Causes, consequences, and reversal of immune system aging

Natural killer cells promote neutrophil extracellular traps and restrain macular degeneration in mice

Neovascular age-related macular degeneration (nvAMD) is the leading cause of blindness in the elderly population. Although it is known that nvAMD is associated with focal inflammation, understanding of the precise immune components governing this process remains limited. Here, we identified natural killer (NK) cells as a prominent lymphocyte population infiltrating the perivascular space of choroidal neovascularization (CNV) lesions in patients with nvAMD and in mouse models. Olink proteomic analysis and single-cell RNA sequencing combined with knockout studies demonstrated the involvement of C-C chemokine receptor 5 (CCR5) in NK cell recruitment and extravasation at the CNV sites of mice. Depletion of NK cells or inhibition of activating receptor NK group 2, member D (NKG2D) inhibited the formation of neutrophil extracellular traps, increased vascular leakage, and exacerbated pathological angiogenesis, indicating that NK cells restrain pathogenesis in this mouse model. Age is the strongest risk factor for AMD, and we show that NK cells from aged human donors exhibited a less cytotoxic phenotype. NK cells from old mice exhibited compromised protective effects in the CNV mouse model. In addition, interleukin-2 complex-mediated expansion of NK cells improved CNV formation in mice. Collectively, our study highlights NK cells as a potential therapeutic target for patients with nvAMD.

Extreme-aged patients (≥ 85 years) experience similar outcomes as younger geriatric patients following chronic subdural hematoma evacuation: a matched cohort study

Subdural hematoma (SDH) evacuation represents one of the most frequently performed neurosurgical procedures. Several reports cite a rise in both the age and number of patient's requiring treatment, due in part to an aging population and expanded anticoagulation use. However, limited data and conflicting conclusions exist on extreme-aged geriatric patients (≥ 85 years of age) after undergoing surgery. Patients undergoing SDH evacuation at a tertiary academic medical center between November 2013-December 2021 were retrospectively identified. The study group consisted of patients ≥ 85 years (Group 1) diagnosed with a chronic SDH surgically evacuated. A control group was created matching patients by 70-84 years of age, gender, and anticoagulation use (Group 2). Multiple metrics were evaluated between the two including length-of hospital-stay, tracheostomy/PEG placement, reoperation rate, complications, discharge location, neurological outcome at the time of discharge, and survival. A total of 130 patients were included; 65 in Group 1 and 65 in Group 2. Patient demographics, medical comorbidities, SDH characteristics, international normalized ratio, partial thromboplastin time, and use of blood thinning agents were similar between the two groups. Kaplan Meier survival analysis at one-year was 80% for Group 1 and 76% for Group 2. No significant difference was identified using the log-rank test for equality of survivor functions (p = 0.26). All measured outcomes including GCS at time of discharge, length of stay, rate of reoperations, and neurological outcome were statistically similar between the two groups. Backwards stepwise conditional logistic regression revealed no significant association between poor outcomes at the time of discharge and age. Alternatively, anticoagulation use was found to be associated with poor outcomes (OR 3.55, 95% CI 1.08-11.60; p = 0.036). Several outcome metrics and statistical analyses were used to compare patients ≥ 85 years of age to younger geriatric patients (70-84 years) in a matched cohort study. Adjusting for age group, gender, and anticoagulation use, no significant difference was found between the two groups including neurological outcome at discharge, reoperation rate, and survival.

The emerging importance of lymphangiogenesis in aging and aging-associated diseases

Lymphatic aging represented by cellular and functional changes, is involved in increased geriatric disorders, but the intersection between aging and lymphatic modulation is less clear. Lymphatic vessels play an essential role in maintaining tissue fluid homeostasis, regulating immune function, and promoting macromolecular transport. Lymphangiogenesis and lymphatic remodeling following cellular senescence and organ deterioration are crosslinked with the progression of some lymphatic-associated diseases, e.g., atherosclerosis, inflammation, lymphoedema, and cancer. Age-related detrimental tissue changes may occur in lymphatic vessels with diverse etiologies, and gradually shift towards chronic low-grade inflammation, so-called inflammaging, and lead to decreased immune response. The investigation of the relationship between advanced age and organ deterioration is becoming an area of rapidly increasing significance in lymphatic biology and medicine. Here we highlight the emerging importance of lymphangiogenesis and lymphatic remodeling in the regulation of aging-related pathological processes, which will help to find new avenues for effective intervention to promote healthy aging.

Differential HBV replicative markers and covalently closed circular DNA transcription in immune-active chronic hepatitis B with and without HBeAg

BACKGROUND AND AIMS

Molecular processes driving immune-active chronic hepatitis B (CHB) with and without hepatitis B e antigen (HBeAg) remain incompletely understood. This study aimed to investigate expression profiles of serum and intrahepatic HBV markers and replicative activity of HBV in CHB patients with or without HBeAg.

METHODS

This study recruited 111 untreated immune-active CHB (60 HBeAg-positive and 51 HBeAg-negative) patients and quantified intrahepatic covalently closed circular DNA (cccDNA), pre-genomic RNA (pgRNA), total HBV DNA (tDNA), and replicative intermediates as well as serum HBV markers (HBV DNA, hepatitis B surface antigen, hepatitis B core-related antigen). Correlations between HBV markers and clinico-virological factors influencing expression levels of HBV markers were analysed.

RESULTS

Levels of all serum markers and intrahepatic cccDNA/tDNA as well as cccDNA transcriptional activity and virion productivity were significantly reduced in HBeAg-negative patients compared to those in HBeAg-positive patients. Additionally, correlations between intrahepatic cccDNA/pgRNA and serum markers were impaired in HBeAg-negative individuals. Aminotransferase levels were positively correlated with cccDNA transcriptional activity in HBeAg-positive patients, but not in HBeAg-negative patients. Notably, among HBeAg-positive patients, there was a progressive decline in pgRNA level, transcriptional activity, and serum HBV markers as liver fibrosis advanced, which was not observed in HBeAg-negative patients.

CONCLUSIONS

HBeAg loss is correlated with diminished intrahepatic HBV reservoirs and cccDNA transcription, leading to decreased serum HBV marker levels. Circulating HBV markers are not reliable indicators of intrahepatic HBV replicative activity for HBeAg-negative patients. Our findings reveal distinct disease phenotypes between immune-active CHB with and without HBeAg, highlighting the need to establish optimal surrogate biomarkers that can accurately mirror intrahepatic viral activity to aid in decision-making for antiviral therapy for immune-active CHB.

Advancing cell-based therapy in sepsis: An anesthesia outlook

ABSTRACT

Sepsis poses a health challenge globally owing to markedly high rates of morbidity and mortality. Despite employing bundle therapy over two decades, approaches including transient organ supportive therapy and clinical trials focusing on signaling pathways have failed in effectively reversing multiple organ failure in patients with sepsis. Prompt and appropriate perioperative management for surgical patients with concurrent sepsis is urgent. Consequently, innovative therapies focusing on remedying organ injuries are necessitated. Cell therapy has emerged as a promising therapeutic avenue for repairing local damage to vital organs and restoring homeostasis during perioperative treatment for sepsis. Given the pivotal role of immune cell responses in the pathogenesis of sepsis, stem cell-based interventions that primarily modulate immune responses by interacting with multiple immune cells have progressed into clinical trials. The strides made in single-cell sequencing and gene-editing technologies have advanced the understanding of disease-specific immune responses in sepsis. Chimeric antigen receptor (CAR)-immune cell therapy offers an intriguing option for the treatment of sepsis. This review provides a concise overview of immune cell therapy, its current status, and the strides made in the context of sepsis research, discussing potential strategies for the management of patients with sepsis during perioperative stages.

Chrono-tailored drug delivery systems: recent advances and future directions

Circadian rhythms influence a range of biological processes within the body, with the central clock or suprachiasmatic nucleus (SCN) in the brain synchronising peripheral clocks around the body. These clocks are regulated by external cues, the most influential being the light/dark cycle, in order to synchronise with the external day. Chrono-tailored or circadian drug delivery systems (DDS) aim to optimise drug delivery by releasing drugs at specific times of day to align with circadian rhythms within the body. Although this approach is still relatively new, it has the potential to enhance drug efficacy, minimise side effects, and improve patient compliance. Chrono-tailored DDS have been explored and implemented in various conditions, including asthma, hypertension, and cancer. This review aims to introduce the biology of circadian rhythms and provide an overview of the current research on chrono-tailored DDS, with a particular focus on immunological applications and vaccination. Finally, we draw on some of the key challenges which need to be overcome for chrono-tailored DDS before they can be translated to more widespread use in clinical practice.

Immunoengineering Biomaterials for Musculoskeletal Tissue Repair across Lifespan

Musculoskeletal diseases and injuries are among the leading causes of pain and morbidity worldwide. Broad efforts have focused on developing pro-regenerative biomaterials to treat musculoskeletal conditions; however, these approaches have yet to make a significant clinical impact. Recent studies have demonstrated that the immune system is central in orchestrating tissue repair and that targeting pro-regenerative immune responses can improve biomaterial therapeutic outcomes. However, aging is a critical factor negatively affecting musculoskeletal tissue repair and immune function. Hence, understanding how age affects the response to biomaterials is essential for improving musculoskeletal biomaterial therapies. This review focuses on the intersection of the immune system and aging in response to biomaterials for musculoskeletal tissue repair. The article introduces the general impacts of aging on tissue physiology, the immune system, and the response to biomaterials. Then, it explains how the adaptive immune system guides the response to injury and biomaterial implants in cartilage, muscle, and bone and discusses how aging impacts these processes in each tissue type. The review concludes by highlighting future directions for the development and translation of personalized immunomodulatory biomaterials for musculoskeletal tissue repair.

Parabolic Changes in Pain Scores Among Partial Herpes Zoster Patients: A Retrospective Study

Background

Herpes zoster (HZ) typically manifests in the acute phase with distinct blisters and severe neuropathic pain. Remarkably, a subset of patients initially presents with only a mild skin rash and moderate pain that gradually intensifies, following a parabolic pattern. Despite being frequently observed in clinical settings, the underlying causes of this trajectory and its potential connection with post-herpetic neuralgia (PHN) remain unclear.

Methods

To investigate this phenomenon in-depth, we conducted a meticulous retrospective study involving 529 eligible HZ patients. All these patients sought medical care at the Third Central Hospital of Tianjin, China, between January 2020 and December 2023.

Results

The research identified that 14.6% of the sample (77 patients) experienced pain scores aligning with a parabolic curve. This trend was significantly more prevalent in patients aged 60 and above, accounting for 90.9% of this group, and demonstrated a positive correlation with age. Moreover, 87.0% of these patients had pre-existing medical conditions, highlighting the potential role of comorbidities in influencing the pain trajectory. A concerning 45.5% of patients sought medical attention more than seven days after the onset of symptoms, a delay that could exacerbate neurological damage. Notably, among those following a parabolic pain pattern, 66.2% eventually developed PHN, a considerably higher rate compared to the broader patient population.

Conclusion

We emphasize that healthcare practitioners meticulously assess patients who initially report lower pain scores for high-risk factors potentially leading to parabolic pain increases, including being over 60 years old, having comorbid conditions, and delaying medical consultation beyond seven days from symptom onset. Early implementation of supplementary pain management therapies may mitigate the risk of PHN development and enhance the quality of life for patients. This study furnishes clinicians with a deeper understanding of the variations in HZ-related pain trajectories, promising to improve treatment approaches and prognoses for HZ patients while paving the way for enriched clinical practice in the future.

Adjuvant Effects of a CC Chemokine for Enhancing the Efficacy of an Inactivated Streptococcus agalactiae Vaccine in Nile Tilapia (Oreochromis niloticus)

In this study, the ability of a CC chemokine (On-CC1) adjuvant to enhance the efficacy of a formalin-killed Streptococcus agalactiae vaccine (WC) in inducing immune responses against S. agalactiae in Nile tilapia was investigated through immune-related gene expression analysis, enzyme-linked immunosorbent assay (ELISA), transcriptome sequencing, and challenge tests. Significantly higher S. agalactiae-specific IgM levels were detected in fish in the WC+CC group than in the WC alone or control groups at 8 days postvaccination (dpv). The WC vaccine group exhibited increased specific IgM levels at 15 dpv, comparable to those of the WC+CC group, with sustained higher levels observed in the latter group at 29 dpv and after challenge with S. agalactiae for 14 days. Immune-related gene expression analysis revealed upregulation of all target genes in the control group compared to those in the vaccinated groups, with notable differences between the WC and WC+CC groups at various time intervals. Additionally, transcriptome analysis revealed differential gene expression profiles between the vaccinated (24 and 96 hpv) and control groups, with notable upregulation of immune-related genes in the vaccinated fish. Differential gene expression (DGE) analysis revealed significant upregulation of immunoglobulin and other immune-related genes in the control group compared to those in the vaccinated groups (24 and 96 hpv), with distinct patterns observed between the WC and WC+CC vaccine groups. Finally, challenge with a virulent strain of S. agalactiae resulted in significantly higher survival rates for fish in the WC and WC+CC groups compared to fish in the control group, with a notable increase in survival observed in fish in the WC+CC group.

Age-Related Clusters and Favorable Immune Phenotypes in Breast Cancer of the Young Patients

Breast cancer (BC) patients aged <40 years at diagnosis experience aggressive disease and poorer survival compared with women diagnosed with BC at 40 to 49 years, but the age-related biology is described to little extent. Here, we explored transcriptional alterations in BC to gain better understanding of age-related tumor biology. We studied a subset of the Bergen in-house cohort (n = 127; age range, 26-49 years) and used the NanoString Breast Cancer 360 expression panel on formalin-fixed paraffin-embedded BC tissue, and publicly available global BC messenger RNA expression data (n = 204, age range, 22-49 years), to explore differentially expressed genes between the young (age <40 years) and older (age 40-49 years) patients. Unsupervised hierarchical clustering was applied to identify gene expression-based patient clusters. We applied established computational approaches to define the PAM50 subtypes, risk of recurrence scores (ROR), and risk groups and to infer the proportions of 22 immune cell types from bulk gene expression profiles of patients aged <50 years at BC diagnosis. Differentially expressed genes and gene sets were investigated using OncoEnrichR and g:Profiler to describe functional profiles and pathway enrichment. We identified 4 age-related patient clusters presenting distinct characteristics of PAM50 subtypes and ROR profiles, which demonstrated independent prognostic value when adjusted for traditional clinicopathologic variables and the known molecular subtypes. Our findings showed better survival than expected in the basal-enriched cluster 2 and in triple-negative and basal-like BC. Deconvolution analyses of immunophenotypes indicated higher levels of M0 and M1 macrophages than M2 macrophages in subsets of young BC. Our approach identifies age-based patient clusters with distinct clinicopathologic profiles, to a large extent overlapping with the PAM50 subtypes, although with independent prognostic values in multivariate survival analyses. The patient clusters provided new insight in the immune cell distribution across tumor subtypes, potentially contributing to survival differences between the clusters and the molecular subtypes and indicating age-related mechanisms improving outcome. Our study confirms the applicability of ROR as a valid prognosticator also in a young BC cohort.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

Case Report: Primary Cutaneous Histoplasmosis in an Immunocompetent Patient After Cosmetic Injection of Platelet-Rich Plasma Treated with Trimethoprim-Sulfamethoxazole

BACKGROUND Histoplasmosis is typically associated with immunocompromised individuals, but cases in immunocompetent patients are rare. Primary cutaneous histoplasmosis (PCH) is a challenging diagnosis due to its clinical polymorphism and can mimic other infectious and non-infectious diseases. Previous cases of PCH have been reported in immunocompetent patients with underlying medical conditions or trauma history. So far there have been no reports of PCH after platelet-rich plasma (PRP) application due to inadequate hygiene measures in an immunocompetent host. CASE REPORT This case report presents a rare occurrence of PCH following a cosmetic procedure (PRP injection) in an immunocompetent patient. The patient developed nodule-like lesions at the application sites, which progressed to ulceration with purulent discharge. Initially, atypical mycobacterial infection was suspected, and empirical antibiotic therapy was initiated. Complementary tests were performed, ruling out immunosuppression and systemic pathogens. The patient showed complete resolution of the lesions after one month of atypical treatment with trimethoprim-sulfamethoxazole (TMP/SMX). Pathological examination confirmed the diagnosis of PCH with intracytoplasmic inclusions of Histoplasma sp. CONCLUSIONS This case highlights the importance of considering histoplasmosis as a diagnostic possibility, especially in hyperendemic areas like Venezuela. Direct inoculation of Histoplasma sp. after aesthetic procedures without proper hygiene measures can lead to pathological lesions, even in immunocompetent individuals. TMP/SMX can be considered as an alternative treatment option in the absence of the first-line medication. Further exploration of this treatment approach may benefit patients with similar clinical conditions or when ideal treatment options are unavailable.

The compensatory role of T cells from lymph nodes in mice with splenectomy

The spleen is a vital organ for the immune system, while splenectomy may be necessary for various reasons. However, there is limited research on the impact of splenectomy on T cell function in peripheral lymph nodes as a compensatory mechanism in preventing infections. This study aimed to investigate the characteristics and function of CD8+ and CD4+ T cells in different peripheral lymph nodes during viral infection using a well-established splenectomy model. The results revealed that splenectomy caused an increase in CD8+GP33+ T cells in the mesenteric lymph nodes (MLN). Moreover, we demonstrated that splenectomy resulted in an increase of effector KLRG1+ T cells in the MLN. Additionally, the number of CD4+ cytotoxic T cells (CD4 CTLs) was also elevated in the peripheral lymph nodes of mice with splenectomy. Surprisingly, aged mice exhibited a stronger compensatory ability than adult mice, as evidenced by an increase in effector CD8+ T cells in all peripheral lymph nodes. These findings provide compelling evidence that T cells in MLN play a crucial role in protecting individuals with splenectomy against viral infections. The study offers new insights into understanding the changes in the immune system of individuals with splenectomy and highlights the potential compensatory mechanisms involved by T cells in peripheral lymph nodes.

Shaping immunity: The influence of natural selection on population immune diversity

Humans exhibit considerable variability in their immune responses to the same immune challenges. Such variation is widespread and affects individual and population-level susceptibility to infectious diseases and immune disorders. Although the factors influencing immune response diversity are partially understood, what mechanisms lead to the wide range of immune traits in healthy individuals remain largely unexplained. Here, we discuss the role that natural selection has played in driving phenotypic differences in immune responses across populations and present-day susceptibility to immune-related disorders. Further, we touch on future directions in the field of immunogenomics, highlighting the value of expanding this work to human populations globally, the utility of modeling the immune response as a dynamic process, and the importance of considering the potential polygenic nature of natural selection. Identifying loci acted upon by evolution may further pinpoint variants critically involved in disease etiology, and designing studies to capture these effects will enrich our understanding of the genetic contributions to immunity and immune dysregulation.

The impact of the senescent microenvironment on tumorigenesis: Insights for cancer therapy

The growing global burden of cancer, especially among people aged 60 years and over, has become a key public health issue. This trend suggests the need for a deeper understanding of the various cancer types in order to develop universally effective treatments. A prospective area of research involves elucidating the interplay between the senescent microenvironment and tumor genesis. Currently, most oncology research focuses on adulthood and tends to ignore the potential role of senescent individuals on tumor progression. Senescent cells produce a senescence-associated secretory phenotype (SASP) that has a dual role in the tumor microenvironment (TME). While SASP components can remodel the TME and thus hinder tumor cell proliferation, they can also promote tumorigenesis and progression via pro-inflammatory and pro-proliferative mechanisms. To address this gap, our review seeks to investigate the influence of senescent microenvironment changes on tumor development and their potential implications for cancer therapies.

Comparison of morbidity and mortality after radical cystectomy between individuals older and younger than 80 years: a systematic review and meta-analysis

OBJECTIVE

To compare outcomes related to survival and post-operative complications in individuals older and younger than 80 years with bladder cancer undergoing radical cystectomy (RC).

METHODS

We conducted a systematic search using three large databases: PubMed, EMBASE, and Scopus. We included observational studies comparing outcomes between individuals older than 80 years and younger patients undergoing RC. The outcomes of interest included overall survival, disease-specific survival, progression-free survival, and risk of post-operative complications. We applied a random effects model for the analysis and reported pooled effect sizes as odds ratios (ORs) or hazards ratios (HRs) along with 95% confidence intervals.

RESULTS

We analyzed 21 studies. Our results show that individuals older than 80 years had higher risks of mortality at 30 days (OR 2.82; 95% CI 1.97, 4.04), 90 days (OR 3.34; 95% CI 2.61, 4.27), 12 months (HR 3.03; 95% CI 2.64, 3.49), and 24 months (HR 3.54; 95% CI 2.27, 5.50) of the post-operative follow-up than younger individuals. In addition, individuals older than 80 years also had poor 5-year survivals (HR 2.17; 95% CI 1.64, 2.88), an increased risk of 5-year cancer-specific mortality (HR 1.58; 95% CI 1.24, 2.03), poor 5-year recurrence free survivals (HR 1.49; 95% CI 1.07, 2.08), and high complications risks (OR 1.20; 95% CI 1.02, 1.42) when compared to younger patients.

CONCLUSION

Individuals older than 80 years undergoing RC are likely to have poor survival-related outcomes and increased complications risks. Pre-planned comprehensive geriatric assessments (CGAs) may be needed to offer better peri- and post-operative care to improve the outcomes in this patient population.

Investigating the shared genetic basis and causal relationships between mucosa-associated lymphoid tissue inflammation and psychiatric disorders

Background

Chronic and acute inflammation of the mucosa-associated lymphoid tissue have been positively linked to the development of psychiatric disorders in observational studies. However, it remains unclear whether this association is causal. In the present study, we investigated this association, using as proxies genetically predicted tonsillectomy, appendectomy and appendicitis on psychiatric disorders including major depressive disorder (MDD), schizophrenia (SCZ), bipolar depression (BD) and anxiety (ANX) via a two-sample Mendelian randomization (MR) analysis.

Methods

Genetic association summary statistics for tonsillectomy, appendectomy and appendicitis were sourced from FinnGen Consortium, comprising data from 342,000 participants. Genetic correlations between all exposures and outcome were calculated with Linkage Disequilibrium Score (LDSC) Regression analysis. MR estimates were then calculated to assess their impact on the risk of developing psychiatric disorders. Sensitivity analysis was employed to test for any directional pleiotropy.

Results

Our results suggest that there is no direct causal association between tonsillectomy, appendectomy or appendicitis with a heightened risk for development of psychiatric disorders. The robustness of the results of the main MR analysis was further confirmed with additional sensitivity analyses. However, a moderate inverse genetic correlation was observed between tonsillectomy and MDD traits (rg=-0.39, p-value (P)=7.5x10-5).

Conclusion

Our findings provide, for the first time, evidence that there is no causal association between tonsillectomy or appendectomy on subsequent vulnerability of developing psychiatric disorders. Future studies using larger sample size GWAS should focus on unraveling the confounding factors and mediators to investigate this relationship further.

Exploration of the causal associations between circulating inflammatory proteins, immune cells, and neuromyelitis optica spectrum disorder: a bidirectional Mendelian randomization study and mediation analysis

Background

An increasing body of research has demonstrated a robust correlation between circulating inflammatory proteins and neuromyelitis optica spectrum disorders (NMOSD). However, whether this association is causal or whether immune cells act as mediators currently remains unclear.

Methods

We employed bidirectional two-sample Mendelian randomization (TSMR) analysis to examine the potential causal association between circulating inflammatory proteins, immune cells, and NMOSD using data from genome-wide association studies (GWAS). Five different methods for Mendelian randomization analyses were applied, with the inverse variance-weighted (IVW) method being the primary approach. Sensitivity analyses were further performed to assess the presence of horizontal pleiotropy and heterogeneity in the results. Finally, a two-step Mendelian randomization (MR) design was employed to examine the potential mediating effects of immune cells.

Results

A notable causal relationship was observed between three circulating inflammatory proteins (CSF-1, IL-24, and TNFRSF9) and genetically predicted NMOSD. Furthermore, two immune cell phenotypes, genetically predicted CD8 on naive CD8+ T cells, and Hematopoietic Stem Cell Absolute Count were negatively and positively associated with genetically predicted NMOSD, respectively, although they did not appear to function as mediators.

Conclusion

Circulating inflammatory proteins and immune cells are causally associated with NMOSD. Immune cells do not appear to mediate the pathway linking circulating inflammatory proteins to NMOSD.

The senescence-associated secretory phenotype and its physiological and pathological implications

Cellular senescence is a state of terminal growth arrest associated with the upregulation of different cell cycle inhibitors, mainly p16 and p21, structural and metabolic alterations, chronic DNA damage responses, and a hypersecretory state known as the senescence-associated secretory phenotype (SASP). The SASP is the major mediator of the paracrine effects of senescent cells in their tissue microenvironment and of various local and systemic biological functions. In this Review, we discuss the composition, dynamics and heterogeneity of the SASP as well as the mechanisms underlying its induction and regulation. We describe the various biological properties of the SASP, its beneficial and detrimental effects in different physiological and pathological settings, and its impact on overall health span. Finally, we discuss the use of the SASP as a biomarker and of SASP inhibitors as senomorphic interventions to treat cancer and other age-related conditions.

Development of a nano-emulsion based multivalent protein subunit vaccine against Pseudomonas aeruginosa

Pseudomonas aeruginosa (Pa) is an opportunistic bacterial pathogen responsible for severe hospital acquired infections in immunocompromised and elderly individuals. Emergence of increasingly drug resistant strains and the absence of a broad-spectrum prophylactic vaccine against both T3SA+ (type III secretion apparatus) and ExlA+/T3SA- Pa strains worsen the situation in a post-pandemic world. Thus, we formulated a candidate subunit vaccine (called ExlA/L-PaF/BECC/ME) against both Pa types. This bivalent vaccine was generated by combining the C-terminal active moiety of exolysin A (ExlA) produced by non-T3SA Pa strains with our T3SA-based vaccine platform, L-PaF, in an oil-in-water emulsion. The ExlA/L-PaF in ME (MedImmune emulsion) was then mixed with BECC438b, an engineered lipid A analogue and a TLR4 agonist. This formulation was administered intranasally (IN) to young and elderly mice to determine its potency across a diverse age-range. The elderly mice were used to mimic the infection seen in elderly humans, who are more susceptible to serious Pa disease compared to their young adult counterparts. After Pa infection, mice immunized with ExlA/L-PaF/BECC/ME displayed a T cell-mediated adaptive response while PBS-vaccinated mice experienced a rapid onset inflammatory response. Important genes and pathways were observed, which give rise to an anti-Pa immune response. Thus, this vaccine has the potential to protect aged individuals in our population from serious Pa infection.

Determinants of health as predictors for differential antibody responses following SARS-CoV-2 primary and booster vaccination in an at-risk, longitudinal cohort

Post vaccine immunity following COVID-19 mRNA vaccination may be driven by extrinsic, or controllable and intrinsic, or inherent health factors. Thus, we investigated the effects of extrinsic and intrinsic on the peak antibody response following COVID-19 primary vaccination and on the trajectory of peak antibody magnitude and durability over time. Participants in a longitudinal cohort attended visits every 3 months for up to 2 years following enrollment. At baseline, participants provided information on their demographics, recreational behaviors, and comorbid health conditions which guided our model selection process. Blood samples were collected for serum processing and spike antibody testing at each visit. Cross-sectional and longitudinal models (linear-mixed effects models) were generated to assess the relationship between selected intrinsic and extrinsic health factors on peak antibody following vaccination and to determine the influence of these predictors on antibody over time. Following cross-sectional analysis, we observed higher peak antibody titers after primary vaccination in females, those who reported recreational drug use, younger age, and prior COVID-19 history. Following booster vaccination, females and Hispanics had higher peak titers after the 3rd and 4th doses, respectively. Longitudinal models demonstrated that Moderna mRNA-1273 recipients, females, and those previously vaccinated had increased peak titers over time. Moreover, drug users and half-dose Moderna mRNA-1273 recipients had higher peak antibody titers over time following the first booster, while no predictive factors significantly affected post-second booster antibody responses. Overall, both intrinsic and extrinsic health factors play a significant role in shaping humoral immunogenicity after initial vaccination and the first booster. The absence of predictive factors for second booster immunogenicity suggests a more robust and consistent immune response after the second booster vaccine administration.

Depleting myeloid-biased haematopoietic stem cells rejuvenates aged immunity

Ageing of the immune system is characterized by decreased lymphopoiesis and adaptive immunity, and increased inflammation and myeloid pathologies1,2. Age-related changes in populations of self-renewing haematopoietic stem cells (HSCs) are thought to underlie these phenomena3. During youth, HSCs with balanced output of lymphoid and myeloid cells (bal-HSCs) predominate over HSCs with myeloid-biased output (my-HSCs), thereby promoting the lymphopoiesis required for initiating adaptive immune responses, while limiting the production of myeloid cells, which can be pro-inflammatory4. Ageing is associated with increased proportions of my-HSCs, resulting in decreased lymphopoiesis and increased myelopoiesis3,5,6. Transfer of bal-HSCs results in abundant lymphoid and myeloid cells, a stable phenotype that is retained after secondary transfer; my-HSCs also retain their patterns of production after secondary transfer5. The origin and potential interconversion of these two subsets is still unclear. If they are separate subsets postnatally, it might be possible to reverse the ageing phenotype by eliminating my-HSCs in aged mice. Here we demonstrate that antibody-mediated depletion of my-HSCs in aged mice restores characteristic features of a more youthful immune system, including increasing common lymphocyte progenitors, naive T cells and B cells, while decreasing age-related markers of immune decline. Depletion of my-HSCs in aged mice improves primary and secondary adaptive immune responses to viral infection. These findings may have relevance to the understanding and intervention of diseases exacerbated or caused by dominance of the haematopoietic system by my-HSCs.

Epidemiology and risk factors of nosocomial infections in a Chinese tertiary-care hospital: a 10-year retrospective case-control study

BACKGROUND

Nosocomial infections (NIs) are the most frequent adverse events among patients and cause a heavy burden on both health and economics. To investigate epidemiology of NIs and identify risk factors for NIs by integrating continuous long-term surveillance data.

METHODS

We performed an observational study among inpatients at the Chinese People's Liberation Army General Hospital between January 1, 2010, and December 31, 2019. Infection rates, mortality rates and percentage of NIs were calculated. Trends of yearly infection rates by pathogens were assessed using Mann-Kendall trend test. Controls were matched to cases (2:1) by age (±2 years), sex, admission date (±1 year) and admission diagnosis, and conditional logistic regression was used to estimate odds ratios.

RESULTS

A total of 1,534,713 inpatients were included among which 33,468 NIs cases occurred with an infection rate of 2.18%. The most common infections were respiratory system infection (52.22%), bloodstream infection (17.60%), and genitourinary system infection (15.62%). Acinetobacter. baumannii (9.6%), Klebsiella. pneumoniae (9.0%), Pseudomonas. aeruginosa (8.6%), Escherichia. coli (8.6%) and Enterococcus. faecium (5.0%) were the top five isolated pathogens. Infection rates of K. pneumoniae and carbapenems-resistant K. pneumoniae significantly increased. Prior ICU stay, surgery, any device placement (including central venous catheter, mechanical ventilation, urinary catheter, and tracheotomy), prior use of triple or more antibiotics combinations, carbapenem, and β-Lactamase inhibitors were significantly associated with NIs.

CONCLUSION

K. pneumoniae has the potential to cause a clinical crisis with increasing infection rates and carbapenem resistance. Clinical management of invasive operations and antibiotics use should be further strengthened.

Assessing melanoma prognosis: the interplay between patient profiles, survival, and BRAF, NRAS, KIT, and TWT mutations in a retrospective multi-study analysis

The incidence and prevalence of melanoma are increasing globally, presenting a significant public health concern. The main genetic drivers of melanoma include BRAF, NRAS, KIT and triple wild-type (TWT) mutations. Little is known about the effects of these mutations on outcomes in terms of demographics and patient characteristics. We examined differences in melanoma mortality risk and mutation count across mutation type and patient disease profile. We extrapolated primary melanoma patient data from 14 studies via the cBioportal database. Patients were divided into demographic groups and classified according to BRAF, NRAS, KIT and TWT mutation status. Analyses included two-sample Student t-test and two-way analysis of variance tests analysis with Tukey's post hoc test. Survival outcomes were compared via Kaplan-Meier curve and Cox regression. NRAS-mutated patients exhibited decreased overall survival compared to BRAF-mutated patients. Male patients had higher mutation counts across all gene groups than females, with the fewest TWT mutations in comparison to BRAF, NRAS and KIT mutations. Males also exhibited increased mortality risk for NRAS, KIT and TWT mutations compared to BRAF mutations. An unknown primary melanoma was associated with increased mortality risk across all gene groups. NRAS-mutated acral melanoma patients had an increased mortality risk compared to NRAS-mutated cutaneous melanoma patients. Older patients had a higher mortality risk than younger patients. Patients with heavier versus lower weights had lower mortality risk, which was more pronounced for BRAF-mutated patients. These relationships highlight the importance of demographic and pathologic relationships to aid in risk assessment and personalize treatment plans.

AagingBase: a comprehensive database of anti-aging peptides

The process of aging is an intrinsic and inevitable aspect of life that impacts every living organism. As biotechnological advancements continue to shape our understanding of medicine, peptide therapeutics have emerged as a promising strategy for anti-aging interventions. This is primarily due to their favorable attributes, such as low immunogenicity and cost-effective production. Peptide-based treatments have garnered widespread acceptance and interest in aging research, particularly in the context of age-related therapies. To effectively develop anti-aging treatments, a comprehensive understanding of the physicochemical characteristics of anti-aging peptides is essential. Factors such as amino acid composition, instability index, hydrophobic areas and other relevant properties significantly determine their efficacy as potential therapeutic agents. Consequently, the creation of 'AagingBase', a comprehensive database for anti-aging peptides, aims to facilitate research on aging by leveraging the potential of peptide therapies. AagingBase houses experimentally validated 282 anti-aging peptides collected from 54 research articles and 236 patents. Employing state-of-the-art computational techniques, the acquired sequences have undergone rigorous physicochemical calculations. Furthermore, AagingBase presents users with various informative analyses highlighting atomic compositions, secondary structure fractions, tertiary structure, amino acid compositions and frequencies. The database also offers advanced search and filtering options and similarity search, thereby aiding researchers in understanding their biological functions. Hence, the database enables efficient identification and prioritization of potential peptide candidates in geriatric medicine and holds immense potential for advancing geriatric medicine research and innovations. AagingBase can be accessed without any restriction. Database URL: https://project.iith.ac.in/cgntlab/aagingbase/.

Senescent T Cells in Age-Related Diseases

Age-induced alterations in human immunity are often considered deleterious and are referred to as immunosenescence. The immune system monitors the number of senescent cells in the body, while immunosenescence may represent the initiation of systemic aging. Immune cells, particularly T cells, are the most impacted and involved in age-related immune function deterioration, making older individuals more prone to different age-related diseases. T-cell senescence can impact the effectiveness of immunotherapies that rely on the immune system's function, including vaccines and adoptive T-cell therapies. The research and practice of using senescent T cells as therapeutic targets to intervene in age-related diseases are in their nascent stages. Therefore, in this review, we summarize recent related literature to investigate the characteristics of senescent T cells as well as their formation mechanisms, relationship with various aging-related diseases, and means of intervention. The primary objective of this article is to explore the prospects and possibilities of therapeutically targeting senescent T cells, serving as a valuable resource for the development of immunotherapy and treatment of age-related diseases.

Development of a prognostic model for long-term survival of young patients with bladder cancer: a retrospective analysis of the SEER Database

OBJECTIVES

This study aims to present the clinical characteristics of young patients with bladder cancer (YBCa), evaluate related risk factors and construct a nomogram based on data acquired from the Surveillance, Epidemiology, and End Results (SEER) Database.

DESIGN

Retrospective analysis of the SEER Database (2004-2015) for primary YBCa.

SETTING AND PARTICIPANTS

Data for YBCa (defined as those aged 40 years or younger) were extracted from the SEER Database, which covers approximately 28% of the US population, using the SEER*Stat software (V.8.4.0.1). A total of 1233 YBCa were identified. Patients were randomly assigned to the training and validation sets. The database included clinicopathological features, demographic information and survival outcomes, such as age, gender, race, year of diagnosis, marital status at diagnosis, primary tumour site, histological type, tumour grade, tumour, node, metastases (TNM) staging, treatment regimen for the primary tumour, cause of death and survival time. A nomogram model was developed using univariate and multivariate analyses. The prediction model was validated using the consistency index (C-index), calibration curve and receiver operating characteristic curve.

PRIMARY OUTCOME MEASURES

3-year, 5-year and 10-year overall survival (OS).

RESULTS

1233 YBCa from 2004 to 2015 were randomly assigned to the training set (n=865) and validation set (n=368). Age, marital status, tumour grade, histological type and TNM staging were included in the nomogram. The C-index of the model was 0.876. The 3-year, 5-year and 10-year OS area under the curve values for the training and validation sets were 0.949, 0.923 and 0.856, and 0.919, 0.890 and 0.904, respectively. Calibration plots showed that the nomogram had a robust predictive accuracy.

CONCLUSIONS

To our knowledge, this is the first study to establish a precise nomogram predicting the 3-year, 5-year and 10-year OS in YBCa based on multivariate analyses. Our nomogram may serve as a valuable reference for future diagnostics and individualised treatments for YBCa. However, external validation is warranted to assess the accuracy and generalisability of our prognostic model.

Clinical Pharmacology Profile of AMG 119, the First Chimeric Antigen Receptor T (CAR-T) Cell Therapy Targeting Delta-Like Ligand 3 (DLL3), in Patients with Relapsed/Refractory Small Cell Lung Cancer (SCLC)

With the promise of a potentially single-dose curative regimen, CAR-T cell therapies have brought a paradigm shift in the treatment and management of hematological malignancies with 6 approved products in the USA. However, there are no approved CAR-T cell therapies for solid tumors. Herein, we report the clinical pharmacology profile of AMG 119, the first CAR-T cell therapy targeting delta-like ligand 3 (DLL3), in patients with relapsed/refractory (R/R) small cell lung cancer (SCLC). AMG 119 demonstrated robust cellular expansion with long-lasting cell persistence and a favorable exposure-response relationship. AMG 119 has been demonstrated to be clinically safe and well tolerated at the doses tested, with no dose-limiting toxicities (DLTs) reported. This is the first publication of the clinical pharmacology profile of a CAR-T cell therapy in SCLC, with encouraging cellular kinetics data supporting the potential for CAR-T cell therapy in solid tumor space.

Obesity, bone marrow adiposity, and leukemia: Time to act

Obesity has taken the face of a pandemic with less direct concern among the general population and scientific community. However, obesity is considered a low-grade systemic inflammation that impacts multiple organs. Chronic inflammation is also associated with different solid and blood cancers. In addition, emerging evidence demonstrates that individuals with obesity are at higher risk of developing blood cancers and have poorer clinical outcomes than individuals in a normal weight range. The bone marrow is critical for hematopoiesis, lymphopoiesis, and myelopoiesis. Therefore, it is vital to understand the mechanisms by which obesity-associated changes in BM adiposity impact leukemia development. BM adipocytes are critical to maintain homeostasis via different means, including immune regulation. However, obesity increases BM adiposity and creates a pro-inflammatory environment to upregulate clonal hematopoiesis and a leukemia-supportive environment. Obesity further alters lymphopoiesis and myelopoiesis via different mechanisms, which dysregulate myeloid and lymphoid immune cell functions mentioned in the text under different sequentially discussed sections. The altered immune cell function during obesity alters hematological malignancies and leukemia susceptibility. Therefore, obesity-induced altered BM adiposity, immune cell generation, and function impact an individual's predisposition and severity of leukemia, which should be considered a critical factor in leukemia patients.

A US payer perspective health economic model assessing value of monitoring disease activity to inform discontinuation and re-initiation of DMT in multiple sclerosis

OBJECTIVES

We evaluate the potential clinical and cost impacts of discontinuing disease-modifying therapy (DMT) in people with multiple sclerosis (PwMS) when age-related immunosenescence can reduce DMT efficacy while increasing associated risks.

METHODS

A Markov model simulated clinical and cost impacts to the patient and payers when a proportion of eligible patients with relapsing remitting multiple sclerosis (RRMS) discontinue DMT. Eligibility was defined as age >55 years, an RRMS diagnosis of >5 years, and no history of relapses for 5 years. Increasing the proportion of eligible patients willing to discontinue therapy was also modeled. Clinical and cost inputs were from published literature.

RESULTS

Difference in EDSS progression between eligible patients who did and did not attempt discontinuation was not significant. After 1 year of eligibility, per-patient costs were $96k lower in the cohort that attempted discontinuation; however a higher proportion of relapses were seen in this group. When the proportion of patients willing to discontinue DMT increased, clinical findings remained consistent while the average cost per patient decreased.

CONCLUSION

While there are increased clinical and cost benefits as more eligible patients attempt discontinuation, the risk of relapses can increase. Timely disease monitoring is required to manage safe DMT discontinuation.

Type 1 interferons and Foxo1 down-regulation play a key role in age-related T-cell exhaustion in mice

Foxo family transcription factors are critically involved in multiple processes, such as metabolism, quiescence, cell survival and cell differentiation. Although continuous, high activity of Foxo transcription factors extends the life span of some species, the involvement of Foxo proteins in mammalian aging remains to be determined. Here, we show that Foxo1 is down-regulated with age in mouse T cells. This down-regulation of Foxo1 in T cells may contribute to the disruption of naive T-cell homeostasis with age, leading to an increase in the number of memory T cells. Foxo1 down-regulation is also associated with the up-regulation of co-inhibitory receptors by memory T cells and exhaustion in aged mice. Using adoptive transfer experiments, we show that the age-dependent down-regulation of Foxo1 in T cells is mediated by T-cell-extrinsic cues, including type 1 interferons. Taken together, our data suggest that type 1 interferon-induced Foxo1 down-regulation is likely to contribute significantly to T-cell dysfunction in aged mice.

Tuberculosis and diabetes mellitus comorbidity in an adult Ugandan population

BACKGROUND

Diabetes mellitus (DM) has a direct impact on the clinical manifestation and prognosis of active tuberculosis disease (TB) and is known to increase the chance of developing the condition. We sought to determine the prevalence of DM in adult Ugandan patients with recently diagnosed TB and the associated sociodemographic, anthropometric, and metabolic characteristics of TB-DM comorbidity.

METHODS

In this cross-sectional study conducted at the adult TB treatment centres of three tertiary healthcare facilities in Uganda, we screened adult participants with recently diagnosed TB (diagnosed in < 2 months) for DM. All participants were screened with five tests; initially with a random blood glucose (RBG) test, and then later with fasting blood glucose (FBG), laboratory-based glycated hemoglobin (HbA1c), point-of-care (POC) HbA1c, and oral glucose tolerance test (OGTT) if the RBG was ≥ 6.1 mmol/l. The WHO guidelines for diagnosing and managing DM were used to support the DM diagnosis. To identify the factors associated with DM-TB comorbidity, logistic regression was used.

RESULTS

A total of 232 participants with recently diagnosed TB were screened for DM. Of these, 160 (69%) were female. The median (IQR) age, body mass index, and RBG of all study participants was 35 (27-42) years, 19.2 (17.6-21.3) kg/m2, and 6.1 (5.5-7.2) mmol/l, respectively. About half of the participants (n = 117, 50.4%) had RBG level ≥ 6.1 mmol/l. Of these, 75 (64.1%) participants returned for re-testing. Diabetes mellitus was diagnosed in 32 participants, corresponding to a prevalence of 13.8% (95% CI 9.9-18.9). A new diagnosis of DM was noted in 29 (90.6%) participants. On logistic regression, age ≥ 40 years was associated with increased odds of TB and DM comorbidity (AOR 3.12, 95% CI 1.35-7.23, p = 0.008) while HIV coinfection was protective (AOR 0.27, 95% CI 0.10-0.74, p = 0.01).

CONCLUSION

TB and DM comorbidity was relatively common in this study population. Routine screening for DM in adult Ugandan patients with recently diagnosed TB especially among those aged ≥ 40 years and HIV-negative patients should be encouraged in clinical practice.

Trends in the Incidence of Disseminated Cryptococcosis in Japan: A Nationwide Observational Study, 2015-2021

BACKGROUND

Cryptococcus species can cause severe disseminated infections in immunocompromised hosts. This study investigated the epidemiological features and trends in disseminated cryptococcosis in Japan.

METHODS

We used publicly available Infectious Diseases Weekly Reports to obtain data on the incidence of disseminated cryptococcosis in Japan from 2015 to 2021. Patient information, including age, sex, and regional and seasonal data, were extracted. The Joinpoint regression program was used to determine the age-adjusted incidence rate (AAR) per 100,000 population, annual percentage change (APC), and average APC (AAPC).

RESULTS

A total of 1047 cases of disseminated cryptococcosis were reported, of which those aged ≥ 70 years accounted for 68.8%. The AAR in men was significantly higher than that in women (median: 0.13 vs. 0.09: p = 0.0024). APC for the overall cases increased by 9.9% (95% confidence interval [95% CI] - 5.4-27.7) from 2015 to 2018 and then decreased by 3.3% (95% CI - 15.5-10.7) from 2018 to 2021. AAPC for the entire study period was 3.1% (95% CI - 1.5-8.0), indicating a possible increase in its number, although not statistically significant. In terms of regional distribution, the average AAR was highest in Shikoku District (0.17) and lowest in Hokkaido District (0.04). Northern Japan exhibited a significantly lower median AAR (median [interquartile range]: 0.06 [0.05, 0.08]) than the Eastern (0.12 [0.12, 0.13]), Western (0.11 [0.10, 0.13]), and Southern (0.14 [0.12, 0.15]) regions. No seasonal variation in incidence was observed.

CONCLUSION

The prevalence of disseminated cryptococcosis has not increased in Japan. Geographically, the incidence is lower in Northern Japan. Further investigations that incorporate detailed clinical data are required.

Single-cell transcriptomics of Treg reveals hallmarks and trajectories of immunological aging

Age-related immunosenescence is characterized by progressive dysfunction of adaptive immune response and increased autoimmunity. Nevertheless, the impact of aging on CD4+ regulatory T cells that are master regulators of the immune system remains largely unclear. Here, we report cellular and molecular hallmarks of regulatory T cells derived from murine lymphoid and adipose tissues at 3, 18, and 24 mo of age, respectively, by analyzing their heterogeneity that displays dynamic changes in transcriptomic effector signatures at a single-cell resolution. Although the proportion of regulatory T cells among total Cd4+ T cells, as well as their expression levels of Foxp3, did not show any global change with time, we have identified 6 transcriptomically distinct clusters of regulatory T cells with cross-tissue conserved hallmarks of aging, including increased numbers of proinflammatory regulatory T cells, reduced precursor cells, increased immature and mature T follicular regulatory cells potentially supported by a metabolic switch from oxidative phosphorylation to glycolysis, a gradual loss of CD150hi regulatory T cells that support hematopoiesis, and increased adipose tissue-specific regulatory T cells that are associated with metabolic disease. To dissect the impact of immunosenescence on humoral immunity, we propose some potential mechanisms underlying T follicular regulatory cell-mediated dysfunction by interactome analysis on T follicular regulatory cells, T follicular helper cells, and B cells during aging. Lastly, spatiotemporal analysis further revealed trajectories of regulatory T-cell aging that demonstrate the most significant changes in marrow and adipose tissues that might contribute to the development of age-related immunosenescence and type 2 diabetes. Taken together, our findings could provide a better understanding of age-associated regulatory T-cell heterogeneity in lymphoid and adipose tissues, as well as regulatory T-cell hallmarks during progressive adaptation to aging that could be therapeutically targeted for rejuvenating the aging immune system in the future.

Aging Hallmarks and Progression and Age-Related Diseases: A Landscape View of Research Advancement

Aging is a dynamic, time-dependent process that is characterized by a gradual accumulation of cell damage. Continual functional decline in the intrinsic ability of living organisms to accurately regulate homeostasis leads to increased susceptibility and vulnerability to diseases. Many efforts have been put forth to understand and prevent the effects of aging. Thus, the major cellular and molecular hallmarks of aging have been identified, and their relationships to age-related diseases and malfunctions have been explored. Here, we use data from the CAS Content Collection to analyze the publication landscape of recent aging-related research. We review the advances in knowledge and delineate trends in research advancements on aging factors and attributes across time and geography. We also review the current concepts related to the major aging hallmarks on the molecular, cellular, and organismic level, age-associated diseases, with attention to brain aging and brain health, as well as the major biochemical processes associated with aging. Major age-related diseases have been outlined, and their correlations with the major aging features and attributes are explored. We hope this review will be helpful for apprehending the current knowledge in the field of aging mechanisms and progression, in an effort to further solve the remaining challenges and fulfill its potential.

Immunological features of ESRD patients undergoing hemodialysis of various ages

AIMS

To investigate the immunological characteristics of hemodialysis (HD) patients with end-stage renal disease (ESRD) of various ages, and the impact of age-related immune alterations on these patients, with a focus on peripheral T cells.

METHODS

From September 2016 to September 2019, HD patients were enrolled and followed prospectively for 3 years. Patients were divided into three groups based on their ages: < 45, 45 to 64, and ≥ 65. The distribution of T cell subsets in different age groups was investigated and compared. The effects of altered T cell subsets on overall survival were also investigated.

RESULTS

A total of 371 HD patients were enrolled. The reduced number of naive CD8+ T cells (P < 0.001) and increased number of EMRA CD8+ T cells (P = 0.024) were independently associated with the advanced age among all T cell subsets studied. Patient survival may be affected by numerical changes in naive CD8+ T cells. However, when HD patients were < 45 or ≥ 65 years, the reduction had no significant impact on survival. Only in HD patients aged 45 to 64 years, the number of naïve CD8+ T cells found to be insufficient but not deficient, identified as an independent predictor of poor survival.

CONCLUSIONS

The most significant age-related immune change in HD patients was a decrease in peripheral naive CD8+ T cells, which was an independent predictor of 3-year overall survival in HD patients aged 45 ~ 64 years.

Modeling human immune responses to vaccination in vitro

The human immune system is a complex network of coordinated components that are crucial for health and disease. Animal models, commonly used to study immunomodulatory agents, are limited by species-specific differences, low throughput, and ethical concerns. In contrast, in vitro modeling of human immune responses can enable species- and population-specific mechanistic studies and translational development within the same study participant. Translational accuracy of in vitro models is enhanced by accounting for genetic, epigenetic, and demographic features such as age, sex, and comorbidity. This review explores various human in vitro immune models, considers evidence that they may resemble human in vivo responses, and assesses their potential to accelerate and de-risk vaccine discovery and development.

Exosomes as a potential therapeutic approach in osteoimmunology

Exosomes are natural extracellular vesicles that play a key role in inter- and intracellular communication. Currently they are considered as a promising therapeutic strategy for the treatment of various diseases. In osteoimmunology, exosomes can serve as biomarkers of bone homeostasis disorders and, at the same time, promising therapeutic agents with high stability in the biological environment, low immunogenicity and good bioavailability. In this review, we attempted to examine exosomes as natural mediators of intercellular communication, playing an essential role in the interaction of the immune system and bone tissue, based on an analysis of the PubMed database up to October 2023.

Age-Related Alternative Splicing: Driver or Passenger in the Aging Process?

Alternative splicing changes are closely linked to aging, though it remains unclear if they are drivers or effects. As organisms age, splicing patterns change, varying gene isoform levels and functions. These changes may contribute to aging alterations rather than just reflect declining RNA quality control. Three main splicing types-intron retention, cassette exons, and cryptic exons-play key roles in age-related complexity. These events modify protein domains and increase nonsense-mediated decay, shifting protein isoform levels and functions. This may potentially drive aging or serve as a biomarker. Fluctuations in splicing factor expression also occur with aging. Somatic mutations in splicing genes can also promote aging and age-related disease. The interplay between splicing and aging has major implications for aging biology, though differentiating correlation and causation remains challenging. Declaring a splicing factor or event as a driver requires comprehensive evaluation of the associated molecular and physiological changes. A greater understanding of how RNA splicing machinery and downstream targets are impacted by aging is essential to conclusively establish the role of splicing in driving aging, representing a promising area with key implications for understanding aging, developing novel therapeutical options, and ultimately leading to an increase in the healthy human lifespan.

A score-based method of immune status evaluation for healthy individuals with complete blood cell counts

BACKGROUND

With the COVID-19 outbreak, an increasing number of individuals are concerned about their health, particularly their immune status. However, as of now, there is no available algorithm that effectively assesses the immune status of normal, healthy individuals. In response to this, a new score-based method is proposed that utilizes complete blood cell counts (CBC) to provide early warning of disease risks, such as COVID-19.

METHODS

First, data on immune-related CBC measurements from 16,715 healthy individuals were collected. Then, a three-platform model was developed to normalize the data, and a Gaussian mixture model was optimized with expectation maximization (EM-GMM) to cluster the immune status of healthy individuals. Based on the results, Random Forest (RF), Light Gradient Boosting Machine (LightGBM) and Extreme Gradient Boosting (XGBoost) were used to determine the correlation of each CBC index with the immune status. Consequently, a weighted sum model was constructed to calculate a continuous immunity score, enabling the evaluation of immune status.

RESULTS

The results demonstrated a significant negative correlation between the immunity score and the age of healthy individuals, thereby validating the effectiveness of the proposed method. In addition, a nonlinear polynomial regression model was developed to depict this trend. By comparing an individual's immune status with the reference value corresponding to their age, their immune status can be evaluated.

CONCLUSION

In summary, this study has established a novel model for evaluating the immune status of healthy individuals, providing a good approach for early detection of abnormal immune status in healthy individuals. It is helpful in early warning of the risk of infectious diseases and of significant importance.

Adult human neurogenesis: A view from two schools of thought

Are we truly losing neurons as we grow older? If yes, why, and how can the lost neurons be replaced or compensated for? Is so-called adult neurogenesis (ANG) still a controversial process, particularly in the human cerebral cortex? How do adult-born neurons -if proven to exist- contribute to brain functions? Is adult neurogenesis a disease-relevant process, meaning that neural progenitor cells are dormant in adulthood, but they may be reactivated, for example, following stroke? Is the earnest hope to cure neurological diseases justifying the readiness to accept ANG claim uncritically? These are all fundamental issues that have not yet been firmly explained. Although it is completely understandable that some researchers believe that we can add new neurons to our inevitably deteriorating brain, the brain regeneration process still possesses intellectually and experimentally diverting views, as until now, there has been significant confusion about the concept of ANG. This paper is not intended to be an extensively analytical review distilling all findings and conclusions presented in the ANG literature. Instead, it is an attempt to discuss the commonly entertained opinions and then present our reflective insight concerning the current status quo of the field, which might help redirect research questions, avoid marketing an exaggerated hope, and more importantly, save the ever-limited resources, namely, intellectuals' time, facilities, and grants.

Non-coding RNA profile for natural killer cell activity

Natural killer cells (NK cells) are a type of cytotoxic lymphocytes which are involved in innate immunity, alongside with assisting with adaptive immune response. Since they have cytotoxic effects, disruptions in their functionality and development leads to a variety of conditions, whether malignant or non-malignant. The profile and interaction of these non-coding RNAs and NK cells in different conditions is extensively studied, and it is now approved that if dysregulated, non-coding RNAs have detrimental effects on NK cell activity and can contribute to the pathogenesis of diverse disorders. In this review, we aim at a thorough inspection on the role of different non-coding RNAs on the activity and development of NK cells, in a broad spectrum of conditions, including blood-related disorders, viral infections, neurological diseases, gastrointestinal disorders, lung disorders, reproductive system conditions and other types of maladies, alongside with providing insight to the future non-coding RNA-NK cell studies.

Resolvin D2-G-Protein Coupled Receptor 18 Enhances Bone Marrow Function and Limits Steatosis and Hepatic Collagen Accumulation in Aging

Aging is associated with nonresolving inflammation and tissue dysfunction. Resolvin D2 (RvD2) is a proresolving ligand that acts through the G-protein-coupled receptor called GPR18. Unbiased RNA sequencing revealed increased Gpr18 expression in macrophages from old mice, and in livers from elderly humans, which was associated with increased steatosis and fibrosis in middle-aged (MA) and old mice. MA mice that lacked GPR18 on myeloid cells had exacerbated steatosis and hepatic fibrosis, which was associated with a decline in Mac2+ macrophages. Treatment of MA mice with RvD2 reduced steatosis and decreased hepatic fibrosis, correlating with increased Mac2+ macrophages, increased monocyte-derived macrophages, and elevated numbers of monocytes in the liver, blood, and bone marrow. RvD2 acted directly on the bone marrow to increase monocyte-macrophage progenitors. A transplantation assay further demonstrated that bone marrow from old mice facilitated hepatic collagen accumulation in young mice. Transient RvD2 treatment to mice transplanted with bone marrow from old mice prevented hepatic collagen accumulation. Together, this study demonstrates that RvD2-GPR18 signaling controls steatosis and fibrosis and provides a mechanistic-based therapy for promoting liver repair in aging.

The Association Between Malignant Otitis Externa and Diabetes Mellitus in Africa: A Systematic Review

Diabetes mellitus is one of the risk factors for malignant otitis externa. There are very few studies on the disease in Africa and there is a need to pool the prior studies to highlight the characteristics of the disease. The study type is a systematic review and the PRISMA guidelines were followed. Using the appropriate terms, relevant medical databases were systematically searched. Thirty-two studies met the eligibility criteria with a total sample size of 848, who were mainly elderly. Diabetes mellitus was present in 94% of the participants. Average duration of diabetes diagnosis in the participants was 12.4 years. The pooled HbA1c was 9.8%. The most common symptoms were otalgia (96.1%), otorrhoea (75.8%) and hearing loss (56.1%). Pseudomonas was the most common isolate (72%). Fluoroquinolones and the 3rd-generation cephalosporins were the preferred antibiotics. The pooled cure rate from antimicrobial usage was 76.2%. In addition to medications, 24.6% of the affected individuals required debridement. About 1.6% of the participants died from malignant otitis externa. Malignant otitis externa is associated with poorly controlled diabetes. Pseudomonas is the most common cause and a significant proportion gets cured with prolonged antibiotherapy.

Toll-like receptor 4 (TLR4): new insight immune and aging

TLR4, a transmembrane receptor, plays a central role in the innate immune response. TLR4 not only engages with exogenous ligands at the cellular membrane's surface but also interacts with intracellular ligands, initiating intricate intracellular signaling cascades. Through MyD88, an adaptor protein, TLR4 activates transcription factors NF-κB and AP-1, thereby facilitating the upregulation of pro-inflammatory cytokines. Another adapter protein linked to TLR4, known as TRIF, autonomously propagates signaling pathways, resulting in heightened interferon expression. Recently, TLR4 has garnered attention as a significant factor in the regulation of symptoms in aging-related disorders. The persistent inflammatory response triggered by TLR4 contributes to the onset and exacerbation of these disorders. In addition, alterations in TLR4 expression levels play a pivotal role in modifying the manifestations of age-related diseases. In this review, we aim to consolidate the impact of TLR4 on cellular senescence and aging-related ailments, highlighting the potential of TLR4 as a novel therapeutic target that extends beyond immune responses.

Burden and associated phenotypic characteristics of tuberculosis infection in adult Africans with diabetes: a systematic review

Diabetes mellitus (DM) increases the risk of developing tuberculosis infection (TBI). However, the evidence on the burden and phenotypic characteristics of TBI in African patients with DM is limited. This study aimed to determine the prevalence and characterisation of TBI in native African patients living with DM. We searched PubMed, EMBASE, and African Journals Online for original studies reporting information on the prevalence and characteristics of TBI in adult Africans with DM. A forest plot was used to describe the pooled prevalence estimate of TBI and the corresponding 95% confidence intervals (CI). Six studies conducted in four African countries involving 721 participants with DM were included in this systematic review. The pooled prevalence estimate of TBI was 40% (95% CI 20-60%, I2 = 98.52%, p < 0.001). Age ≥ 40 years and glycated haemoglobin levels independently predicted TBI positivity in patients with DM in three studies. Africans with DM have a high prevalence of TBI, especially those who are older or with poorly controlled diabetes. This justifies the need for studies to explore how to screen and manage TBI to avert the progression to active TB disease.

The Impact of Vaccination Time on the Antibody Response to an Inactivated Vaccine against SARS-CoV-2 (IMPROVE-2): A Randomized Controlled Trial

There is still controversy about whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination at different times of day will induce a stronger immune response. Therefore, a randomized controlled trial (ChiCTR2100045109) is conducted to investigate the impact of vaccination time on the antibody response to the inactivated vaccine against SARS-CoV-2 from April 15 to 28, 2021. Participants are randomly assigned in a 1:1 ratio to receive inactivated SARS-CoV-2 vaccine in the morning or afternoon. The primary endpoint is the change of neutralizing antibody between baseline and 28 days after the second dose. In total, 503 participants are randomized, and 469 participants (238 in the morning group and 231 in the afternoon group) complete the follow-up. There is no significant difference in the change of neutralizing antibody between baseline and 28 days after the second dose between the morning and afternoon groups (22.2 [13.2, 45.0] AU mL-1  vs 22.0 [14.4, 40.7] AU mL-1 , P = 0.873). In prespecified age and sex subgroup analyses, there is also no significant difference in the morning and afternoon group (all P > 0.05). This study demonstrates that the vaccination time does not affect the antibody response of two doses of inactivated SARS-CoV-2 vaccine.

Side effects of COVID-19 vaccinations in patients treated for breast cancer

Lymph node swelling is a side effect of the mRNA COVID-19 vaccines, a distressing side effect for women treated for breast cancer. The purpose of this study is to present side effects reported by a cohort of patients treated for breast cancer. A survey link was sent to 4945 women who received breast cancer treatment and were prospectively screened for breast cancer-related lymphedema. In total, 621 patients who received an mRNA vaccine and responded to the survey were included in analysis. We assessed the frequency and predictors of side effects. The most frequent side effects reported were injection site soreness, fatigue, generalized muscle soreness, headache, and chills, with median duration  ≤ 48 h. Lymph node swelling occurred most often in the axilla ipsilateral to the vaccine. The median duration was 1 week or less after all doses. These data will inform patient education regarding future vaccine doses, including reassurances about which side effects to expect, particularly lymph node swelling which may impact mammograms after vaccination. Type and duration of side effects were similar to that reported by the general population in Phase 3 testing trials of the mRNA vaccines. Clinical Trial Registration NCT04872738 posted May 4, 2021.

The multifaceted role of macrophages in homeostatic and injured skeletal muscle

Skeletal muscle is essential for body physical activity, energy metabolism, and temperature maintenance. It has excellent capabilities to maintain homeostasis and to regenerate after injury, which indispensably relies on muscle stem cells, satellite cells (MuSCs). The quiescence, activation, and differentiation of MuSCs are tightly regulated in homeostatic and regenerating muscles. Among the important regulators are intramuscular macrophages, which are functionally heterogeneous with different subtypes present in a spatiotemporal manner to regulate the balance of different MuSC statuses. During chronic injury and aging, intramuscular macrophages often undergo aberrant activation, which in turn disrupts muscle homeostasis and regenerative repair. Growing evidence suggests that the aberrant activation is mainly triggered by altered muscle microenvironment. The trained immunity that affects myeloid progenitors during hematopoiesis may also contribute. Aged immune system may contribute, in part, to the aging-related sarcopenia and compromised skeletal muscle injury repair. As macrophages are actively involved in the progression of many muscle diseases, manipulating their functional activation has become a promising therapeutic approach, which requires comprehensive knowledge of the cellular and molecular mechanisms underlying the diverse activation. To this end, we discuss here the current knowledge of multifaceted role of macrophages in skeletal muscle homeostasis, injury, and repair.