Aging and Options to Halt Declining Immunity to Virus Infections

Transcriptome analysis of cynomolgus macaques throughout their lifespan reveals age-related immune patterns

Despite the different perspectives by diverse research sectors spanning several decades, aging research remains uncharted territory for human beings. Therefore, we investigated the transcriptomic characteristics of eight male healthy cynomolgus macaques, and the annual sampling was designed with two individuals in four age groups. As a laboratory animal, the macaques were meticulously shielded from all environmental factors except aging. The results showed recent findings of certain immune response and the age-associated network of primate immunity. Three important aging patterns were identified and each gene clusters represented a different immune response. The increased expression pattern was predominantly associated with innate immune cells, such as Neutrophils and NK cells, causing chronic inflammation with aging whereas the other two decreased patterns were associated with adaptive immunity, especially "B cell activation" affecting antibody diversity of aging. Furthermore, the hub gene network of the patterns reflected transcriptomic age and correlated with human illness status, aiding in future human disease prediction. Our macaque transcriptome profiling results offer systematic insights into the age-related immunological features of primates.

Fine-tuning spatial-temporal dynamics and surface receptor expression support plasma cell-intrinsic longevity

Durable serological memory following vaccination is critically dependent on the production and survival of long-lived plasma cells (LLPCs). Yet, the factors that control LLPC specification and survival remain poorly resolved. Using intravital two-photon imaging, we find that in contrast to most plasma cells (PCs) in the bone marrow (BM), LLPCs are uniquely sessile and organized into clusters that are dependent on APRIL, an important survival factor. Using deep, bulk RNA sequencing, and surface protein flow-based phenotyping, we find that LLPCs express a unique transcriptome and phenotype compared to bulk PCs, fine-tuning expression of key cell surface molecules, CD93, CD81, CXCR4, CD326, CD44, and CD48, important for adhesion and homing. Conditional deletion of Cxcr4 in PCs following immunization leads to rapid mobilization from the BM, reduced survival of antigen-specific PCs, and ultimately accelerated decay of antibody titer. In naïve mice, the endogenous LLPCs BCR repertoire exhibits reduced diversity, reduced somatic mutations, and increased public clones and IgM isotypes, particularly in young mice, suggesting LLPC specification is non-random. As mice age, the BM PC compartment becomes enriched in LLPCs, which may outcompete and limit entry of new PCs into the LLPC niche and pool.

The Impact of Immune System Aging on Infectious Diseases

Immune system aging is becoming a field of increasing public health interest because of prolonged life expectancy, which is not paralleled by an increase in health expectancy. As age progresses, innate and adaptive immune systems undergo changes, which are defined, respectively, as inflammaging and immune senescence. A wealth of available data demonstrates that these two conditions are closely linked, leading to a greater vulnerability of elderly subjects to viral, bacterial, and opportunistic infections as well as lower post-vaccination protection. To face this novel scenario, an in-depth assessment of the immune players involved in this changing epidemiology is demanded regarding the individual and concerted involvement of immune cells and mediators within endogenous and exogenous factors and co-morbidities. This review provides an overall updated description of the changes affecting the aging immune system, which may be of help in understanding the underlying mechanisms associated with the main age-associated infectious diseases.

Fine-tuning spatial-temporal dynamics and surface receptor expression support plasma cell-intrinsic longevity

Durable serological memory following vaccination is critically dependent on the production and survival of long-lived plasma cells (LLPCs). Yet, the factors that control LLPC specification and survival remain poorly resolved. Using intra-vital two-photon imaging, we find that in contrast to most plasma cells in the bone marrow, LLPCs are uniquely sessile and organized into clusters that are dependent on April, an important survival factor. Using deep, bulk RNA sequencing, and surface protein flow-based phenotyping, we find that LLPCs express a unique transcriptome and proteome compared to bulk PCs, fine tuning expression of key cell surface molecules, CD93, CD81, CXCR4, CD326, CD44 and CD48, important for adhesion and homing, and phenotypically label LLPCs within mature PC pool. Conditional deletion of Cxcr4 in PCs following immunization leads to rapid mobilization from the BM, reduced survival of antigen-specific PCs, and ultimately accelerated decay of antibody titer. In naive mice, the endogenous LLPCs BCR repertoire exhibits reduced diversity, reduced somatic mutations, and increased public clones and IgM isotypes, particularly in young mice, suggesting LLPC specification is non-random. As mice age, the BM PC compartment becomes enriched in LLPCs, which may outcompete and limit entry of new PC into the LLPC niche and pool.

Immune-boosting effect of Yookgong-dan against cyclophosphamide-induced immunosuppression in mice

Immune responses must be strictly regulated to prevent autoimmune and infectious diseases and to protect against infectious agents. As people age, their immunity wanes, leading to a decrease in lymphocyte production in bone marrow and thymus and a decline in the efficacy of mature lymphocytes in secondary lymphoid organs. This study explores the immune-boosting potential of Yookgong-dan (YGD) in enhancing the immune system by activating immune cells. In our in vitro experiments, cyclophosphamide (Cy) treatment led to a significant decrease in primary splenocyte viability. However, subsequent treatment with YGD significantly improved cell viability, with doses ranging between 1 and 25 μg/mL in Cy-treated splenocytes. Flow cytometry analysis demonstrated that the Cy group exhibited reduced positivity of CD3+ T cells and CD45+ leukocytes compared to the blank group. In contrast, treatment with YGD led to a notable, dose-responsive increase in these immune cell types. In our in vivo experiments, YGD was orally administered to Cy-induced immunosuppressed mice at 20 and 100 mg/kg doses for 10 days. The results indicated a dose-dependent elevation in immunoglobulin (Ig)G and IgM levels in the serum, emphasizing the immunostimulatory effect of YGD. Furthermore, the Cy-treated group showed decreased T cells, B (CD19+) cells, and leukocytes in the total splenocyte population. Yet, YGD treatment resulted in a dose-dependent reversal of this pattern, suggesting its ability to counter immunosuppression. Notably, YGD was found to effectively stimulate T (CD4+ and CD8+) lymphocyte subsets and natural killer cells, along with enhancing Th1/Th2 cytokines in immunosuppressed conditions. These outcomes correlated with the modulation of BCL-2 and BAX expression, which are critical for apoptosis. In conclusion, YGD has the potential to bolster immune functionality through the activation of immune cells, thereby enhancing the immune system's capacity to combat diseases and improve overall health and wellness.

Antibody and Cell-Based Therapies against Virus-Induced Cancers in the Context of HIV/AIDS

Infectious agents, notably viruses, can cause or increase the risk of cancer occurrences. These agents often disrupt normal cellular functions, promote uncontrolled proliferation and growth, and trigger chronic inflammation, leading to cancer. Approximately 20% of all cancer cases in humans are associated with an infectious pathogen. The International Agency for Research on Cancer (IARC) recognizes seven viruses as direct oncogenic agents, including Epstein-Barr Virus (EBV), Kaposi's Sarcoma-associated herpesvirus (KSHV), human T-cell leukemia virus type-1 (HTLV-1), human papilloma virus (HPV), hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus type 1 (HIV-1). Most viruses linked to increased cancer risk are typically transmitted through contact with contaminated body fluids and high-risk behaviors. The risk of infection can be reduced through vaccinations and routine testing, as well as recognizing and addressing risky behaviors and staying informed about public health concerns. Numerous strategies are currently in pre-clinical phases or undergoing clinical trials for targeting cancers driven by viral infections. Herein, we provide an overview of risk factors associated with increased cancer incidence in people living with HIV (PLWH) as well as other chronic viral infections, and contributing factors such as aging, toxicity from ART, coinfections, and comorbidities. Furthermore, we highlight both antibody- and cell-based strategies directed against virus-induced cancers while also emphasizing approaches aimed at discovering cures or achieving complete remission for affected individuals.

Host Responses to Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) infections are a constant public health problem, especially in infants and older adults. Virtually all children will have been infected with RSV by the age of two, and reinfections are common throughout life. Since antigenic variation, which is frequently observed among other respiratory viruses such as SARS-CoV-2 or influenza viruses, can only be observed for RSV to a limited extent, reinfections may result from short-term or incomplete immunity. After decades of research, two RSV vaccines were approved to prevent lower respiratory tract infections in older adults. Recently, the FDA approved a vaccine for active vaccination of pregnant women to prevent severe RSV disease in infants during their first RSV season. This review focuses on the host response to RSV infections mediated by epithelial cells as the first physical barrier, followed by responses of the innate and adaptive immune systems. We address possible RSV-mediated immunomodulatory and pathogenic mechanisms during infections and discuss the current vaccine candidates and alternative treatment options.

Spatial association between socio-economic health service factors and sepsis mortality in Thailand

Sepsis is a significant global health issue causing organ failure and high mortality. The number of sepsis cases has recently increased in Thailand making it crucial to comprehend the factors behind these infections. This study focuses on exploring the spatial autocorrelation between socio-economic factors and health service factors on the one hand and sepsis mortality on the other. We applied global Moran's I, local indicators of spatial association (LISA) and spatial regression to examine the relationship between these variables. Based on univariate Moran's I scatter plots, sepsis mortality in all 77 provinces in Thailand were shown to exhibit a positive spatial autocorrelation that reached a significant value (0.311). The hotspots/ high-high (HH) clusters of sepsis mortality were mostly located in the central region of the country, while the coldspots/low-low (LL) clusters were observed in the north-eastern region. Bivariate Moran's I indicated a spatial autocorrelation between various factors and sepsis mortality, while the LISA analysis revealed 7 HH clusters and 5 LL clusters associated with population density. Additionally, there were 6 HH and 4 LL clusters in areas with the lowest average temperature, 4 HH and 2 LL clusters in areas with the highest average temperature, 8 HH and 5 LL clusters associated with night-time light and 6 HH and 5 LL clusters associated with pharmacy density. The spatial regression models conducted in this study determined that the spatial error model (SEM) provided the best fit, while the parameter estimation results revealed that several factors, including population density, average lowest and highest temperature, night-time light and pharmacy density, were positively correlated with sepsis mortality. The coefficient of determination (R2) indicated that the SEM model explained 56.4% of the variation in sepsis mortality. Furthermore, based on the Akaike Information Index (AIC), the SEM model slightly outperformed the spatial lag model (SLM) with an AIC value of 518.1 compared to 520.

Low Prevalence of HSV-1 and Helicobacter pylori in HNSCC and Chronic Tonsillitis Patients Compared to Healthy Individuals

Recent studies identified viral and bacterial factors, including HSV-1 and H. pylori, as possible factors associated with diseases such as chronic tonsillitis and cancers, including head and neck squamous cell carcinoma (HNSCC). We assessed the prevalence of HSV-1/2 and H. pylori in patients with HNSCC, chronic tonsillitis, and healthy individuals using PCR after DNA isolation. Associations were sought between the presence of HSV-1, H. pylori, and clinicopathological and demographic characteristics and stimulant use. HSV-1 and H. pylori were most frequently identified in controls (HSV-1: 12.5% and H. pylori: 6.3%). There were 7 (7.8%) and 8 (8.6%) patients with positive HSV-1 in HNSCC and chronic tonsillitis patients, respectively, while the prevalence of H. pylori was 0/90 (0%) and 3/93 (3.2%), respectively. More cases of HSV-1 were observed in older individuals in the control group. All positive HSV-1 cases in the HNSCC group were associated with advanced tumor stage (T3/T4). The prevalence of HSV-1 and H. pylori was highest in the controls compared to HNSCC and chronic tonsillitis patients, which indicates that the pathogens were not risk factors. However, since all positive HSV-1 cases in the HNSCC group were observed only in patients with advanced tumor stage, we suggested a possible link between HSV-1 and tumor progression. Further follow-up of the study groups is planned.

Long-term human spaceflight and inflammaging: Does it promote aging?

Spaceflight and its associated stressors, such as microgravity, radiation exposure, confinement, circadian derailment and disruptive workloads represent an unprecedented type of exposome that is entirely novel from an evolutionary stand point. Within this perspective, we aimed to review the effects of prolonged spaceflight on immune-neuroendocrine systems, brain and brain-gut axis, cardiovascular system and musculoskeletal apparatus, highlighting in particular the similarities with an accelerated aging process. In particular, spaceflight-induced muscle atrophy/sarcopenia and bone loss, vascular and metabolic changes, hyper and hypo reaction of innate and adaptive immune system appear to be modifications shared with the aging process. Most of these modifications are mediated by molecular events that include oxidative and mitochondrial stress, autophagy, DNA damage repair and telomere length alteration, among others, which directly or indirectly converge on the activation of an inflammatory response. According to the inflammaging theory of aging, such an inflammatory response could be a driver of an acceleration of the normal, physiological rate of aging and it is likely that all the systemic modifications in turn lead to an increase of inflammaging in a sort of vicious cycle. The most updated countermeasures to fight these modifications will be also discussed in the light of their possible application not only for astronauts' benefit, but also for older adults on the ground.

Meeting Summary: Global Vaccine and Immunization Research Forum, 2021

The 2021 Global Vaccine and Immunization Research Forum highlighted the considerable advances and recent progress in research and development for vaccines and immunization, critically reviewed lessons learned from COVID-19 vaccine programs, and looked ahead to opportunities for this decade. For COVID-19, decades of investments in basic and translational research, new technology platforms, and vaccines targeting prototype pathogens enabled a rapid, global response. Unprecedented global coordination and partnership have played an essential role in creating and delivering COVID-19 vaccines. More improvement is needed in product attributes such as deliverability, and in equitable access to vaccines. Developments in other priority areas included: the halting of two human immunodeficiency virus vaccine trials due to lack of efficacy in preventing infection; promising efficacy results in Phase 2 trials of two tuberculosis vaccines; pilot implementation of the most advanced malaria vaccine candidate in three countries; trials of human papillomavirus vaccines given in single-dose regimens; and emergency use listing of a novel, oral poliomyelitis type 2 vaccine. More systematic, proactive approaches are being developed for fostering vaccine uptake and demand, aligning on priorities for investment by the public and private sectors, and accelerating policy making. Participants emphasized that addressing endemic disease is intertwined with emergency preparedness and pandemic response, so that advances in one area create opportunities in the other. In this decade, advances made in response to the COVID-19 pandemic should accelerate availability of vaccines for other diseases, contribute to preparedness for future pandemics, and help to achieve impact and equity under Immunization Agenda 2030.

Bibliometric and visualization analysis of global research trends on immunosenescence (1970-2021)

BACKGROUND

Immunosenescence, the aging of the immune system, leads to a decline in the body's adaptability to the environment and plays an important role in various diseases. Immunosenescence has been widely studied in recent years. However, to date, no relevant bibliometric analyses have been conducted. This study aimed to analyze the foundation and frontiers of immunosenescence research through bibliometric analysis.

METHODS

Articles and reviews on immunosenescence from 1970 to 2021 were obtained from the Web of Science Core Collection. Countries, institutions, authors, journals, references, and keywords were analyzed and visualized using VOSviewer and CiteSpace. The R language and Microsoft Excel 365 were used for statistical analyses.

RESULTS

In total, 3763 publications were included in the study. The global literature on immunosenescence research has increased from 1970 to 2021. The United States was the most productive country with 1409 papers and the highest H-index. Italy had the highest average number of citations per article (58.50). Among the top 10 institutions, 50 % were in the United States. The University of California was the most productive institution, with 159 articles. Kroemer G, Franceschi C, Goronzy JJ, Solana R, and Fulop T were among the top 10 most productive and co-cited authors. Experimental Gerontology (n = 170) published the most papers on immunosenescence. The analysis of keywords found that current research focuses on "inflammaging", "gut microbiota", "cellular senescence", and "COVID-19".

CONCLUSIONS

Immunosenescence research has increased over the years, and future cooperation and interaction between countries and institutions must be expanded. The connection between inflammaging, gut microbiota, age-related diseases, and immunosenescence is a current research priority. Individualized treatment of immunosenescence, reducing its negative effects, and promoting healthy longevity will become an emerging research direction.

High titers of neutralizing SARS-CoV-2 antibodies six months after symptom onset are associated with increased severity in COVID-19 hospitalized patients

BACKGROUND

Viral shedding and neutralizing antibody (NAb) dynamics among patients hospitalized with severe coronavirus disease 2019 (COVID-19) and immune correlates of protection have been key questions throughout the pandemic. We investigated the duration of reverse transcriptase-polymerase chain reaction (RT-PCR) positivity, infectious viral shedding and NAb titers as well as the association between NAb titers and disease severity in hospitalized COVID-19 patients in Denmark 2020-2021.

MATERIALS AND METHODS

Prospective single-center observational cohort study of 47 hospitalized COVID-19 patients. Oropharyngeal swabs were collected at eight time points during the initial 30 days of inclusion. Serum samples were collected after a median time of 7 (IQR 5 - 10), 37 (IQR 35 - 38), 97 (IQR 95 - 100), and 187 (IQR 185 - 190) days after symptom onset. NAb titers were determined by an in-house live virus microneutralization assay. Viral culturing was performed in Vero E6 cells.

RESULTS

Patients with high disease severity had higher mean log₂ NAb titers at day 37 (1.58, 95% CI [0.34 -2.81]), 97 (2.07, 95% CI [0.53-3.62]) and 187 (2.49, 95% CI [0.20- 4.78]) after symptom onset, compared to patients with low disease severity. Peak viral load (0.072, 95% CI [- 0.627 - 0.728]), expressed as log₁₀ SARS-CoV-2 copies/ml, was not associated with disease severity. Virus cultivation attempts were unsuccessful in almost all (60/61) oropharyngeal samples collected shortly after hospital admission.

CONCLUSIONS

We document an association between high disease severity and high mean NAb titers at days 37, 97 and 187 after symptom onset. However, peak viral load during admission was not associated with disease severity.

TRIAL REGISTRATION

The study is registered at https://clinicaltrials.gov/ (NCT05274373).

Immunogenicity Characterization of COVID-19 Vaccines: A Systematic Review and Meta-analysis

INTRODUCTION

Immunogenicity has emerged as a challenge in the development of vaccines against coronavirus disease of 2019 (COVID-19). Immunogenicity is a determinant of the efficacy and safety of vaccines. This systematic review and associated meta-analysis summarized and characterized the immunogenicity of COVID-19 vaccines in randomized controlled trials (RCTs).

METHODS

Relevant RCTs were systematically sourced from different medical databases in August 2021. The risk ratios and mean differences with 95% confidence intervals were calculated.

RESULTS

Of 2,310 papers, 16 RCTs were eligible for review. These RCTs involved a total of 26,698 participants (15,292 males and 11,231 females). The pooled results showed a significant difference in the geometric mean titer between the vaccinated and control groups in favor of the vaccine group after 1 and 2 months of follow-up, for the young age group (18 - < 55y), and with different doses (P < 0.001). The difference in the older age group (>55y) was insignificant (P = 0.24). The seroconversion rate of spike neutralizing antibodies favored the vaccine groups 1 or 2 months after vaccination (P < 0.001). The seroconversion rate of the vaccine group was significantly different (P < 0.001) from that of the control group.

CONCLUSIONS

Vaccination elicits immunogenicity in the follow-up period for all age groups and at low and large doses. Therefore, people should be encouraged to receive vaccines currently being offered. A boost dose has been asserted for the elderly.

Herpes Zoster Following COVID-19 Vaccine Booster

BACKGROUND Herpes zoster is a condition in which there is reactivation of varicella zoster virus (VZV), which is usually seen in the elderly and those with immunocompromised states. Recently, however, there have been many reports of herpes zoster after administration of COVID-19 vaccines, although initial trials showed that these vaccines have good safety and immunogenicity profiles. At the time of writing, about 5 billion people worldwide had received their full course of COVID-19 vaccination. This case report describes an elderly man who developed herpes zoster after receiving a booster dose of the Pfizer-BioNTech (BNT162b2) vaccine, with no adverse effects after the first and second dose. CASE REPORT An 82-year-old man with underlying type 2 diabetes mellitus, hypertension, dyslipidemia, and cerebrovascular disease presented with left-sided chest and upper back pain. The pain was intermittent, burning in nature, and disturbed his sleep. A week prior to his presentation, he received a COVID-19 vaccine (BNT162b2) booster dose. Examination revealed multiple vesicles along his anterior and posterior T3 dermatome. He was diagnosed with herpes zoster and treated with a course of oral acyclovir. Upon review 7 days later, he had recovered well, with resolution of his vesicles and pain. CONCLUSIONS COVID-19 vaccination remains an important measure to prevent transmission of infection and to reduce the mortality and morbidity caused by it. However, healthcare practitioners should be aware of the possible association between COVID-19 vaccination and herpes zoster. Appropriate explanation and safety advice on the possible adverse events following COVID-19 vaccination, including herpes zoster infection, should be given to patients. This will facilitate early recognition and treatment of this condition.

Kinetics of the serological response up to one year after tularemia

Serological analysis is the predominant method used to diagnose tularemia, a zoonotic disease caused by the highly virulent bacterium F. tularensis. We determined F. tularensis-specific IgM and IgG antibody titers by an LPS-based ELISA assay on five occasions one to twelve months after onset of ulceroglandular tularemia in 19 individuals. Peak IgM antibody titers were observed at the one-month time point and peak IgG antibody titers at the two-month time point. Both IgG and IgM antibody levels declined linearly thereafter with rather similar kinetics. Compared to the average one-month antibody titers, average IgG titers were not significantly lower before the 12-month time point and IgM titers before the 4-month time point. All, but one average titer, were significantly increased compared to the cut-off of the assay. Average IgG and IgM titers were significantly lower for the group = 69 years old compared to the group < 69 years. Collectively, the data demonstrate a persistence of F. tularensis-specific IgM and IgG antibody titers for at least 12 months after ulceroglandular tularemia. Thus, low, but significantly elevated F. tularensis-specific antibody titers are of limited diagnostic value since they are not indicative of ongoing tularemia.

The Aging Human Liver: The Weal and Woe of Evolutionary Legacy

Aging is characterized by the progressive decline of biological integrity and its compensatory mechanisms as well as immunological dysregulation. This goes along with an increasing risk of frailty and disease. Against this background, we here specifically focus on the aging of the human liver. For the first time, we shed light on the intertwining evolutionary underpinnings of the liver's declining regenerative capacity, the phenomenon of inflammaging, and the biotransformation capacity in the process of aging. In addition, we discuss how aging influences the risk for developing nonalcoholic fatty liver disease, hepatocellular carcinoma, and/or autoimmune hepatitis, and we describe chronic diseases as accelerators of biological aging.

Combined plasma levels of IL-10 and testosterone, but not soluble HLA-G5, predict the risk of death in COVID-19 patients

BACKGROUND

The identification of biomarkers correlated with coronavirus disease 2019 (COVID-19) outcomes is a relevant need for clinical management. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by elevated interleukin (IL)-6, IL-10, HLA-G, and impaired testosterone production.

OBJECTIVES

We aimed at defining the combined impact of sex hormones, interleukin-10, and HLA-G on COVID-19 pathophysiology and their relationship in male patients.

MATERIALS AND METHODS

We measured by chemiluminescence immunoassay, electrochemiluminescent assays, and enzyme-linked immunosorbent assay circulating total testosterone, 17β-estradiol (E₂ ), IL-10, and -HLAG5 as well as SARS-CoV-2 S1/S2 Immunoglobulin G from 292 healthy controls and 111 COVID-19 patients with different disease severity at hospital admission, and in 53 COVID-19 patients at 7-month follow-up.

RESULTS AND DISCUSSION

We found significantly higher levels of IL-10, HLA-G, and E₂ in COVID-19 patients compared to healthy controls and an inverse correlation between IL-10 and testosterone, with IL-10, progressively increasing and testosterone progressively decreasing with disease severity. This correlation was lost at the 7-month follow-up. The risk of death in COVID-19 patients with low testosterone increased in the presence of high IL-10. A negative correlation between SARS-CoV-2 Immunoglobulin G and HLA-G or IL-10 at hospitalization was observed. At the 7-month follow-up, IL-10 and testosterone normalized, and  HLA-G decreased.

CONCLUSION

Our findings indicate that combined evaluation of IL-10 and testosterone predicts the risk of death in men with COVID-19 and support the hypothesis that IL-10 fails to suppress excessive inflammation by promoting viral spreading.

Signs of immunosenescence correlate with poor outcome of mRNA COVID-19 vaccination in older adults

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is effective in preventing COVID-19 hospitalization and fatal outcome. However, several studies indicated that there is reduced vaccine effectiveness among older individuals, which is correlated with their general health status^1,2. How and to what extent age-related immunological defects are responsible for the suboptimal vaccine responses observed in older individuals receiving SARS-CoV-2 messenger RNA vaccine, is unclear and not fully investigated^1,3-5. In this observational study, we investigated adaptive immune responses in adults of various ages (22-99 years old) receiving 2 doses of the BNT162b2 mRNA vaccine. Vaccine-induced Spike-specific antibody, and T and memory B cell responses decreased with increasing age. These responses positively correlated with the percentages of peripheral naïve CD4⁺ and CD8⁺ T cells and negatively with CD8⁺ T cells expressing signs of immunosenescence. Older adults displayed a preferred T cell response to the S2 region of the Spike protein, which is relatively conserved and a target for cross-reactive T cells induced by human 'common cold' coronaviruses. Memory T cell responses to influenza virus were not affected by age-related changes, nor the SARS-CoV-2-specific response induced by infection. Collectively, we identified signs of immunosenescence correlating with the outcome of vaccination against a new viral antigen to which older adults are immunologically naïve. This knowledge is important for the management of COVID-19 infections in older adults.

The Th1/Tfh-like biased responses elicited by the rASP-1 innate adjuvant are dependent on TRIF and Type I IFN receptor pathways

Ov-ASP-1 (rASP-1), a parasite-derived protein secreted by the helminth Onchocerca volvulus, is an adjuvant which enhances the potency of the influenza trivalent vaccine (IIV3), even when used with 40-fold less IIV3. This study is aimed to provide a deeper insight into the molecular networks that underline the adjuvanticity of rASP-1. Here we show that rASP-1 stimulates mouse CD11c+ bone marrow-derived dendritic (BMDCs) to secrete elevated levels of IL-12p40, TNF-α, IP-10 and IFN-β in a TRIF-dependent but MyD88-independent manner. rASP-1-activated BMDCs promoted the differentiation of naïve CD4+ T cells into Th1 cells (IFN-γ+) that was TRIF- and type I interferon receptor (IFNAR)-dependent, and into Tfh-like cells (IL21+) and Tfh1 (IFN-γ+ IL21+) that were TRIF-, MyD88- and IFNAR-dependent. rASP-1-activated BMDCs promoted the differentiation of naïve CD4+ T cells into Th17 (IL-17+) cells only when the MyD88 pathway was inhibited. Importantly, rASP-1-activated human blood cDCs expressed upregulated genes that are associated with DC maturation, type I IFN and type II IFN signaling, as well as TLR4-TRIF dependent signaling. These activated cDCs promoted the differentiation of naïve human CD4+ T cells into Th1, Tfh-like and Th17 cells. Our data thus confirms that the rASP-1 is a potent innate adjuvant that polarizes the adaptive T cell responses to Th1/Tfh1 in both mouse and human DCs. Notably, the rASP-1-adjuvanted IIV3 vaccine elicited protection of mice from a lethal H1N1 infection that is also dependent on the TLR4-TRIF axis and IFNAR signaling pathway, as well as on its ability to induce anti-IIV3 antibody production.

How Can We Improve Vaccination Response in Old People? Part I: Targeting Immunosenescence of Innate Immunity Cells

Vaccination, being able to prevent millions of cases of infectious diseases around the world every year, is the most effective medical intervention ever introduced. However, immunosenescence makes vaccines less effective in providing protection to older people. Although most studies explain that this is mainly due to the immunosenescence of T and B cells, the immunosenescence of innate immunity can also be a significant contributing factor. Alterations in function, number, subset, and distribution of blood neutrophils, monocytes, and natural killer and dendritic cells are detected in aging, thus potentially reducing the efficacy of vaccines in older individuals. In this paper, we focus on the immunosenescence of the innate blood immune cells. We discuss possible strategies to counteract the immunosenescence of innate immunity in order to improve the response to vaccination. In particular, we focus on advances in understanding the role and the development of new adjuvants, such as TLR agonists, considered a promising strategy to increase vaccination efficiency in older individuals.

Effects of Acupuncture Combined with Exercise on Expression of Immune Factors in Aging Rats and Its Significance in Antiaging Intervention

Background

With the improvement of people's living standards, how to maintain health and delay aging to improve the quality of life and achieve longevity has become a hot topic of concern. objective. To investigate the effect of acupuncture combined with exercise on the expression of immune factors in aging rats and its significance in antiaging intervention.

Materials and Methods

Forty-three SD rats included 12 rats in the control group, and the remaining rats were injected intraperitoneally with D-galactose 500 mg/kg to prepare a subacute aging rat model. The 24 rats that were successfully modeled were divided into acupuncture exercise groups and exercise groups according to the random number table method, with 12 rats in each group. After the modeling, the comparison group did not do any intervention, the exercise group was given aerobic exercise intervention, and the acupuncture exercise group was given acupuncture combined with exercise intervention. The effect of immune factor expression in rats was compared.

Results

The levels of IgM, IgA, and IgG in the acupuncture exercise group were significantly higher than those in the exercise group (P < 0.05). The IL-10 content in the acupuncture exercise group was significantly higher than that in the exercise group (P < 0.05) and was significantly reduced in the acupuncture exercise group compared with the comparison group (P < 0.05). The level of IL-6 in the acupuncture exercise group was significantly lower than that in the exercise group, and the level of IL-6 in the acupuncture exercise group was significantly increased compared with the comparison group (P < 0.05). The C3 and C4 levels in the acupuncture exercise group were significantly higher than those in the exercise group (P < 0.05). The levels of IFN-γ and TNP-α were significantly lower in the acupuncture exercise group than in the exercise group and significantly increased in the acupuncture exercise group compared with the comparison group (P < 0.05).

Conclusion

Ling turtle eight method acupuncture combined with exercise promoted the development of immune organ spleen, enhances the body's immune function and complement system, inhibits the immune inflammatory response and regulates immune balance, reduces the inflammatory response caused by the aging of D-type galactose, and achieves the effect of delaying aging.

An immunologist's guide to immunosenescence and its treatment

INTRODUCTION

: The ageing process causes several changes in the immune system, although immune ageing is strongly influenced by individual immunological history, as well as genetic and environmental factors leading to inter-individual variability.

AREAS COVERED

: Here, we focused on the biological and clinical meaning of immunosenescence. Data on SARS-CoV-2 and Yellow Fever vaccine have demonstrated the clinical relevance of immunosenescence, while inconsistent results, obtained from longitudinal studies aimed at looking for immune risk phenotypes, have revealed that the immunosenescence process is highly context-dependent. Large projects have allowed the delineation of the drivers of immune system variance, including genetic and environmental factors, sex, smoking, and co-habitation. Therefore, it is difficult to identify the interventions that can be envisaged to maintain or improve immune function in older people. That suggests that drug treatment of immunosenescence should require personalized intervention. Regarding this, we discussed the role of changes in lifestyle as a potential therapeutic approach.

EXPERT OPINION

: Our review points out that age is only part of the problem of immunosenescence. Everyone ages differently because he/she is unique in genetics and experience of life and this applies even more to the immune system (immunobiography). Finally, the present review shows how appreciable results in the modification of immunosenescence biomarkers can be achieved with lifestyle modification.

Dynamic organization of the bone marrow plasma cell niche

Prophylactic, serological memory relies on maintaining stable reservoirs of plasma cells, capable of constitutively-secreting high-affinity, anti-pathogen antibody for a lifetime. Although antibody titers generated by some vaccines (e.g. measles) can last a lifetime, other vaccinations (e.g. tetanus) need repeated boosting because long-lived plasma cells are not produced or maintained. Moreover, in old age, the ability to generate long-lived humoral responses diminishes. Despite their importance to health, it is unknown how long-lived plasma cells survive over years, whereas most antibody secreting cells die off within weeks after vaccination. In this review, we focus on how known factors regulate the longevity of plasma cell fitness and survival, and how that landscape is shaped by environmental influences, such as inflammation, infection and aging. In addition, we highlight newly discovered cellular dynamics in the bone marrow that may reframe the mechanisms supporting long-lived plasma cell survival and function.

A diminished immune response underlies age-related SARS-CoV-2 pathologies

Morbidity and mortality in response to SARS-CoV-2 infection are significantly elevated in people of advanced age. To understand the underlying biology of this phenotype, we utilize the golden hamster model to compare how the innate and adaptive immune responses to SARS-CoV-2 infection differed between younger and older animals. We find that while both hamster cohorts showed similar virus kinetics in the lungs, the host response in older animals was dampened, with diminished tissue repair in the respiratory tract post-infection. Characterization of the adaptive immune response also revealed age-related differences, including fewer germinal center B cells in older hamsters, resulting in reduced potency of neutralizing antibodies. Moreover, older animals demonstrate elevated suppressor T cells and neutrophils in the respiratory tract, correlating with an increase in TGF-β and IL-17 induction. Together, these data support that diminished immunity is one of the underlying causes of age-related morbidity.

Immunosenescence and Altered Vaccine Efficiency in Older Subjects: A Myth Difficult to Change

Organismal ageing is associated with many physiological changes, including differences in the immune system of most animals. These differences are often considered to be a key cause of age-associated diseases as well as decreased vaccine responses in humans. The most often cited vaccine failure is seasonal influenza, but, while it is usually the case that the efficiency of this vaccine is lower in older than younger adults, this is not always true, and the reasons for the differential responses are manifold. Undoubtedly, changes in the innate and adaptive immune response with ageing are associated with failure to respond to the influenza vaccine, but the cause is unclear. Moreover, recent advances in vaccine formulations and adjuvants, as well as in our understanding of immune changes with ageing, have contributed to the development of vaccines, such as those against herpes zoster and SARS-CoV-2, that can protect against serious disease in older adults just as well as in younger people. In the present article, we discuss the reasons why it is a myth that vaccines inevitably protect less well in older individuals, and that vaccines represent one of the most powerful means to protect the health and ensure the quality of life of older adults.