From Genesis to Old Age: Exploring the Immune System One Cell at a Time with Flow Cytometry.

The immune system is a highly complex and tightly regulated system that plays a crucial role in protecting the body against external threats, such as pathogens, and internal abnormalities, like cancer cells. It undergoes development during fetal stages and continuously learns from each encounter with pathogens, allowing it to develop immunological memory and provide a wide range of immune protection. Over time, after numerous encounters and years of functioning, the immune system can begin to show signs of erosion, which is commonly named immunosenescence. In this review, we aim to explore how the immune system responds to initial encounters with antigens and how it handles persistent stimulations throughout a person's lifetime. Our understanding of the immune system has greatly benefited from advanced technologies like flow cytometry. In this context, we will discuss the valuable contribution of flow cytometry in enhancing our knowledge of the immune system behavior in aging, with a specific focus on T-cells. Moreover, we will expand our discussion to the flow cytometry-based assessment of extracellular vesicles, a recently discovered communication channel in biology, and their implications for immune system functioning.

Assessing serum cytokine profiles in inflammatory breast cancer patients using Luminex® technology.

BACKGROUND: Inflammatory breast cancer (IBC), accounts for the majority of deaths associated with breast tumors. Because this form is aggressive from its appearance and has a strong metastatic potential. The majority of patients are not diagnosed until late stages, highlighting the need for the development of novel diagnostic biomarkers. Immune mediators may affect IBC progression and metastasis installation. AIM OF THE STUDY: Analysis of serum proteins to identify a panel of prognostic biomarkers for IBC. PATIENTS AND METHODS: Serum levels of 65 analytes were determined in IBC and Non-IBC patients with the ProcartaPlex Human Immune Monitoring 65-Plex Panel. RESULTS: Fifteen analytes: 5 cytokines (IL-8, IL-16, IL-21, IL-22 and MIF), 7 chemokines (Eotaxin, eotaxin-3, Fractalkine, IP-10, MIP-1α, MIP-1ß and SDF-1α), One growth factors (FGF-2) and 2 soluble receptors (TNFRII and Tweak); were significantly differentially expressed between the two groups. ROC curves showed that twelve of them (IL-8, IL-16, IL-21, IL-22, MIF, MIP-1α, MIP-1ß, SDF-1α, TNFRII, FGF-2, Eotaxin-3, and Fractalkine) had AUC values greater than 0.70 and thus had potential clinical utility. Moreover, seven cytokines: IL-8, IL-16, MIF, Eotaxin-3, MIP-1α, MIP-1ß, and CD-30 are positively associated with patients who developed distant metastasis. Ten analytes: Eotaxin-3, Fractalkine, IL-16, IL-1α, IL-22, IL-8, MIF, MIP-1α, MIP-1ß, and TNFRII are positively associated with patients who had Lymph-Nodes invasion. CONCLUSION: This study has uncovered a set of 8 analytes (Eotaxin-3, Fractalkine, IL-16, IL-8, IL-22, MIF, MIP-1α, MIP-1ß) that can be used as biomarkers of IBC, and can be utilized for early detection of IBC, preventing metastasis and lymph-Nodes invasion.

Immune checkpoints as potential theragnostic biomarkers for epithelial ovarian cancer.

BACKGROUND: Epithelial ovarian cancer (EOC) is the leading cause of death associated with gynecologic tumors. EOC is asymptomatic in early stages, so most patients are not diagnosed until late stages, highlighting the need to develop new diagnostic biomarkers. Mediators of the tumoral microenvironment may influence EOC progression and resistance to treatment. AIM: To analyze immune checkpoints to evaluate them as theranostic biomarkers for EOC. PATIENTS AND METHODS: Serum levels of 16 immune checkpoints were determined in EOC patients and healthy controls using the MILLIPLEX MAP® Human Immuno-Oncology Checkpoint Protein Magnetic Bead Panel. RESULTS: Seven receptors: BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2 are differentially expressed between EOC and healthy controls. Serum levels of immune checkpoints in EOC patients are positively significantly correlated with levels of their ligands, with a higher significant correlation between CD80 and CTLA4 than between CD28 and CD80. Four receptors, CD40, HVEM, PD-1, and PD-L1, are positively associated with the development of resistance to Taxol-platinum-based chemotherapy. All of them have an acceptable area under the curve (>0.7). CONCLUSION: This study has yielded a first panel of seven immune checkpoints (BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2) associated with a higher risk of EOC and a second panel of four immune checkpoints (CD40, HVEM, PD-1, PD-L1) that may help physicians to identify EOC patients who are at high risk of developing resistance to EOC chemotherapy.

Identification of two theranostic biomarker panels for epithelial ovarian cancer.

BACKGROUND: Epithelial Ovarian cancer (EOC) is the leading cause of death associated with gynecologic tumors. Because the disease is asymptomatic in early-stage, the majority of patients are not diagnosed until late stages, highlighting the need for the development of novel diagnostic biomarkers. Mediators of tumoral microenvironment may affect EOC progression and resistance to treatment. AIM OF THE STUDY: Analysis of serum proteins to identify a panel of theranostic biomarkers for EOC. PATIENTS AND METHODS: Serum levels of 65 analytes were determined in EOC patients, and healthy controls with the ProcartaPlex Human Immune Monitoring 65-Plex Panel. RESULTS: Twenty-one analytes: 7 cytokines (IFN-γ, IL-12p70, IL-13, IL-18 and TSLP), 7 chemokines (Eotaxin, eotaxin-2, IP-10, BLC, I-TAC, SDF-1α, and fractalkine), 2 growth factors (MMP-1, VEGF-α), and 5 soluble receptors (APRIL, CD40L, TWEAK, CD30 and TNFRII; were significantly differentially expressed between the two groups. ROC curves showed that only seven of them (IL-9, TNF-α, Eotaxin, IP-10, BLC, Fractalkine, and Tweak) had AUC values greater than 0.70 and thus had potential clinical utility. Moreover, five cytokines: IFN-γ, IL-1 ß, IL-8, MIP-1ß, and TNF-α are positively associated with patients who developed resistance to taxol-platinum-based chemotherapy (CT). CONCLUSION: This study has revealed a first panel of 7 analytes (IL-9, TNF-α, Eotaxin, IP-10, BLC, Fractalkine and Tweak) that can be used for early detection of EOC and a second panel of five cytokines (IFN-γ, IL-1ß, IL-8, MIP-1ß, TNF-α) that can help clinicians to identify EOC patients who are at higher risk to develop resistance to CT of EOC.

Deep learning-based image analysis reveals significant differences in the number and distribution of mucosal CD3 and γδ T cells between Crohn's disease and ulcerative colitis.

Colon mucosae of ulcerative colitis (UC) and Crohn's disease (CD) display differences in the number and distribution of immune cells that are difficult to assess by eye. Deep learning-based analysis on whole slide images (WSIs) allows extraction of complex quantitative data that can be used to uncover different inflammatory patterns. We aimed to explore the distribution of CD3 and γδ T cells in colon mucosal compartments in histologically inactive and active inflammatory bowel disease. By deep learning-based segmentation and cell detection on WSIs from a well-defined cohort of CD (n = 37), UC (n = 58), and healthy controls (HCs, n = 33), we quantified CD3 and γδ T cells within and beneath the epithelium and in lamina propria in proximal and distal colon mucosa, defined by the Nancy histological index. We found that inactive CD had significantly fewer intraepithelial γδ T cells than inactive UC, but higher total number of CD3 cells in all compartments than UC and HCs. Disease activity was associated with a massive loss of intraepithelial γδ T cells in UC, but not in CD. The total intraepithelial number of CD3 cells remained constant regardless of disease activity in both CD and UC. There were more mucosal CD3 and γδ T cells in proximal versus distal colon. Oral corticosteroids had an impact on γδ T cell numbers, while age, gender, and disease duration did not. Relative abundance of γδ T cells in mucosa and blood did not correlate. This study reveals significant differences in the total number of CD3 and γδ T cells in particularly the epithelial area between CD, UC, and HCs, and demonstrates useful application of deep segmentation to quantify cells in mucosal compartments.

Notch-dependent cooperativity between myeloid lineages promotes Langerhans cell histiocytosis pathology.

Langerhans cell histiocytosis (LCH) is a potentially fatal neoplasm characterized by the aberrant differentiation of mononuclear phagocytes, driven by mitogen-activated protein kinase (MAPK) pathway activation. LCH cells may trigger destructive pathology yet remain in a precarious state finely balanced between apoptosis and survival, supported by a unique inflammatory milieu. The interactions that maintain this state are not well known and may offer targets for intervention. Here, we used single-cell RNA-seq and protein analysis to dissect LCH lesions, assessing LCH cell heterogeneity and comparing LCH cells with normal mononuclear phagocytes within lesions. We found LCH discriminatory signatures pointing to senescence and escape from tumor immune surveillance. We also uncovered two major lineages of LCH with DC2- and DC3/monocyte-like phenotypes and validated them in multiple pathological tissue sites by high-content imaging. Receptor-ligand analyses and lineage tracing in vitro revealed Notch-dependent cooperativity between DC2 and DC3/monocyte lineages during expression of the pathognomonic LCH program. Our results present a convergent dual origin model of LCH with MAPK pathway activation occurring before fate commitment to DC2 and DC3/monocyte lineages and Notch-dependent cooperativity between lineages driving the development of LCH cells.

Inflammatory markers and incident depression: Evidence in a population-based prospective study.

The association between pro-inflammatory cytokines and depression is widely acknowledged. However, longitudinal data that show they lead to depression are few. In a community-based sample of older individuals (n = 2761, ages = 55-98 y) in the Singapore Longitudinal Ageing Study (SLAS), we analyzed the associations between inflammatory markers (CRP, IL6, TNFα, and inflammation risk score) and depression (defined as the presence of depressive symptoms, depression history or treatment). Cross-sectional analysis showed that CRP, IL-6 and TNFα were significantly associated with depression at baseline. Longitudinal analysis controlling for a host of potentially confounding risk factors and initial depression revealed that IL-6, TNFα, and inflammation risk score were associated with elevated risk of depression at follow-ups. However, there was no significant association between CRP and subsequent depression after adjusting for sociodemographic, lifestyles and inflammatory medical condition variables. In summary, this prospective study shows that inflammation predicts depression in older adults, and suggests that the heterogeneous findings among studies may be due to differences in study population characteristics, depression, inflammatory markers, and the extent of adjusting for confounders.

Transitional premonocytes emerge in the periphery for host defense against bacterial infections.

Circulating Ly6Chi monocytes often undergo cellular death upon exhaustion of their antibacterial effector functions, which limits their capacity for subsequent macrophage differentiation. This shrouds the understanding on how the host replaces the tissue-resident macrophage niche effectively during bacterial invasion to avert infection morbidity. Here, we show that proliferating transitional premonocytes (TpMos), an immediate precursor of mature Ly6Chi monocytes (MatMos), were mobilized into the periphery in response to acute bacterial infection and sepsis. TpMos were less susceptible to apoptosis and served as the main source of macrophage replenishment when MatMos were vulnerable toward bacteria-induced cellular death. Furthermore, TpMo and its derived macrophages contributed to host defense by balancing the proinflammatory cytokine response of MatMos. Consequently, adoptive transfer of TpMos improved the survival outcome of lethal sepsis. Our findings hence highlight a protective role for TpMos during bacterial infections and their contribution toward monocyte-derived macrophage heterogeneity in distinct disease outcomes.

Lifetime pathogen burden, inflammatory markers, and depression in community-dwelling older adults.

The link between pathogen exposure and mental health has long been hypothesized, but evidence remains limited. We investigated the association of seropositivity to common pathogens and total pathogen burden with depression and mental health and explored the role of mediating inflammatory cytokines. We profiled in 884 participants in the Singapore Longitudinal Ageing Studies, mean (SD) age: 67.9 (8.1) years, their seropositivities for 11 pathogens (CMV, HSV 1, HSV 2, HHV-6, EBV, VZV, RSV, Dengue, Chikungunya, H. Pylori and Plasmodium) and pathogen burden, Geriatric Depression Scale (GDS) score at baseline and 3-4 and 6-8 years follow-up, and baseline Mental Component Score (MCS) of 12-Item Short Form Survey (SF-12). Inflammatory markers included CRP, TNF-α, IL-6, MIP-1α, sgp130, sTNF-RI, sTNF-RII, C3a, and MCP-2. Controlling for age, sex, ethnicity, education, marital status, living alone, and smoking status, high pathogen burden (7 + cumulative infections) compared to low pathogen burden (1-5 cumulative infections) was significantly associated with period prevalence (the highest GDS score from baseline and follow-up measurements) of depressive symptoms (OR = 2.36, 95% CI = 1.05-5.33) and impaired mental health (OR = 2.25, 95% CI = 1.18-4.30). CMV seropositivity and HSV1 seropositivity, which are highly prevalent and most widely studied, were associated with estimated 2-fold increased odds of depression, but only HSV1 seropositivity was significantly associated with depression after adjusting for confounders. Notably, adjusted for confounders, RSV, H. pylori and Plasmodium seropositivity were significantly associated with increased odds, and Dengue seropositivity was associated with unexpectedly deceased odds of depressive symptoms and impaired mental health. The association of pathogen exposure with depression and mental health were at least in parts explained by inflammatory markers. Adding certain inflammatory markers to the models attenuated or weakened the association. Bootstrap method showed that MIP-1α significantly mediated the association between pathogen burden and mental health. In conclusion, lifelong pathogen burden and specific infections are associated with depression and impaired mental health in older adults.

In Vivo Efficacy of Neutrophil-Mediated Bone Regeneration Using a Rabbit Calvarial Defect Model.

Reconstruction of bone due to surgical removal or disease-related bony defects is a clinical challenge. It is known that the immune system exerts positive immunomodulatory effects on tissue repair and regeneration. In this study, we evaluated the in vivo efficacy of autologous neutrophils on bone regeneration using a rabbit calvarial defect model. Methods: Twelve rabbits, each with two surgically created calvarial bone defects (10 mm diameter), were randomly divided into two groups; (i) single application of neutrophils (SA-NP) vs. SA-NP control, and (ii) repetitive application of neutrophils (RA-NP) vs. RA-NP control. The animals were euthanized at 4 and 8 weeks post-operatively and the treatment outcomes were evaluated by micro-computed tomography, histology, and histomorphometric analyses. Results: The micro-CT analysis showed a significantly higher bone volume fraction (bone volume/total volume) in the neutrophil-treated groups, i.e., median interquartile range (IQR) SA-NP (18) and RA-NP (24), compared with the untreated controls, i.e., SA-NP (7) and RA-NP (14) at 4 weeks (p < 0.05). Similarly, new bone area fraction (bone area/total area) was significantly higher in neutrophil-treated groups at 4 weeks (p < 0.05). Both SA-NP and RA-NP had a considerably higher bone volume and bone area at 8 weeks, although the difference was not statistically significant. In addition, immunohistochemical analysis at 8 weeks revealed a higher expression of osteocalcin in both SA-NP and RA-NP groups. Conclusions: The present study provides first hand evidence that autologous neutrophils may have a positive effect on promoting new bone formation. Future studies should be performed with a larger sample size in non-human primate models. If proven feasible, this new promising strategy could bring clinical benefits for bone defects to the field of oral and maxillofacial surgery.

Horticultural Therapy Reduces Biomarkers of Immunosenescence and Inflammaging in Community-Dwelling Older Adults: A Feasibility Pilot Randomized Controlled Trial.

BACKGROUND: With the challenges that aging populations pose to health care, interventions that facilitate alleviation of age-related morbidities are imperative. A prominent risk factor for developing age-related morbidities is immunosenescence, characterized by increased chronic low-grade inflammation, resulting in T-cell exhaustion and senescence. Contact with nature and associated physical activities have been shown to boost immunity in older adults and may be promoted in the form of horticultural therapy (HT). We aimed to examine the effects of HT on immunosenescence. METHOD: We conducted a randomized controlled trial with 59 older adults assigned to either the HT intervention or waitlist control group. Older adults in the HT intervention group underwent HT intervention program over 6 months. Venous blood was drawn at baseline and at the third and sixth month from the commencement of this study. For participants who attended all 3 blood collection time points (HT: n = 22; waitlist: n = 24), flow cytometry analysis was performed on whole blood samples to evaluate the kinetics of lymphocyte subsets over the intervention period, revealing the composition of CD4+ and CD8+ subsets expressing exhaustion markers-CD57, CTLA4, and KLRG1. Enzyme-linked immunosorbent assays were employed to measure changes in plasma IL-6 levels. RESULTS: HT is associated with increased numbers of naive CD8+ T cells and fewer CTLA4-expressing terminally differentiated effector CD4+ and CD8+ memory T cells re-expressing CD45RA (TEMRA). Furthermore, IL-6 levels were reduced during HT, and the frequencies of naive and TEMRA CD8+ T cells were found to be associated with IL-6 levels. CONCLUSION: HT is associated with a reduction in the levels of biomarkers that measure the extent of T-cell exhaustion and inflammaging in older adults. The positive effects of HT on T-cell exhaustion were associated with the reduction of IL-6 levels.

Socio-Environmental, Lifestyle, Behavioural, and Psychological Determinants of Biological Ageing: The Singapore Longitudinal Ageing Study.

INTRODUCTION: The identification of modifiable health span-promoting factors is a public health priority. OBJECTIVE: To explore the socio-environmental, lifestyle, behavioural, and psychological determinants of a clinical phenotypic measure of biological ageing in the Singapore Longitudinal Ageing Study (SLAS) cohort. METHODS: Using cross-sectional data on 2,844 SLAS-2 adults with a chronological age (CA) ≥55 years, we estimated biological age (BA) using a validated panel of clinical, biochemical, physiological, and functional indicators (8 in men and 10 in women) and calculated the difference between BA and CA (BA - CA in years). Potential determinants included education, housing status, loss of a spouse, living alone, lifestyle and health activity, smoking, alcohol consumption, nutritional risks, consumption of milk, soy, fruit, vegetables, coffee and tea, sleep parameters, and life satisfaction. RESULTS: The mean CA was 67.0 (standard deviation [SD] 7.9; range 55-94) years. The estimated BA varied more widely (SD 8.9 years; range 47.5-119.9 years), and BA - CA ranged from -11.3 to 30.0 years. In stepwise selection regression analyses, multiple significant independent determinants in a final model were larger for private housing, being single/divorced/widowed, productivity, cognitive and leisure time activity scores, 10 h/week of moderate-to-vigorous physical activity, unintended loss of weight, life satisfaction, and daily consumption of fruits 1-2 or ≥3 servings and Chinese tea 1-2 or ≥3 cups daily, together explaining 16% of BA - CA variance in men and 14% in women. Associated BA - CA estimates were highest in men with high-end housing status (-1.8 years, effect size 0.015) and unintended weight loss (1.5 years, effect size 0.017). CONCLUSION: We identified determinants of biological ageing which can promote health span.

Pathogenic load and frailty in older adults: Singapore longitudinal ageing study.

Human evidence for the role of continuous antigenic stimulation from persistent latent infections in frailty is limited. We conducted a nested case-control study (99 deceased and 43 survivors) of participants aged 55 and above in a longitudinal ageing cohort followed up from 2003 to 2017. Using blood samples and baseline data collected in 2003-2004, we examined the association of pathogenic load (PL) count of seropositivity to 10 microbes (viruses, bacteria and mycoplasma) with cumulated deficit-frailty index (CD-FI) and the physical frailty (PF) phenotype, and mortality. Controlling for age, sex, education, smoking and alcohol histories, high PL (7-9) versus low PL (3-6) was associated with an estimated increase of 0.035 points in the CD-FI (Cohen's D=0.035 / 0.086, or 0.41). High PL was associated with 8.5 times odds of being physically frail (p=0.001), 2.8 times odds of being weak (p=0.010), 3.4 times odds of being slow (p=0.024), and mortality hazard ratio of 1.53 (p=0.046). There were no significant associations for specific pathogens, except marginal associations for Epstein-Barr virus and Chikungunya. Conclusion: A high pathogenic load of latent infections was associated with increased risks of frailty and mortality.

Whole blood immunophenotyping uncovers immature neutrophil-to-VD2 T-cell ratio as an early marker for severe COVID-19.

SARS-CoV-2 is the novel coronavirus responsible for the current COVID-19 pandemic. Severe complications are observed only in a small proportion of infected patients but the cellular mechanisms underlying this progression are still unknown. Comprehensive flow cytometry of whole blood samples from 54 COVID-19 patients reveals a dramatic increase in the number of immature neutrophils. This increase strongly correlates with disease severity and is associated with elevated IL-6 and IP-10 levels, two key players in the cytokine storm. The most pronounced decrease in cell counts is observed for CD8 T-cells and VD2 γδ T-cells, which both exhibit increased differentiation and activation. ROC analysis reveals that the count ratio of immature neutrophils to VD2 (or CD8) T-cells predicts pneumonia onset (0.9071) as well as hypoxia onset (0.8908) with high sensitivity and specificity. It would thus be a useful prognostic marker for preventive patient management and improved healthcare resource management.

The Aging of γδ T Cells.

In the coming decades, many developed countries in the world are expecting the "greying" of their populations. This phenomenon poses unprecedented challenges to healthcare systems. Aging is one of the most important risk factors for infections and a myriad of diseases such as cancer, cardiovascular and neurodegenerative diseases. A common denominator that is implicated in these diseases is the immune system. The immune system consists of the innate and adaptive arms that complement each other to provide the host with a holistic defense system. While the diverse interactions between multiple arms of the immune system are necessary for its function, this complexity is amplified in the aging immune system as each immune cell type is affected differently-resulting in a conundrum that is especially difficult to target. Furthermore, certain cell types, such as γδ T cells, do not fit categorically into the arms of innate or adaptive immunity. In this review, we will first introduce the human γδ T cell family and its ligands before discussing parallels in mice. By covering the ontogeny and homeostasis of γδ T cells during their lifespan, we will better capture their evolution and responses to age-related stressors. Finally, we will identify knowledge gaps within these topics that can advance our understanding of the relationship between γδ T cells and aging, as well as age-related diseases such as cancer.

Sestrins induce natural killer function in senescent-like CD8+ T cells.

Aging is associated with remodeling of the immune system to enable the maintenance of life-long immunity. In the CD8+ T cell compartment, aging results in the expansion of highly differentiated cells that exhibit characteristics of cellular senescence. Here we found that CD27-CD28-CD8+ T cells lost the signaling activity of the T cell antigen receptor (TCR) and expressed a protein complex containing the agonistic natural killer (NK) receptor NKG2D and the NK adaptor molecule DAP12, which promoted cytotoxicity against cells that expressed NKG2D ligands. Immunoprecipitation and imaging cytometry indicated that the NKG2D-DAP12 complex was associated with sestrin 2. The genetic inhibition of sestrin 2 resulted in decreased expression of NKG2D and DAP12 and restored TCR signaling in senescent-like CD27-CD28-CD8+ T cells. Therefore, during aging, sestrins induce the reprogramming of non-proliferative senescent-like CD27-CD28-CD8+ T cells to acquire a broad-spectrum, innate-like killing activity.

Examining Immunotherapy Response Using Multiple Radiotracers.

PURPOSE: Cancer immunotherapy has shown huge potential in the fight against cancer, but only a small proportion of patients respond successfully to treatment. Non-invasive methods to stratify responders from non-responders are critically important as immune therapies are often associated with immune-related side effects. Currently, conventional clinical imaging modalities do not provide a useful measure of immune therapy efficacy. Sensitive imaging biomarkers that provide information about the tumoural microenvironment may provide useful insights allowing for improved patient management. PROCEDURES: We have assessed the ability of a number of radiopharmaceuticals to non-invasively measure different aspects of the tumour microenvironment and correlated tumour uptake to immune therapy response in a syngeneic model of colon cancer, CT26-WT. Four radiopharmaceuticals, [18F]FDG (a glucose analogue), [18F]FEPPA (a marker for macrophage activation), [18F]FB-IL2 (a marker for CD25+ cells) and [68Ga] Ga-mNOTA-GZP (a marker for granzyme B, the serine protease downstream effector of cytotoxic T cells), were assessed as potential biomarkers to help stratify response to PD-1 monotherapy or combined anti-PD1 and CLTA4 therapy in vivo correlating tumour uptake with changes in tumour-associated immune cell populations. RESULTS: [18F]FDG, [18F]FEPPA and [18F]FB-IL2 (a marker for CD25+ cells) showed limited ability to determine therapy response and showed little correlation to tumour-associated immune cell changes. However, [68Ga] Ga-mNOTA-GZP showed good predictive ability and correlated well with changes in tumour-associated T cells, especially CD8+ T cells. CONCLUSIONS: [68Ga]Ga-mNOTA-GZP uptake correlates well with changes in CD8+ T cell populations supporting continued development of granzyme B-based imaging agents for stratification of response to immunotherapy. Early assessment of immunotherapy efficacy with [68Ga]Ga-mNOTA-GZP may allow for the reduction of unnecessary side effects while significantly improving patient management.

Mindfulness improves inflammatory biomarker levels in older adults with mild cognitive impairment: a randomized controlled trial.

Few randomized controlled trials investigated the effects of mindfulness intervention on older adults diagnosed with mild cognitive impairment (MCI). Furthermore, there have been hypotheses and theoretical mechanisms on the benefits of mindfulness intervention on biomarkers of stress, inflammation, and neuroplasticity implicated in MCI that warrant empirical evidence. We conducted a pilot randomized controlled trial to examine whether Mindful Awareness Practice (MAP) improved biomarker levels in older adults with MCI. Fifty-five community-dwelling older adults aged 60 and above were randomized into either the treatment arm, MAP, or the active control arm, the health education program (HEP). Researchers who were blinded to treatment allocation assessed the outcomes at baseline, 3-month, and 9-month follow-ups. Linear-mixed models were used to examine the effect of MAP on biomarker levels. MAP participants had significantly decreased high-sensitivity c-reactive protein (hs-CRP) levels at 9-month (ß = -0.307, 95% CI = -0.559 to -0.054 P = 0.018). Exploratory sub-group analyses by sex showed significantly decreased hs-CRP in females only (ß = -0.445, 95% CI = -0.700 to -0.189, P = 0.001), while stratification by MCI subtype showed hs-CRP decreased only in amnestic-MCI (aMCI) (ß = -0.569, 95% CI = -1.000 to -0.133, P = 0.012). Although total sample analyses were not significant, males had significantly decreased interleukin (IL)-6 (ß = -1.001, 95% CI = -1.761 to -0253, P = 0.011) and IL-1ß (ß = -0.607, 95% CI = -1.116 to -0.100, P = 0.021) levels at 3-month and non-significant improvements at 9-month time-point. MAP improved inflammatory biomarkers in sex- and MCI subtype-specific manners. These preliminary findings suggest the potential of mindfulness intervention as a self-directed and low-cost preventive intervention in improving pathophysiology implicated in MCI.

Associations of lifestyle activities and a heathy diet with frailty in old age: a community-based study in Singapore.

Frailty is an age-related state characterized by a reduced physiological reserve, and is associated with adverse health outcomes in the elderly. We analyzed the data from 895 adults aged 60 years and above, and investigated the relationships between midlife and late-life social activities, intellectual activities, working hours, and dietary habits and frailty status. Participation in social or intellectual activities in late life was less prevalent among those who were frail than among those who were robust. A greater proportion of those who were frail had worked long hours in midlife. After adjustment for confounders, participating in social activities or intellectual activities in late life was associated with a reduced risk for prefrailty and frailty, while working long hours in midlife was associated with a higher risk for frailty. The risk of frailty decreased with increasing healthy diet scores in midlife and late life. When the results were stratified by gender, late-life participation in social activities and midlife or late-life participation in intellectual activities correlated negatively with prefrailty/frailty only in women. Our study suggests that social and intellectual activities are inversely associated with frailty status, but the association seems to differ based on gender.

Plasmacytoid dendritic cells develop from Ly6D+ lymphoid progenitors distinct from the myeloid lineage.

Dendritic cells (DC) are currently classified as conventional DCs (cDCs) and plasmacytoid DCs (pDCs). Through a combination of single-cell transcriptomic analysis, mass cytometry, in vivo fate mapping and in vitro clonal assays, here we show that, at the single-cell level, the priming of mouse hematopoietic progenitor cells toward the pDC lineage occurs at the common lymphoid progenitor stage, indicative of early divergence of the pDC and cDC lineages. We found the transcriptional signature of a pDC precursor stage, defined here, in the IL-7Rα+ common lymphoid progenitor population and identified Ly6D, IL-7Rα, CD81 and CD2 as key markers of pDC differentiation, which distinguish pDC precursors from cDC precursors. In conclusion, pDCs developed in the bone marrow from a Ly6DhiCD2hi lymphoid progenitor cell and differentiated independently of the myeloid cDC lineage.