Interleukin-7 and Immunosenescence

In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development

Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent sequences (SCSs) in the spike protein are present in the human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against human proteins. To evaluate this possibility of "molecular mimicry" in silico and in vitro, we exhaustively identified common SCSs (cSCSs) found both in spike and human proteins bioinformatically. The commonality of SCSs between the two systems seemed to be coincidental, and only some cSCSs were likely to be relevant to potential self-epitopes based on three-dimensional information. Among three antibodies raised against cSCS-containing spike peptides, only the antibody against EPLDVL showed high affinity for the spike protein and reacted with an EPLDVL-containing peptide from the human unc-80 homolog protein. Western blot analysis revealed that this antibody also reacted with several human proteins expressed mainly in the small intestine, ovary, and stomach. Taken together, these results showed that most cSCSs are likely incapable of inducing autoantibodies but that at least EPLDVL functions as a self-epitope, suggesting a serious possibility of infection-induced or vaccine-induced autoantibodies in humans. High-risk cSCSs, including EPLDVL, should be excluded from vaccine epitopes to prevent potential autoimmune disorders.

Cellular senescence in cancer: molecular mechanisms and therapeutic targets

Aging exhibits several hallmarks in common with cancer, such as cellular senescence, dysbiosis, inflammation, genomic instability, and epigenetic changes. In recent decades, research into the role of cellular senescence on tumor progression has received widespread attention. While how senescence limits the course of cancer is well established, senescence has also been found to promote certain malignant phenotypes. The tumor-promoting effect of senescence is mainly elicited by a senescence-associated secretory phenotype, which facilitates the interaction of senescent tumor cells with their surroundings. Targeting senescent cells therefore offers a promising technique for cancer therapy. Drugs that pharmacologically restore the normal function of senescent cells or eliminate them would assist in reestablishing homeostasis of cell signaling. Here, we describe cell senescence, its occurrence, phenotype, and impact on tumor biology. A "one-two-punch" therapeutic strategy in which cancer cell senescence is first induced, followed by the use of senotherapeutics for eliminating the senescent cells is introduced. The advances in the application of senotherapeutics for targeting senescent cells to assist cancer treatment are outlined, with an emphasis on drug categories, and the strategies for their screening, design, and efficient targeting. This work will foster a thorough comprehension and encourage additional research within this field.

Study on characterization of Bupleurum chinense polysaccharides with antioxidant mechanisms focus on ROS relative signaling pathways and anti-aging evaluation in vivo model

This study explored the structures of three polysaccharides from Bupleurum chinense DC. (BCPRs), and evaluated their antioxidant and anti-aging properties. The HPGPC and ion chromatography analyses revealed that the molecular weights of the BCPRs ranged from 12.05 to 21.20 kDa, and were primarily composed of rhamnose, arabinose, xylose, galactose, glucose and galacturonic acid. Methylation and NMR studies identified 10 PMAAs, establishing the various backbones of BCPRs 1-3. BCPR-3 demonstrated potent antioxidant activities, including DPPH, ABTS, hydroxy, and superoxide radicals scavenging in vitro. At concentrations between 125 and 500 μg/mL, BCPR-3 increased T-AOC, SOD and GSH-Px activities, while decreasing MDA levels in H2O2-induced SH-SY5Y cells. In addition, RNA-seq results indicated that BCPR-3 considerably downregulated the expression of 49 genes and upregulated five genes compared with the control group. KEGG analysis suggested that these differentially expressed genes (DEGs) were predominantly involved in the TNF and PI3K/Akt signaling pathways. Furthermore, in vivo experiment with Drosophila melanogaster showed that BCPR-3 could extend the average lifespan of flies. In conclusion, polysaccharides from B. chinense exhibited potential antioxidant and anti-aging activities, which could be developed as new ingredients to combat oxidative stress damage and slow the aging process.

Novel Synonymous Variant in IL7R Causes Preferential Expression of the Soluble Isoform

PURPOSE

The interleukin-7 receptor (IL-7R) is primarily expressed on lymphoid cells and plays a crucial role in the development, proliferation, and survival of T cells. Autosomal recessive mutations that disrupt IL-7Rα chain expression give rise to a severe combined immunodeficiency (SCID), which is characterized by lymphopenia and a T-B+NK+ phenotype. The objective here was to diagnose two siblings displaying the T-B+NK+ SCID phenotype as initial clinical genetic testing did not detect any variants in known SCID genes.

METHODS

Whole genome sequencing (WGS) was utilized to identify potential variants causing the SCID phenotype. Splicing prediction tools were employed to assess the deleterious impact of the mutation. Polymerase Chain Reaction (PCR), Sanger sequencing, flow cytometry, and ELISA were then used to validate the pathogenicity of the detected mutation.

RESULTS

We discovered a novel homozygous synonymous mutation in the IL7R gene. Our functional studies indicate that this variant is pathogenic, causing exon 6, which encodes the transmembrane domain, to be preferentially spliced out.

CONCLUSION

In this study, we identified a novel rare synonymous mutation causing a loss of IL-7Rα expression at the cellular membrane. This case demonstrates the value of reanalyzing genetic data based on the clinical phenotype and highlights the significance of functional studies in determining the pathogenicity of genetic variants.

Population-enriched innate immune variants may identify candidate gene targets at the intersection of cancer and cardio-metabolic disease

Both cancer and cardio-metabolic disease disparities exist among specific populations in the US. For example, African Americans experience the highest rates of breast and prostate cancer mortality and the highest incidence of obesity. Native and Hispanic Americans experience the highest rates of liver cancer mortality. At the same time, Pacific Islanders have the highest death rate attributed to type 2 diabetes (T2D), and Asian Americans experience the highest incidence of non-alcoholic fatty liver disease (NAFLD) and cancers induced by infectious agents. Notably, the pathologic progression of both cancer and cardio-metabolic diseases involves innate immunity and mechanisms of inflammation. Innate immunity in individuals is established through genetic inheritance and external stimuli to respond to environmental threats and stresses such as pathogen exposure. Further, individual genomes contain characteristic genetic markers associated with one or more geographic ancestries (ethnic groups), including protective innate immune genetic programming optimized for survival in their corresponding ancestral environment(s). This perspective explores evidence related to our working hypothesis that genetic variations in innate immune genes, particularly those that are commonly found but unevenly distributed between populations, are associated with disparities between populations in both cancer and cardio-metabolic diseases. Identifying conventional and unconventional innate immune genes that fit this profile may provide critical insights into the underlying mechanisms that connect these two families of complex diseases and offer novel targets for precision-based treatment of cancer and/or cardio-metabolic disease.

Effects of low-dose rapamycin on lymphoid organs of mice prone and resistant to accelerated senescence

Aging is a complex, natural, and irreversible phenomenon that subjects the body to numerous changes in the physiological process, characterized by a gradual decline in the organism's homeostatic mechanisms, closely related to immunosenescence. Here, we evaluated the regulation of immunosenescence in lymphoid organs of senescence-accelerated prone 8 (SAM-P8) and senescence-accelerated resistant 1 (SAM-R1) mice treated with a low dose of rapamycin (RAPA). Mice were treated with a dose of 7.1 µg/kg RAPA for 2 months and had body mass and hematological parameters analyzed prior and during treatment. Cellular and humoral parameters of serum, bone marrow, thymus, and spleen samples were evaluated by ELISA, histology, and flow cytometry. Changes in body mass, hematological parameters, cell number, and in the secretion of IL-1β, IL-6, TNF-α, IL-7, and IL-15 cytokines were different between the 2 models used. In histological analyses, we observed that SAM-P8 mice showed faster thymic involution than SAM-R1 mice. Regarding the T lymphocyte subpopulations in the spleen, CD4+ and CD8+ T cell numbers were higher and lower, respectively, in SAM-P8 mice treated with RAPA, with the opposite observed in SAM-R1. Additionally, we found that the low dose of RAPA used did not trigger changes that could compromise the immune response of these mice and the administered dose may have contributed to changes in important lymphocyte populations in the adaptive immune response and the secretion of cytokines that directly collaborate with the maturation and proliferation of these cells.

Population Structure and Genomic Characterisation of the Ashanti Dwarf Pig of Ghana

There is still limited information on the genomic structure and genetic diversity of African pigs. Genetic diversity studies can contribute significantly to the genetic improvement and conservation of African pigs. This study presents a genetic diversity analysis and population structure of pig breeds in Ghana, with a focus on the Ashanti Dwarf pig (ADP), an indigenous pig breed of Ghana. A total of 167 pigs sampled in Ghana and populations consisting of Ashanti Dwarf pigs (n = 106), exotics (mostly European pigs) (n = 11), crosses (between indigenous and exotic breeds) (n = 44), and unknown breeds (nondescript) (n = 6) were genotyped using Porcine SNP60K BeadChip. Moderate heterozygosity levels, ranging from 0.28 for Ashanti Dwarf pigs to 0.31 for exotic pigs (mostly European pigs), were observed. Principal component analysis of the pig populations within Ghana resulted in two distinct clusters of pigs: (i) Northern and (ii) Southern regional clusters. The PCA based on breed also resulted in four clusters: (i) ADPs; (ii) exotics (iii) crossbreeds between ADP and exotics; (iv) unknown breed types. The PCA demonstrated that the clustering was influenced by genetics, geographical location, production systems, and practices. ADMIXTURE-based analysis also showed that the populations within Ghana are admixed. FST analysis revealed SNPs associated with QTLs for traits such as disease resilience and growth among ADP populations within the different regional and ecological zones of Ghana.

B Cells Dynamic in Aging and the Implications of Nutritional Regulation

Aging negatively affects B cell production, resulting in a decrease in B-1 and B-2 cells and impaired antibody responses. Age-related B cell subsets contribute to inflammation. Investigating age-related alterations in the B-cell pool and developing targeted therapies are crucial for combating autoimmune diseases in the elderly. Additionally, optimal nutrition, including carbohydrates, amino acids, vitamins, and especially lipids, play a vital role in supporting immune function and mitigating the age-related decline in B cell activity. Research on the influence of lipids on B cells shows promise for improving autoimmune diseases. Understanding the aging B-cell pool and considering nutritional interventions can inform strategies for promoting healthy aging and reducing the age-related disease burden.

Innate and Adaptive Immunity-Related Markers as Predictors of the Short-Term Progression of Subclinical Atherosclerosis in Middle-Aged Patients

Assessment of inflammation is a promising approach to monitoring the progression of asymptomatic atherosclerosis. The aim of the present study was to investigate the predictive value of innate and adaptive immunity-related markers, in relation to the short-term progression of subclinical atherosclerosis. The study included 183 patients aged 40-64 years who underwent duplex scanning of the carotid and lower limb arteries at two visits with an interval of 12-24 months between examinations. Phenotyping of circulating lymphocytes and monocytes subpopulations were performed through flow cytometry. An increase in the number of circulating TLR4-positive intermediate monocytes (>447.0-467.0 cells/μL) was an independent predictor of the short-term progression of lower limb artery atherosclerosis (p < 0.0001) and polyvascular atherosclerosis (p = 0.003). The assessment of TLR4-positive monocytes significantly improved the prognostic model for the progression of lower limb arterial atherosclerosis (C-index 0.728 (0.642-0.815) versus 0.637 (0.539-0.735); p = 0.038). An increase in the number of circulating TLR4-positive intermediate monocytes was an independent predictor of the short-term progression of lower limb artery and polyvascular atherosclerosis. Their inclusion into models containing conventional risk factors significantly improved their prognostic effectiveness regarding lower limb artery atherosclerosis progression.

Regulatory mechanism underlying liver X receptor effects on the tumor microenvironment, inflammation and tumorigenesis

INTRODUCTION

Liver X receptors (LXRs) have emerged as novel targets for tumor treatment. LXRs within the tumor microenvironment show the capacity to impact tumorigenesis and tumor development by regulating the infiltration of immune cells and release of cytokines to moderate inflammation.

AREAS COVERED

In this review, we present a systematic description of recent progress in understanding the impact of LXRs on the tumor microenvironment and tumorigenesis. We also summarize the antitumor effects mediated by LXRs via their regulation of cytokine expression. Additionally, we discuss the limitations of LXR research in tumor studies to date.

EXPERT OPINION

Previous studies have demonstrated abnormal LXR expression in tumor tissues, and activation of LXRs has been shown to inhibit tumorigenesis and promote apoptosis in tumor cells. However, LXRs can also affect tumorigenesis by regulating immune cell functions within the tumor immune microenvironment. By summarizing the impact of LXRs on immune cells, we provide new insights into the multifaceted nature of LXRs as antitumor targets.

Impact of aging on immunity in the context of COVID-19, HIV, and tuberculosis

Knowledge of aging biology needs to be expanded due to the continuously growing number of elderly people worldwide. Aging induces changes that affect all systems of the body. The risk of cardiovascular disease and cancer increases with age. In particular, the age-induced adaptation of the immune system causes a greater susceptibility to infections and contributes to the inability to control pathogen growth and immune-mediated tissue damage. Since the impact of aging on immune function, is still to be fully elucidated, this review addresses some of the recent understanding of age-related changes affecting key components of immunity. The emphasis is on immunosenescence and inflammaging that are impacted by common infectious diseases that are characterized by a high mortality, and includes COVID-19, HIV and tuberculosis.

Recent Developments in Protein Lactylation in PTSD and CVD: Novel Strategies and Targets

In 1938, Corneille Heymans received the Nobel Prize in physiology for discovering that oxygen sensing in the aortic arch and carotid sinus was mediated by the nervous system. The genetics of this process remained unclear until 1991 when Gregg Semenza while studying erythropoietin, came upon hypoxia-inducible factor 1, for which he obtained the Nobel Prize in 2019. The same year, Yingming Zhao found protein lactylation, a posttranslational modification that can alter the function of hypoxia-inducible factor 1, the master regulator of cellular senescence, a pathology implicated in both post-traumatic stress disorder (PTSD) and cardiovascular disease (CVD). The genetic correlation between PTSD and CVD has been demonstrated by many studies, of which the most recent one utilizes large-scale genetics to estimate the risk factors for these conditions. This study focuses on the role of hypertension and dysfunctional interleukin 7 in PTSD and CVD, the former caused by stress-induced sympathetic arousal and elevated angiotensin II, while the latter links stress to premature endothelial cell senescence and early vascular aging. This review summarizes the recent developments and highlights several novel PTSD and CVD pharmacological targets. They include lactylation of histone and non-histone proteins, along with the related biomolecular actors such as hypoxia-inducible factor 1α, erythropoietin, acid-sensing ion channels, basigin, and Interleukin 7, as well as strategies to delay premature cellular senescence by telomere lengthening and resetting the epigenetic clock.

Immunosenescence: molecular mechanisms and diseases

Infection susceptibility, poor vaccination efficacy, age-related disease onset, and neoplasms are linked to innate and adaptive immune dysfunction that accompanies aging (known as immunosenescence). During aging, organisms tend to develop a characteristic inflammatory state that expresses high levels of pro-inflammatory markers, termed inflammaging. This chronic inflammation is a typical phenomenon linked to immunosenescence and it is considered the major risk factor for age-related diseases. Thymic involution, naïve/memory cell ratio imbalance, dysregulated metabolism, and epigenetic alterations are striking features of immunosenescence. Disturbed T-cell pools and chronic antigen stimulation mediate premature senescence of immune cells, and senescent immune cells develop a proinflammatory senescence-associated secretory phenotype that exacerbates inflammaging. Although the underlying molecular mechanisms remain to be addressed, it is well documented that senescent T cells and inflammaging might be major driving forces in immunosenescence. Potential counteractive measures will be discussed, including intervention of cellular senescence and metabolic-epigenetic axes to mitigate immunosenescence. In recent years, immunosenescence has attracted increasing attention for its role in tumor development. As a result of the limited participation of elderly patients, the impact of immunosenescence on cancer immunotherapy is unclear. Despite some surprising results from clinical trials and drugs, it is necessary to investigate the role of immunosenescence in cancer and other age-related diseases.

Effect of Peripheral Blood Lymphocytes on Prognosis of Multiple Cancers

BACKGROUND

In the era of immunotherapy, the immune function of patients with cancer has attracted increasingly more attention. The immune scoring system is an important supplement to the classical tumor staging and classification process. The immune system plays a controversial role in the development of cancer. Meanwhile, the prognostic significance of peripheral blood lymphocytes is still controversial. The present study aimed to assess the prognostic significance of peripheral blood lymphocytes in eight types of cancers.

METHODS

We performed a retrospective analysis of 32731 patients with cancer hospitalized in Shanxi Cancer Hospital from January 2012 to December 2016. The percentages of CD3+, CD4+, CD8+, CD19+, CD56+, and CD127+ lymphocytes in the peripheral blood of all patients were examined using flow cytometry. The immune cell subsets of patients with cancer were classified into three groups using the K-means clustering method via the R language software. Differences in the overall survival rate were analyzed using the Kaplan-Meier method. The Cox regression model was utilized for univariate and multivariate analysis.

RESULTS

The mean survival time of patients with liver cancer, rectal cancer, gastric cancer, breast cancer, esophageal cancer, colon cancer, ovarian cancer, and lymphoma was 30.25, 21.74, 37.67, 16.28, 21.62, 30.25, 31.43, and 34.27 months, respectively. The survival curves showed that the most prognostically beneficial immune state of the patients was when the expression of the immune cells in the peripheral blood was in equilibrium. Moreover, Cox proportional hazards regression model analysis revealed that the factors affecting the overall survival (OS) of patients with eight different kinds of cancer were not identical. However, CD19+ lymphocytes had the most significant impact on the prognosis of these patients.

CONCLUSIONS

Cancer occurrence and development were associated with the density of lymphocyte infiltration. Thus, immune homeostasis could be an effective indicator to evaluate prognosis and judge cancer treatment.

The DARC Side of Inflamm-Aging: Duffy Antigen Receptor for Chemokines (DARC/ACKR1) as a Potential Biomarker of Aging, Immunosenescence, and Breast Oncogenesis among High-Risk Subpopulations

The proclivity of certain pre-malignant and pre-invasive breast lesions to progress while others do not continues to perplex clinicians. Clinicians remain at a crossroads with effectively managing the high-risk patient subpopulation owing to the paucity of biomarkers that can adequately risk-stratify and inform clinical decisions that circumvent unnecessary administration of cytotoxic and invasive treatments. The immune system mounts the most important line of defense against tumorigenesis and progression. Unfortunately, this defense declines or "ages" over time-a phenomenon known as immunosenescence. This results in "inflamm-aging" or the excessive infiltration of pro-inflammatory chemokines, which alters the leukocyte composition of the tissue microenvironment, and concomitant immunoediting of these leukocytes to diminish their antitumor immune functions. Collectively, these effects can foster the sequelae of neoplastic transformation and progression. The erythrocyte cell antigen, Duffy antigen receptor for chemokines(DARC/ACKR1), binds and internalizes chemokines to maintain homeostatic levels and modulate leukocyte trafficking. A negative DARC status is highly prevalent among subpopulations of West African genetic ancestry, who are at higher risk of developing breast cancer and disease progression at a younger age. However, the role of DARC in accelerated inflamm-aging and malignant transformation remains underexplored. Herein, we review compelling evidence suggesting that DARC may be protective against inflamm-aging and, therefore, reduce the risk of a high-risk lesion progressing to malignancy. We also discuss evidence supporting that immunotherapeutic intervention-based on DARC status-among high-risk subpopulations may evade malignant transformation and progression. A closer look into this unique role of DARC could glean deeper insight into the immune response profile of individual high-risk patients and their predisposition to progress as well as guide the administration of more "cyto-friendly" immunotherapeutic intervention to potentially "turn back the clock" on inflamm-aging-mediated oncogenesis and progression.

Development of Nectin4/FAP-targeted CAR-T cells secreting IL-7, CCL19, and IL-12 for malignant solid tumors

Background

Chimeric antigen receptor T (CAR-T) cell therapy has made significant advances for hematological malignancies but encounters obstacles in the treatment of solid tumors mainly due to tumor immunosuppressive microenvironment.

Methods

Immunohistochemistry analysis was performed to examine the cellular expression of nectin cell adhesion molecule-4 (Nectin4) and fibroblast activation protein (FAP) in a variety of malignant solid tumors. Then, we engineered the fourth-generation Nectin4-targeted CAR-T (Nectin4-7.19 CAR-T) and FAP-targeted CAR-T (FAP-12 CAR-T) cells to evaluate their safety and efficacy in vitro and in vivo.

Results

In our study, we firstly demonstrated the aberrant overexpression of Nectin4 on both primary and metastatic solid tumors and FAP on cancer-associated fibroblasts. Then, we found that our fourth-generation Nectin4-7.19 CAR-T cells expressed IL-7 and CCL19 efficiently and exhibited superior proliferation, migration, and cytotoxicity compared to the second-generation Nectin4 CAR-T cells, while FAP-12 CAR-T cells exerted their ability of targeting both murine and human FAP effectively in vitro. In a fully immune-competent mouse model of metastatic colorectal cancer, lymphodepletion pretreated mice achieved complete remission with human Nectin4-targeted murine CAR-T (Nectin4 mCAR-T) cells. In the NSG mouse model of lung metastases, Nectin4-7.19 CAR-T cells eradicated metastatic tumors and prolonged survival in combination with FAP-12 CAR-T cells.

Conclusions

These findings showed that Nectin4-7.19 CAR-T cells had potential therapeutic efficacy and exerted a synergistic role with FAP-12 CAR-T cells, further demonstrating that Nectin4 and FAP were able to serve as promising targets for safe and effective CAR-T therapy of malignant solid tumors.

Immune checkpoint inhibitors for PD-1/PD-L1 axis in combination with other immunotherapies and targeted therapies for non-small cell lung cancer

It has been widely acknowledged that the use of immune checkpoint inhibitors (ICI) is an effective therapeutic treatment in many late-stage cancers. However, not all patients could benefit from ICI therapy. Several biomarkers, such as high expression of PD-L1, high mutational burden, and higher number of tumor infiltration lymphocytes have shown to predict clinical benefit from immune checkpoint therapies. One approach using ICI in combination with other immunotherapies and targeted therapies is now being investigated to enhance the efficacy of ICI alone. In this review, we summarized the use of other promising immunotherapies and targeted therapies in combination with ICI in treatment of lung cancers. The results from multiple animals and clinical trials were reviewed. We also briefly discussed the possible outlooks for future treatment.

IL-7/IL7R axis dysfunction in adults with severe community-acquired pneumonia (CAP): a cross-sectional study

Community-acquired pneumonia (CAP) is a worldwide leading cause of death. Recognized risk factors in some severe cases have not been identified. Lymphocytopenia has been frequently described in CAP. Since IL-7, membrane-bound receptor (IL7Rα;CD127) and soluble IL7Rα (sIL7R) are critical in lymphocytes homeostasis, in this work we aimed to evaluate the involvement of the IL-7/IL7Rα axis in the severity of adult CAP, since it has not been explored. The IL7Rα SNPs rs6897932, rs987106, and rs3194051 SNPs in IL7α were genotyped, the systemic expression of the IL7R gene, sIL7R, IL-7, and levels of peripheral IL7Rα⁺ T lymphocytes were quantified in 202 hospitalized CAP cases. rs3194051GG was more frequent in non-survivors than in survivors; rs987106TT was more frequent and rs3194051AA less frequent in patients at intensive care unit (ICU) than in those not admitted to ICU. IL7Rα gene expression was lower in non-survivors than in survivors, and in severe than in mild cases. CD3⁺CD127⁺ lymphocytes were lower in severe than in mild cases; in non-survivors than in survivors and in ICU than in non- ICU admitted cases. sIL7Rα plasmatic levels were higher in non-survivors than in survivors, and in severe than in mild cases. rs6897932CC, rs987106AA and rs3194051GG carriers showed the highest while rs6897932TT showed the lowest sIL7Rα levels. The AUC of sIL7Rα levels predicting 30-day mortality was 0.71. Plasma IL-7 levels were lower in ICU-admitted than in not ICU-admitted and in non-survivors than in survivors. No additional association was detected. In conclusion, rs3194051GG and rs987106TT IL7R genotypes were associated with a poorer prognosis. A significant association between sIL7R levels and SNPs of the IL7R gene is described for the first time in adult CAP. Increased plasmatic sIL7R could contribute to identifying adult CAP cases at risk of death.

Interleukin-7 regulates CD127 expression and promotes CD8+ T cell activity in patients with primary cutaneous melanoma

Background

Interleukin (IL)-7 signaling through CD127 is impaired in lymphocytes in cancers and chronic infections, resulting in CD8⁺ T cell exhaustion. The mechanisms underlying CD8⁺ T cell responses to IL-7 in melanoma remain not completely elucidated. We previously showed reduced IL-7 level in melanoma patients. Thus, the aim of this study was to investigate the effect of IL-7 regulation on CD127 expression and CD8⁺ T cell responses in melanoma.

Methods

Healthy controls and primary cutaneous melanoma patients were enrolled. Membrane-bound CD127 (mCD127) expression on CD8⁺ T cells was determined by flow cytometry. Soluble CD127 (sCD127) protein level was measured by ELISA. Total CD127 and sCD127 mRNA level was measured by real-time PCR. CD8⁺ T cells were stimulated with recombinant human IL-7, along with signaling pathway inhibitors. CD8⁺ T cells were co-cultured with melanoma cell line, and the cytotoxicity of CD8⁺ T cells was assessed by measurement of lactate dehydrogenase expression.

Results

Plasma sCD127 was lower in melanoma patients compared with controls. The percentage of CD8⁺ T cells expressing mCD127 was higher, while sCD127 mRNA level was lower in peripheral and tumor-infiltrating CD8⁺ T cells from melanoma patients. There was no significant difference of total CD127 mRNA expression in CD8⁺ T cells between groups. IL-7 stimulation enhanced total CD127 and sCD127 mRNA expression and sCD127 release by CD8⁺ T cells. However, mCD127 mRNA expression on CD8⁺ T cells was not affected. This process was mainly mediated by phosphatidylinositol 3-kinase (PI3K) pathway. CD8⁺ T cells from melanoma patients exhibited decreased cytotoxicity. IL-7 stimulation promoted CD8⁺ T cell cytotoxicity, while inhibition of PI3K dampened IL-7-induced elevation of CD8⁺ T cell cytotoxicity.

Conclusion

The current data suggested that insufficient IL-7 secretion might contribute to CD8⁺ T cell exhaustion and CD127 dysregulation in patients with primary cutaneous melanoma.

Genetic, parental and lifestyle factors influence telomere length

The average length of telomere repeats (TL) declines with age and is considered to be a marker of biological ageing. Here, we measured TL in six blood cell types from 1046 individuals using the clinically validated Flow-FISH method. We identified remarkable cell-type-specific variations in TL. Host genetics, environmental, parental and intrinsic factors such as sex, parental age, and smoking are associated to variations in TL. By analysing the genome-wide methylation patterns, we identified that the association of maternal, but not paternal, age to TL is mediated by epigenetics. Single-cell RNA-sequencing data for 62 participants revealed differential gene expression in T-cells. Genes negatively associated with TL were enriched for pathways related to translation and nonsense-mediated decay. Altogether, this study addresses cell-type-specific differences in telomere biology and its relation to cell-type-specific gene expression and highlights how perinatal factors play a role in determining TL, on top of genetics and lifestyle.

Transcriptome regulation of extracellular vesicles derived from porcine uterine flushing fluids during peri-implantation on endometrial epithelial cells and embryonic trophoblast cells

The extracellular vesicles (EVs) in uterine fluids play a vital role in embryo implantation by mediating intrauterine communication between conceptus and maternal endometrium in pigs. However, the regulatory mechanism of EVs in uterine fluids is largely unclear. In order to understand the effect of EVs in uterine flushing fluids (UFs) during embryo implantation on endometrial epithelial cells (EECs) and embryonic trophoblast cells (PTr2 cells). The UFs-EVs on day 13 of pregnancy (D13) were added to the culture medium of EECs and PTr2 cells. It was found that PKH-67 labeled UFs-EVs could be taken up in EECs and PTr2 cells. Transcriptome sequencing analysis showed that a total of 1793 and 6279 genes were differentially expressed in the EECs and PTr2 cells after the treatment of UFs-EVs on D13, respectively. Among these genes, real-time quantitative PCR (RT-qPCR) results indicated that ID2, ITGA5, CXCL10 and CXCL11 genes were differentially expressed in both EECs and PTr2 cells after treatment. Bioinformatics analysis showed that the differentially expressed (DE) genes in EECs and PTr2 cells after treatment are involved in immune regulation, cell migration, cell adhesion and the secretion and uptake of EVs. Our research offers novel insight into the regulation mechanism of UFs-EVs on D13 in EECs and PTr2 cells.

Differences in Expression of Selected Interleukins in HIV-Infected Subjects Undergoing Antiretroviral Therapy

The use of combined antiretroviral therapy (cART) inhibits the replication of the Human Immunodeficiency Virus (HIV) and thus may affect the functioning of the immune system, e.g., induce changes in the expression of certain cytokines. The aim was to examine the effect of cART on the expression of selected cytokines: interleukin -4, -7 and -15 in HIV-infected subjects. The test material was the plasma of HIV-infected men and healthy men (C, control group). The levels of interleukin were measured by immunoenzymatic method before cART and one year after treatment in relation to the C group. HIV-infected men were analyzed in subgroups depending on the HIV-RNA viral load, CD4⁺ and CD8⁺T-cell counts, and the type of therapeutic regimen. A significantly higher level of IL-4 was demonstrated in HIV-infected men before cART compared to those after treatment and in the control group. The use of cART resulted in a significant decrease in the level of IL-7 in HIV-infected men; however, high levels of IL-7 were associated with a low number of CD4⁺ T cells and CD8⁺ T cells. An increase in the level of IL-15 in HIV-infected men was noted after the use of cART. There was no difference in the expression of interleukins depending on the treatment regimen used. The study showed the effect of cART on the expression of interleukins, especially IL-4 and IL-7. Further research in this direction seems promising, confirming the role of these interleukins in the course of the disease.

Effects of 3 months of multi-nutrient supplementation on the immune system and muscle and respiratory function of older adults in aged care (The Pomerium Study): protocol for a randomised controlled trial

INTRODUCTION

Immunosenescence leads to increased morbidity and mortality associated with viral infections and weaker vaccine responses. This has been well documented for seasonal influenza and the current pandemic with SARS-CoV-2 (COVID-19), which disproportionately impact older adults, particularly those in residential aged care facilities. Inadequate nutrient intakes associated with impaired immunity, respiratory and muscle function are likely to augment the effects of immunosenescence. In this study, we test whether the impact of inadequate nutrition can be reversed using multi-nutrient supplementation, consequently enhancing vaccine responses, reducing the risk of viral infections and improving respiratory and muscle function.

METHODS AND ANALYSIS

The Pomerium Study is a 3-month, single-blind, randomised, controlled trial testing the effects of two daily servings of an oral multi-nutrient supplement (330 kcal, 20 g protein, 1.5 g calcium 3-hydroxy-3-methylbutyrate monohydrate (CaHMB), 449 mg calcium, 500 IU vitamin D₃ and 25 vitamins and minerals) on the immune system and muscle and respiratory function of older adults in aged care in Melbourne, Australia. 160 older adults (≥75 years old) will be recruited from aged care facilities and randomised to treatment (multi-nutrient supplement) or control (usual care). The primary outcome is a change in T-cell subsets CD8 + and CD28null counts at months 1 and 3. Secondary outcomes measured at baseline and month 3 are multiple markers of immunosenescence (also at 1 month), body composition (bioimpedance), handgrip strength (dynamometer), physical function (short physical performance battery), respiratory function (spirometry) and quality of life (EQ-5D-5L). Incidence and complications of COVID-19 and/or viral infections (ie, hospitalisation, complications or death) will be recorded throughout the trial, including 3 months after supplementation is ceased.

ETHICS AND DISSEMINATION

This study was approved by Melbourne Health Human Research Ethics Committee (Ref No. HREC/73985/MH-2021, ERM Ref No. RMH73985, Melbourne Health Site Ref No. 2021.115). Written informed consent will be obtained from participants. Results will be published in peer-reviewed journals and made available to key aged care stakeholders, including providers, residents, and government bodies.

TRIAL REGISTRATION NUMBER

ACTRN12621000420842.

Dangshen Erling Decoction Ameliorates Myocardial Hypertrophy via Inhibiting Myocardial Inflammation

Myocardial hypertrophy plays an essential role in the structural remodeling of the heart and the progression to heart failure (HF). There is an urgent need to understand the mechanisms underlying cardiac hypertrophy and to develop treatments for early intervention. Dangshen Erling decoction (DSELD) is a clinically used formula in Chinese medicine for treating coronary heart disease in patients with HF. However, the mechanism by which DSELD produces its cardioprotective effects remains largely unknown. This study explored the effects of DSELD on myocardial hypotrophy both in vitro and in vivo. In vitro studies indicated that DSELD significantly (p < 0.05) reduced the cross-sectional area of the myocardium and reduced elevated lactate dehydrogenase (LDH), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 levels in the induced H9C2 cell model to study inflammation. In vivo experiments revealed that DSELD restores cardiac function and significantly reduces myocardial fibrosis in isoproterenol (ISO)-induced HF mouse model (p < 0.05). In addition, DSELD downregulated the expression of several inflammatory cytokines, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte CSF (G-CSF), IL-1α, IL-1β, IL-3, IL-5, IL-7, IL-12, IL-13, and TNF-α in HF (p < 0.05). Further analysis of the cardiac tissue demonstrated that DSELD produces its anti-inflammatory effects via the Toll-like receptor (TLR)4 signaling pathway. The expression of TLR4 downstream proteins such as matrix metalloproteinase-9 (MMP9) and myeloid differentiation factor-88 (MyD88) was among the regulated targets. In conclusion, these observations suggest that DSELD exerts antihypertrophic effects by alleviating the inflammatory injury via the TLR4 signaling pathway in HF and thus holds promising therapeutic potentials.

Age- and Sex-Adjusted Reference Intervals in Tear Cytokine Levels in Healthy Subjects

Alterations in tear cytokine levels have been associated with various ocular disorders as compared to those in healthy subjects. However, age and sex are not always considered in these comparisons. In this study we aimed to establish age and sex reference intervals (RIs) for tear cytokine levels in healthy people. Tear samples were taken from 75 males and 82 females, aged 18–88 years, and tear cytokine levels were determined. Age- and sex-adjusted RIs for epidermal growth factor (EGF), fractalkine, interleukin (IL)-1 receptor antagonist (RA), IL-7, IL-8, interferon inducible protein (IP)-10, monocyte chemotactic protein (MCP)-1, and vascular endothelial growth factor (VEGF) tear cytokine levels in a healthy sample were established using generalized additive for location, scale and shape (GAMLSS) models. RIs were tested in two external samples: a validation sample of 40 individuals with normal results at four Dry Eye Disease (DED) clinical diagnostic tests (OSDI, T-BUT, corneal staining and Schirmer test); and a utility sample of 13 severe DED cases. IL-1RA, IL-8, IP-10, and MCP-1 levels showed a positive association with age, while EGF was negatively correlated. IL-7 concentration increased up to 40 years and again after 70 years, observing a quasi-linear decrease between them. For VEGF, higher levels were observed in the middle-aged range. Regarding sex-influence, fractalkine tear levels were higher in men, whereas those of IL-7, IL-8, and IP-10 were higher in women. Using the estimated age- and sex-adjusted RIs, more than 92% of the validation sample was correctly classified, and 100% of the severe DED patients in the utility sample had concentrations outside the RIs in at least two of the cytokines evaluated.

Targeting immune dysfunction in aging

Human aging is a multifactorial phenomenon that affects numerous organ systems and cellular processes, with the immune system being one of the most dysregulated. Immunosenescence, the gradual deterioration of the immune system, and inflammaging, a chronic inflammatory state that persists in the elderly, are among the plethora of immune changes that occur during aging. Almost all populations of immune cells change with age in terms of numbers and/or activity. These alterations are in general highly detrimental, resulting in an increased susceptibility to infections, reduced healing abilities, and altered homeostasis that promote the emergence of age-associated diseases such as cancer, diabetes, and other diseases associated with inflammation. Thanks to recent developments, several strategies have been proposed to target central immunological processes or specific immune subpopulations affected by aging. These therapeutic approaches could soon be applied in the clinic to slow down or even reverse specific age-induced immune changes in order to rejuvenate the immune system and prevent or reduce the impact of various diseases. Due to its systemic nature and interconnection with all the other systems in the body, the immune system is an attractive target for aging intervention because relatively targeted modifications to a small set of cells have the potential to improve the health of multiple organ systems. Therefore, anti-aging immune targeting therapies could represent a potent approach for improving healthspan. Here, we review aging changes in the major components of the immune system, we summarize the current immune-targeting therapeutic approaches in the context of aging and discuss the future directions in the field of immune rejuvenation.

Dietary carbohydrate, particularly glucose, drives B cell lymphopoiesis and function

While diet modulates immunity, its impact on B cell ontogeny remains unclear. Using mixture modeling, a large-scale isocaloric dietary cohort mouse study identified carbohydrate as a major driver of B cell development and function. Increasing dietary carbohydrate increased B cell proportions in spleen, mesenteric lymph node and Peyer's patches, and increased antigen-specific immunoglobulin G production after immunization. This was linked to increased B lymphopoiesis in the bone marrow. Glucose promoted early B lymphopoiesis and higher total B lymphocyte numbers than fructose. It drove B cell development through glycolysis and oxidative phosphorylation, independently of fatty acid oxidation in vitro and reduced B cell apoptosis in early development via mTOR activation, independently of interleukin-7. Ours is the first comprehensive study showing the impact of macronutrients on B cell development and function. It shows the quantitative and qualitative interplay between dietary carbohydrate and B cells and argues for dietary modulation in B cell-targeting strategies.

Lanthionine, a Novel Uremic Toxin, in the Vascular Calcification of Chronic Kidney Disease: The Role of Proinflammatory Cytokines

Vascular calcification (VC) is a risk factor for cardiovascular events and mortality in chronic kidney disease (CKD). Several components influence the occurrence of VC, among which inflammation. A novel uremic toxin, lanthionine, was shown to increase intracellular calcium in endothelial cells and may have a role in VC. A group of CKD patients was selected and divided into patients with a glomerular filtration rate (GFR) of <45 mL/min/1.73 m² and ≥45 mL/min/1.73 m². Total Calcium Score (TCS), based on the Agatston score, was assessed as circulating lanthionine and a panel of different cytokines. A hemodialysis patient group was also considered. Lanthionine was elevated in CKD patients, and levels increased significantly in hemodialysis patients with respect to the two CKD groups; in addition, lanthionine increased along with the increase in TCS, starting from one up to three. Interleukin IL-6, IL-8, and Eotaxin were significantly increased in patients with GFR < 45 mL/min/1.73 m² with respect to those with GFR ≥ 45 mL/min/1.73 m². IL-1b, IL-7, IL-8, IL-12, Eotaxin, and VEGF increased in calcified patients with respect to the non-calcified. IL-8 and Eotaxin were elevated both in the low GFR group and in the calcified group. We propose that lanthionine, but also IL-8 and Eotaxin, in particular, are a key feature of VC of CKD, with possible marker significance.

Descriptive modification of inflammatory markers in HIV patients after cART initiation according to gender, smoking habit, CMV infection, BMI and serum lipids

Persistent inflammation, despite anti-retroviral therapy (ART), is an independent predictor of mortality and comorbidities in HIV infection. Multiple factors, including lifestyle and chronic viral coinfections, may contribute. Several of these factors are also associated with a chronic inflammation in the general population. Little is known about the degree to which these factors influence inflammation in HIV infection, particularly within the first year of ART. The purpose of this study was to distinguish the effects of factors (gender, body mass index, cholesterol and triglyceride levels, smoke habit and cytomegalovirus seropositivity), known to contribute to inflammation, on inflammation biomarkers over the first year of ART in HIV-infected patients. Linear mixed model analysis revealed significant biomarker decreases [soluble CD14 (s-CD14), soluble CD163 (s-CD163) and D-dimer (DD)], or increases [C Reactive Protein (CRP) and interleukin-6 (IL-6)] over time in the whole cohort, differences in most categories (genders for IL-6, smoke habit for s-CD14, cytomegalovirus infection for s-CD163 and IL-6) and in some category × time interactions [gender for interleukin-7 (IL-7)], cytomegalovirus infection for s-CD14 and cholesterol levels for s-CD14 and Tumor Necrosis Factor α (TNF-α)]. This explorative longitudinal study suggests further investigations on targeting inflammation pathophysiology in HIV-infected patients on ART.

Tissue-Resident Memory-Like CD8+ T Cells Exhibit Heterogeneous Characteristics in Tuberculous Pleural Effusion

Tissue-resident memory T (TRM) cells are well known to play critical roles in peripheral tissues during virus infection and tumor immunology. Our previous studies indicated that CD69+CD4+ and CD69+CD8+ T cells in tuberculous pleural effusion (TPE) were antigen-specific memory T cells. However, the phenotypical and functional characteristics of CD8+ TRM cells in tuberculosis remain unknown. We found that CD103+CD8+ T cells were the predominant subset of CD103+ lymphocytes in TPE; both CD103 and CD69 expressed on memory CD8+ T cells from TPE were significantly increased compared with those from paired peripheral blood. Phenotypically, CD103+CD69+ and CD103+CD69-CD8+ T cells expressed higher levels of CD45RO than CD103-CD69+CD8+ T cells did; CD103+CD69-CD8+ T cells highly expressed CD27, CD127, and CD62L and some chemokine receptors. We further compared the functional differences among the four distinct CD45RO+CD8+ T subsets identified by CD103 and CD69 expression. In consist with our published results, CD69+CD8+ T cells, but not CD103+CD8+, produced high levels of IFN-γ after treatment with BCG in the presence of BFA. Nevertheless, CD103-CD69+ and CD103+CD69+ memory CD8+ T cells expressed higher levels of Granzyme B, while CD103+CD69- memory CD8+ T cells were characterized as a possibly immunosuppressive subset by highly expressing CTLA-4, CD25, and FoxP3. Furthermore, TGF-β extremely increased CD103 expression but not CD69 in vitro. Together, CD103+CD8+ T cells form the predominant subset of CD103+ lymphocytes in TPE; CD103 and CD69 expression defines distinct CD8+ TRM-like subsets exhibiting phenotypical and functional heterogeneity. Our findings provide an important theoretical basis to optimize and evaluate new tuberculosis vaccines.

Distinct cellular immune profiles in the airways and blood of critically ill patients with COVID-19

Background

Knowledge of the pathophysiology of COVID-19 is almost exclusively derived from studies that examined the immune response in blood. We here aimed to analyse the pulmonary immune response during severe COVID-19 and to compare this with blood responses.

Methods

This was an observational study in patients with COVID-19 admitted to the intensive care unit (ICU). Mononuclear cells were purified from bronchoalveolar lavage fluid (BALF) and blood, and analysed by spectral flow cytometry; inflammatory mediators were measured in BALF and plasma.

Findings

Paired blood and BALF samples were obtained from 17 patients, four of whom died in the ICU. Macrophages and T cells were the most abundant cells in BALF, with a high percentage of T cells expressing the ƴδ T cell receptor. In the lungs, both CD4 and CD8 T cells were predominantly effector memory cells (87·3% and 83·8%, respectively), and these cells expressed higher levels of the exhaustion marker programmad death-1 than in peripheral blood. Prolonged ICU stay (>14 days) was associated with a reduced proportion of activated T cells in peripheral blood and even more so in BALF. T cell activation in blood, but not in BALF, was higher in fatal COVID-19 cases. Increased levels of inflammatory mediators were more pronounced in BALF than in plasma.

Interpretation

The bronchoalveolar immune response in COVID-19 has a unique local profile that strongly differs from the immune profile in peripheral blood. Fully elucidating COVID-19 pathophysiology will require investigation of the pulmonary immune response.

Effect of Interleukin-7 on Radiation-Induced Lymphopenia and Its Antitumor Effects in a Mouse Model

PURPOSE

Local ionizing radiation (IR) can lead to systemic lymphocyte depletion, which is associated with poor survival outcomes in patients with cancer. Interleukin-7 (IL-7) plays an important role in lymphocyte homeostasis; however, its role in alleviating radiation-induced lymphopenia remains unclear. Hence, we established a radiation-induced lymphopenia animal model and evaluated the effect of exogenous IL-7 administration.

METHODS

C3H/HeN mice underwent x-ray irradiation of 30 Gy in 10 fractions at the right hind limbs. Next, 10 mg/kg of IL-7 was injected subcutaneously, and the lymphocyte count in blood was measured. Murine hepatocellular carcinoma (HCa-1) cells were inoculated subcutaneously into the right thighs of tumor model mice, which underwent the same treatment.

RESULTS

In the naïve mouse model, the decreased CD45⁺ cell count after irradiation gradually recovered to the initial level over 3 weeks in the IR group, whereas it markedly increased to 373% of the initial level in 1 week in the IR+IL-7 group. Similar trends were observed for the CD3⁺, CD8⁺, CD4⁺, regulatory T cells, and CD19⁺ B cell counts. Similar findings were observed in the tumor mouse model. CD8⁺ and CD4⁺ T cell infiltration in tumor specimens was higher in the IL-7 and IR+IL-7 groups than in the nontreated and IR groups. Tumor growth was significantly more suppressed in the IR+IL-7 group than in the IR group. The median survival time was significantly longer in the IR+IL-7 group (not reached) than in the IR (56 days; P = .0382), IL-7 (36 days; P = .0004), or nontreated groups (36 days; P < .0001).

CONCLUSIONS

Administration of exogenous IL-7 after IR not only restored lymphocyte counts but also enhanced the antitumor effect. Exogenous IL-7 can be beneficial in overcoming radiation-induced lymphopenia and in enhancing the treatment outcome in combination with radiation therapy, which needs validation through future clinical studies.

Extensive longitudinal immune profiling reveals sustained innate immune activation in COVID-19 patients with unfavorable outcome

COVID-19 differs substantially between individuals, ranging from mild to severe or even fatal. Heterogeneity in the immune response against SARS-COV-2 likely contributes to this. Therefore, we explored the temporal dynamics of key cellular and soluble mediators of innate and adaptive immune activation in relation to COVID-19 severity and progression.

Forty-four patients with a PCR-proven diagnosis of COVID-19 were included. Extensive cellular (leukocytes and T-lymphocyte subsets) and serological immune profiling (cytokines, soluble cell surface molecules, and SARS-CoV-2 antibodies) was performed at hospital admission and every 3–4 days during hospitalization. Measurements and disease outcome were compared between patients with an unfavorable (IC admission and/or death) and favorable (all others) outcome.

Patients with an unfavorable outcome had higher leukocyte numbers at baseline, mostly due to increased neutrophils, whereas lymphocyte and monocyte numbers were reduced. CRP, IL-6, CCL2, CXCL10, and GM-CSF levels were higher at baseline in the unfavorable group, whereas IL-7 levels were lower. SARS-CoV-2 antibodies were more frequently absent in the unfavorable group. Longitudinal analysis revealed delayed kinetics of activated CD4 and CD8 T-lymphocyte subsets in the unfavorable group. Furthermore, whereas CRP, IL-6, CXCL10, and GM-CSF declined in the favorable group, these cytokines declined with delayed kinetics, remained increased, or even increased further in the unfavorable group.

Our data indicate a state of increased innate immune activation in COVID19-patients with an unfavorable outcome at hospital admission, which remained over time, as compared with patients with a favorable outcome.

Immunogenicity, safety, and reactogenicity of combined reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine administered as a booster vaccine dose in healthy Russian participants: a phase III, open-label study

As vaccine-induced immunity and protection following natural pertussis infection wane over time, adults and adolescents may develop pertussis and become transmitters to unprotected infants. In Russia, diphtheria and tetanus but not pertussis-containing vaccines are registered for older children, adolescents, or adults. The reduced-antigen-content diphtheria toxoid, tetanus toxoid, and acellular pertussis (dTpa) vaccine (Boostrix, GSK) was developed for booster vaccination of children ≥4 years of age, adolescents, and adults. A phase III, open-label, non-randomized study was performed in eight centers in Russia between January and July 2018. The objective of this study was to assess immunogenicity, reactogenicity and safety of a single dose of dTpa vaccine in healthy Russian participants ≥4 years of age (age categories 4-9 years, 10-17 years, 18-64 years, and ≥65 years). At 1 month post-booster vaccination, across all age groups, >99.0% of participants were seroprotected against diphtheria and tetanus and >96.0% of participants were seropositive for anti-pertussis antibodies. For all antibodies across all age groups, antibody GMCs increased from pre- to 1 month post-booster vaccination and booster responses to diphtheria (in 71.5% of participants), tetanus (85.3%), and pertussis antigens (≥85.6%) were observed. One serious adverse event that was not causally related to the study vaccine was reported. No fatal cases were reported throughout the study period. In conclusion, administration of the dTpa vaccine as a booster dose in healthy Russian participants induced a robust immune response to all vaccine antigens and was generally well tolerated across all age groups.

Distinct organization of adaptive immunity in the long-lived rodent Spalax galili

A balanced immune response is a cornerstone of healthy aging. Here, we uncover distinctive features of the long-lived blind mole-rat (Spalax spp.) adaptive immune system, relative to humans and mice. The T-cell repertoire remains diverse throughout the Spalax lifespan, suggesting a paucity of large long-lived clones of effector-memory T cells. Expression of master transcription factors of T-cell differentiation, as well as checkpoint and cytotoxicity genes, remains low as Spalax ages. The thymus shrinks as in mice and humans, while interleukin-7 and interleukin-7 receptor expression remains high, potentially reflecting the sustained homeostasis of naive T cells. With aging, immunoglobulin hypermutation level does not increase and the immunoglobulin-M repertoire remains diverse, suggesting shorter B-cell memory and sustained homeostasis of innate-like B cells. The Spalax adaptive immune system thus appears biased towards sustained functional and receptor diversity over specialized, long-lived effector-memory clones-a unique organizational strategy that potentially underlies this animal's extraordinary longevity and healthy aging.

Immune Cell Number, Phenotype, and Function in the Elderly with Sepsis

Sepsis is a form of life-threatening organ dysfunction caused by dysregulated host responses to an infection that can be partly attributed to immune dysfunction. Although sepsis affects patients of all ages, elderly individuals display increased susceptibility and mortality. This is partly due to immunosenescence, a decline in normal immune system function associated with physiological aging that affects almost all cell types in the innate and adaptive immune systems. In elderly patients with sepsis, these alterations in immune cells such as endothelial cells, neutrophils, monocytes, macrophages, natural killer cells, dendritic cells, T lymphocytes, and B lymphocytes, are largely responsible for their poor prognosis and increased mortality. Here, we review recent studies investigating the events affecting both innate and adaptive immune cells in elderly mice and patients with sepsis, including alterations in their number, phenotype, and function, to shed light on possible new therapeutic strategies.

Identification of selected genes associated with the SARS-CoV-2: a therapeutic approach and disease severity

BACKGROUND

The ongoing pandemic of COVID-19 viruses takes its sole origin from the Wuhan Huanan seafood market, China. The first case was recorded as viral pneumonia and later became a worldwide pandemic (officially declared by WHO on March 11, 2020).

MAIN BODY

SARS-CoV-2 is an extremely infectious and transferrable virus that develops severe conditions like respiratory syndrome, high blood pressure and weakens the immune system. Coronavirus falls under the Coronaviridae family and Beta coronavirus genus. Affected individuals will encounter problems starting with fever followed by severe complications like SARS, ARDS, and many others. These SARS-CoV and MERS-CoV enter the host cells by the endosomal pathway, and about 16 non-structural proteins are involved in assembling the viral RNA synthesis complex. They possess a positive-sense single-stranded RNA, and about four major genes are mainly associated with the development of ASRD, SARS, and other respiratory problems.

CONCLUSION

Susceptibility of these four major genes such as ACE2, IL-2, 7 and 10, TNF, and VEGF is associated with COVID-19. This highlights the identification of the above-mentioned genes that can be used as potential biomarkers for early diagnosis and targeted drug delivery for treating the SARS-CoV-2 neurological symptoms and reducing inflammation in the brain.

Immunosenescence: a key player in cancer development

Immunosenescence is a process of immune dysfunction that occurs with age and includes remodeling of lymphoid organs, leading to changes in the immune function of the elderly, which is closely related to the development of infections, autoimmune diseases, and malignant tumors. T cell-output decline is an important feature of immunosenescence as well as the production of senescence-associated secretory phenotype, increased glycolysis, and reactive oxygen species. Senescent T cells exhibit abnormal phenotypes, including downregulation of CD27, CD28, and upregulation of CD57, killer cell lectin-like receptor subfamily G, Tim-3, Tight, and cytotoxic T-lymphocyte-associated protein 4, which are tightly related to malignant tumors. The role of immunosenescence in tumors is sophisticated: the many factors involved include cAMP, glucose competition, and oncogenic stress in the tumor microenvironment, which can induce the senescence of T cells, macrophages, natural killer cells, and dendritic cells. Accordingly, these senescent immune cells could also affect tumor progression. In addition, the effect of immunosenescence on the response to immune checkpoint blocking antibody therapy so far is ambiguous due to the low participation of elderly cancer patients in clinical trials. Furthermore, many other senescence-related interventions could be possible with genetic and pharmacological methods, including mTOR inhibition, interleukin-7 recombination, and NAD⁺ activation. Overall, this review aims to highlight the characteristics of immunosenescence and its impact on malignant tumors and immunotherapy, especially the future directions of tumor treatment through senescence-focused strategies.

The Role of Age, Neutrophil Infiltration and Antibiotics Timing in the Severity of Streptococcus pneumoniae Pneumonia. Insights from a Multi-Level Mathematical Model Approach

Bacterial pneumonia is one of the most prevalent infectious diseases and has high mortality in sensitive patients (children, elderly and immunocompromised). Although an infection, the disease alters the alveolar epithelium homeostasis and hinders normal breathing, often with fatal consequences. A special case is hospitalized aged patients, which present a high risk of infection and death because of the community acquired version of the Streptococcus pneumoniae pneumonia. There is evidence that early antibiotics treatment decreases the inflammatory response during pneumonia. Here, we investigate mechanistically this strategy using a multi-level mathematical model, which describes the 24 first hours after infection of a single alveolus from the key signaling networks behind activation of the epithelium to the dynamics of the local immune response. With the model, we simulated pneumonia in aged and young patients subjected to different antibiotics timing. The results show that providing antibiotics to elderly patients 8 h in advance compared to young patients restores in aged individuals the effective response seen in young ones. This result suggests the use of early, probably prophylactic, antibiotics treatment in aged hospitalized people with high risk of pneumonia.

Uraemia-induced immune senescence and clinical outcomes in chronic kidney disease patients

BACKGROUND

Patients with chronic kidney disease (CKD) are more prone to develop premature age-related diseases. Data on immune senescence are scarce in CKD populations, except in end-stage renal disease and dialysis. We designed a longitudinal prospective study to evaluate immune senescence at different CKD stages and its influence on CKD patient outcomes.

METHODS

Clinical and biological data collections were performed on 222 patients at different CKD stages [1-2 (n = 85), 4 (n = 53) and 5 (n = 84)]. Immune senescence biomarkers were measured by cytometry on T cells (CD28, CD57, CD45RA, CD31, γH2A.X) or by quantitative polymerase chain reaction [relative telomere length (RTL)] on peripheral blood mononuclear cells and analysed according to CKD stages and outcomes.

RESULTS

CKD was associated with an increase in immune senescence and inflammation biomarkers, as follows: low thymic output (197 ± 25 versus 88 ± 13 versus 73 ± 21 CD4+CD45RA+CD31+ T cells/mm3), an increased proportion of terminally differentiated T cells (CD8+CD28-CD57+) (24 ± 18 versus 32 ± 17 versus 35 ± 19%) restricted to cytomegalovirus-positive patients, telomere shortening (1.11 ± 0.36 versus 0.78 ± 0.24 versus 0.97 ± 0.21 telomere:single copy ratio) and an increase in C-reactive protein levels [median 2.9 (range 1.8-4.9) versus 5.1 (27-9.6) versus 6.2 (3.4-10.5) mg/L]. In multivariate analysis, shorter RTL was associated with death {hazard ratio [HR] 4.12 [95% confidence interval (CI) 1.44-11.75]}. Low thymic output was associated with infections [HR 1.79 (95% CI (1.34-9.58)] and terminally differentiated CD8+ T-cell expansion with a risk of cardiovascular events [CEs; HR 4.86 (95% CI 1.72-13.72)].

CONCLUSION

CKD was associated with premature immune ageing. Each of these alterations increased the risk of specific age-related diseases, such as RTL and death, thymic function and infections and terminally differentiated CD8+ T-cell expansion and CEs.

Interleukin-6 knockout reverses macrophage differentiation imbalance and alleviates cardiac dysfunction in aging mice

Several interleukins (ILs) have been shown to be involved in aging, but the effects of IL-6 on aging-related cardiac dysfunction remain unknown. In this study, the expression and sources of cardiac IL-6 in aging hearts were investigated for the first time. The results showed that cardiac IL-6 expression in mice gradually increased with age, and the expression at 16 months, 20 months and 25 months was higher than that at 3 months. In addition, cardiac macrophages (Møs) were shown to be the main sources of IL-6 in aging mice. IL-6 knockout (KO) significantly alleviated cardiac dysfunction, increased M2 macrophage (Mø2) differentiation, reduced M1 macrophage (Mø1) differentiation and protected against cardiomyocyte apoptosis in aging mice. IL-6 KO also reversed the stimulatory effect of doxorubicin (DOX) treatment on Mø1s and the inhibitory effect of DOX treatment on Mø2s in vitro. Furthermore, the mRNA expression of both aging markers and apoptosis-related markers was markedly inhibited by IL-6 KO. Our results suggest that aging can be significantly reversed by IL-6 KO and that the mechanisms of this effect are related to alleviation of Mø1/Mø2 imbalance and protection against apoptosis in cardiomyocytes.

Postulated Adjuvant Therapeutic Strategies for COVID-19

The number of COVID-19 patients is still growing exponentially worldwide due to the high transmissibility of the SARS-CoV-2 virus. Therapeutic agents currently under investigation are antiviral drugs, vaccines, and other adjuvants that could relieve symptoms or improve the healing process. In this review, twelve therapeutic agents that could play a role in prophylaxis or improvement of the COVID-19-associated symptoms (as add-on substances) are discussed. Agents were identified based on their known pharmacologic mechanism of action in viral and/or nonviral fields and are postulated to interact with one or more of the seven known mechanisms associated with the SARS-CoV-2 virus: (i) regulation of the immune system; (ii) virus entrance in the cell; (iii) virus replication; (iv) hyperinflammation; (v) oxidative stress; (vi) thrombosis; and (vii) endotheliitis. Selected agents were immune transfer factor (oligo- and polypeptides from porcine spleen, ultrafiltered at <10 kDa; Imuno TF®), anti-inflammatory natural blend (Uncaria tomentosa, Endopleura uchi and Haematoccocus pluvialis; Miodesin®), zinc, selenium, ascorbic acid, cholecalciferol, ferulic acid, spirulina, N-acetylcysteine, glucosamine sulfate potassium hydrochloride, trans-resveratrol, and maltodextrin-stabilized orthosilicic acid (SiliciuMax®). This review gives the scientific background on the hypothesis that these therapeutic agents can act in synergy in the prevention and improvement of COVID-19-associated symptoms.

Relationship of HIV Status and Fatigue, Cardiorespiratory Fitness, Myokines, and Physical Activity

People living with HIV (PLWH) experience high rates of fatigue, which can be improved with physical activity. We examined relationships between HIV infection, fatigue, cardiorespiratory fitness, physical activity, and myokines. Twenty PLWH and 20 HIV-uninfected adults completed a fatigue assessment, a maximal cardiometabolic exercise test, serum measures of myokines, and wore an accelerometer for 7 days. Measures were completed at baseline, 3 months, and 6 months. At baseline, PLWH had more fatigue (4.7 ± 2.6 vs. 2.8 ± 2.5, p = .01) and higher peak ventilatory efficiency (VE/VCO2; 33 ± 5.5 vs. 30.2 ± 2.5; p = .06). Half of PLWH engaged in at least one 10-minute bout of physical activity in the previous week, compared with control subjects (65%). Over time, HIV infection and fibroblast growth factor 21 were associated with fatigue (p < .05). People living with HIV have more fatigue and a higher ventilatory efficiency; expression of fibroblast growth factor 21 may underpin this relationship.

[Immunotoxins and immunocytokines]

Cytokines and biological toxins represent two potent classes of biomolecules that have long been explored for their potential as therapeutics. Considerable side effects and poor pharmacokinetics frequently observed with both have limited their broad application. Recombinant protein engineering has allowed the construction of immunocytokines and immunotoxins that seek to exploit the advantageous properties of immunoglobulins to address these issues. Whole antibodies, antibody fragments, constant domains and derivatives have been fused genetically to a range of cytokines and toxins. This review considers the strategies that have been employed and the problems sought to be resolved in the clinical evaluation of this class of biotherapeutic.

Interleukin-12p35 deficiency enhances mitochondrial dysfunction and aggravates cardiac remodeling in aging mice

Our previous studies have demonstrated that interleukin-12p35 knockout (IL-12p35 KO) regulates the progression of various cardiovascular diseases, such as acute cardiac injury and hypertension. The aims of this study were to investigate whether IL-12p35 KO affects aging-related cardiac remodeling and to explore the possible mechanisms. First, the effects of IL-12p35 KO on heart structure and function were detected, and the results showed that IL-12p35 KO exacerbated cardiac remodeling and increased cardiac senescence-related protein levels in aged mice. In addition, whether IL-12p35 KO regulates cardiac senescence-related protein expression, cardiac mitochondrial dysfunction and cardiomyocyte apoptosis was also investigated. IL-12p35 KO increased mitochondrial calcium fluorescence intensity and ROS fluorescence intensity, while it reduced mitochondrial membrane potential. Furthermore, reduced mitochondrial complex (I-IV) activity and ATP levels and increased apoptosis-inducing factor (AIF)-related cardiomyocyte apoptosis were observed in aged IL-12p35 KO mice compared with wild-type mice. Our results demonstrate that aging is aggravated by IL-12p35 KO and that the mechanism may be related to exacerbation of mitochondrial dysfunction and AIF-related cardiomyocyte apoptosis.

Research progress on immune aging and its mechanisms affecting geriatric diseases

Immunosenescence, also known as immune aging, refers to the degeneration, compensation, and reconstruction of the immune system with aging. Immune aging is an important factor in the increased susceptibility of the elderly to infectious diseases, malignant tumors, and a variety of chronic diseases and has long been a hotspot in geriatrics and immunology research. In this paper, the characteristics and progression of immune aging are briefly reviewed for clinicians' reference.

The burden of pertussis in older adults: what is the role of vaccination? A systematic literature review

INTRODUCTION

Pertussis (whooping cough) is a vaccine-preventable disease; however, neither natural- nor vaccine-induced protection is life-long. Although generally not severe in adults, pertussis can be associated with complications in patients with chronic conditions such as asthma or chronic obstructive pulmonary disease, and can be readily transmitted to more vulnerable populations, including neonates before they complete their primary vaccination. Furthermore, as the global population ages, the health and economic burden of the disease is expected to rise. Areas covered: A systematic literature review was conducted to ascertain the current epidemiological and financial burden of pertussis in older adults and to discuss the potential value of a booster vaccination in this population. Expert commentary: Our review indicates a considerable underestimation of the pertussis burden amongst older adults. Seroprevalence studies consistently demonstrate that the reported incidence may be much lower than the actual incidence. Tetanus toxoid-reduced diphtheria toxoid and acellular pertussis vaccines are immunogenic in older adults, induce high booster responses and are well-tolerated. There is therefore a good rationale for the advocacy of booster pertussis vaccination throughout life to prevent pertussis infection and its transmission, especially in adults aged ≥50 years.