Inflammaging and the Lung

IL-10 deficiency aggravates cell senescence and accelerates BLM-induced pulmonary fibrosis in aged mice via PTEN/AKT/ERK pathway

BACKGROUND

Pulmonary fibrosis (PF) is an aging-related progressive lung disorder. The aged lung undergoes functional and structural changes termed immunosenescence and inflammaging, which facilitate the occurrence of fibrosis. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunoregulatory cytokine, yet it remains unclear how IL-10 deficiency-induced immunosenescence participates in the development of PF.

METHODS

Firstly we evaluated the susceptibility to fibrosis and IL-10 expression in aged mice. Then 13-month-old wild-type (WT) and IL-10 knockout (KO) mice were subjected to bleomycin(BLM) and analyzed senescence-related markers by PCR, western blot and immunohistochemistry staining of p16, p21, p53, as well as DHE and SA-β-gal staining. We further compared 18-month-old WT mice with 13-month-old IL-10KO mice to assess aging-associated cell senescence and inflamation infiltration in both lung and BALF. Moreover, proliferation and apoptosis of alveolar type 2 cells(AT2) were evaluated by FCM, immunofluorescence, TUNEL staining, and TEM analysis. Recombinant IL-10 (rIL-10) was also administered intratracheally to evaluate its therapeutic potential and related mechanism. For the in vitro experiments, 10-week-old naïve pramily lung fibroblasts(PLFs) were treated with the culture medium of 13-month PLFs derived from WT, IL-10KO, or IL-10KO + rIL-10 respectively, and examined the secretion of senescence-associated secretory phenotype (SASP) factors and related pathways.

RESULTS

The aged mice displayed increased susceptibility to fibrosis and decreased IL-10 expression. The 13-month-old IL-10KO mice exhibited significant exacerbation of cell senescence compared to their contemporary WT mice, and even more severe epithelial-mesenchymal transition (EMT) than that of 18 month WT mice. These IL-10 deficient mice showed heightened inflammatory responses and accelerated PF progression. Intratracheal administration of rIL-10 reduced lung CD45 + cell infiltration by 15%, including a 6% reduction in granulocytes and a 10% reduction in macrophages, and increased the proportion of AT2 cells by approximately 8%. Additionally, rIL-10 significantly decreased α-SMA and collagen deposition, and reduced the expression of senescence proteins p16 and p21 by 50% in these mice. In vitro analysis revealed that conditioned media from IL-10 deficient mice promoted SASP secretion and upregulated senescence genes in naïve lung fibroblasts, which was mitigated by rIL-10 treatment. Mechanistically, rIL-10 inhibited TGF-β-Smad2/3 and PTEN/PI3K/AKT/ERK pathways, thereby suppressing senescence and fibrosis-related proteins.

CONCLUSIONS

IL-10 deficiency in aged mice leads to accelerated cell senescence and exacerbated fibrosis, with IL-10KO-PLFs displaying increased SASP secretion. Recombinant IL-10 treatment effectively mitigates these effects, suggesting its potential as a therapeutic target for PF.

The aging lung: microenvironment, mechanisms, and diseases

With the development of global social economy and the deepening of the aging population, diseases related to aging have received increasing attention. The pathogenesis of many respiratory diseases remains unclear, and lung aging is an independent risk factor for respiratory diseases. The aging mechanism of the lung may be involved in the occurrence and development of respiratory diseases. Aging-induced immune, oxidative stress, inflammation, and telomere changes can directly induce and promote the occurrence and development of lung aging. Meanwhile, the occurrence of lung aging also further aggravates the immune stress and inflammatory response of respiratory diseases; the two mutually affect each other and promote the development of respiratory diseases. Explaining the mechanism and treatment direction of these respiratory diseases from the perspective of lung aging will be a new idea and research field. This review summarizes the changes in pulmonary microenvironment, metabolic mechanisms, and the progression of respiratory diseases associated with aging.

Pulmonary Diseases in Older Patients: Understanding and Addressing the Challenges

As the global population ages, pulmonary diseases among older people have emerged as a significant and growing public health concern. The increasing incidence of these conditions has led to higher rates of morbidity and mortality among older adults. This perspective study offers a thorough overview of the prevalent pulmonary diseases affecting the elderly demographic. It delves into the challenges encountered during the diagnosis and management of these conditions in older individuals, considering factors such as comorbidities, functional limitations, and medication complexities. Furthermore, innovative strategies and personalized interventions such as precision medicine, advanced therapies, telemedicine solutions, and patient-centered support systems aimed at enhancing the care provided to older individuals grappling with pulmonary disorders are thoroughly explored. By addressing the unique needs and complexities of this vulnerable population, healthcare systems can strive towards improving outcomes and enhancing the quality of life for elderly individuals affected by pulmonary diseases.

A genomic perspective of the aging human and mouse lung with a focus on immune response and cellular senescence

BACKGROUND

The aging lung is a complex process and influenced by various stressors, especially airborne pathogens and xenobiotics. Additionally, a lifetime exposure to antigens results in structural and functional changes of the lung; yet an understanding of the cell type specific responses remains elusive. To gain insight into age-related changes in lung function and inflammaging, we evaluated 89 mouse and 414 individual human lung genomic data sets with a focus on genes mechanistically linked to extracellular matrix (ECM), cellular senescence, immune response and pulmonary surfactant, and we interrogated single cell RNAseq data to fingerprint cell type specific changes.

RESULTS

We identified 117 and 68 mouse and human genes linked to ECM remodeling which accounted for 46% and 27%, respectively of all ECM coding genes. Furthermore, we identified 73 and 31 mouse and human genes linked to cellular senescence, and the majority code for the senescence associated secretory phenotype. These cytokines, chemokines and growth factors are primarily secreted by macrophages and fibroblasts. Single-cell RNAseq data confirmed age-related induced expression of marker genes of macrophages, neutrophil, eosinophil, dendritic, NK-, CD4+, CD8+-T and B cells in the lung of aged mice. This included the highly significant regulation of 20 genes coding for the CD3-T-cell receptor complex. Conversely, for the human lung we primarily observed macrophage and CD4+ and CD8+ marker genes as changed with age. Additionally, we noted an age-related induced expression of marker genes for mouse basal, ciliated, club and goblet cells, while for the human lung, fibroblasts and myofibroblasts marker genes increased with age. Therefore, we infer a change in cellular activity of these cell types with age. Furthermore, we identified predominantly repressed expression of surfactant coding genes, especially the surfactant transporter Abca3, thus highlighting remodeling of surfactant lipids with implications for the production of inflammatory lipids and immune response.

CONCLUSION

We report the genomic landscape of the aging lung and provide a rationale for its growing stiffness and age-related inflammation. By comparing the mouse and human pulmonary genome, we identified important differences between the two species and highlight the complex interplay of inflammaging, senescence and the link to ECM remodeling in healthy but aged individuals.

Inflammation and aging: signaling pathways and intervention therapies

Aging is characterized by systemic chronic inflammation, which is accompanied by cellular senescence, immunosenescence, organ dysfunction, and age-related diseases. Given the multidimensional complexity of aging, there is an urgent need for a systematic organization of inflammaging through dimensionality reduction. Factors secreted by senescent cells, known as the senescence-associated secretory phenotype (SASP), promote chronic inflammation and can induce senescence in normal cells. At the same time, chronic inflammation accelerates the senescence of immune cells, resulting in weakened immune function and an inability to clear senescent cells and inflammatory factors, which creates a vicious cycle of inflammation and senescence. Persistently elevated inflammation levels in organs such as the bone marrow, liver, and lungs cannot be eliminated in time, leading to organ damage and aging-related diseases. Therefore, inflammation has been recognized as an endogenous factor in aging, and the elimination of inflammation could be a potential strategy for anti-aging. Here we discuss inflammaging at the molecular, cellular, organ, and disease levels, and review current aging models, the implications of cutting-edge single cell technologies, as well as anti-aging strategies. Since preventing and alleviating aging-related diseases and improving the overall quality of life are the ultimate goals of aging research, our review highlights the critical features and potential mechanisms of inflammation and aging, along with the latest developments and future directions in aging research, providing a theoretical foundation for novel and practical anti-aging strategies.

"Just right" combinations of adjuvants with nanoscale carriers activate aged dendritic cells without overt inflammation

BACKGROUND

The loss in age-related immunological markers, known as immunosenescence, is caused by a combination of factors, one of which is inflammaging. Inflammaging is associated with the continuous basal generation of proinflammatory cytokines. Studies have demonstrated that inflammaging reduces the effectiveness of vaccines. Strategies aimed at modifying baseline inflammation are being developed to improve vaccination responses in older adults. Dendritic cells have attracted attention as an age-specific target because of their significance in immunization as antigen presenting cells that stimulate T lymphocytes.

RESULTS

In this study, bone marrow derived dendritic cells (BMDCs) were generated from aged mice and used to investigate the effects of combinations of adjuvants, including Toll-like receptor, NOD2, and STING agonists with polyanhydride nanoparticles and pentablock copolymer micelles under in vitro conditions. Cellular stimulation was characterized via expression of costimulatory molecules, T cell-activating cytokines, proinflammatory cytokines, and chemokines. Our results indicate that multiple TLR agonists substantially increase costimulatory molecule expression and cytokines associated with T cell activation and inflammation in culture. In contrast, NOD2 and STING agonists had only a moderate effect on BMDC activation, while nanoparticles and micelles had no effect by themselves. However, when nanoparticles and micelles were combined with a TLR9 agonist, a reduction in the production of proinflammatory cytokines was observed while maintaining increased production of T cell activating cytokines and enhancing cell surface marker expression. Additionally, combining nanoparticles and micelles with a STING agonist resulted in a synergistic impact on the upregulation of costimulatory molecules and an increase in cytokine secretion from BMDCs linked with T cell activation without excessive secretion of proinflammatory cytokines.

CONCLUSIONS

These studies provide new insights into rational adjuvant selection for vaccines for older adults. Combining appropriate adjuvants with nanoparticles and micelles may lead to balanced immune activation characterized by low inflammation, setting the stage for designing next generation vaccines that can induce mucosal immunity in older adults.

COVID-19: A Comprehensive Review on Cardiovascular Alterations, Immunity, and Therapeutics in Older Adults

Here, we present a review focusing on three relevant issues related to COVID-19 and its impact in older adults (60 years and older). SARS-CoV-2 infection starts in the respiratory system, but the development of systemic diseases accompanied by severe clinical manifestations has also been reported, with cardiovascular and immune system dysfunction being the major ones. Additionally, the presence of comorbidities and aging represent major risk factors for the severity and poor prognosis of the disease. Since aging-associated decline has been largely related to immune and cardiovascular alterations, we sought to investigate the consequences and the underlying mechanisms of these pathologies to understand the severity of the illness in this population. Understanding the effects of COVID-19 on both systems should translate into comprehensive and improved medical care for elderly COVID-19 patients, preventing cardiovascular as well as immunological alterations in this population. Approved therapies that contribute to the improvement of symptoms and a reduction in mortality, as well as new therapies in development, constitute an approach to managing these disorders. Among them, we describe antivirals, cytokine antagonists, cytokine signaling pathway inhibitors, and vaccines.

Hepcidin as a Diagnostic Biomarker in Anaemic Lung Cancer Patients

We aim to describe the characteristics of hepcidin, IL-6, and TNF-α levels in anaemia of lung cancer patients with operative tumour as well as to investigate the potential diagnostic capabilities of hepcidin in combination with IL-6, TNF-α, and acute phase proteins. We present a retrospective study of 112 lung cancer patients (41 women and 71 men) who were surgically treated at the Lower Silesian Centre for Lung Diseases in Wroclaw, Poland. Serum blood samples were collected from all these patients prior to any surgical treatment and used to determine hepcidin, IL-6, TNF-α, SAA₁, and CRP concentrations. Patients were also examined with a complete blood count several times during their hospitalization. The female and male groups were divided based on the occurrence of anaemia during their hospitalization. Patients who developed anaemia post-operatively had significantly lower hepcidin concentrations than non-anaemic patients (p = 0.000694 in females with ≥3 complete blood count examinations and p = 0.007905 in males with 2 complete blood count examinations), whereas patients with anaemia since hospital admission had higher hepcidin concentrations. We observed two hepcidin roles related to two cancer anaemia pathogeneses: (1) higher hepcidin concentrations in patients with anaemia since hospital admission (anaemia of inflammation) and (2) lower hepcidin concentrations in patients who developed anaemia after surgery (anaemia of iron deficiency). Our data support the role of hepcidin, IL-6, and TNF-α in cancer-related anaemia and provide diagnostic values for predicting post-operative anaemia in lung cancer patients.

Tuberculosis in an Aging World

Tuberculosis (TB) is one of the leading causes of death due to its being an infectious disease, caused by the airborne pathogen Mycobacterium tuberculosis (M.tb). Approximately one-fourth of the world’s population is infected with latent M.tb, and TB is considered a global threat killing over 4000 people every day. The risk of TB susceptibility and mortality is significantly increased in individuals aged 65 and older, confirming that the elderly represent one of the largest reservoirs for M.tb infection. The elderly population faces many challenges that increase their risk of developing respiratory diseases, including TB. The challenges the elderly face in this regard include the following: decreased lung function, immuno-senescence, inflammaging, adverse drug effects, low tolerance to anti-TB drugs, lack of suitable diagnoses/interventions, and age-associated comorbidities. In order to find new therapeutic strategies to maintain lung homeostasis and resistance to respiratory infections as we age, it is necessary to understand the molecular and cellular mechanisms behind natural lung aging. This review focuses primarily on why the elderly are more susceptible to TB disease and death, with a focus on pulmonary function and comorbidities.

Charlson comorbidity index, neutrophil-to-lymphocyte ratio and undertreatment with renin-angiotensin-aldosterone system inhibitors predict in-hospital mortality of hospitalized COVID-19 patients during the omicron dominant period

Purpose

To investigate the clinical predictors of in-hospital mortality in hospitalized patients with Coronavirus disease 2019 (COVID-19) infection during the Omicron period.

Methods

All consecutive hospitalized laboratory‐confirmed COVID-19 patients between January and May 2022 were retrospectively analyzed. All patients underwent accurate physical, laboratory, radiographic and echocardiographic examination. Primary endpoint was in-hospital mortality.

Results

74 consecutive COVID-19 patients (80.0 ± 12.6 yrs, 45.9% males) were included. Patients who died during hospitalization (27%) and those who were discharged alive (73%) were separately analyzed. Compared to patients discharged alive, those who died were significantly older, with higher comorbidity burden and greater prevalence of laboratory, radiographic and echographic signs of pulmonary and systemic congestion. Charlson comorbidity index (CCI) (OR 1.76, 95%CI 1.07-2.92), neutrophil-to-lymphocyte ratio (NLR) (OR 1.24, 95%CI 1.10-1.39) and absence of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin II receptor blockers (ARBs) therapy (OR 0.01, 95%CI 0.00-0.22) independently predicted the primary endpoint. CCI ≥7 and NLR ≥9 were the best cut-off values for predicting mortality. The mortality risk for patients with CCI ≥7, NLR ≥9 and not in ACEI/ARBs therapy was high (86%); for patients with CCI <7, NLR ≥9, with (16.6%) or without (25%) ACEI/ARBs therapy was intermediate; for patients with CCI <7, NLR <9 and in ACEI/ARBs therapy was of 0%.

Conclusions

High comorbidity burden, high levels of NLR and the undertreatment with ACEI/ARBs were the main prognostic indicators of in-hospital mortality. The risk stratification of COVID-19 patients at hospital admission would help the clinicians to take care of the high-risk patients and reduce the mortality.

Gender dimension in cardio-pulmonary continuum

Cardio-pulmonary diseases, which were once regarded as a man's illness, have been one of the leading causes of morbidity and mortality for both men and women in many countries in recent years. Both gender and sex influence the functional and structural changes in the human body and therefore play an important role in disease clinical manifestation, treatment choice, and/or response to treatment and prognosis of health outcomes. The gender dimension integrates sex and gender analysis in health sciences and medical research, however, it is still relatively overlooked suggesting the need for empowerment in the medical research community. Latest advances in the field of cardiovascular research have provided supportive evidence that the application of biological variables of sex has led to the understanding that heart disease in females may have different pathophysiology compared to males, particularly in younger adults. It has also resulted in new diagnostic techniques and a better understanding of symptomatology, while gender analysis has informed more appropriate risk stratification and prevention strategies. The existing knowledge in the pulmonary field shows the higher prevalence of pulmonary disorders among females, however, the role of gender as a socio-cultural construct has yet to be explored for the implementation of targeted interventions. The purpose of this review is to introduce the concept of gender dimension and its importance for the cardiopulmonary continuum with a focus on shared pathophysiology and disease presentation in addition to interrelation with chronic kidney disease. The review presents basic knowledge of what gender dimension means, and the application of sex and gender aspects in cardiovascular medicine with a specific focus on early pulmonary development, pulmonary hypertension, and chronic obstructive pulmonary disease (COPD). Early vascular aging and inflammation have been presented as a potential pathophysiological link, with further interactions between the cardiopulmonary continuum and chronic kidney disease. Finally, implications for potential future research have been provided to increase the impact of gender dimension on research excellence that would add value to everybody, foster toward precision medicine and ultimately improve human health.

Factors Modulating COVID-19: A Mechanistic Understanding Based on the Adverse Outcome Pathway Framework

Addressing factors modulating COVID-19 is crucial since abundant clinical evidence shows that outcomes are markedly heterogeneous between patients. This requires identifying the factors and understanding how they mechanistically influence COVID-19. Here, we describe how eleven selected factors (age, sex, genetic factors, lipid disorders, heart failure, gut dysbiosis, diet, vitamin D deficiency, air pollution and exposure to chemicals) influence COVID-19 by applying the Adverse Outcome Pathway (AOP), which is well-established in regulatory toxicology. This framework aims to model the sequence of events leading to an adverse health outcome. Several linear AOPs depicting pathways from the binding of the virus to ACE2 up to clinical outcomes observed in COVID-19 have been developed and integrated into a network offering a unique overview of the mechanisms underlying the disease. As SARS-CoV-2 infectibility and ACE2 activity are the major starting points and inflammatory response is central in the development of COVID-19, we evaluated how those eleven intrinsic and extrinsic factors modulate those processes impacting clinical outcomes. Applying this AOP-aligned approach enables the identification of current knowledge gaps orientating for further research and allows to propose biomarkers to identify of high-risk patients. This approach also facilitates expertise synergy from different disciplines to address public health issues.

Assessment of some Physiological Biomarkers in COVID-19 Patients in Thi-Qar, Iraq

It is believed that many biomarkers and factors could be linked to the prognosis of coronavirus disease 2019 (COVID-19). Therefore, this study aimed to evaluate the association of lactate dehydrogenase (LDH), D-Dimer, vitamin D, and ferritin statuses with the prognosis of COVID-19; moreover, it was attempted to investigate its prevalence according to age, employment status, body mass index (BMI), and place of residency in a population sample of hospitalized patients in Thi-Qar, Iraq. This study evaluated 200 COVID-19 patients and 100 controls. The BMI of all individuals was calculated, and such demographic characteristics as age, gender, place of residency, and occupational status were collected from all participants. Blood samples were taken and used to estimate D-Dimer, LDH, vitamin D, ferritin, oxygen, and pulse rate. The mean age of the patients approached the fifth decade, and 72% of the cases were more than 40 years of age. In addition, 60% of the patients were living in the countryside, and 52% of the participants were employed, compared to only 8% of the cases who were students. The BMI of the patients was obtained at 31.44±10.2 kg/m2; accordingly, 47% and 40% of the cases were obese and overweight, respectively, compared to only 12% of the patients who had normal weight (P˂0.05). There were significantly lower vitamin D levels in the patients; however, the concentrations of LDH, serum ferritin, and D-Dimer were significantly higher in the patients, compared to the control group (P˂0.05). Not only age and body weight but also employment status and place of residency maybe also the important risk factors for COVID-19 distribution. LDH, D-dimer, vitamin D, and ferritin statuses could be used as good biomarkers for this disease and its severity.

Elevated C-reactive protein in early COVID-19 predicts worse survival among hospitalized geriatric patients

BACKGROUND

The objective of this cohort study was to determine whether elevated CRP in early COVID-19 was associated with 14-day mortality in geriatric patients.

METHODS

Plasma CRP levels at hospital admission and 14-day all-cause mortality were assessed in geriatric inpatients hospitalized for COVID-19. Potential confounders were age, sex, functional abilities, history of malignancies, hypertension, cardiomyopathy, albuminemia, number of acute health issues, use of antibiotics and respiratory treatments.

RESULTS

Ninety-five participants (mean±SD 88.0±5.5years; 49.5%women; mean CRP, 76.7±77.5mg/L; mean albuminemia, 32.9±6.0g/L) were included. Sixteen participants who did not survive at day 14 exhibited higher CRP level at baseline than the others (120.3±71.2 versus 67.9±76.1 mg/L, P = 0.002). There was no difference in albuminemia (P = 0.329). Plasma CRP level was directly associated with 14-day mortality (fully adjusted HR = 1.11, P = 0.025). The cut-off for CRP associated with 14-day mortality was set at 35mg/L (sensitivity = 0.88; specificity = 0.56). Those with CRP<35mg/L had longer survival time than the others (log-rank P<0.001).

CONCLUSIONS

Elevated CRP levels were associated with poorer 14-day survival in hospitalized geriatric COVID-19 patients.

Ageing mechanisms that contribute to tissue remodeling in lung disease

Age is a major risk factor for chronic respiratory diseases such as idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and certain phenotypes of asthma. The recent COVID-19 pandemic also highlights the increased susceptibility of the elderly to acute respiratory distress syndrome (ARDS), a diffuse inflammatory lung injury with often long-term effects (ie parenchymal fibrosis). Collectively, these lung conditions are characterized by a pathogenic reparative process that, rather than restoring organ function, contributes to structural and functional tissue decline. In the ageing lung, the homeostatic control of wound healing following challenge or injury has an increased likelihood of being perturbed, increasing susceptibility to disease. This loss of fidelity is a consequence of a diverse range of underlying ageing mechanisms including senescence, mitochondrial dysfunction, proteostatic stress and diminished autophagy that occur within the lung, as well as in other tissues, organs and systems of the body. These ageing pathways are highly interconnected, involving localized and systemic increases in inflammatory mediators and damage associated molecular patterns (DAMPs); along with corresponding changes in immune cell function, metabolism and composition of the pulmonary and gut microbiomes. Here we comprehensively review the roles of ageing mechanisms in the tissue remodeling of lung disease.

Frailty Pathogenesis, Assessment, and Management in Older Adults With COVID-19

The 2019 coronavirus disease (COVID-19) is a highly contagious and deadly disease. The elderly people are often accompanied by chronic inflammation and immunodeficiency, showing a frail state. The strength, endurance, and physiological function of the elderly are significantly decreased, and the ability to deal with stress response is weakened. They are the high-risk group that suffering from COVID-19, and rapidly developing to critical illness. Several recent studies suggest that the incidence rate of COVID-19 in elderly patients with frailty is high. Early assessment, detection, and effective intervention of frailty in COVID-19 patients are conducive to significantly improve the quality of life and improve prognosis. However, there are insufficient understanding and standards for the current evaluation methods, pathogenesis and intervention measures for COVID-19 combined with frailty. This study reviews the progress of the research on the potential pathogenesis, evaluation methods and intervention measures of the elderly COVID-19 patients with frailty, which provides a reference for scientific and reasonable comprehensive diagnosis and treatment in clinical.

Towards Goals to Refine Prophylactic and Therapeutic Strategies Against COVID-19 Linked to Aging and Metabolic Syndrome

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gave rise to the coronavirus disease 2019 (COVID-19) pandemic. A strong correlation has been demonstrated between worse COVID-19 outcomes, aging, and metabolic syndrome (MetS), which is primarily derived from obesity-induced systemic chronic low-grade inflammation with numerous complications, including type 2 diabetes mellitus (T2DM). The majority of COVID-19 deaths occurs in people over the age of 65. Individuals with MetS are inclined to manifest adverse disease consequences and mortality from COVID-19. In this review, we examine the prevalence and molecular mechanisms underlying enhanced risk of COVID-19 in elderly people and individuals with MetS. Subsequently, we discuss current progresses in treating COVID-19, including the development of new COVID-19 vaccines and antivirals, towards goals to elaborate prophylactic and therapeutic treatment options in this vulnerable population.

Older but Not Wiser: the Age-Driven Changes in Neutrophil Responses during Pulmonary Infections

Elderly individuals are at increased risk of life-threatening pulmonary infections. Neutrophils are a key determinant of the disease course of pathogen-induced pneumonia. Optimal host defense balances initial robust pulmonary neutrophil responses to control pathogen numbers, ultimately followed by the resolution of inflammation to prevent pulmonary damage. Recent evidence suggests that phenotypic and functional heterogeneity in neutrophils impacts host resistance to pulmonary pathogens. Apart from their apparent role in innate immunity, neutrophils also orchestrate subsequent adaptive immune responses during infection. Thus, the outcome of pulmonary infections can be shaped by neutrophils. This review summarizes the age-driven impairment of neutrophil responses and the contribution of these cells to the susceptibility of the elderly to pneumonia. We describe how aging is accompanied by changes in neutrophil recruitment, resolution, and function. We discuss how systemic and local changes alter the neutrophil phenotype in aged hosts. We highlight the gap in knowledge of whether these changes in neutrophils also contribute to the decline in adaptive immunity seen with age. We further detail the factors that drive dysregulated neutrophil responses in the elderly and the pathways that may be targeted to rebalance neutrophil activity and boost host resistance to pulmonary infections.

Association between ABO blood groups and susceptibility to COVID-19: profile of age and gender in Iraqi patients

Background

A case-control study was performed to examine age, gender, and ABO blood groups in 1014 Iraqi hospitalized cases with Coronavirus disease 2019 (COVID-19) and 901 blood donors (control group). The infection was molecularly diagnosed by detecting coronavirus RNA in nasal swabs of patients.

Results

Mean age was significantly elevated in cases compared to controls (48.2 ± 13.8 vs. 29.9 ± 9.0 year; probability [p] < 0.001). Receiver operating characteristic analysis demonstrated the predictive significance of age in COVID-19 evolution (Area under curve = 0.858; 95% CI: 0.841 - 0.875; p < 0.001). Males outnumbered females in cases (60.4 vs. 39.6%) and controls (56 vs. 44%). Stratification by age group (< 30, 30 - 39, 40 - 49 and ≥ 50 years) revealed that 48.3% of cases clustered in the age group ≥ 50 years. ABO blood group analysis showed that group A was the most common among cases, while group O was the most common among controls (35.5 and 36.7%, respectively). Blood groups A (35.5 vs. 32.7; corrected p [pc] = 0.021), A+AB (46.3 vs. 41.7%; pc = 0.021) and A+B+AB (68.0 vs. 63.3%; pc = 0.007) showed significantly elevated frequencies in cases compared to controls. Logistic regression analysis estimated odds ratios (ORs) of 1.53 (95% confidence interval [CI]: 1.16 - 2.02), 1.48 (95% CI: 1.14 - 1.93) and 1.50 (95% CI: 1.17 - 1.82) for blood groups A, A+AB and A+B+AB, respectively. Blood group frequencies showed no significant differences between age groups of cases or controls. Regarding gender, male cases were marked with increased frequency of group A (39.9 vs. 28.9%) and decreased frequency of group O (25.9 vs. 41.0%) compared to female cases. Independent re-analysis of ABO blood groups in male and female cases demonstrated that group A was increased in male cases compared to male controls (39.9 vs. 33.1%; OR = 1.65; 95% CI: 1.24 - 2.21; pc = 0.006). On the contrary, no significant differences were found between females of cases and controls.

Conclusions

The study results indicated that blood group A may be associated with an increased risk of developing COVID-19, particularly in males.

Respiratory tissue-associated commensal bacteria offer therapeutic potential against pneumococcal colonization

Under eubiotic conditions commensal microbes are known to provide a competitive barrier against invading bacterial pathogens in the intestinal tract, on the skin or on the vaginal mucosa. Here, we evaluate the role of lung microbiota in Pneumococcus colonization of the lungs. In eubiosis, the lungs of mice were dominantly colonized by Lactobacillus murinus. Differential analysis of 16S rRNA gene sequencing or L. murinus-specific qPCR of DNA from total organ homogenates vs.broncho alveolar lavages implicated tight association of these bacteria with the host tissue. Pure L. murinus conditioned culture medium inhibited growth and reduced the extension of pneumococcal chains. Growth inhibition in vitro was likely dependent on L. murinus-produced lactic acid, since pH neutralization of the conditioned medium aborted the antibacterial effect. Finally, we demonstrate that L. murinus provides a barrier against pneumococcal colonization in a respiratory dysbiosis model after an influenza A virus infection, when added therapeutically.

I mmunosenescence and Inflammaging: Risk Factors of Severe COVID-19 in Older People

Old individuals are more susceptible to various infections due to immunological changes that occur during the aging process. These changes named collectively as "immunosenescence" include decreases in both the innate and adaptive immune responses in addition to the exacerbated production of inflammatory cytokines. This scenario of immunological dysfunction and its relationship with disease development in older people has been widely studied, especially in infections that can be fatal, such as influenza and, more recently, COVID-19. In the current scenario of SARS-CoV-2 infection, many mechanisms of disease pathogenesis in old individuals have been proposed. To better understand the dynamics of COVID-19 in this group, aspects related to immunological senescence must be well elucidated. In this article, we discuss the main mechanisms involved in immunosenescence and their possible correlations with the susceptibility of individuals of advanced age to SARS-CoV-2 infection and the more severe conditions of the disease.

SARS-CoV-2, immunosenescence and inflammaging: partners in the COVID-19 crime

Pneumonia outbreak in the city of Wuhan, China, prompted the finding of a novel strain of severe acute respiratory syndrome virus (SARS-CoV-2). Here, we discuss potential long-term consequences of SARS-CoV-2 infection, and its possibility to cause permanent damage to the immune system and the central nervous system. Advanced chronological age is one of the main risk factors for the adverse outcomes of COVID-19, presumably due to immunosenescence and chronic low-grade inflammation, both characteristic of the elderly. The combination of viral infection and chronic inflammation in advanced chronological age might cause multiple detrimental unforeseen consequences for the predisposition and severity of neurodegenerative diseases and needs to be considered so that we can be prepared to deal with future outcomes of the ongoing pandemic.

Delayed severe cytokine storm and immune cell infiltration in SARS-CoV-2-infected aged Chinese rhesus macaques

As of June 2020, Coronavirus Disease 2019 (COVID-19) has killed an estimated 440 000 people worldwide, 74% of whom were aged ≥65 years, making age the most significant risk factor for death caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To examine the effect of age on death, we established a SARS-CoV-2 infection model in Chinese rhesus macaques ( Macaca mulatta) of varied ages. Results indicated that infected young macaques manifested impaired respiratory function, active viral replication, severe lung damage, and infiltration of CD11b + and CD8 + cells in lungs at one-week post infection (wpi), but also recovered rapidly at 2 wpi. In contrast, aged macaques demonstrated delayed immune responses with a more severe cytokine storm, increased infiltration of CD11b + cells, and persistent infiltration of CD8 + cells in the lungs at 2 wpi. In addition, peripheral blood T cells from aged macaques showed greater inflammation and chemotaxis, but weaker antiviral functions than that in cells from young macaques. Thus, the delayed but more severe cytokine storm and higher immune cell infiltration may explain the poorer prognosis of older aged patients suffering SARS-CoV-2 infection.

Age-Related Differences in Immunological Responses to SARS-CoV-2

There is a striking age-related disparity in the prevalence and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced coronavirus disease 2019 infections, which might be explained by age-dependent immunological mechanisms. These include age-related physiological differences in immunological responses, cross-neutralizing antibodies, and differences in levels and binding affinity of angiotensin-converting enzyme 2, the SARS-CoV-2 target receptor; antibody-dependent enhancement in adults manifesting with an overexuberant systemic inflammation in response to infection; and the increased likelihood of comorbidities in adults and the elderly. Emerging immunological phenomena such as Pediatric Multi-System Inflammatory Disorder Temporally associated with SARS-CoV-2 or Multisystem Inflammatory Syndrome in Children are now being observed, though the underlying mechanisms are still unclear. Understanding the mechanisms through which pediatric patients are protected from severe novel coronaviruses infections will provide critical clues to the pathophysiology of coronavirus disease 2019 infection and inform future therapeutic and prophylactic interventions. Asymptomatic carriage in children may have major public health implications, which will have an impact on social and health care policies on screening and isolation practices, school reopening, and safe distancing requirements in the community.

Inflamm-aging: Why older men are the most susceptible to SARS-CoV-2 complicated outcomes

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by a high mortality of elderly men with age-related comorbidities. In most of these patients, uncontrolled local and systemic hyperinflammation induces severe and often lethal outcomes. The aging process is characterized by the gradual development of a chronic subclinical systemic inflammation (inflamm-aging) and by acquired immune system impairment (immune senescence). Here, we advance the hypothesis that four well-recognized features of aging contribute to the disproportionate SARS-CoV-2 mortality suffered by elderly men: i. the presence of subclinical systemic inflammation without overt disease, ii. a blunted acquired immune system and type I interferon response due to the chronic inflammation; iii. the downregulation of ACE2 (i.e. the SARS-CoV-2 receptor); and iv. accelerated biological aging. The high mortality rate of SARS-CoV-2 infection suggests that clarification of the mechanisms of inflamm-aging and immune senescence can help combat not only age-related disorders but also SARS-CoV-2 infection.

Why does COVID-19 disproportionately affect older people?

The severity and outcome of coronavirus disease 2019 (COVID-19) largely depends on a patient's age. Adults over 65 years of age represent 80% of hospitalizations and have a 23-fold greater risk of death than those under 65. In the clinic, COVID-19 patients most commonly present with fever, cough and dyspnea, and from there the disease can progress to acute respiratory distress syndrome, lung consolidation, cytokine release syndrome, endotheliitis, coagulopathy, multiple organ failure and death. Comorbidities such as cardiovascular disease, diabetes and obesity increase the chances of fatal disease, but they alone do not explain why age is an independent risk factor. Here, we present the molecular differences between young, middle-aged and older people that may explain why COVID-19 is a mild illness in some but life-threatening in others. We also discuss several biological age clocks that could be used in conjunction with genetic tests to identify both the mechanisms of the disease and individuals most at risk. Finally, based on these mechanisms, we discuss treatments that could increase the survival of older people, not simply by inhibiting the virus, but by restoring patients' ability to clear the infection and effectively regulate immune responses.

Metformin and SARS-CoV-2: mechanistic lessons on air pollution to weather the cytokine/thrombotic storm in COVID-19

Pathological signaling in the lung induced by particulate matter (PM) air pollution partially overlaps with that provoked by COVID-19, the pandemic disease caused by infection with the novel coronavirus SARS-CoV-2. Metformin is capable of suppressing one of the molecular triggers of the proinflammatory and prothrombotic processes of urban PM air pollution, namely the mitochondrial ROS/Ca2+ release-activated Ca2+ channels (CRAC)/IL-6 cascade. Given the linkage between mitochondrial functionality, ion channels, and inflamm-aging, the ability of metformin to target mitochondrial electron transport and prevent ROS/CRAC-mediated IL-6 release might illuminate new therapeutic avenues to quell the raging of the cytokine and thrombotic-like storms that are the leading causes of COVID-19 morbidity and mortality in older people. The incorporation of infection rates, severity and lethality of SARS-CoV-2 infections as new outcomes of metformin usage in elderly populations at risk of developing severe COVID-19, together with the assessment of bronchial/serological titers of inflammatory cytokines and D-dimers, could provide a novel mechanistic basis for the consideration of metformin as a therapeutic strategy against the inflammatory and thrombotic states underlying the gerolavic traits of SARS-CoV-2 infection.

Human Immunodeficiency Virus Infection and Diverse Physical Health Outcomes: An Umbrella Review of Meta-analyses of Observational Studies

BACKGROUND

Our aim was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies and physical health outcomes associated with human immunodeficiency virus (HIV) but not acquired immunodeficiency syndrome.

METHODS

We performed an umbrella review of observational studies. Evidence was graded as convincing, highly suggestive, suggestive, weak, or nonsignificant.

RESULTS

From 3413 studies returned, 20 were included, covering 55 health outcomes. Median number of participants was 18 743 (range 403-225 000 000). Overall, 45 (81.8%) of the 55 unique outcomes reported nominally significant summary results (P < .05). Only 5 outcomes (9.0%; higher likelihood of presence of breathlessness, higher chronic obstructive pulmonary disease [COPD] prevalence, maternal sepsis, higher risk of anemia, and higher risk of all fractures among people living with HIV [PLWHIV]) showed suggestive evidence, with P values < 10-3; only 3 (5.5%; higher prevalence of cough in cross-sectional studies, higher incidence of pregnancy-related mortality, and higher incidence of ischemic heart disease among PLWHIV in cohort studies) outcomes showed stronger evidence using a stringent P value (<10-6). None of the unique outcomes presented convincing evidence (Class I), yet 3 outcomes presented highly suggestive evidence, 5 outcomes presented suggestive evidence, and 37 outcomes presented weak evidence.

CONCLUSIONS

Results show highly suggestive and suggestive evidence for HIV and the presence of a cough, COPD, ischemic heart disease, pregnancy-related mortality, maternal sepsis, and bone fractures. Public health policies should reflect and accommodate these changes, especially in light of the increases in the life expectancy and the incidence of comorbidities in this population.

Effect of Aging on the Macrophage Response to Titanium Particles

Macrophage-mediated inflammatory reaction to implant wear particles drives bone loss around total joint replacements (TJR). Although most TJR recipients are elderly, studies linking wear particle-activated macrophages and peri-implant osteolysis have not taken into account the multiple effects that aging has on the innate immune system and, in particular, on macrophages. To address this, we compared the wear particle responses of bone marrow macrophages obtained from young (2-month) and aged (18-month) mice. Macrophages were polarized to M0, M1, or M2 phenotypes in vitro, challenged with titanium particles, and their inflammatory response was characterized at multiple time points by quantitative reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. In addition, age-dependent changes in activation of transcription factor nuclear factor-κB were analyzed by a lentiviral vector-based luciferase reporter system. The particle stimulation experiment was further repeated using human primary macrophages isolated from blood donors of different ages. We found that the pro-inflammatory responses were generally higher in macrophages obtained from young mice, but differences between the age groups remained small and of uncertain biological significance. Noteworthily, M2 polarization effectively suppressed the particle-induced inflammation in both young and aged macrophages. These results suggest that aging of the innate immune system per se plays no significant role in the response of macrophages to titanium particles, whereas induction of M2 polarization appears a promising strategy to limit macrophage-mediated inflammation regardless of age. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:405-416, 2020.

Handgrip Strength and Pulmonary Disease in the Elderly: What is the Link?

Societies in developed countries are aging at an unprecedented rate. Considering that aging is the most significant risk factor for many chronic lung diseases (CLDs), understanding this process may facilitate the development of new interventionist approaches. Skeletal muscle dysfunction is a serious problem in older adults with CLDs, reducing their quality of life and survival. In this study, we reviewed the possible links between handgrip strength (HGS)—a simple, noninvasive, low-cost measure of muscle function—and CLDs in the elderly. Different mechanisms appear to be involved in this association, including systemic inflammation, chronic hypoxemia, physical inactivity, malnutrition, and corticosteroid use. Respiratory and peripheral myopathy, associated with muscle atrophy and a shift in muscle fiber type, also seem to be major etiological contributors to CLDs. Moreover, sarcopenic obesity, which occurs in older adults with CLDs, impairs common inflammatory pathways that can potentiate each other and further accelerate the functional decline of HGS. Our findings support the concept that the systemic effects of CLDs may be determined by HGS, and HGS is a relevant measurement that should be considered in the clinical assessment of the elderly with CLDs. These reasons make HGS a useful practical tool for indirectly evaluating functional status in the elderly. At present, early muscle reconditioning and optimal nutrition appear to be the most effective approaches to reduce the impact of CLDs and low muscle strength on the quality of life of these individuals. Nonetheless, larger in-depth studies are needed to evaluate the link between HGS and CLDs.

Immunogenicity and safety of a quadrivalent plant-derived virus like particle influenza vaccine candidate-Two randomized Phase II clinical trials in 18 to 49 and ≥50 years old adults

Background

New influenza vaccines eliciting more effective protection are needed, particularly for the elderly who paid a large and disproportional toll of hospitalization and dead during seasonal influenza epidemics. Low (≤15 μg/strain) doses of a new plant-derived virus-like-particle (VLP) vaccine candidate have been shown to induce humoral and cellular responses against both homologous and heterologous strains in healthy adults 18–64 years of age. The two clinical trials reported here addressed the safety and immunogenicity of higher doses (≥15 μg/strain) of quadrivalent VLP candidate vaccine on 18–49 years old and ≥50 years old subjects. We also investigated the impact of alum on the immunogenicity induced by lower doses of the vaccine candidate.

Method

In the first Phase II trial reported here (NCT02233816), 18–49 year old subjects received 15, 30 or 60 μg/strain of a hemagglutinin-bearing quadrivalent virus-like particle (QVLP) vaccine or placebo. In the second trial (NCT02236052), ≥50 years old subjects received QVLP as above or placebo with additional groups receiving 7.5 or 15 μg/strain with alum. Along with safety recording, the humoral and cell-mediated immune responses were analyzed.

Results

Local and systemic side-effects were similar to those reported previously. The QVLP vaccine induced significant homologous and heterologous antibody responses at the two higher doses, the addition of alum having little-to-no effect. Serologic outcomes tended to be lower in ≥50 years old subjects previously vaccinated. The candidate vaccine also consistently elicited both homologous and heterologous antigen-specific CD4⁺ T cells characterized by their production of interferon-gamma (IFN-γ), interleukine-2 (IL-2) and/or tumor-necrosis factor alpha (TNF-α) upon ex vivo antigenic restimulation.

Conclusion

Overall, the 30 μg dose produced the most consistent humoral and cellular responses in both 18–49 and ≥50 years old subjects, strongly supporting the clinical development of this candidate vaccine. That particular dose was chosen to test in the ongoing Phase III clinical trial.

Triptych of the Hermit Saints: pneumococcal polysaccharide vaccines for the elderly

Pneumococcal pneumonia is a serious disease with considerable morbidity and mortality in the elderly. Despite adequate antibiotic treatment, the long-term mortality of pneumococcal pneumonia remains high. Preventive measures in the form of vaccination, therefore, are warranted. Twenty-three-valent polysaccharide vaccines have a broad coverage but limited efficacy. Pneumococcal conjugate vaccines have been shown in children to be able to prevent invasive and mucosal pneumococcal diseases. It should be realized that the serotype composition of current pneumococcal conjugate vaccines is not tailored for the elderly, and that replacement disease can occur. Yet, the current 13-valent conjugate vaccine has been shown to protect against infections with vaccine serotypes. Long-term mortality of pneumococcal pneumonia should be included in policy making about the introduction of these vaccines for the elderly.

The Contribution of Oxidative Stress and Inflamm-Aging in Human and Equine Asthma

Aging is associated with a dysregulation of the immune system, leading to a general pro-inflammatory state of the organism, a process that has been named inflamm-aging. Oxidative stress has an important role in aging and in the regulation of immune responses, probably playing a role in the development of age-related diseases. The respiratory system function physiologically declines with the advancement of age. In elderly asthmatic patients, this may contribute to disease expression. In this review, we will focus on age-related changes affecting the immune system and in respiratory structure and function that could contribute to asthma occurrence, and/or clinical presentation in the elderly. Also, naturally occurring equine asthma will be discussed as a possible model for studying the importance of oxidative stress and immun-aging/inflamm-aging in humans.