T-cell Senescence Research Articles

Effects of concentric and eccentric exercise regimens on bioenergetic efficiency of lymphocytes in sedentary males.

Eccentric exercise training (EET) increases physical performance while having lower metabolic demand than concentric exercise training (CET). Whether EET influences bioenergetic efficiency in peripheral blood mononuclear cells (PBMCs) remains unclear. This study investigates the effects of EET and CET on PBMC phenotypes and mitochondrial functions in blood. Thirty three sedentary healthy males were randomly assigned to either EET (n=11) or CET (n=11) that performed at progressively increased from 60% to 80% of maximal absolute workload for 30min/day, 5days/week for 6weeks, or a control group (n=11) that did not receive any exercise intervention. A graded exercise stress test (GXT) was performed before and after the intervention. PBMC phenotypes and mitochondrial respiratory capacity were analyzed using flowcytometry and high-resolution respirometry, respectively. In the same absolute workload, EET elicited lower heart rate and rating of perceived exertion than CET. However, EET as CET increased the VO2 level at the ventilatory threshold. Notably, both EET and CET increased central memory (CD45RO+/CD62+/CD3+) T cells and decreased effector memory T cells reexpressing CD45RA (CD45RA+/CD62-/CD3+). Moreover, the two exercise regimens diminished the loss of mitochondrial membrane potential (ΔΨm) caused by GXT, increased maximal/reserve O2 consumption rates (OCR), and bioenergetic health index in intact PBMCs and enhanced complex I-/II-related OCR in PBMCs with a substrate-rich environment. EET improves aerobic fitness with a lower cardiovascular response to exercise than CET. Moreover, EET as CET reduces senescent T-cell distribution in blood and improves PBMC bioenergetic efficiency by stabilizing ΔΨm and increasing capacity of oxidative phosphorylation.

T-Cell Senescence in Human Metabolic Diseases.

Immunosenescence denotes a state of dysregulated immune cell function characterized by a confluence of factors, including arrested cell cycle, telomere shortening, markers of cellular stress, mitochondrial dysfunction, loss of proteostasis, epigenetic reprogramming, and secretion of proinflammatory mediators. This state primarily manifests during the aging process but can also be induced in various pathological conditions, encompassing chronic viral infections, autoimmune diseases, and metabolic disorders. Age-associated immune system alterations extend to innate and adaptive immune cells, with T-cells exhibiting heightened susceptibility to immunosenescence. In particular, senescent T-cells have been identified in the context of metabolic disorders such as obesity, diabetes, and cardiovascular diseases. Recent investigations suggest a direct link between T-cell senescence, inflammation, and insulin resistance. The perturbation of biological homeostasis by senescent T-cells appears intricately linked to the initiation and progression of metabolic diseases, particularly through inflammation-mediated insulin resistance. Consequently, senescent T-cells are emerging as a noteworthy therapeutic target. This review aims to elucidate the intricate relationship between metabolic diseases and T-cell senescence, providing insights into the potential roles of senescent T-cells in the pathogenesis of metabolic disorders. Through a comprehensive examination of current research findings, this review seeks to contribute to a deeper understanding of the complex interplay between immunosenescence and metabolic health.

T-cell senescence was correlated with early atherosclerosis inpatients with systemic lupus erythematosus.

To investigate the correlation between T-cell senescence with the atherosclerosis markers in patients with systemic lupus erythematosus (SLE). The study participants were 40 female SLE patients aged 18-45 years who met the 2019 EULAR/ACR criteria and 40 healthy individuals. The atherosclerosis markers were investigated using the Doppler ultrasonography examinations to measure the cIMT (carotid intima-media thickness) and flow-mediated dilation (FMD) and serological markers using soluble ICAM-1 and VCAM-1. Flow cytometry of CD4+CD57+, CD8+CD57+, CD4+CD28null, and CD8+CD28null T cells were used to assess the immunosenescence markers. The cIMT (p < .001), sICAM-1 (p < .001), and sVCAM-1 (p < .001) were significantly higher in SLE patients compared with control, while FMD was significantly lower in SLE patients (p < .001). The percentages of all T-cell senescence markers are also significantly higher in SLE patients than in healthy individuals. Positive correlations were shown between cIMT with the CD4+CD57+ (R = .301, p = .005), CD4+CD28null (R = .448, p < .001), and CD8+CD28null (R = .422, p < .001). Conversely, negative correlations were demonstrated between the FMD with CD4+CD57+ (R = -.236, p = .023), CD8+CD57+ (R = -.409, p < .001), CD4+CD28null (R = -.422, p < .001), and CD8+CD28null (R = -.318, p = .003). The soluble markers of sICAM-1 and sVCAM-1 were also positively correlated with the T-cell senescence markers. Early sign of atherosclerosis was demonstrated in patients with SLE in this study. T-cell senescence markers had significant correlations with the atherosclerosis markers, including the cIMT, FMD, and soluble adhesion molecules levels. Understanding the link between immunosenescence and atherosclerosis might help to identify a new method for early detection and treatment of atherosclerosis in SLE.

Mitochondrial Transplantation Promotes Protective Effector and Memory CD4+ T Cell Response During Mycobacterium Tuberculosis Infection and Diminishes Exhaustion and Senescence in Elderly CD4+ T cells.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is a major global health concern, particularly affecting those with weakened immune systems, including the elderly. CD4+ T cell response is crucial for immunity against M.tb, but chronic infections and aging can lead to T cell exhaustion and senescence, worsening TB disease. Mitochondrial dysfunction, prevalent in aging and chronic diseases, disrupts cellular metabolism, increases oxidative stress, and impairs T-cell functions. This study investigates the effect of mitochondrial transplantation (mito-transfer) on CD4+ T cell differentiation and function in aged mouse models and human CD4+ T cells from elderly individuals. Mito-transfer in naïve CD4+ T cells is found to promote protective effector and memory T cell generation during M.tb infection in mice. Additionally, it improves elderly human T cell function by increasing mitochondrial mass and altering cytokine production, thereby reducing markers of exhaustion and senescence. These findings suggest mito-transfer as a novel approach to enhance aged CD4+ T cell functionality, potentially benefiting immune responses in the elderly and chronic TB patients. This has broader implications for diseases where mitochondrial dysfunction contributes to T-cell exhaustion and senescence.

Low-level HIV-1 viremia affects T-cell activation and senescence in long-term treated adults in the INSTI era

BackgroundAround 10% of people with HIV (PWH) exhibit a low-level viremia (LLV) under antiretroviral therapy (ART). However, its origin and clinical significance are largely unknown, particularly at viremias between 50 and 200 copies/mL and under modern ART based on integrase strand transfer inhibitors (INSTIs). Our aim was to characterize their poor immune response against HIV in comparison to individuals with suppressed viremia (SV) and non-HIV controls (NHC).MethodsTransversal observational study in 81 matched participants: 27 PWH with LLV, 27 PWH with SV, and 27 NHC. Activation (CD25, HLA-DR, and CD38) and senescence [CD57, PD1, and HAVCR2 (TIM3)] were characterized in peripheral T-cell subsets by spectral flow cytometry. 45 soluble biomarkers of systemic inflammation were evaluated by immunoassays. Differences in cell frequencies and plasma biomarkers among groups were evaluated by a generalized additive model for location, scale, and shape (GAMLSS) and generalized linear model (GLM) respectively, adjusted by age, sex at birth, and ART regimen.ResultsThe median age was 53 years and 77.8% were male. Compared to NHC, PWH showed a lower CD4+/CD8+ ratio and increased activation, senescence, and inflammation, highlighting IL-13 in LLV. In addition, LLV showed a downtrend in the frequency of CD8+ naive and effector memory (EM) type 1 compared to SV, along with higher activation and senescence in CD4+ and CD8+ EM and terminally differentiated effector memory RA+ (TEMRA) subpopulations. No significant differences in systemic inflammation were observed between PWH groups.ConclusionLLV between 50 and 200 copies/mL leads to reduced cytotoxic activity and T-cell dysfunction that could affect cytokine production, being unable to control and eliminate infected cells. The increase in senescence markers suggests a progressive loss of immunological memory and a reduction in the proliferative capacity of immune cells. This accelerated immune aging could lead to an increased risk of developing future comorbidities. These findings strongly advocate for heightened surveillance of these PWH to promptly identify potential future complications.

Effect of physical activity in lymphocytes senescence burden in patients with COPD.

Chronic obstructive pulmonary disease (COPD) is regarded as an accelerated-age disease in which chronic inflammation, maladaptive immune responses, and senescence cell burden coexist. Accordingly, cellular senescence has emerged as a potential mechanism involved in COPD pathophysiology. In this study, 25 stable patients with COPD underwent a daily physical activity promotion program for 6 mo. We reported that increase of physical activity was related to a reduction of the senescent cell burden in circulating lymphocytes of patients with COPD. Senescent T-lymphocyte population, characterized by absence of surface expression of CD28, was reduced after physical activity intervention, and the reduction was associated to the increase of physical activity level. In addition, the mRNA expression of cyclin-dependent kinase inhibitors, a hallmark of cell senescence, was reduced and, in accordance, the proliferative capacity of lymphocytes was improved postintervention. Moreover, we observed an increase in functionality in T cells from patients after intervention, including improved markers of activation, enhanced cytotoxicity, and altered cytokine secretions in response to viral challenge. Lastly, physical activity intervention reduced the potential of lymphocytes' secretome to induce senescence in human primary fibroblasts. In conclusion, our study provides, for the first time, evidence of the potential of physical activity intervention in patients with COPD to reduce the senescent burden in circulating immune cells.NEW & NOTEWORTHY For the first time, we identified in patients with COPD a relation between physical activity intervention with respiratory function improvement and cellular senescence burden in lymphocytes that improved the T cell functionality and proliferative capacity of patients. In addition, our experiments highlight the possible impact of T-cell senescence in other cell types which could be related to some of the clinical lung complications observed in COPD.

Characteristics and mechanisms of T-cell senescence: A potential target for cancer immunotherapy.

Immunosenescence, the aging of the immune system, leads to functional deficiencies, particularly in T cells, which undergo significant changes. While numerous studies have investigated age-related T-cell phenotypes in healthy aging, senescent T cells have also been observed in younger populations during pathological conditions like cancer. This review summarizes the recent advancements in age-associated alterations and markers of T cells, mechanisms, and the relationship between senescent T cells and the tumor microenvironment. We also discuss potential strategies for targeting senescent T cells to prevent age-related diseases and enhance tumor immunotherapy efficacy.

Vaccination with Tozimameran Induces T-Cell Activation, but Not Senescent or Exhaustive Alterations, in Kidney Transplant Recipients.

Multiple vaccinations have potential inimical effects on the immune system aging process. We examined whether response to SARS-CoV-2 vaccination with Tozinameran is associated with immunosenescence and immunoexhaustion in kidney transplant recipients (KTRs). In this prospective observational study, we observed 39 adult kidney transplant recipients (KTRs) who had no pre-existing anti-SARS-CoV-2 antibodies and were on stable immunosuppression. CD4+ and CD8+ T-cell subpopulations [comprising CD45RA+CCR7+ (naïve), CD45RA-CCR7+ (T-central memory, TCM), CD45RA-CCR7- (T-effector memory, TEM) and CD45RA+CCR7- (T-effector memory re-expressing CD45RA, TEMRA, senescent), CD28- (senescent) and PD1+ (exhausted)] were evaluated at 2 time points: T1 (48 h prior to the 3rd), and T2 (3 weeks following the 3rd Tozinameran dose administration). At each time point, patients were separated into Humoral and/or Cellular Responders and Non-Responders. From T1 to T2, CD4+TCM and CD8+TEM were increased, while naïve CD4+ and CD8+ proportions were reduced in the whole cohort of patients, more prominently among responders. At T2, responders compared to non-responders had higher CD8+CD28+ [227.15 (166) vs. 131.44 (121) cells/µL, p: 0.036], lower CD4+CD28- T-lymphocyte numbers [59.65 (66) cells/µL vs. 161.19 (92) cells/µL, p: 0.026] and percentages [6.1 (5.5)% vs. 20.7 (25)%, p: 0.04]. In KTRs, response to vaccination is not associated with an expansion of senescent and exhausted T-cell concentrations, but rather with a switch from naïve to differentiated-activated T-cell forms.

Similar Viral and Immune Characteristics of Kaposi Sarcoma in ART-treated People Living With HIV and Older Patients With Classic Kaposi Sarcoma.

Reemergence of human herpesvirus 8 (HHV-8)-induced Kaposi sarcoma (KS) in people living with HIV (PLWH) despite antiretroviral therapy (ART) poses a clinical challenge because they already have favorable CD4 T-cell numbers and undetectable viral loads. We observed that clinical presentation in PLWH on ART resembled classic KS found in older HIV-uninfected patients and hypothesized that immunosenescence may thus play a role in occurrence of KS on ART. We compared viral and immune factors implicated in the development of KS in ART-treated PLWH (HIV KS) and HIV-uninfected classic KS patients (cKS), compared to controls without KS (HIV Control, cControls respectively). Plasma, peripheral blood mononuclear cell, and skin tissues were obtained from 11 HIV KS and 11 cKS patients and 2 groups of age-matched controls. HIV KS participants were younger than cKS (aged 53 vs 75 years). HHV-8 genotypes did not differ between groups. Despite the younger age and a lower CD4/CD8 ratio, activated, exhausted, and senescent T-cell frequencies were similar between HIV KS and cKS. Anti-HHV-8 immunoglobulin G levels were higher and circulating HHV-8 DNA lower in HIV KS compared with cKS. Circulating platelet-derived growth factors AA-BB and granulocyte colony-stimulating factors were higher in HIV KS We observed similar levels of HHV-8 DNA and PD-1 expression in skin lesions from HIV KS and cKS patients. Altogether, early immune senescence could be involved in the development of KS in ART-treated PLWH. Higher anti-HHV-8 immunoglobulin G levels could be linked with lower circulating viral load. Such insights should help developing therapeutical strategies to prevent development and treat KS in PLWH on ART.

Влияние хронического облучения на показатели цитогенетических маркеров старения у жителей прибрежных сел реки Теча

The understanding of the exposure effects on the human health could be improved by analyzing the influence of the chronic low dose rate exposure on the senescence of the immune system cells. It will also help to develop the measures aimed at the mitigation of the adverse effects. The objective of the study is to investigate the influence of the chronic low dose rate exposure on the senescence of the immune system cells using the cytogenetic markers. In the course of the research the authors evaluated the cellular senescence markers — genome instability and telomere depletion — in T-lymphocytes of the individuals exposed in the Southern Urals (exposure doses were 0.001 Gy — 4.7 Gy, the age of examined people was 40–89 years). The data analysis has demonstrated that the effect of chronic exposure on the T-cell senescence was indirect. Unstable chromosome aberrations occurred statistically significantly more frequently in exposed people aged 40–59 years (p = 0.012). Frequency of lymphocytes with micronuclei in exposed individuals differed in men and women (p = 0.001). Statistically significant decrease in the telomere length was revealed (for the chromosome arms 1q, 3p, 3q, 20p, 20q, 13q, 15p, 22q (p &lt; 0.05); 19p, 21q (p &lt; 0.01)).

Association of circulating T lymphocytes and their functional states with pathologic complete response (pCR) in breast cancer (BC). A prospective Italian study.

559 Background: In BC, pCR is associated with substantial survival benefit. Hence, escalated neoadjuvant treatments (NATs) are being increasingly employed to improve pCR rates, warranting biomarkers for better patients’ selection. T-cell exhaustion and senescence are dysfunctional states that coexist in patients with cancer, impairing antitumor immunity and sustaining a suppressive immune microenvironment. Here, we assessed the impact of such states on pCR across different BC subtypes and NATs. Methods: This is a prospective study on patients undergoing NAT for BC at the Maggiore Hospital of Novara, Italy. Blood was collected at baseline and after NAT. Circulating T lymphocytes were characterized with exhausted (CD28, PD1, LAG3) and senescent (CD57, KLRG-1) biomarkers utilizing flow cytometry. Neutrophiles/lymphocytes ratio (NLR) and lymphocytes/monocytes ratio (LMR) were also retrieved. Subpopulations with frequency &lt;1% were normalized for total CD3+ cells. Results: From October 2020 to January 2024, 134 patients were enrolled and 115 completed NAT (85.8%). Fifty-one (38,1%) had adequate samples for analysis, 16 (31,4%) with hormone receptor positive HER2 negative BC (HR+HER2-), 15 (29,4%) with HER2+, and 20 (39,2%) with triple negative BC (TN). At baseline, patients with TNBC had the lowest NLR (p=0.018) and lowest senescent CD4+CD28- (p=0.042). Associations with pCR are shown in the Table. Overall, LMR associated with increased pCR (OR 1.34 [95% CIs 1.00-1.89]), and NLR with decreased pCR (OR 0.67 [0.39-1.04]). Both associations were driven by HR+ status (interaction p = 0.061 and 0.060). Senescent CD4+ predicted lower pCR in both HR-HER2+ (OR 0.10 [0.01-0.36]) and TNBC (OR 0.10 [0.01-0.5]). In TNBC, exhausted CD8+ predicted higher pCR (OR 1.78 [1.08-3.79]). When assessed separately in patients who received NAT with or without pembrolizumab, exhausted CD8+ remained predictor of pCR in chemotherapy + pembrolizumab (OR 1.84 [1.03-5.00]), but not with chemotherapy alone (p=0.203). The dynamics of paired pre-NAT and post-NAT TNBC samples revealed significant differences. Senescent CD4+ increased after chemotherapy, but not with chemotherapy + pembrolizumab (p=0.007). Pembrolizumab was associated with depletion of PD1-positive CD8+, while chemotherapy alone was not (p=0.020). Conclusions: The characterization of circulating T lymphocytes could help identify patients who benefit more in terms of pCR from specific NATs, including chemoimmunotherapy. [Table: see text]

Decreased but persistent epigenetic age acceleration is associated with changes in T-cell subsets after initiation of highly active antiretroviral therapy in persons living with HIV.

Persons living with HIV (PLWH) experience the early onset of age-related illnesses, even in the setting of successful human immunodeficiency virus (HIV) suppression with highly active antiretroviral therapy (HAART). HIV infection is associated with accelerated epigenetic aging as measured using DNA methylation (DNAm)-based estimates of biological age and of telomere length (TL). DNAm levels (Infinium MethylationEPIC BeadChip) from peripheral blood mononuclear cells from 200 PLWH and 199 HIV-seronegative (SN) participants matched on chronologic age, hepatitis C virus, and time intervals were used to calculate epigenetic age acceleration, expressed as age-adjusted acceleration residuals from 4 epigenetic clocks [Horvath's pan-tissue age acceleration residual (AAR), extrinsic epigenetic age acceleration (EEAA), phenotypic epigenetic age acceleration (PEAA), and grim epigenetic age acceleration (GEAA)] plus age-adjusted DNAm-based TL (aaDNAmTL). Epigenetic age acceleration was compared for PLWH and SN participants at two visits: up to 1.5years prior and 2-3years after HAART (or equivalent visits). Flow cytometry was performed in PLWH and SN participants at both visits to evaluate T-cell subsets. Epigenetic age acceleration in PLWH decreased after the initiation of HAART but remained greater post-HAART than that in age-matched SN participants, with differences in medians of 6.6, 9.1, and 7.7 years for AAR, EEAA, and PEAA, respectively, and 0.39 units of aaDNAmTL shortening (all p < 0.001). Cumulative HIV viral load after HAART initiation was associated with some epigenetic acceleration (EEAA, PEAA, and aaDNAmTL), but even PLWH with undetectable HIV post-HAART showed persistent epigenetic age acceleration compared to SN participants (p < 0.001). AAR, EEAA, and aaDNAmTL showed significant associations with total, naïve, and senescent CD8 T-cell counts; the total CD4 T-cell counts were associated with AAR, EEAA, and PEAA (p = 0.04 to <0.001). In an epigenome-wide analysis using weighted gene co-methylation network analyses, 11 modules demonstrated significant DNAm differences pre- to post-HAART initiation. Of these, nine were previously identified as significantly different from pre- to post-HIV infection but in the opposite direction. In this large longitudinal study, we demonstrated that, although the magnitude of the difference decreases with HAART is associated with the cumulative viral load, PLWH are persistently epigenetically older than age-matched SN participants even after the successful initiation of HAART, and these changes are associated with changes in T-cell subsets.

#2238 In kidney transplant recipients, response to vaccination with Tozimameran is associated with T-cell activation, but not senescence or exhaustion

Abstract Background and Aims Responses to vaccinations among kidney transplant recipients (KTRs) tend to be impaired compared to those of healthy individuals, a fact that can, to some degree, be attributed to their more senescent immune system profile. However, in the current literature, few data regarding the potential effects of multiple vaccinations on these patients’ immune system aging process are available. The aim of our research was to examine whether response to anti-SARS-CoV-2 vaccination with Tozinameran is associated with immunosenescence and immunoexhaustion in KTRs, focusing on CD4+ and CD8+ T-cell subsets. We additionally attempted to define parameters implicated in CD4+ and CD8+ differentiation process. Method We performed a prospective, observational study. Our sample consisted of 39 adult KTRs on stable immunosuppression, naïve to SARS-CoV-2. We evaluated them at two time points: T1 (48 hours prior to the 3rd Tozinameran dose) and T2 (3 weeks after the 3rd Tozinameran dose), by measuring: a) anti-SARS-CoV-2 neutralizing antibody (NAb) levels with chemiluminescence immunoassay (CLIA) b) viral-specific interferon gamma (IFN-γ) production with enzyme-linked immunosorbent spot (ELISpot) and concentrations of CD4+ and CD8+ subpopulations [comprising CD45RA+CCR7+ (naïve), CD45RA-CCR7+ (central memory -CM-), CD45RA-CCR7- (effector memory -EM-) and CD45RA+CCR7- (effector memory re-expressing CD45RA -EMRA-, senescent) CD4+/CD8+, CD28-expressing (CD8+) and CD28-null (CD8-, senescent) CD4+/CD8+ and CD3+PD1+ (exhausted) T-cells]. At each time point, we divided patients into responders (NAb ≥ 0.3 AU/mL and/or ELISpot ≥ 30SFC/5 × 105 PBMCs) and non-responders (NAb &amp;lt; 0.3 AU/mL and ELISpot &amp;lt; 30SFC/5 × 105 PBMCs). We compared the cellular subsets’ compositions and their alterations (with regards to the differentiation-senescence and the immunoexhaustion processes) between responders and non-responders. We also examined the potential association of several other parameters with the above-mentioned cellular concentrations. Results From T1 to T2, we observed: a) in the total number of patients: an increase in T-cell EM (TEM) CD8+ concentrations and in TCM CD4+ and TEM CD8+ percentages and a drop in naïve CD4+ and CD8+ proportions, b) in responders at T1 (RT1): an ascent of TEM CD8+ numbers and of TCM CD4+ and TEM CD8+ percentages and a reduction of naïve CD4+ proportions, c) in responders at T2 (RT2): an elevation in TEM CD8+ concentrations and in TCM CD4+ percentages and a drop in naïve CD4+ counts and proportions and in TEMRA CD4+ numbers (Figs 1 and 2). At T2, responders compared to non-responders had higher concentrations of CD28+ CD4+ and CD8+ [756.34(368) vs. 446.57(925) and 227.15(166) vs. 131.44(121) cells/μL, p: 0.026 and 0.036 respectively] and greater percentages of CD28+CD4+ [93.8(6)% vs. 72.05(30.73)%, p: 0.05], as well as smaller proportions of CD28-CD4+ T-cells [6.1(5.5)% vs. 20.7(25)%, p: 0.04]. There was a negative association between age and naïve CD4+ and CD8+ T-cell and CD28+CD8+ concentrations at T1 (p: 0.042, 0.042 and 0.006, Spearman's ρ: −0.346, −0.345 and −0.444 respectively) and a positive correlation between exhausted T-cell (CD3+PD1+) numbers prior to the first vaccination and TEM / TEMRA CD4+ concentrations at T1 (p: 0.001 and 0.001, Spearman's ρ: 0.558 and 0.578 respectively), as well as TEMRA CD8+ counts at T2 (p: 0.037, Spearman's ρ: 0.396). There was also a positive association of eGFR value with TEMRA and CD28+ CD4+ counts at T1 (p: 0.021 and 0.014, Spearman's ρ: 0.389 and 0.402 respectively). Conclusion In KTRs, response to vaccination is not associated with an expansion of senescent and exhausted T-cell concentrations, but rather with a switch from naïve to differentiated-activated T-cell forms (including TEM and TCM). Age, T-cell exhaustion status at baseline and eGFR also to be correlated to the differentiation-senescence process.

Chemoradiotherapy-induced ACKR2+ tumor cells drive CD8+ T cell senescence and cervical cancer recurrence

Tumor recurrence after chemoradiotherapy is challenging to overcome, and approaches to predict the recurrence remain elusive. Here, human cervical cancer tissues before and after concurrent chemoradiotherapy (CCRT) analyzed by single-cell RNA sequencing reveal that CCRT specifically promotes CD8+ Tcell senescence, driven by atypical chemokine receptor 2 (ACKR2)+ CCRT-resistant tumor cells. Mechanistically, ACKR2 expression is increased in response to CCRT and is also upregulated through the ligation of CC chemokines that are produced by activated myeloid and Tcells. Subsequently, ACKR2+ tumor cells are induced to produce transforming growth factor β to drive CD8+ Tcell senescence, thereby compromising antitumor immunity. Moreover, retrospective analysis reveals that ACKR2 expression and CD8+ Tcell senescence are enhanced in patients with cervical cancer who experienced recurrence after CCRT, indicating poor prognosis. Overall, we identify a subpopulation of CCRT-resistant ACKR2+ tumor cells driving CD8+ Tcell senescence and tumor recurrence and highlight the prognostic value of ACKR2 and CD8+ Tcell senescence for chemoradiotherapy recurrence.

CD4+ T-Cell Senescence in Neurodegenerative Disease: Pathogenesis and Potential Therapeutic Targets.

With the increasing proportion of the aging population, neurodegenerative diseases have become one of the major health issues in society. Neurodegenerative diseases (NDs), including multiple sclerosis (MS), Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), are characterized by progressive neurodegeneration associated with aging, leading to a gradual decline in cognitive, emotional, and motor functions in patients. The process of aging is a normal physiological process in human life and is accompanied by the aging of the immune system, which is known as immunosenescence. T-cells are an important part of the immune system, and their senescence is the main feature of immunosenescence. The appearance of senescent T-cells has been shown to potentially lead to chronic inflammation and tissue damage, with some studies indicating a direct link between T-cell senescence, inflammation, and neuronal damage. The role of these subsets with different functions in NDs is still under debate. A growing body of evidence suggests that in people with a ND, there is a prevalence of CD4+ T-cell subsets exhibiting characteristics that are linked to senescence. This underscores the significance of CD4+ T-cells in NDs. In this review, we summarize the classification and function of CD4+ T-cell subpopulations, the characteristics of CD4+ T-cell senescence, the potential roles of these cells in animal models and human studies of NDs, and therapeutic strategies targeting CD4+ T-cell senescence.

Abstract 7: Ginsenoside Rb1 delays the senescence of CD8+ T cells to expand T cells with superior antitumor immunity

Abstract Background and Objective: Immunosenescence represents a distinct state of T cell dysfunction in the TME, and plays crucial role in many age-related diseases including tumor. Senescent cell removal by senolytic agents or therapies that inhibit the SASP have demonstrated benefit in both preclinical and clinical models of geriatric decline and chronic diseases. Here, we aimed to screen anti-aging compounds to delay T-cell senescence in TME, and explore novel strategies of reversing tumor induced T-cell senescence to restore antitumor immunity. Methods and Results: Using in vitro senescence inducing system, we screened ginsenoside Rb1 from 22 anti-aging compounds as the compound that had the most effective activity to reduce CD8+ T cell senescence, displayed as decreased β-gal, p16, and p21. Further analysis showed that ginsenoside Rb1 promoted anti-CD3/CD28-induced TCR signaling and the secretion of effector cytokines IFN-γ, TNF-α and IL -2 in OTI T cells. Intriguingly, ginsenoside Rb1 treatment significantly increased TCF-1 in CD8+ T cells, and ginsenoside Rb1 treated OT-I T cells significantly inhibited tumor growth. Moreover, ginsenoside Rb1 greatly enhanced the efficiency of CD19-CART cells to kill Namalwa tumor cells. Conclusion: Ginsenoside Rb1 delays T cell senescence and enhances T cell antitumor activity. This data provides a new insight into T cell based antitumor therapy. Citation Format: Chunhong Ma, Xue Sheng, Chunyang Li. Ginsenoside Rb1 delays the senescence of CD8+ T cells to expand T cells with superior antitumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7.

Excess of body weight is associated with accelerated T-cell senescence in hospitalized COVID-19 patients

BackgroundSeveral risk factors have been involved in the poor clinical progression of coronavirus disease-19 (COVID-19), including ageing, and obesity. SARS-CoV-2 may compromise lung function through cell damage and paracrine inflammation; and obesity has been associated with premature immunosenescence, microbial translocation, and dysfunctional innate immune responses leading to poor immune response against a range of viruses and bacterial infections. Here, we have comprehensively characterized the immunosenescence, microbial translocation, and immune dysregulation established in hospitalized COVID-19 patients with different degrees of body weight.ResultsHospitalised COVID-19 patients with overweight and obesity had similarly higher plasma LPS and sCD14 levels than controls (all p < 0.01). Patients with obesity had higher leptin levels than controls. Obesity and overweight patients had similarly higher expansions of classical monocytes and immature natural killer (NK) cells (CD56+CD16−) than controls. In contrast, reduced proportions of intermediate monocytes, mature NK cells (CD56+CD16+), and NKT were found in both groups of patients than controls. As expected, COVID-19 patients had a robust expansion of plasmablasts, contrasting to lower proportions of major T-cell subsets (CD4 + and CD8+) than controls. Concerning T-cell activation, overweight and obese patients had lower proportions of CD4+CD38+ cells than controls. Contrasting changes were reported in CD25+CD127low/neg regulatory T cells, with increased and decreased proportions found in CD4+ and CD8+ T cells, respectively. There were similar proportions of T cells expressing checkpoint inhibitors across all groups. We also investigated distinct stages of T-cell differentiation (early, intermediate, and late-differentiated – TEMRA). The intermediate-differentiated CD4 + T cells and TEMRA cells (CD4+ and CD8+) were expanded in patients compared to controls. Senescent T cells can also express NK receptors (NKG2A/D), and patients had a robust expansion of CD8+CD57+NKG2A+ cells than controls. Unbiased immune profiling further confirmed the expansions of senescent T cells in COVID-19.ConclusionsThese findings suggest that dysregulated immune cells, microbial translocation, and T-cell senescence may partially explain the increased vulnerability to COVID-19 in subjects with excess of body weight.

Podocyte Ercc1 is indispensable for glomerular integrity

As life expectancy continues to increase, age-related kidney diseases are becoming more prevalent. Chronic kidney disease (CKD) is not only a consequence of aging but also a potential accelerator of aging process. Here we report the pivotal role of podocyte ERCC1, a DNA repair factor, in maintaining glomerular integrity and a potential effect on multiple organs. Podocyte-specific ERCC1-knockout mice developed severe proteinuria, glomerulosclerosis, and renal failure, accompanied by a significant increase in glomerular DNA single-strand breaks (SSBs) and double-strand breaks (DSBs). ERCC1 gene transfer experiment in the knockout mice attenuated proteinuria and glomerulosclerosis with reduced DNA damage. Notably, CD44+CD8+ memory T cells, indicative of T-cell senescence, were already elevated in the peripheral blood of knockout mice at 10 weeks old. Additionally, levels of senescence-associated secretory phenotype (SASP) factors were significantly increased in both the circulation and multiple organs of the knockout mice. In older mice and human patients, we observed an accumulation of DSBs and an even greater buildup of SSBs in glomeruli, despite no significant reduction in ERCC1 expression with age in mice. Collectively, our findings highlight the crucial role of ERCC1 in repairing podocyte DNA damage, with potential implications for inflammation in various organs.

The interplay between obesity, immunosenescence, and insulin resistance.

Obesity, which is the accumulation of fat in adipose tissue, has adverse impacts on human health. Obesity-related metabolic dysregulation has similarities to the metabolic alterations observed in aging. It has been shown that the adipocytes of obese individuals undergo cellular aging, known as senescence. Senescence can be transmitted to other normal cells through a series of chemical factors referred to as the senescence-associated secretory phenotype (SASP). Most of these factors are pro-inflammatory compounds. The immune system removes these senescent T-cells, but immunosenescence, which is the senescence of immune cells, disrupts the clearance of senescent T-cells. Immunosenescence occurs as a result of aging or indirectly through transmission from senescent tissues. The significant occurrence of senescence in obesity is expected to cause immunosenescence and impairs the immune response to resolve inflammation. The sustained and chronic inflammation disrupts insulin's metabolic actions in metabolic tissues. Therefore, this review focuses on the role of senescent adipocyte cells in obesity-associated immunosenescence and subsequent metabolic dysregulation. Moreover, the article suggests novel therapeutic approaches to improve metabolic syndrome by targeting senescent T-cells or using senotherapeutics.

Bone marrow-derived mesenchymal stromal cells obstruct AML-targeting CD8+ clonal effector and CAR T-cell function while promoting a senescence-associated phenotype

Bone marrow mesenchymal stromal cells (MSCs) have been described as potent regulators of T-cell function, though whether they could impede the effectiveness of immunotherapy against acute myeloid leukemia (AML) is still under investigation. We examine whether they could interfere with the activity of leukemia-specific clonal cytotoxic T-lymphocytes (CTLs) and chimeric antigen receptor (CAR) T cells, as well as whether the immunomodulatory properties of MSCs could be associated with the induction of T-cell senescence. Co-cultures of leukemia-associated Wilm’s tumor protein 1 (WT1) and tyrosine-protein kinase transmembrane receptor 1 (ROR1)-reactive CTLs and of CD123-redirected switchable CAR T cells were prepared in the presence of MSCs and assessed for cytotoxic potential, cytokine secretion, and expansion. T-cell senescence within functional memory sub-compartments was investigated for the senescence-associated phenotype CD28−CD57+ using unmodified peripheral blood mononuclear cells. We describe inhibition of expansion of AML-redirected switchable CAR T cells by MSCs via indoleamine 2,3-dioxygenase 1 (IDO-1) activity, as well as reduction of interferon gamma (IFNγ) and interleukin-2 (IL-2) release. In addition, MSCs interfered with the secretory potential of leukemia-associated WT1- and ROR1-targeting CTL clones, inhibiting the release of IFNγ, tumor necrosis factor alpha, and IL-2. Abrogated T cells were shown to retain their cytolytic activity. Moreover, we demonstrate induction of a CD28loCD27loCD57+KLRG1+ senescent T-cell phenotype by MSCs. In summary, we show that MSCs are potent modulators of anti-leukemic T cells, and targeting their modes of action would likely be beneficial in a combinatorial approach with AML-directed immunotherapy.