250 research outputs found
How does cytomegalovirus factor into diseases of aging and vaccine responses, and by what mechanisms?
Cytomegalovirus (CMV) is an important pathogen for both clinical and population settings. There is a growing body of research implicating CMV in multiple health outcomes across the life course. At the same time, there is mounting evidence that individuals living in poverty are more likely to be exposed to CMV and more likely to experience many of the chronic conditions for which CMV has been implicated. Further research on the causal role of CMV for health and well-being is needed. However, the strong evidence implicating CMV in type 2 diabetes, autoimmunity, cancer, cardiovascular disease, vaccination, and age-related alterations in immune function warrants clinical and public health action. This imperative is even higher among individuals living in socioeconomically disadvantaged settings and those exposed to high levels of chronic psychosocial stress
Mini-review: Angiotensin- converting enzyme 1 (ACE1) and the impact for diseases such as Alzheimer’s disease, sarcopenia, cancer, and COVID-19
Ageing has been associated with comorbidities, systemic low-grade of inflammation, and immunosenescence. Hypertension is the most common morbidity and anti-hypertensives are used for more than 50%. Angiotensin-converting enzyme 1 inhibitors (ACEi) and angiotensin II receptor blockers (ARB) control blood pressure but also seem to play a role in comorbidities such as Alzheimer’s disease, sarcopenia and cancer. The impact of anti-hypertensives in comorbidities is due to the expression of renin-angiotensin system (RAS) in several tissues and body fluids. Angiotensin-converting enzyme 1 (ACE1) has been linked to oxidative stress, metabolism, and inflammation. The levels and activity of ACE1 are under genetic control and polymorphisms have been correlated with susceptibility to Alzheimer’s disease. In addition, some results found that ACEi and ARB users present delayed cognitive decline and reduced risk of dementia. Regarding to sarcopenia, RAS has been linked to the catabolic and anabolic pathways for muscle mass maintenance. In some studies, older adults using ACEi were highly benefited by exercise training. In cancer, RAS and its products have been shown to play a role since their inhibition in animal models modulates tumor microenvironment and improves the delivery of chemotherapy drugs. Clinically, the incidence of colorectal cancer is reduced in patients using ACEi and ARB. During the pandemic COVID-19 it was found that ACE2 receptor plays a role in the entry of SARS-CoV-2 into the host cell. ACE1 genotypes have been linked to an increased risk for COVID-19 and severe disease. In some studies COVID-19 patients taking ARB or ACEi presented better outcome
Influence of Obesity on Pneumococcus Infection Risk in the Elderly
Obesity negatively affects immune function and host defense mechanisms. Obesity is associated with chronic activation of the innate immune system and consequent local and systemic inflammation which contribute to pathologic conditions such as type-2 diabetes mellitus, cancer, psoriasis, atherosclerosis, and inflammatory bowel disease. Individuals with obesity have increased susceptibility to contract viral, bacterial, and fungal infections and respond sub-optimally to vaccination. In this review, we summarize research findings on the effects of obesity on immune responses to respiratory tract infections (RTI), focusing on Streptococcus pneumoniae (“pneumococcus”) infection, which is a major cause of morbidity and mortality in the US, causing community-acquired infections such as pneumonia, otitis media and meningitis. We show that the risk of infection is higher in elderly individuals and also in individuals of certain ethnic groups, although in a few reports obesity has been associated with better survival of individuals admitted to hospital with pneumococcus infection, a phenomenon known as “obesity paradox.” We discuss factors that are associated with increased risk of pneumococcal infection, such as recent infection with RTI, chronic medical conditions, and immunosuppressive medications
Satisfaction level and masticatory capacity in edentulous patients before and after new complete dentures.
Purpose: Evaluation of the level of satisfaction and capacity, efficiency and masticatory performance in edentulous patients at 5 different times: old complete dentures; at installation day with the new complete dentures; after 2 weeks; 1 month and 3 months of usage. Materials and methods: Satisfaction level and masticatory capacity were analyzed using a questionnaire for edentulous patients, while the masticatory efficiency and performance were evaluated using tests performed on artificial chewable material. The patients triturated the material for 20 and 40 seconds (efficiency) and 40 chewing cycles (performance) and the fragments were separated using a system of sieves. Tests were performed in seven volunteers. Data were analyzed descriptively using SPSS 13.0. Results: In masticatory efficiency test with 20 s, there was a decrease in the average particle size from 8.33 mm to 6.37 mm. The same occurred for masticatory efficiency test with 40 s (7.09 to 5.12 mm) and for masticatory performance with 40 cycles (6.48 to 4.52 mm). Data from the questionnaires showed an increase in the satisfaction level of 43.99% to 95.5%, as in the masticatory capacity of 42.31% to 94.51%. Conclusion: The new rehabilitation increased efficiency and masticatory performance, as well as satisfaction and chewing abilit
Mechanisms for Decreased Function of B Cells in Aged Mice and Humans
Abstract
The immune system has been known for some time to be compromised in aged individuals, e.g., both mice and humans, and in both humoral and cellular responses. Our studies have begun to elucidate intrinsic B lymphocyte defects in Ig class switch recombination, activation-induced cytidine deaminase, and E47 transcription factor expression. These defects occur in both mice and humans. Our studies have also shown that tristetraprolin is one of the key players in regulating the decreased E47 mRNA stability in aged B lymphocytes. These and current studies should lead to improvements in B lymphocyte function in aged populations
CD3+CD4+LAP+Foxp3-regulatory cells of the colonic lamina propria limit disease extension in ulcerative colitis
Background and Aims: In ulcerative colitis (UC), inflammation begins in the rectum and
can extend proximally throughout the entire colon. The extension of inflammation is an
important determinant of disease course, and may be limited by the action of regulatory
T cells (Tregs). In this cross-sectional study, we evaluated the relationship between UC
extension and the proportions of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-
Tregs in the colonic lamina propria (LP) of 79 UC patients and 29 controls. The role of
these cells in UC extension was also investigated in the murine oxazolone-induced colitis
model.
Methods: Patients: Disease extension was classified according to the Montreal
classification. Where possible, endoscopic biopsies of involved and uninvolved
tissue were obtained from UC patients. Mouse model: Colitis was induced by
intrarectal oxazolone administration. Lamina propria mononuclear cells were isolated
from patient biopsies and mouse colon tissue using enzymatic method and the
percentage of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-cells evaluated by
immunofluorescence. Confocal microscopy was applied for the visualization and
quantification of CD4+LAP+ cells on tissue histological sections.
Results: In UC patients with distal colitis the proportion of LP CD3+CD4+Foxp3+
Tregs was significantly higher in inflamed tissue than uninvolved tissue. As opposite, the
proportion of LP CD3+CD4+LAP+ Tregs was significantly higher in uninvolved tissue
than involved tissue. Both LP CD3+CD4+Foxp3+ and LP CD3+CD4+LAP+ Tregs
proportion in involved tissue was significantly higher than in controls irrespective of the
extension of inflammation. In mice with oxazolone-induced distal colitis, treatment with
LAP-depleting antibody was associated with the development of extensive colitis.
Conclusions: Our findings suggest that CD3+CD4+LAP+Foxp3-Tregs limit the
extension of inflammatory lesions in UC patients
Age-associated alterations in γδ T-cells are present predominantly in individuals infected with Cytomegalovirus
BACKGROUND: Despite the common perception that latent Cytomegalovirus (CMV) infection is usually symptom-free, emerging epidemiological evidence suggests that it may in fact be associated with higher mortality over extended follow-up. Mechanisms responsible for this potentially important effect are unclear. CMV infection is known to have a large impact on the distribution of T cell phenotypes, especially the accumulation of late-stage differentiated CD8(+), as well as Vδ2(-) γδ T-cells, which are the main subset of γδ T-cells involved in anti-CMV immunity. Its impact on γδ T-cells in the aging context is less well-defined. RESULTS: Here, we investigated a group of healthy individuals aged between 21 and 89 years, in order to correlate the frequency and differentiation status of γδ T-cells with age. We found that these parameters were only marginally influenced by age, but were marked in people with a latent CMV infection. Thus, we observed a significant age-associated accumulation of late-differentiated T-cells within the Vδ2(-) population, but only in CMV-seropositive donors. There was also a strong trend towards reduced frequency of early-differentiated cells within the Vδ2(-) phenotype. Older people had significantly higher anti-CMV IgG titers, which in turn correlated significantly with a lower Vδ2(+)/Vδ2(-) ratio and a shift from early- to a late-differentiated Vδ2(-) T-cell phenotype. CONCLUSIONS: Our findings demonstrate a strong influence of CMV on γδ T-cells during human ageing, similar to that observed for αβ T-cells. Differences between donors of different ages are more marked in CMV-infected individuals. The biological implications of this potent age-associated CMV-mediated immune-modulation require clarification
Recommended from our members
Aging and chronic inflammation: highlights from a multidisciplinary workshop
: Aging is a gradual, continuous series of natural changes in biological, physiological, immunological, environmental, psychological, behavioral, and social processes. Aging entails changes in the immune system characterized by a decrease in thymic output of naĂŻve lymphocytes, an accumulated chronic antigenic stress notably caused by chronic infections such as cytomegalovirus (CMV), and immune cell senescence with acquisition of an inflammatory senescence-associated secretory phenotype (SASP). For this reason, and due to the SASP originating from other tissues, aging is commonly accompanied by low-grade chronic inflammation, termed "inflammaging". After decades of accumulating evidence regarding age-related processes and chronic inflammation, the domain now appears mature enough to allow an integrative reinterpretation of old data. Here, we provide an overview of the topics discussed in a recent workshop "Aging and Chronic Inflammation" to which many of the major players in the field contributed. We highlight advances in systematic measurement and interpretation of biological markers of aging, as well as their implications for human health and longevity and the interventions that can be envisaged to maintain or improve immune function in older people
Lifelong bilingualism and mechanisms of neuroprotection in Alzheimer dementia.
Lifelong bilingualism is associated with delayed dementia onset, suggesting a protective effect on the brain. Here, we aim to study the effects of lifelong bilingualism as a dichotomous and continuous phenomenon, on brain metabolism and connectivity in individuals with Alzheimer's dementia. Ninety-eight patients with Alzheimer's dementia (56 monolinguals; 42 bilinguals) from three centers entered the study. All underwent an [18F]-fluorodeoxyglucose positron emission tomography (PET) imaging session. A language background questionnaire measured the level of language use for conversation and reading. Severity of brain hypometabolism and strength of connectivity of the major neurocognitive networks was compared across monolingual and bilingual individuals, and tested against the frequency of second language life-long usage. Age, years of education, and MMSE score were included in all above mentioned analyses as nuisance covariates. Cerebral hypometabolism was more severe in bilingual compared to monolingual patients; severity of hypometabolism positively correlated with the degree of second language use. The metabolic connectivity analyses showed increased connectivity in the executive, language, and anterior default mode networks in bilingual compared to monolingual patients. The change in neuronal connectivity was stronger in subjects with higher second language use. All effects were most pronounced in the left cerebral hemisphere. The neuroprotective effects of lifelong bilingualism act both against neurodegenerative processes and through the modulation of brain networks connectivity. These findings highlight the relevance of lifelong bilingualism in brain reserve and compensation, supporting bilingual education and social interventions aimed at usage, and maintenance of two or more languages, including dialects, especially crucial in the elderly people
- …