheral memory T cell subsets sensitively indicate the severity of nonalcoholic fatty liver disease

AIM

Differential patterns of peripheral memory T cell subsets in nonalcoholic fatty liver disease (NAFLD) were assessed using flow cytometry (FCM) to elucidate their association with NAFLD severity and provide a new noninvasive method to sensitively detect the disease severity in addition to existing biomarkers.

METHODS

We assessed the differential frequencies of peripheral memory T cell subsets in 103 patients with NAFLD according to the degree of liver fibrosis (FIB) using FCM analysis. We focused on the following populations: CCR7+ CD45RA+ naïve T, CCR7+ CD45RA- central memory T cells (TCM), CCR7- CD45RA- effector memory T, and CCR7- CD45RA+ terminally differentiated effector memory T (TEMRA) cells in CD4+ and CD8+ T, Th1, Th2, and Th17 cells, respectively. To evaluate the pathological progression of the disease, these frequencies were also examined according to the degree of the NAFLD activity score (NAS).

RESULTS

Several significant correlations were observed between laboratory parameters and peripheral memory T lymphocyte frequencies according to the degree of liver FIB and NAS in NAFLD. In univariate and multivariate analyses, the frequency of CD8+ TEMRA cells predicted severe FIB, and the predictive power was validated in an independent cohort. Furthermore, the frequencies of several memory T cell subsets sensitively indicated the pathological progression of NAFLD (Th17 TCM: steatosis, CD4+ TCM: lobular inflammation, and CD8+ TEMRA and effector memory T cells: hepatocellular ballooning).

CONCLUSIONS

Our results suggest that the analysis of peripheral memory T lymphocyte frequencies can noninvasively predict severe FIB and sensitively indicate the pathological progression of NAFLD.

Associations between immune cell phenotypes and lung cancer subtypes: insights from mendelian randomization analysis

INTRODUCTION

Lung cancer is a common malignant tumor, and different types of immune cells may have different effects on the occurrence and development of lung cancer subtypes, including lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). However, the causal relationship between immune phenotype and lung cancer is still unclear.

METHODS

This study utilized a comprehensive dataset containing 731 immune phenotypes from the European Bioinformatics Institute (EBI) to evaluate the potential causal relationship between immune phenotypes and LUSC and LUAD using the inverse variance weighted (IVW) method in Mendelian randomization (MR). Sensitivity analyses, including MR-Egger intercept, Cochran Q test, and others, were conducted for the robustness of the results. The study results were further validated through meta-analysis using data from the Transdisciplinary Research Into Cancer of the Lung (TRICL) data. Additionally, confounding factors were excluded to ensure the robustness of the findings.

RESULTS

Among the final selection of 729 immune cell phenotypes, three immune phenotypes exhibited statistically significant effects with LUSC. CD28 expression on resting CD4 regulatory T cells (OR 1.0980, 95% CI: 1.0627-1.1344, p < 0.0001) and CD45RA + CD28- CD8 + T cell %T cell (OR 1.0011, 95% CI: 1.0007; 1.0015, p < 0.0001) were associated with increased susceptibility to LUSC. Conversely, CCR2 expression on monocytes (OR 0.9399, 95% CI: 0.9177-0.9625, p < 0.0001) was correlated with a decreased risk of LUSC. However, no significant causal relationships were established between any immune cell phenotypes and LUAD.

CONCLUSION

This study demonstrates that specific immune cell types are associated with the risk of LUSC but not with LUAD. While these findings are derived solely from European populations, they still provide clues for a deeper understanding of the immunological mechanisms underlying lung cancer and may offer new directions for future therapeutic strategies and preventive measures.

Virus-reactive T cells expanded in aplastic anemia eliminate hematopoietic progenitor cells by molecular mimicry

ABSTRACT

Acquired aplastic anemia is a bone marrow failure syndrome characterized by hypocellular bone marrow and peripheral blood pancytopenia. Frequent clinical responses to calcineurin inhibition and antithymocyte globulin strongly suggest critical roles for hematopoietic stem/progenitor cell-reactive T-cell clones in disease pathophysiology; however, their exact contribution and antigen specificities remain unclear. We determined differentiation states and targets of dominant T-cell clones along with their potential to eliminate hematopoietic progenitor cells in the bone marrow of 15 patients with acquired aplastic anemia. Single-cell sequencing and immunophenotyping revealed oligoclonal expansion and effector differentiation of CD8+ T-cell compartments. We reexpressed 28 dominant T-cell receptors (TCRs) of 9 patients in reporter cell lines to determine reactivity with (1) in vitro-expanded CD34+ bone marrow, (2) CD34- bone marrow, or (3) peptide pools covering immunodominant epitopes of highly prevalent viruses. Besides 5 cytomegalovirus-reactive TCRs, we identified 3 TCRs that recognized antigen presented on hematopoietic progenitor cells. T cells transduced with these TCRs eliminated hematopoietic progenitor cells of the respective patients in vitro. One progenitor cell-reactive TCR (11A5) also recognized an epitope of the Epstein-Barr virus-derived latent membrane protein 1 (LMP1) presented on HLA-A∗02:01. We identified 2 LMP1-related mimotopes within the human proteome as activating targets of TCR 11A5, providing proof of concept that molecular mimicry of viral and self-epitopes can drive T cell-mediated elimination of hematopoietic progenitor cells in aplastic anemia.

Identification of distinct immune signatures in inclusion body myositis by peripheral blood immunophenotyping using machine learning models

Objective

Inclusion body myositis (IBM) is a progressive late-onset muscle disease characterised by preferential weakness of quadriceps femoris and finger flexors, with elusive causes involving immune, degenerative, genetic and age-related factors. Overlapping with normal muscle ageing makes diagnosis and prognosis problematic.

Methods

We characterised peripheral blood leucocytes in 81 IBM patients and 45 healthy controls using flow cytometry. Using a random forest classifier, we identified immune changes in IBM compared to HC. K-means clustering and the random forest one-versus-rest model classified patients into three immunophenotypic clusters. Functional outcome measures including mTUG, 2MWT, IBM-FRS, EAT-10, knee extension and grip strength were assessed across clusters.

Results

The random forest model achieved a 94% AUC ROC with 82.76% specificity and 100% sensitivity. Significant differences were found in IBM patients, including increased CD8+ T-bet+ cells, CD4+ T cells skewed towards a Th1 phenotype and altered γδ T cell repertoire with a reduced proportion of Vγ9+Vδ2+ cells. IBM patients formed three clusters: (i) activated and inflammatory CD8+ and CD4+ T-cell profile and the highest proportion of anti-cN1A-positive patients in cluster 1; (ii) limited inflammation in cluster 2; (iii) highly differentiated, pro-inflammatory T-cell profile in cluster 3. Additionally, no significant differences in patients' age and gender were detected between immunophenotype clusters; however, worsening trends were detected with several functional outcomes.

Conclusion

These findings unveil distinct immune profiles in IBM, shedding light on underlying pathological mechanisms for potential immunoregulatory therapeutic development.

Characterizing CD8+ TEMRA Cells in CP/CPPS Patients: Insights from Targeted Single-Cell Transcriptomic and Functional Investigations

Background

The specific involvement of the CD8+ T effector memory RA (TEMRA) subset in patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) has largely not been explored in the literature.

Methods

Targeted single-cell RNA sequencing (scRNA-seq) profiles were generated from peripheral blood mononuclear cells (PBMCs) obtained from two CP/CPPS patients and two healthy controls (HCs) in our recent study. Pseudotime series algorithms were used to reveal the differentiation trajectory, CellChat analysis was used to explore the communication between individual cells, and the SCENIC program was used to identify potential transcription factors (TFs). Based on the cosine similarity, clusters of differentially expressed genes (DEGs) were considered to be further enriched in different pathways. To confirm the functional role of the critical clusters, flow cytometry was employed.

Results

The results revealed the molecular landscape of these clusters, with TEMRA cells exhibiting pronounced cytokine-mediated signaling pathway enrichment. Pseudotime trajectory analysis further mapped the evolution from naïve T cells to that of TEMRA cells, elucidating the developmental pathways involved in the immune context. A significant finding from CellChat analysis was the differential expression of ligands and receptors, with CD8+ TEMRA cells showing enhanced signaling, particularly in the CP/CPPS context, compared to HCs. Flow cytometry confirmed these results, revealing a heightened proinflammatory cytokine profile in patients with chronic prostatitis-like symptoms (CP-LS), suggesting that TEMRA cells play a significant role in disease pathogenesis. TF profiling across the T-cell clusters identified key regulators of cellular identity, identifying novel therapeutic targets. Elevated TNF signaling activity in CD8+ TEMRA cells underscored the involvement of these cells in disease mechanisms.

Conclusion

This study elucidates the pivotal role of the CD8+ TEMRA cell subset in CP/CPPS, which is characterized by increased TNF signaling and proinflammatory factor expression, highlighting potential biomarkers and opening new avenues for therapeutic intervention.

Cytotoxic CD8+ Temra cells show loss of chromatin accessibility at genes associated with T cell activation

As humans age, their memory T cell compartment expands due to the lifelong exposure to antigens. This expansion is characterized by terminally differentiated CD8+ T cells (Temra), which possess NK cell-like phenotype and are associated with chronic inflammatory conditions. Temra cells are predominantly driven by the sporadic reactivation of cytomegalovirus (CMV), yet their epigenomic patterns and cellular heterogeneity remain understudied. To address this gap, we correlated their gene expression profiles with chromatin openness and conducted single-cell transcriptome analysis, comparing them to other CD8+ subsets and CMV-responses. We confirmed that Temra cells exhibit high expression of genes associated with cytotoxicity and lower expression of costimulatory and chemokine genes. The data revealed that CMV-responsive CD8+ T cells (Tcmv) were predominantly derived from a mixed population of Temra and memory cells (Tcm/em) and shared their transcriptomic profiles. Using ATAC-seq analysis, we identified 1449 differentially accessible chromatin regions between CD8+ Temra and Tcm/em cells, of which only 127 sites gained chromatin accessibility in Temra cells. We further identified 51 gene loci, including costimulatory CD27, CD28, and ICOS genes, whose chromatin accessibility correlated with their gene expression. The differential chromatin regions Tcm/em cells were enriched in motifs that bind multiple transcriptional activators, such as Jun/Fos, NFkappaB, and STAT, whereas the open regions in Temra cells mainly contained binding sites of T-box transcription factors. Our single-cell analysis of CD8+CCR7loCD45RAhi sorted Temra population showed several subsets of Temra and NKT-like cells and CMC1+ Temra populations in older individuals that were shifted towards decreased cytotoxicity. Among CD8+CCR7loCD45RAhi sorted cells, we found a decreased proportion of IL7R+ Tcm/em-like and MAIT cells in individuals with high levels of CMV antibodies (CMVhi). These results shed new light on the molecular and cellular heterogeneity of CD8+ Temra cells and their relationship to aging and CMV infection.

Single-Cell Atlas of Atherosclerosis Patients by Cytof: Circulatory and Local Immune Disorders

Atherosclerosis (AS) is a common underlying pathology of coronary artery disease, peripheral artery disease, and stroke. The characteristics of immune cells within plaques and their functional relationships with blood are crucial in AS. In this study, Mass cytometry (CyTOF), RNA-sequencing and immunofluorescence were combined to comprehensively analyze plaque tissues and peripheral blood from 25 AS patients (22 for Mass cytometry and 3 for RNA-sequencing), as well as blood from 20 healthy individuals. The study identified a complexity of leukocytes in the plaque, including both defined anti-inflammatory and pro-inflammatory subsets such as M2-like CD163+ macrophages, Natural killer T cells (NKT), CD11b+ CD4+ T effector memory cells (Tem), and CD8+ terminally differentiated effector memory cells (TEMRA). Functionally activated cell subsets were also found in peripheral blood in AS patients, highlighting the vivid interactions between leukocytes in plaque and blood. The study provides an atlas of the immune landscape in atherosclerotic patients, where pro-inflammatory activation was found to be a major feature of peripheral blood. The study identified NKT, CD11b+ CD4+ Tem, CD8+ TEMRA and CD163+ macrophages as key players in the local immune environment.

Terminally differentiated effector memory T cells associate with cognitive and AD-related biomarkers in an aging-based community cohort

Background and Purpose

The immune response changes during aging and the progression of Alzheimer's disease (AD) and related dementia (ADRD). Terminally differentiated effector memory T cells (called TEMRA) are important during aging and AD due to their cytotoxic phenotype and association with cognitive decline. However, it is not clear if the changes seen in TEMRAs are specific to AD-related cognitive decline specifically or are more generally correlated with cognitive decline. This study aimed to examine whether TEMRAs are associated with cognition and plasma biomarkers of AD, neurodegeneration, and neuroinflammation in a community-based cohort of older adults.

Methods

Study participants from a University of Kentucky Alzheimer's Disease Research Center (UK-ADRC) community-based cohort of aging and dementia were used to test our hypothesis. There were 84 participants, 44 women and 40 men. Participants underwent physical examination, neurological examination, medical history, cognitive testing, and blood collection to determine plasma biomarker levels (Aβ42/Aβ40 ratio, total tau, Neurofilament Light chain (Nf-L), Glial Fibrillary Acidic Protein (GFAP)) and to isolate peripheral blood mononuclear cells (PBMCs). Flow cytometry was used to analyze PBMCs from study participants for effector and memory T cell populations, including CD4+ and CD8+ central memory T cells (TCM), Naïve T cells, effector memory T cells (TEM), and effector memory CD45RA+ T cells (TEMRA) immune cell markers.

Results

CD8+ TEMRAs were positively correlated with Nf-L and GFAP. We found no significant difference in CD8+ TEMRAs based on cognitive scores and no associations between CD8+ TEMRAs and AD-related biomarkers. CD4+ TEMRAs were associated with cognitive impairment on the MMSE. Gender was not associated with TEMRAs, but it did show an association with other T cell populations.

Conclusion

These findings suggest that the accumulation of CD8+ TEMRAs may be a response to neuronal injury (Nf-L) and neuroinflammation (GFAP) during aging or the progression of AD and ADRD. As our findings in a community-based cohort were not clinically-defined AD participants but included all ADRDs, this suggests that TEMRAs may be associated with changes in systemic immune T cell subsets associated with the onset of pathology.

Human virome profiling identified CMV as the major viral driver of a high accumulation of senescent CD8+ T cells in patients with advanced NSCLC

Circulating senescent CD8+ T (T8sen) cells are characterized by a lack of proliferative capacities but retain cytotoxic activity and have been associated to resistance to immunotherapy in patients with advanced non-small cell lung cancer (aNSCLC). We aimed to better characterize T8sen and to determine which factors were associated with their accumulation in patients with aNSCLC. Circulating T8sen cells were characterized by a higher expression of SA-βgal and the transcription factor T-bet, confirming their senescent status. Using whole virome profiling, cytomegalovirus (CMV) was the only virus associated with T8sen. CMV was necessary but not sufficient to explain high accumulation of T8sen (T8senhigh status). In CMV+ patients, the proportion of T8sen cells increased with cancer progression. Last, CMV-induced T8senhigh phenotype but not CMV seropositivity itself was associated with worse progression-free and overall survival in patients treated with anti-PD-(L)1 therapy but not with chemotherapy. Overall, CMV is the unique viral driver of T8sen-driven resistance to anti-PD-(L)1 antibodies in patients with aNSCLC.

Relevance of tissue-resident memory CD8 T cells in the onset of Parkinson's disease and examination of its possible etiologies: infectious or autoimmune?

Tissue-resident memory CD8 T cells are responsible for local immune surveillance in different tissues, including the brain. They constitute the first line of defense against pathogens and cancer cells and play a role in autoimmunity. A recently published study demonstrated that CD8 T cells with markers of residency containing distinct granzymes and interferon-γ infiltrate the parenchyma of the substantia nigra and contact dopaminergic neurons in an early premotor stage of Parkinson's disease. This infiltration precedes α-synuclein aggregation and neuronal loss in the substantia nigra, suggesting a relevant role for CD8 T cells in the onset of the disease. To date, the nature of the antigen that initiates the adaptive immune response remains unknown. This review will discuss the role of tissue-resident memory CD8 T cells in brain immune homeostasis and in the onset of Parkinson's disease and other neurological diseases. We also discuss how aging and genetic factors can affect the CD8 T cell immune response and how animal models can be misleading when studying human-related immune response. Finally, we speculate about a possible infectious or autoimmune origin of Parkinson's disease.

Autoantibodies Neutralizing Type III Interferons Are Uncommon in Patients with Severe Coronavirus Disease 2019 Pneumonia

Autoantibodies (AABs) neutralizing type I interferons (IFN) underlie about 15% of cases of critical coronavirus disease 2019 (COVID-19) pneumonia. The impact of autoimmunity toward type III IFNs remains unexplored. We included samples from 1,002 patients with COVID-19 (50% with severe disease) and 1,489 SARS-CoV-2-naive individuals. We studied the prevalence and neutralizing capacity of AABs toward IFNλ and IFNα. Luciferase-based immunoprecipitation method was applied using pooled IFNα (subtypes 1, 2, 8, and 21) or pooled IFNλ1-IFNλ3 as antigens, followed by reporter cell-based neutralization assay. In the SARS-CoV-2-naive cohort, IFNλ AABs were more common (8.5%) than those targeting IFNα2 (2.9%) and were related with older age. In the COVID-19 cohort the presence of autoreactivity to IFNλ did not associate with severe disease [odds ratio (OR) 0.84; 95% confidence interval (CI) 0.40-1.73], unlike to IFNα (OR 4.88; 95% CI 2.40-11.06; P < 0.001). Most IFNλ AAB-positive COVID-19 samples (67%) did not neutralize any of the 3 IFNλ subtypes. Pan-IFNλ neutralization occurred in 5 patients (0.50%), who all suffered from severe COVID-19 pneumonia, and 4 of them neutralized IFNα2 in addition to IFNλ. Overall, AABs to type III IFNs are rarely neutralizing, and do not seem to predispose to severe COVID-19 pneumonia on their own.

Immune Response after SARS-CoV-2 Infection with Residual Post-COVID Symptoms

Many patients develop post-acute COVID syndrome (long COVID (LC)). We compared the immune response of LC and individuals with post-COVID full recovery (HC) during the Omicron pandemic. Two hundred ninety-two patients with confirmed COVID infections from January to May 2022 were enrolled. We observed anti-SARS-CoV-2 receptor-binding domain immunoglobulin G, surrogate virus neutralization test, T cell subsets, and neutralizing antibodies against Wuhan, BA.1, and BA.5 viruses (NeuT). NeuT was markedly reduced against BA.1 and BA.5 in HC and LC groups, while antibodies were more sustained with three doses and an updated booster shot than ≤2-dose vaccinations. The viral neutralization ability declined at >84-days after COVID-19 onset (PC) in both groups. PD1-expressed central and effector memory CD4+ T cells, and central memory CD8+ T cells were reduced in the first months PC in LC. Therefore, booster vaccines may be required sooner after the most recent infection to rescue T cell function for people with symptomatic LC.

Tofacitinib treatment of rheumatoid arthritis increases senescent T cell frequency in patients and limits T cell function in vitro

Unraveling the immune signatures in rheumatoid arthritis (RA) patients receiving various treatment regimens can aid in comprehending the immune mechanisms' role in treatment efficacy and side effects. Given the critical role of cellular immunity in RA pathogenesis, we sought to identify T-cell profiles characterizing RA patients under specific treatments. We compared 75 immunophenotypic and biochemical variables in healthy donors (HD) and RA patients, including those receiving different treatments as well as treatment-free patients. Additionally, we conducted in vitro experiments to evaluate the direct effect of tofacitinib on purified naïve and memory CD4+ and CD8+ T cells. Multivariate analysis revealed that tofacitinib-treated patients segregated from HD at the expense of T-cell activation, differentiation, and effector function-related variables. Additionally, tofacitinib led to an accumulation of peripheral senescent memory CD4+ and CD8+ T cells. In vitro, tofacitinib impaired the activation, proliferation, and effector molecules expression and triggered senescence pathways in T-cell subsets upon TCR-engagement, with the most significant impact on memory CD8+ T cells. Our findings suggest that tofacitinib may activate immunosenescence pathways while simultaneously inhibiting effector functions in T cells, both effects likely contributing to the high clinical success and reported side effects of this JAK inhibitor in RA.

Age-associated systemic factors change central and peripheral immunity in adult male mice

Aging coincides with major changes in brain immunity that aid in a decline in neuronal function. Here, we postulate that systemic, pro-aging factors contribute to immunological changes that occur within the brain during aging. To investigate this hypothesis, we comprehensively characterized the central and peripheral immune landscape of 20-month-old male mice using cytometry by time-of-flight (CyTOF) and investigated the role of age-associated circulating factors. We found that CD8+ T cells expressing programmed cell death protein 1 (PD1) and tissue-resident memory CD8+ T cells accumulated in the aged brain while levels of memory T cells rose in the periphery. Injections of plasma derived from 20-month-old mice into 5-month-old receiving mice decreased the frequency of splenic and circulating naïve T cells, increased memory CD8+ T cells, and non-classical, patrolling monocytes in the spleen, and elevated levels of regulatory T cells and non-classical monocytes in the blood. Notably, CD8+ T cells accumulated within white matter areas of plasma-treated mice, which coincided with the expression of vascular cell adhesion molecule 1 (VCAM-1), a mediator of immune cell trafficking, on the brain vasculature. Taken together, we here describe age-related immune cell changes in the mouse brain and circulation and show that age-associated systemic factors induce the expansion of CD8+ T cells in the aged brain.

Senolytic and senomorphic interventions to defy senescence-associated mitochondrial dysfunction

The accumulation of senescent cells in the aging individual is associated with an increase in the occurrence of age-associated pathologies that contribute to poor health, frailty, and mortality. The number and type of senescent cells is viewed as a contributor to the body's senescence burden. Cellular models of senescence are based on induction of senescence in cultured cells in the laboratory. One type of senescence is triggered by mitochondrial dysfunction. There are several indications that mitochondria defects contribute to body aging. Senotherapeutics, targeting senescent cells, have been shown to induce their lysis by means of senolytics, or repress expression of their secretome, by means of senomorphics, senostatics or gerosuppressors. An outline of the mechanism of action of various senotherapeutics targeting mitochondria and senescence-associated mitochondria dysfunction will be here addressed. The combination of geroprotective interventions together with senotherapeutics will help to strengthen mitochondrial energy metabolism, biogenesis and turnover, and lengthen the mitochondria healthspan, minimizing one of several molecular pathways contributing to the aging phenotype.

Peripheral immune cell profiling of double-hit lymphoma by mass cytometry

BACKGROUND

Double-hit or Triple-hit lymphoma (DHL/THL) is a subset of high-grade B cell lymphoma harboring rearrangements of MYC and BCL2 and/or BCL6, and usually associate with aggressive profile, while current therapies tend to provide poor clinical outcomes and eventually relapsed. Further explorations of DHL at cellular and molecular levels are in demand to offer guidance for clinical activity.

METHODS

We collected the peripheral blood of DHL patients and diffused large B cell lymphoma (DLBCL) patients from single institute and converted them into PBMC samples. Mass cytometry was then performed to characterize these samples by 42 antibody markers with samples of healthy people as control. We divided the immune cell subtypes based on the expression profile of surface antigens, and the proportion of each cell subtype was also analyzed. By comparing the data of the DLBCL group and the healthy group, we figured out the distinguished immune cell subtypes of DHL patients according to their abundance and marker expression level. We further analyzed the heterogeneity of DHL samples by pairwise comparison based on clinical characteristics.

RESULTS

We found double-positive T cells (DPT) cells were in a significantly high percentage in DHL patients, whereas the ratio of double-negative T cells (DNT) was largely reduced in patients. Besides, CD38 was uniquely expressed at a high level on some naïve B cells of DHL patients, which could be a marker for the diagnosis of DHL (distinguishing from DLBCL), or even be a drug target for the treatment of DHL. In addition, we illustrated the heterogeneity of DHL patients in terms of immune cell landscape, and highlighted TP53 as a major factor that contributes to the heterogeneity of the T cells profile.

CONCLUSION

Our study demonstrated the distinct peripheral immune cell profile of DHL patients by contrast to DLBCL patients and healthy people, as well as the heterogeneity within the DHL group, which could provide valuable guidance for the diagnosis and treatment of DHL.

Prospective Evaluation of CD45RA+/CCR7- Effector Memory T (TEMRA) Cell Subsets in Patients with Primary and Secondary Brain Tumors during Radiotherapy of the Brain within the Scope of the Prospective Glio-CMV-01 Clinical Trial

Radiotherapy (RT) of the brain is a common treatment for patients with high-grade gliomas and brain metastases. It has previously been shown that reactivation of cytomegalovirus (CMV) frequently occurs during RT of the brain. This causes neurological decline, demands antiviral treatment, and is associated with a worse prognosis. CMV-specific T cells are characterized by a differentiated effector memory phenotype and CD45RA+ CCR7- effector memory T (T_EMRA) cells were shown to be enriched in CMV seropositive individuals. In this study, we investigated the distribution of T_EMRA cells and their subsets in the peripheral blood of healthy donors and, for the first time, prospectively within the scope of the prospective Glio-CMV-01 clinical trial of patients with high-grade glioma and brain metastases during radiation therapy as a potential predictive marker. First, we developed a multicolor flow cytometry-based assay to monitor the frequency and distribution of T_EMRA cells in a longitudinal manner. The CMV serostatus and age were considered as influencing factors. We revealed that patients who had a reactivation of CMV have significantly higher amounts of CD8+ T_EMRA cells. Further, the distribution of the subsets of T_EMRA cells based on the expression of CD27, CD28, and CD57 is highly dependent on the CMV serostatus. We conclude that the percentage of CD8+ T_EMRA cells out of all CD8+ T cells has the potential to serve as a biomarker for predicting the risk of CMV reactivation during RT of the brain. Furthermore, this study highlights the importance of taking the CMV serostatus into account when analyzing T_EMRA cells and their subsets.

Construction and evaluation of an aging-associated genes-based model for pancreatic adenocarcinoma prognosis and therapies

Objectives: Pancreatic adenocarcinoma (PAAD) is a highly malignant tumor. Despite extensive research, the precise role of aging-related genes in the initiation, microenvironment regulation, and progression of PAAD remains unclear.Methods: Patients with PAAD were selected from the International Cancer Genome Consortium (ICGC), and The Cancer Genome Atlas (TCGA) cohorts and the cell senescence-associated genes were obtained from CellAge. ConsensusClusterPlus was utilized for cluster identification. The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was performed to construct a prognosis prediction model.Results: We identified three clusters (C1, C2, and C3) based on aging-associated gene profiles. The C1 cluster had a shorter overall survival time, advanced clinical grades, lower immune ESTIMATE score, and tumor immune dysfunction and exclusion (TIDE) score than the C3 subgroup. Moreover, signaling pathways for cell cycle activation were enriched in the C1 cluster. We also identified eight hub genes and constructed a risk model. The high cellular senescence-related signature (CSRS) score subtype exhibited poor prognosis, advanced clinical grades, M2 macrophage infiltration, higher immune checkpoint gene expression, and lower immunotherapeutic benefits.Conclusion: Our risk score model shows high prediction accuracy and survival prediction ability in individual clinical prognosis and pre-immunotherapy evaluation.