The increasing aging population and aging-associated diseases have become a global issue for decades. People over 65 show an increased prevalence and greater severity of periodontitis, which poses threats to overall health. Studies have demonstrated a significant association between aging and the dysfunction of neutrophils, critical cells in the early stages of periodontitis, and their crosstalk with macrophages and T and B lymphocytes to establish the periodontal lesion. Neutrophils differentiate and mature in the bone marrow before entering the circulation; during an infection, they are recruited to infected tissues guided by the signal from chemokines and cytokines to eliminate invading pathogens. Neutrophils are crucial in maintaining a balanced response between host and microbes to prevent periodontal diseases in periodontal tissues. The impacts of aging on neutrophils' chemotaxis, anti-microbial function, cell activation, and lifespan result in impaired neutrophil functions and excessive neutrophil activation, which could influence periodontitis course. We summarize the roles of neutrophils in periodontal diseases and the aging-related impacts on neutrophil functional responses. We also explore the underlying mechanisms that can contribute to periodontitis manifestation in aging. This review could help us better understand the pathogenesis of periodontitis, which could offer novel therapeutic targets for periodontitis.
Humans ; Neutrophils/immunology* ; Periodontitis/immunology* ; Aging/physiology*

The rise in global life expectancy has led to an increase in the older population, presenting significant challenges in managing infectious diseases. Aging affects the innate and adaptive immune systems, resulting in chronic low-grade inflammation (inflammaging) and immune function decline (immunosenescence). These changes would impair defense mechanisms, increase susceptibility to infections and reduce vaccine efficacy in older adults. Cellular senescence exacerbates these issues by releasing pro-inflammatory factors, further perpetuating chronic inflammation. Moreover, comorbidities, such as cardiovascular disease and diabetes, which are common in older adults, amplify immune dysfunction, while immunosuppressive medications further complicate responses to infections. This review explores the molecular and cellular mechanisms driving inflammaging and immunosenescence, focusing on genomic instability, telomere attrition, and mitochondrial dysfunction. Additionally, we discussed how aging-associated immune alterations influence responses to bacterial, viral, and parasitic infections and evaluated emerging antiaging strategies, aimed at mitigating these effects to improve health outcomes in the aging population.
Humans ; Aging/physiology* ; Communicable Diseases/immunology* ; Immunosenescence/physiology* ; Inflammation/immunology* ; Genomic Instability

Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult

Aging is a complex process associated with dysregulation of the immune system and low levels of inflammation, often associated with the onset of many pathologies. The lacrimal gland (LG) plays a vital role in the maintenance of ocular physiology and changes related to aging directly affect eye diseases. The dysregulation of the immune system in aging leads to quantitative and qualitative changes in antibodies and cytokines. While there is a gradual decline of the immune system, there is an increase in autoimmunity, with a reciprocal pathway between low levels of inflammation and aging mechanisms. Elderly C57BL/6J mice spontaneously show LGs infiltration that is characterized by Th1 but not Th17 cells. The aging of the LG is related to functional alterations, reduced innervation and decreased secretory activities. Lymphocytic infiltration, destruction, and atrophy of glandular parenchyma, ductal dilatation, and secretion of inflammatory mediators modify the volume and composition of tears. Oxidative stress, the capacity to metabolize and eliminate toxic substances decreased in aging, is also associated with the reduction of LG functionality and the pathogenesis of autoimmune diseases. Although further studies are required for a better understanding of autoimmunity and aging of the LG, we described anatomic and immunology aspects that have been described so far.
Aged ; Aging ; Allergy and Immunology ; Animals ; Antibodies ; Atrophy ; Autoimmune Diseases ; Autoimmunity ; Cytokines ; Dilatation ; Eye Diseases ; Humans ; Immune System ; Inflammation ; Lacrimal Apparatus ; Mice ; Ocular Physiological Phenomena ; Oxidative Stress ; Pathology ; Tears ; Th17 Cells

OBJECTIVEAging is associated with the development of diseases because of immunosuppression and altered functioning of the neuroendocrine system. The medicinal properties of Morinda citrifolia L. have been widely exploited for the treatment of age-associated diseases. This study aims to investigate the in vitro and in vivo effects of noni (M. citrifolia) fruit juice (NFJ) on neuro-immunomodulation in the lymph node lymphocytes of F344 rats.

METHODSLymphocytes isolated from axillary and inguinal lymph nodes of young (3-4 months) and old (18-21 months) rats were treated in vitro with different concentrations (0.0001%, 0.01%, and 1%) of NFJ for a period of 24 h. In the in vivo study, old (16-17 months) male F344 rats were treated with 5 mL/kg body weight of 5%, 10% and 20% of NFJ, twice a day, by oral gavage, and lymph node lymphocytes were isolated after 60 d. Concanavalin A (Con A)-induced lymphocyte proliferation, interleukin-2 (IL-2) and interferon-γ (IFN-γ) production and expression of intracellular markers, such as phospho-extracellular signal-regulated kinase (p-ERK1/2), phospho-cAMP response element-binding protein, phospho-protein kinase B (p-Akt), phospho-tyrosine hydroxylase (p-TH), phospho-nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor-α (p-IκB-α) and phospho-nuclear factor-κB (p-NF-κB p65 and p50) were examined in the lymphocytes of lymph nodes.

RESULTSNFJ increased Con A-induced lymphocyte proliferation, IL-2 and IFN-γ production, and p-ERK1/2 expression both in vitro and in vivo. In in vivo NFJ-treated old rats, lymph node lymphocytes showed increased expression of p-TH and Akt, nitric oxide production and decreased expression of p-NF-κB p65 and p50.

CONCLUSIONThese results suggest that the immunostimulatory properties of NFJ are facilitated through intracellular signaling pathways involving ERK1/2, Akt and NF-κB.

Adjuvants, Immunologic ; metabolism ; Aging ; immunology ; metabolism ; Animals ; Cell Proliferation ; Fruit ; chemistry ; metabolism ; Fruit and Vegetable Juices ; analysis ; Humans ; Interleukin-2 ; immunology ; Lymph Nodes ; cytology ; immunology ; Lymphocytes ; cytology ; immunology ; Male ; Morinda ; chemistry ; metabolism ; NF-kappa B ; immunology ; Plant Preparations ; metabolism ; Rats ; Rats, Inbred F344 ; Transcription Factor RelA ; immunology

Inflammaging is the chronic, systematic, and controllable upregulation of a pro-inflammation state with advancing age. Chronic low-grade inflammation accompanied by sustained stimuli is correlated with various age-related diseases (ARDs). Recent studies on ARDs have prompted further research interest in the inner mechanisms underlying inflammaging to establish prevention and treatment plans for inflammatory diseases. In this article, we discuss inflammaging and its significant role in periodontitis.
Aging ; Humans ; Inflammation ; Periodontitis ; immunology

Porcine circovirus type 2 (PCV2) is the primary causative agent for post-weaning, multisystemic, wasting syndrome. Consequently, serologic detection of and vaccination against PCV2 are important for the swine industry. Among several serological tests, the enzyme-linked immunosorbent assay (ELISA) is commonly used to measure anti-PCV2 antibody levels. In the present study, we used two commercial ELISA systems to comparatively evaluate anti-PCV2 antibodies in field pigs treated with three different PCV2 vaccines. Among a total of 517 serum samples, the results of the two ELISAs were fully concordant for 365 positive and 42 negative samples, indicating 78.7% agreement. In addition, the Pearson coefficient (0.636) indicated a moderate correlation between data from the two ELISAs. Results from the farms with pigs vaccinated with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance.
Aging ; Animals ; Antibodies, Viral/*blood ; Circovirus/*classification/immunology ; Enzyme-Linked Immunosorbent Assay/methods/*veterinary ; Female ; Porcine Postweaning Multisystemic Wasting Syndrome/blood/immunology/*prevention & control ; Republic of Korea/epidemiology ; Swine ; Swine Diseases/*prevention & control/virology ; Viral Vaccines/*immunology

OBJECTIVETo explore the effect of non-methylated cytosine-phosphate-guanine oligodeoxynucleotides (CpG-ODN) on serum transforming growth factor (TGF)-β and immune regulation in ovalbumin (OVA)-sensitized young mice.

METHODSThirty female BALB/c mice (2-3 weeks old) were randomly divided into control, model, and CpG-ODN intervention groups. A young mouse model of food allergy was established by OVA sensitization. Normal saline of the same volume was used for replacement in the control group. The mice in the intervention group were intraperitoneally injected with CpG-ODN solution 1 hour before every OVA sensitization. Allergic symptoms were observed and scored for each group. The jejunal tissue was histopathologically examined with hematoxylin-eosin staining. Serum OVA-IgE level was measured using ELISA. Serum concentrations of interleukin (IL)-4, interferon (IFN)-γ, and TGF-β were determined by CBA.

RESULTSAllergic symptoms were observed in the model group and the jejunal tissue showed the pathological characteristics of type I allergic reaction. The allergic symptom scores in the model and CpG-ODN intervention groups were significantly higher than in the control group (P<0.01). The serum levels of OVA-IgE, IL-4, and TGF-β were significantly higher in the model group than in the control and CpG-ODN intervention groups (P<0.05). The CpG-ODN intervention group had significantly higher serum levels of OVA-IgE, IL-4, and TGF-β than the control group (P<0.05). Compared with the control and CpG-ODN intervention groups, the model group had a significantly reduced IFN-γ level (P<0.05).

CONCLUSIONSThe serum TGF-β level is increased in the young mouse model of OVA-sensitized food allergy and is involved in the allergy mechanism. Non-methylated CpG-ODN can reduce the serum TGF-β level in sensitized young mice and play an immunoregulatory role in food allergy.

Aging ; Animals ; DNA Methylation ; Female ; Food Hypersensitivity ; drug therapy ; immunology ; Immunoglobulin E ; blood ; Interleukin-4 ; blood ; Mice ; Mice, Inbred BALB C ; Oligodeoxyribonucleotides ; pharmacology ; Ovalbumin ; immunology ; Transforming Growth Factor beta ; blood

Melatonin affects diverse physiological functions through its receptor and plays an important role in the central nervous system. In the present study, we compared immunoreactivity patterns of arylalkylamine N-acetyltransferase (AANAT), an enzyme essential for melatonin synthesis, and melatonin receptor type 1B (MT2) in the spinal cord of young adult (2~3 years) and aged (10~12 years) beagle dogs using immunohistochemistry and Western blotting. AANAT-specific immunoreactivity was observed in the nuclei of spinal neurons, and was significantly increased in aged dog spinal neurons compared to young adult spinal neurons. MT2-specific immunoreactivity was found in the cytoplasm of spinal neurons, and was predominantly increased in the margin of the neuron cytoplasm in aged spinal cord compared to that in the young adult dogs. These increased levels of AANAT and MT2 immunoreactivity in aged spinal cord might be a feature of normal aging and associated with a feedback mechanism that compensates for decreased production of melatonin during aging.
Age Factors ; Aging/physiology ; Animals ; Arylalkylamine N-Acetyltransferase/*analysis/immunology/physiology ; Blotting, Western ; Dogs ; Fluorescent Antibody Technique ; Male ; Receptor, Melatonin, MT2/*analysis/immunology/physiology ; Spinal Cord/*chemistry/immunology/physiology

OBJECTIVETo study the effects of the Rich Selenium-Banqiao-Codonopsis Pilosula (BCPA) injecta on the aged rats' immune functions and its underlying mechanism.

METHODSTotally 60 rats, composed of 2, 12 and 22 month age old (half male and half female), were served as a young group, middle-age group and aged group respectively. Each group rats were randomly divided into the control and the BCPA subgroup (n = 10). The BCPA group was injected with BCPA at 7.2 g/kg intraperitoneally every day and the control group was injected the same volume of normal saline. All rats were conventionally fed for 45 days. An immune injection was performed after 15 days of BCPA injection. On the 22nd day, late-onset immune response would be induced. The caudal vein blood was collected and the antigen specific IgG, IgG1 and IgG2a antibody was detected on the 15th, 30th and 45th day. On the 45th day, the major T cell subgroups of splenic cells were analyzed and splenic cells were proliferated.

RESULTSNo significant difference in the delayed-type hypersensivity (DTH) reaction was found between the control and the BCPA subgroups in the young and middle-aged rats while the aged BCPA subgroup had a stronger DTH reaction. There was no significant difference in the blood content of specific IgG, IgG1 and IgG2a antibody between the young and middle-age BCPA group while the aged BCPA group rats had an obvious enhancing reaction to the three antibodies mentioned above (P < 0.05). There was no obvious difference in the number of the CD3+ lymphocytes and the CD4+ T helper lymphocytes between the control and the BCPA subgroup in the young aged rats while a significant increase was spotted between the middle-aged and the aged group (P < 0.05). The splenic cells from young BCPA group rats had a strong proliferation response (P < 0.05).

CONCLUSIONBCPA can enhance DTH reaction, potentiate the production of specific IgG, IgG1 and IgG2a antibody to resist KLH, improve the reaction to antigen, increase the amount of CD4+ cell, promote the immune response and had an important role in anti-immunosenescence and antioxidant capacity improvement in the aged rats.

Aging ; Animals ; CD4-Positive T-Lymphocytes ; immunology ; Codonopsis ; chemistry ; Drugs, Chinese Herbal ; pharmacology ; Female ; Immune System ; drug effects ; Immunoglobulin G ; blood ; Male ; Rats ; Selenium ; pharmacology ; Spleen ; immunology