T Cell Immunosenescence in Aging, Obesity, and Cardiovascular Disease.

Although advances in preventive medicine have greatly improved prognosis, cardiovascular disease (CVD) remains the leading cause of death worldwide. This clearly indicates that there remain residual cardiovascular risks that have not been targeted by conventional therapies. The results of multiple animal studies and clinical trials clearly indicate that inflammation is the most important residual risk and a potential target for CVD prevention. The immune cell network is intricately regulated to maintain homeostasis. Ageing associated changes to the immune system occurs in both innate and adaptive immune cells, however T cells are most susceptible to this process. T-cell changes due to thymic degeneration and homeostatic proliferation, metabolic abnormalities, telomere length shortening, and epigenetic changes associated with aging and obesity may not only reduce normal immune function, but also induce inflammatory tendencies, a process referred to as immunosenescence. Since the disruption of biological homeostasis by T cell immunosenescence is closely related to the development and progression of CVD via inflammation, senescent T cells are attracting attention as a new therapeutic target. In this review, we discuss the relationship between CVD and T cell immunosenescence associated with aging and obesity.

The Role of Cysteine Peptidases in Hematopoietic Stem Cell Differentiation and Modulation of Immune System Function.

Cysteine cathepsins are primarily involved in the degradation and recycling of proteins in endo-lysosomal compartments but are also gaining recognition as pivotal proteolytic contributors to various immune functions. Through their extracellular proteolytic activities within the hematopoietic stem cell niche, they are involved in progenitor cell mobilization and differentiation. Cysteine cathepsins, such as cathepsins L and S contribute to antigen-induced adaptive immunity through major histocompatibility complex class II antigen presentation whereas cathepsin X regulates T-cell migration. By regulating toll-like receptor signaling and cytokine secretion cysteine cathepsins activate innate immune cells and affect their functional differentiation. Cathepsins C and H are expressed in cytotoxic T lymphocytes and natural killer cells and are involved in processing of pro-granzymes into proteolytically active forms. Cytoplasmic activities of cathepsins B and L contribute to the maintenance of homeostasis of the adaptive immune response by regulating cell death of T and B lymphocytes. The expression pattern, localization, and activity of cysteine cathepsins is tightly connected to their function in immune cells. Furthermore, cysteine cathepsins together with their endogenous inhibitors, serve as mediators in the interplay between cancer and immune cells that results in immune cell anergy. The aim of the present article is to review the mechanisms of dysregulation of cysteine cathepsins and their inhibitors in relation to immune dysfunction to address new possibilities for regulation of their function.

Effects of Hormone Therapy and Flavonoids Capable on Reversal of Menopausal Immune Senescence.

Menopause, probably the most important natural change in a woman's life and a major component of female senescence, is characterized, inter alia, by cessation of ovarian estrogen and progesterone production, resulting in a gradual deterioration of the female immune system. Hormone replacement therapy (HRT) is used in postmenopausal women to relieve some of the peri- and postmenopausal symptoms, while there is also evidence that the therapy may additionally partially reverse menopausal immune senescence. Flavonoids, and especially isoflavones, are widely used for the treatment of menopausal symptoms, although it is not at present clear whether they can reverse or alleviate other menopausal changes. HRT reverses the menopausal CD4/CD8 ratio and also limits the general peri- and postmenopausal inflammatory state. Moreover, the increased levels of interleukins (IL)-1ß, IL-6, and IL-8, as well as of tumor necrosis factor-α (TNF-α) are decreased after the initiation of HRT. However, some reports show no effect of HRT on IL-4, IL-10, and IL-12. It is thus evident that the molecular pathways connecting HRT and female immune senescence need to be clarified. Interestingly, recent studies have suggested that the anti-inflammatory properties of isoflavones possibly interact with inflammatory cytokines when applied in menopause treatments, thereby potentially reversing immune senescence. This narrative review presents the latest data on the effect of menopausal therapies, including administration of flavonoid-rich products, on age-associated immune senescence reversal with the aim of revealing possible directions for future research and treatment development.

An aged immune system drives senescence and ageing of solid organs.

Ageing of the immune system, or immunosenescence, contributes to the morbidity and mortality of the elderly1,2. To define the contribution of immune system ageing to organism ageing, here we selectively deleted Ercc1, which encodes a crucial DNA repair protein3,4, in mouse haematopoietic cells to increase the burden of endogenous DNA damage and thereby senescence5-7 in the immune system only. We show that Vav-iCre+/-;Ercc1-/fl mice were healthy into adulthood, then displayed premature onset of immunosenescence characterized by attrition and senescence of specific immune cell populations and impaired immune function, similar to changes that occur during ageing in wild-type mice8-10. Notably, non-lymphoid organs also showed increased senescence and damage, which suggests that senescent, aged immune cells can promote systemic ageing. The transplantation of splenocytes from Vav-iCre+/-;Ercc1-/fl or aged wild-type mice into young mice induced senescence in trans, whereas the transplantation of young immune cells attenuated senescence. The treatment of Vav-iCre+/-;Ercc1-/fl mice with rapamycin reduced markers of senescence in immune cells and improved immune function11,12. These data demonstrate that an aged, senescent immune system has a causal role in driving systemic ageing and therefore represents a key therapeutic target to extend healthy ageing.

Tumor Microenvironment-Regulating Immunosenescence-Independent Nanostimulant Synergizing with Near-Infrared Light Irradiation for Antitumor Immunity.

The combination of photothermal therapy (PTT) and toll-like receptor (TLR)-mediated immunotherapy can elicit antitumor immunity and modulate the immunosuppressive tumor microenvironment (TME). Unlike other TLRs, TLR-5 is a promising target for immune activation, as its expression is well-maintained even during immunosenescence. Here, we developed a unique tumor microenvironment-regulating immunosenescence-independent nanostimulant consisting of TLR-5 adjuvant Vibrio vulnificus flagellin B (FlaB) conjugated onto the surface to an IR 780-loaded hyaluronic acid-stearylamine (HIF) micelles. These HIF micelles induced immune-mediated cell death via PTT when irradiated with a near-infrared laser. In comparison with PTT alone, the combination of in situ-generated tumor-associated antigens produced during PTT and the immune adjuvant FlaB demonstrated enhanced vaccine-like properties and modulated the TME by suppressing immune-suppressive regulatory cells (Tregs) and increasing the fraction of CD103+ migratory dendritic cells, which are responsible for trafficking tumor antigens to draining lymph nodes (DLNs). This combinatorial strategy (i.e., applying a TLR-5 adjuvant targeted to immunosenescence-independent TLR-5 and the in situ photothermal generation of tumor-associated antigens) is a robust system for next-generation immunotherapy and could even be applied in elderly patients, thus broadening the clinical scope of immunotherapy strategies.

A randomized pilot trial to evaluate the benefit of the concomitant use of atorvastatin and Raltegravir on immunological markers in protease-inhibitor-treated subjects living with HIV.

OBJECTIVE: Optimization of antiretroviral therapy and anti-inflammatory treatments, such as statins, are among the strategies aimed at reducing metabolic disorders, inflammation and immune activation in people living with HIV (PLWH). We evaluated the potential benefit of combining both strategies. DESIGN: Forty-two PLWH aged ≥40 years receiving a protease inhibitor (PI)-based regimen were randomized (1:1) to switch from PI to Raltegravir (n = 20), or to remain on PI (n = 22). After 24 weeks, all patients received atorvastatin 20mg/day for 48 weeks. METHODS: We analyzed plasma inflammatory as well as T-cell maturation, activation, exhaustion and senescence markers at baseline, 24 and 72 weeks. RESULTS: Plasma inflammatory markers remained unchanged. Furthermore, no major changes on T-cell maturation subsets, immunoactivation, exhaustion or immunosenescence markers in both CD4 and CD8 T cell compartments were observed. Only a modest decrease in the frequency of CD38+ CD8 T cells and an increase in the frequency of CD28-CD57+ in both CD4 and CD8 T-cell compartments were noticed in the Raltegravir-switched group. CONCLUSIONS: The study combined antiretroviral switch to Raltegravir and Statin-based anti-inflammatory strategies to reduce inflammation and chronic immune activation in PLWH. Although this combination was safe and well tolerated, it had minimal impact on inflammatory and immunological markers. CLINICAL TRIALS REGISTRATION: NCT02577042.

Biomodulina T May Restore Immunity in Older Adults.

Worldwide, there has been a progressive demographic shift over the past 50 years resulting in a larger proportion of older adults in the general population. Aging itself is a complex biological phenomenon characterized in part by changes in the immune system known as "immunosenescence", which makes older adults more susceptible to infectious, cardiovascular and autoimmune diseases, as well as cancers. Several strategies have been proposed in an attempt to reverse immunosenescence, including use of hormones, cytokines and thymic factors. A promising drug in the search to restore the thymic microenvironment (which plays an important role in the regulation and maintenance of the immune system) in older adults is Biomodulina T, a Cuban product registered for use in patients with recurrent respiratory infections. The administration of Biomodulina T increases the number of naïve T-lymphocyte, CD4-positive cells that have recently migrated from the thymus gland (recent thymic emigrants) and memory CD8-positive T lymphocytes, which have characteristics akin to stem cells (stem cell-like memory). Furthermore, the expression of programmed cell death 1 protein in CD4-positive T lymphocytes and CD4-positive T lymphocytes decreases, and the proliferative capacity of CD4-positive T lymphocytes increases, without changes in the frequency of regulatory T lymphocytes. These results suggest that the administration of Biomodulina T could be used to restore immunity in older adults and in other immunocompromised individuals, improve response to other immunotherapies in cancer patients, and increase the effi cacy of vaccinations in older adults. Its use has been approved in Cuba for immune system restoration.KEYWORDS Immunosenescence, aging, immunotherapy, immuno-modulation, antineoplastic protocols, Cuba.

Age-Related Lymphocyte Output During Disease-Modifying Therapies for Multiple Sclerosis.

BACKGROUND: Patients with multiple sclerosis exhibit the same qualitative and quantitative changes in immune system cells observed in aging. In the last 20 years, multiple sclerosis patients have shown an increase in life expectancy and average age, but clinical trial inclusion criteria typically exclude patients over the age of 55 years. Therefore, disease-modifying therapies are likely administered to patients older than those enrolled in clinical trials. OBJECTIVE: In order to investigate whether disease-modifying therapies for multiple sclerosis induce modifications to the immune system that may have (super)additive effects resulting in an acceleration of immunosenescence, we quantified the number of T-cell receptor excision circles (TRECs) and K-deleting recombination excision circles (KRECs). These molecules are contained in new T and B lymphocytes released by the thymus and bone marrow and are considered molecular age-related markers. METHODS: The markers of aging were measured by a multiplex quantitative real-time PCR assay in 122 patients who had started therapy with interferon-beta (IFN-ß), fingolimod, alemtuzumab, or natalizumab. Samples were obtained before the therapy and at 6 and 12 months of treatment. Comparisons between the variables were performed by a non-parametric statistical analysis. RESULTS: In therapy-naive patients, a significant and direct correlation was found between a lower number of newly produced T and B cells and older age. Although disease-modifying therapies induced different changes (both increases and decreases) in the production of new T and B lymphocytes, 12 months of therapy with IFN-ß or natalizumab did not affect the correlations found at baseline between the release of lymphocytes containing TRECs or KRECs and age. On the contrary, in patients treated with alemtuzumab, both correlations were lost, while in fingolimod-treated patients, only the correlation between TRECs and age disappeared. CONCLUSIONS: This observational study indicated that different age-related changes of the new T and B lymphocyte production could be one of the reasons for the emergence, in the real-world setting, of adverse events not otherwise observed in clinical trials; thus, caution is advised when choosing disease-modifying therapies for multiple sclerosis patients.

Does Older Age have an Impact on Rituximab Efficacy and Safety? Results from the NOR-DMARD Register.

OBJECTIVE: The objective of this study was to compare the efficacy and safety of rituximab in older vs younger patients with rheumatoid arthritis. METHODS: Data on 367 patients with rheumatoid arthritis treated with rituximab in the Norwegian Disease-Modifying Antirheumatic Drug (NOR-DMARD) register were analysed, comparing patients aged ≥ 65 years (n = 91) with patients aged < 65 years (n = 276). Drug survival was compared using a Kaplan-Meier analysis and Cox proportional hazard models. Disease activity, as assessed by the Disease Activity Score based on 28 joints and erythrocyte sedimentation rate (DAS28-ESR) and the Simplified Disease Activity Index, was analysed with linear mixed models. The occurrence of adverse events was analysed by quasi-Poisson regression models. RESULTS: Drug survival was similar in the two age groups. The proportion of patients who remained taking rituximab over 2 years was 72% in those under aged 65 years vs 74% in those aged ≥ 65 years. No statistically significant association with age was found for drug survival in either the unadjusted (hazard ratio 1.13, p = 0.65) or adjusted Cox proportional hazard analyses for the model with DAS28-ESR as a confounder (effect size 1.11, p = 0.73). Models including the Simplified Disease Activity Index instead of DAS28-ESR yielded similar results. Age was furthermore not significantly associated with disease activity over time, although there was a tendency towards a poorer response in older patients. In the older age group, there was a higher incidence of pneumonia (107 vs 51 per 1000 patient-years) and other serious infections (142 vs 66 per 1000 patient-years). CONCLUSIONS: Rituximab is a reasonable therapeutic option for older patients with rheumatoid arthritis although vigilance is needed with regard to the infection profile. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01581294.

The paradigm of immunosenescence in atherosclerosis-cardiovascular disease (ASCVD).

The new immunosenescence paradigm (2015) was an attempt to explain a mechanism by which macrophages could be immunosuppressed and dysfunctional, yet paradoxically release proinflammatory factors in an unregulated manner. This mechanism was linked to the loss of dehydroepiandrosterone (DHEA) with aging and thus explained how immunosenescence could be causally related to the risk of stress and/or age-associated chronic diseases. At the center of this paradigm was lipid body negative (LB-) foamy macrophage (CD14+CD16+) which produced human endogenous retrovirus K102 (HERV-K102) particles. HERV-K102 may be a protector foamy virus of humans, and its induction may generate trained innate immunity, a special type of autoimmunity, in response to intracellular pathogens, their constituents, toxins, and/or tumors. Overwhelming evidence now suggests that the proinflammatory foamy macrophages driving ASCVD are LB-. Moreover, the monocyte/macrophage phenotype implicated in atherosclerosis-cardiovascular disease (ASCVD) appears to be the CD14+CD16+ intermediate phenotype. These and other observations directly challenge the cholesterol hypothesis. For the prevention and treatment of ASCVD, it is important to address the putative cause of ASCVD -- immunosenescence, rather than the signs or symptoms such as inflammation or elevated cholesterol. Therefore, strategies to reverse or prevent immunosenescence, which improve or maintain an optimal cortisol/DHEA ratio such as isoflavonoids, would be expected to alleviate not only ASCVD but the risk of many other age-associated chronic diseases. Here, the new immunosenescence paradigm will be appraised for its suitability to explain ASCVD risks.

CD70 contributes to age-associated T cell defects and overwhelming inflammatory responses.

Aging is associated with immune dysregulation, especially T cell disorders, which result in increased susceptibility to various diseases. Previous studies have shown that loss of co-stimulatory receptors or accumulation of co-inhibitory molecules play important roles in T cell aging. In the present study, CD70, which was generally regarded as a costimulatory molecule, was found to be upregulated on CD4+ and CD8+ T cells of elderly individuals. Aged CD70+ T cells displayed a phenotype of over-activation, and expressed enhanced levels of numerous inhibitory receptors including PD-1, 2B4 and LAG-3. CD70+ T cells from elderly individuals exhibited increased susceptibility to apoptosis and high levels of inflammatory cytokines. Importantly, the functional dysregulation of CD70+ T cells associated with aging was reversed by blocking CD70. Collectively, this study demonstrated CD70 as a prominent regulator involved in immunosenescence, which led to defects and overwhelming inflammatory responses of T cells during aging. These findings provide a strong rationale for targeting CD70 to prevent dysregulation related to immunosenescence.

Lymphocyte senescence in COPD is associated with decreased sirtuin 1 expression in steroid resistant pro-inflammatory lymphocytes.

BACKGROUND: The class III NAD-dependent histone deacetylase (HDAC) sirtuin 1 (SIRT1) is an important regulator of senescence, aging, and inflammation. SIRT1de-acetylates chromatin histones, thereby silencing inflammatory gene transcription. We have reported increased steroid-resistant senescent pro-inflammatory CD28nullCD8+ T cells in patients with chronic obstructive pulmonary disease (COPD). We hypothesized that SIRT1 is reduced in these cells in COPD, and that treatment with SIRT1 activators (resveratrol, curcumin) and agents preventing NAD depletion (theophylline) would upregulate SIRT1 and reduce pro-inflammatory cytokine expression in these steroid-resistant cells. METHODS: Blood was collected from n = 10 COPD and n = 10 aged-matched controls. Expression of CD28, SIRT1, and pro-inflammatory cytokines was determined in CD8+ and CD8- T and natural killer T (NKT)-like cells cultured in the presence of ±1 µM prednisolone, ±5 mg/L theophylline, ±1 µM curcumin, ±25 µM resveratrol, using flow cytometry and immunofluorescence. RESULTS: There was an increase in the percentage of CD28nullCD8+ T and NKT-like cells in COPD patients compared with controls. Decreased SIRT1 expression was identified in CD28nullCD8+T and NKT-like cells compared with CD28+ counterparts from both patients and controls (e.g. CD28null 11 ± 3% versus CD28+ 57 ± 9%). Loss of SIRT1 was associated with increased production of IFNγ and TNFα, steroid resistance, and disease severity. SIRT1 expression was upregulated in the presence of all drugs and was associated with a decrease in steroid resistance and IFNγ and TNFα production by CD28nullCD8+T and NKT-like cells. The presence of the SIRT1 inhibitor, EX-527 negated [by 92 ± 12% (median ± SEM)] the effect of the SIRT1 activator SRT720 on the percentage of CD8+ T cells producing IFNγ and TNFα. CONCLUSIONS: Steroid resistance in pro-inflammatory CD28nullCD8+ T and NKT-like cells is associated with decreased SIRT1 expression. Treatment with prednisolone, in combination with theophylline, curcumin or resveratrol increases SIRT1 expression, restores steroid sensitivity, and inhibits pro-inflammatory cytokine production from these cells and may reduce systemic inflammation in COPD. The reviews of this paper are available via the supplemental material section.

Regulatory Effect of Anwulignan on the Immune Function Through Its Antioxidation and Anti-Apoptosis in D-Galactose-Induced Aging Mice.

BACKGROUND: Aging is a spontaneous and inevitable phenomenon of biology, which can lead to the gradual deterioration of tissues and organs. One of the age-related deterioration processes is immunosenescence, which leads to changes in the function of immune systems, including immune cells and associated cytokines. A proper modulation of immune responses can improve the age-related immunosenescence process and then reach healthy aging. Schisandra sphenanthera, a traditional Chinese medicine, has been used as both a medicine and a nutritional supplement for thousands of years. Anwulignan, a monomer compound of Schisandra sphenanthera lignans, has been reported to possess an immunomodulatory effect. Therefore, this study was designed to further explore whether Anwulignan could also modulate the immune functions in aging model mice and the underlying mechanism. METHODS: D-galactose (D-gal) is often used as an inducer of immunosenescence in animals. In this study, a mice model was created by subcutaneous D-gal (220 mg kg-1) for successive 42 days. Then, the blood and spleen tissue samples were taken for the analysis and observation of cytokine levels, immunoglobulin levels, leukocyte numbers, and the phagocytic activity of macrophages, as well as the histological changes, the proliferation ability of lymphocytes, and the biochemical parameters in the spleen tissue. RESULTS: Anwulignan significantly increased the serum levels of IL-2, IL-4, IFN-γ, lgG, lgM, and lgA, decreased the content of TNF-α and IL-6 in the aging mice, and increased the blood leukocyte number, the phagocytic activity, the lymphocyte proliferation, and the spleen index in vitro. Anwulignan also significantly increased the activities of SOD and GSH-Px, decreased the contents of MDA and 8-OHdG in the spleen tissue, up-regulated the expressions of Nrf2, HO-1, and Bcl2, down-regulated the expressions of Keap1, Caspase-3, and Bax in the spleen cells, and reduced the apoptosis of spleen lymphocytes. CONCLUSION: Anwulignan can restore the immune function that is declined in D-gal-induced aging mice partly related to its antioxidant capacity by activating the Nrf2/ARE pathway and downstream enzymes, as well as its anti-apoptotic effect by regulating Caspase-3 and the ratio of Bcl2 to Bax in the spleen.

cGAMP/Saponin Adjuvant Combination Improves Protective Response to Influenza Vaccination by Microneedle Patch in an Aged Mouse Model.

Current strategies for improving protective response to influenza vaccines during immunosenescence do not adequately protect individuals over 65 years of age. Here, we used an aged mouse model to investigate the potential of co-delivery of influenza vaccine with the recently identified combination of a saponin adjuvant Quil-A and an activator of the STING pathway, 2'3 cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) via dissolving microneedle patches (MNPs) applied to skin. We demonstrate that synergy between the two adjuvant components is observed after their incorporation with H1N1 vaccine into MNPs as revealed by analysis of the immune responses in adult mice. Aged 21-month-old mice were found to be completely protected against live influenza challenge after vaccination with the MNPs adjuvanted with the Quil-A/cGAMP combination (5 µg each) and demonstrated significantly reduced morbidity compared to the observed responses in these mice vaccinated with unadjuvanted MNPs. Analysis of the lung lysates of the surviving aged mice post challenge revealed the lowest level of residual inflammation in the adjuvanted groups. We conclude that combining influenza vaccine with a STING pathway activator and saponin-based adjuvant in MNPs is a novel option for skin vaccination of the immunosenescent population, which is at high risk for influenza.

Leptin induces immunosenescence in human B cells.

Leptin is an adipokine secreted primarily by the adipocytes. Leptin has endocrine and immune functions and increases the secretion of pro-inflammatory cytokines by immune cells. Here we show that incubation of B cells from young lean individuals with leptin increases the frequencies of pro-inflammatory B cells and induces intrinsic B cell inflammation, characterized by mRNA expression of pro-inflammatory cytokines (TNF-α and IL-6), chemokines (IL-8), micro-RNAs (miR-155 and miR-16), TLR4 and p16, a cell cycle regulator associated with immunosenescence. We have previously shown that the expression of these pro-inflammatory markers in unstimulated B cells is negatively associated with the response of the same B cells after in vivo or in vitro stimulation. B cells from young lean individuals, after in vitro incubation with leptin, show reduced class switch and influenza vaccine-specific IgG production. Our results altogether show that leptin makes B cells from youn lean individuals similar to those from young obese and elderly lean individuals, suggesting that leptin may be a mechanisms of immunosenescence in human B cells.

Probiotic bacteria as modulators of cellular senescence: emerging concepts and opportunities.

Probiotic bacteria are increasingly gaining importance in human nutrition owing to their multifaceted health beneficial effects. Studies have also shown that probiotic supplementation is useful in mitigating age-associated oxi-inflammatory stress, immunosenescence, and gut dysbiosis thereby promoting health and longevity. However, our current understanding of the process of aging suggests a strong interrelationship between the accumulation of senescent cells and the development of aging phenotype, including the predisposition to age-related disorders. The present review studies the documented pro-longevity effects of probiotics and highlights how these beneficial attributes of probiotics could be related to the mitigation of cellular senescence. We present a perspective that to fully understand and comprehend the anti-aging characteristics of probiotic bacteria; it is imperative that probiotics or their synbiotic amalgamation with plant polyphenols, be studied under the purview of cellular senescence, that may ultimately help devise probiotic-based anti-senescence strategies.

Polyamines Control eIF5A Hypusination, TFEB Translation, and Autophagy to Reverse B Cell Senescence.

Failure to make adaptive immune responses is a hallmark of aging. Reduced B cell function leads to poor vaccination efficacy and a high prevalence of infections in the elderly. Here we show that reduced autophagy is a central molecular mechanism underlying immune senescence. Autophagy levels are specifically reduced in mature lymphocytes, leading to compromised memory B cell responses in old individuals. Spermidine, an endogenous polyamine metabolite, induces autophagy in vivo and rejuvenates memory B cell responses. Mechanistically, spermidine post-translationally modifies the translation factor eIF5A, which is essential for the synthesis of the autophagy transcription factor TFEB. Spermidine is depleted in the elderly, leading to reduced TFEB expression and autophagy. Spermidine supplementation restored this pathway and improved the responses of old human B cells. Taken together, our results reveal an unexpected autophagy regulatory mechanism mediated by eIF5A at the translational level, which can be harnessed to reverse immune senescence in humans.

Diet supplemented with phytochemical epigallocatechin gallate and probiotic Lactobacillus fermentum confers second generation synbiotic effects by modulating cellular immune responses and antioxidant capacity in aging mice.

PURPOSE: In the present study, we systematically identified and evaluated a synbiotic combination of phytochemical epigallocatechin gallate (EGCG) and probiotic bacteria in amelioration of immunosenescence and oxidative stress in aged mice. METHODS: Inhibitory effects of EGCG against different bacterial species were evaluated in vitro, followed by analysis to identify potential combination of EGCG and probiotic bacteria against alleviation of oxidative and inflammatory stress ex vivo. The best synbiotic combination, vis-à-vis prebiotic and probiotic supplementation alone, was then evaluated in aged Swiss albino mice for modulation of various immunological and antioxidative parameters. RESULTS: EGCG strongly inhibited the growth of pathogenic microbes as compared to probiotic bacteria. A combination of EGCG with probiotic Lactobacillus fermentum (LF) provided evidence of additive effects in the amelioration of oxidative and inflammatory stress-induced cell death. In vivo study revealed that combined supplementation of LF and EGCG significantly enhanced neutrophil oxidative index, CD3+ cell numbers and activation status, Th1/Th2 cytokines in splenic supernatants as well as liver Nrf-2 expression in comparison with treatments with LF or EGCG alone. The combined application of EGCG and LF did not simply result in additive or synergistic effects in relation with individual treatments. CONCLUSION: These observations suggest that EGCG could be considered as a potential prebiotic that can offer second generation synbiotic health beneficial effects for the alleviation of some of the deleterious aspects of immunosenescence and aging.

Voluntary exercise reverses immune aging induced by oxidative stress in aging mice.

Excessive oxidative stress leads to aging due to persistent damage to the cells, tissues, and the entire organism. Immunosenescence is also a devastating consequence of oxidative stress, but there is a lack of research on effective ways to overcome it. In this study, we used physiologic and immunological aging mouse models that had sustained oxidative stress to investigate whether voluntary exercise and/or antioxidant treatment could overcome oxidative damage as well as aging. We established an aging model induced by continuously administering d-galactose (d-gal) to 6-week-old female C57BL/6J mice. We also assessed reversal of immunosenescence by providing free-wheel running and vitamin E (vit E) supplementation to this aging model. As an aging index, the level of advanced glycation end products (AGEs) in the blood was measured. Phenotypes of T cells in the thymus and spleen were examined as an index of immunosenescence. Intracellular reactive oxygen species (ROS) levels in the mouse spleen and levels of AGEs in the blood were significantly higher after 6 weeks of d-gal administration. In addition, immunosenescence was observed, in which the naïve:effector cell ratio in the spleen decreased. After 4 weeks of free-wheel running and vit E administration, both intracellular ROS and serum AGE levels decreased. Above all, free-wheel running restored the naïve:effector ratio of cytotoxic T lymphocytes reduced by d-gal administration. Taken together, these results suggest that voluntary exercise may be effective in restoring immunosenescence induced by oxidative stress.

Is Chronic Exposure to Low-Dose Organochlorine Pesticides a New Risk Factor of T-cell Immunosenescence?

Background: T-cell immunosenescence, a hallmark of an aging immune system, is potentially linked to the risk of developing cancer and other aging-related diseases. Chronic infection by cytomegalovirus (CMV) has been widely studied as a risk factor for T-cell immunosenescence, but the role of persistent chemicals has never been examined. As a typical example of persistent chemicals, we evaluated whether organochlorine pesticides (OCPs) are related to T-cell immunosenescence in the general population.Methods: Serum concentrations of ß-hexachlorocyclohexane, p,p'-DDT, p,p'-DDE, and trans-nonachlor were measured in 95 Korean adults ages 30 to 64 years. T-cell immunosenescence was assessed by the frequencies of CD8+CD57+, CD8+CD28-, CD4+CD57+, and CD4+CD28- T lymphocytes in 20 mL of fresh peripheral blood.Results: The senescence of CD8+ T lymphocytes was the most consistently associated with OCPs. For quartiles of measurements of OCPs, adjusted mean percentages of CD8+CD57+ and CD8+CD28- T lymphocytes in the CD8+ T lymphocyte population were 23.9, 27.6, 31.0, and 38.7 (P trend < 0.01) and 25.6, 27.3, 28.0, and 35.5 (P trend = 0.02), respectively. When we compared the strength of the associations among OCPs, CMV IgG titer, and age, OCPs showed the strongest association with markers of immunosenescence. Importantly, the association between OCPs and immunosenescence markers was more prominent among participants without known risk factors, such as a young age or low CMV immunoglobulin G titer.Conclusions: Chronic exposure to low-dose OCPs may be a new risk factor for T-cell immunosenescence.Impact: T-cell immunosenescence may be one possible mechanism linking low-dose OCPs and many chronic diseases. Cancer Epidemiol Biomarkers Prev; 27(10); 1159-67. ©2018 AACR.