Preparing for the Next Pandemic - The WHO's Global Influenza Strategy

Screening of Small-Molecule Libraries Using SARS-CoV-2-Derived Sequences Identifies Novel Furin Inhibitors

SARS-CoV-2 is the pathogen responsible for the most recent global pandemic, which has claimed hundreds of thousands of victims worldwide. Despite remarkable efforts to develop an effective vaccine, concerns have been raised about the actual protection against novel variants. Thus, researchers are eager to identify alternative strategies to fight against this pathogen. Like other opportunistic entities, a key step in the SARS-CoV-2 lifecycle is the maturation of the envelope glycoprotein at the RARR685↓ motif by the cellular enzyme Furin. Inhibition of this cleavage greatly affects viral propagation, thus representing an ideal drug target to contain infection. Importantly, no Furin-escape variants have ever been detected, suggesting that the pathogen cannot replace this protease by any means. Here, we designed a novel fluorogenic SARS-CoV-2-derived substrate to screen commercially available and custom-made libraries of small molecules for the identification of new Furin inhibitors. We found that a peptide substrate mimicking the cleavage site of the envelope glycoprotein of the Omicron variant (QTQTKSHRRAR-AMC) is a superior tool for screening Furin activity when compared to the commercially available Pyr-RTKR-AMC substrate. Using this setting, we identified promising novel compounds able to modulate Furin activity in vitro and suitable for interfering with SARS-CoV-2 maturation. In particular, we showed that 3-((5-((5-bromothiophen-2-yl)methylene)-4-oxo-4,5 dihydrothiazol-2-yl)(3-chloro-4-methylphenyl)amino)propanoic acid (P3, IC50 = 35 μM) may represent an attractive chemical scaffold for the development of more effective antiviral drugs via a mechanism of action that possibly implies the targeting of Furin secondary sites (exosites) rather than its canonical catalytic pocket. Overall, a SARS-CoV-2-derived peptide was investigated as a new substrate for in vitro high-throughput screening (HTS) of Furin inhibitors and allowed the identification of compound P3 as a promising hit with an innovative chemical scaffold. Given the key role of Furin in infection and the lack of any Food and Drug Administration (FDA)-approved Furin inhibitor, P3 represents an interesting antiviral candidate.

Novel Influenza Vaccines: From Research and Development (R&D) Challenges to Regulatory Responses

Influenza vaccines faced significant challenges in achieving sufficient protective efficacy and production efficiency in the past. In recent decades, novel influenza vaccines, characterized by efficient and scalable production, advanced platforms, and new adjuvant technologies, have overcome some of these weaknesses and have been widely licensed. Furthermore, researchers are actively pursuing the development of next-generation and universal influenza vaccines to provide comprehensive protection against potential pandemic subtypes or strains. However, new challenges have emerged as these novel vaccines undergo evaluation and authorization. In this review, we primarily outline the critical challenges and advancements in research and development (R&D) and highlight the improvements in regulatory responses for influenza vaccines.

Qingfei Jiedu Granules fight influenza by regulating inflammation, immunity, metabolism, and gut microbiota

Background and aim

Qingfei Jiedu Granules (QFJD) are a new Traditional Chinese Medicine (TCM) which has been clinically used against coronavirus pneumonia in China. In this study, the therapeutic effect and the underlying mechanisms of QFJD against influenza were investigated.

Experimental procedure

Pneumonia mice were induced by influenza A virus. Survival rate, weight loss, lung index and lung pathology were measured to evaluate the therapeutic effect of QFJD. The expression of inflammatory factors and lymphocytes was used to assess anti-inflammatory and immunomodulatory effect of QFJD. Gut microbiome analysis was performed to decipher the potential effect of QFJD on intestinal microbiota. Metabolomics approach was conducted to explore the overall metabolic regulation of QFJD.

Result and conclusion

QFJD shows a significant therapeutic effect on the treatment of influenza and the expression of many pro-inflammatory cytokines were obviously inhibited. QFJD also markedly modulates the level of T and B lymphocytes. The high-dose QFJD has shown similar therapeutic efficiency compared to positive drugs. QFJD profoundly enriched Verrucomicrobia and maintained the balance between Bacteroides and Firmicutes. QFJD associated with 12 signaling pathways in metabolomics study, 9 of which were the same as the model group and were closely related to citrate cycle and amino acid metabolism.To sum up, QFJD is a novel and promising drug against influenza. It can regulate inflammation, immunity, metabolism, and gut microbiota to fight influenza. Verrucomicrobia shows great potential to improve influenza infection and may be an important target.

Popper's Critical Rationalism as a Response to the Problem of Induction: Predictive Reasoning in the Early Stages of the Covid-19 Epidemic

The extent of harm and suffering caused by the coronavirus pandemic has prompted a debate about whether the epidemic could have been contained, had the gravity of the crisis been predicted earlier. In this paper, the philosophical debate on predictive reasoning is framed by Hume's problem of induction. Hume argued that it is rationally unjustified to move from the finite observations of past incidences to the predictions of future events. Philosophy has offered two major responses to the problem of induction: the pragmatic induction of Peirce and the critical rationalism of Popper. It is argued that of these two, Popper's critical rationalism provides a more potent tool for preparing for unanticipated events such as the Covid-19 pandemic. Popper's notion of risky predictions equips strategic foresight with clear hypotheticals regarding potential crisis scenarios. Peirce's pragmatic induction, instead, leans on probabilities that are slower to be amended as unexpected events start unfolding. The difference between the two approaches is demonstrated through a case study of the patterns of reasoning within the World Health Organization in the early stages of the coronavirus pandemic.

Supplementary information

The online version contains supplementary material available at 10.1007/s40926-022-00203-6.

Preventive Measures against COVID-19 in Small- and Mid-sized Enterprises from an Early Stage of the Epidemic in Daegu and Gyeongsangbuk-do

Background

In the early stage of the coronavirus disease 2019 (COVID-19) epidemic, small- and mid-sized enterprises (SMEs) may be an important transmission consideration. The study aimed to identify the pattern of COVID-19 prevention measures during the outbreaks in Daegu and Gyeongsangbuk-do at the early stage of COVID-19. Moreover, we investigated whether SME size and past experiences affected the preventive measures implemented in the region.

Methods

A survey detailing the general characteristics and implementation of 12 preventive activities was conducted in 122 SMEs in Daegu and Gyeongsangbuk-do. The survey was analyzed by size and operation period.

Results

The study subjects consisted of 53 (43.4%) workplaces with 1–5 employees, 50 (40.9%) workplaces with 6–30 employees, and 19 (15.6%) workplaces with 31–49 employees. The lowest three items among those surveyed were ‘symptomatic workers to stay home for 3–4 days’ (17.2%), ‘work remotely’ (18.9%), and ‘video meetings’ (20.5%). There were significant differences in the rate of several preventive measures implemented. The larger sized SMEs, the higher the number of implementations (p < 0.01). The operation period had no significant relationship with the implementation of preventive measures. The same pattern was observed in multiple generalized linear regression with covariate adjustment.

Conclusion

Preventive measures among SMEs with fewer than 50 employees were identified. Even within SMEs, a gap in preventive measures according to size was confirmed. To prevent the spread of infection and protect workers' right to health, different support for different sized SMEs is necessary.

Cangma Huadu granules, a new drug with great potential to treat coronavirus and influenza infections, exert its efficacy through anti-inflammatory and immune regulation

ETHNOPHARMACOLOGICAL RELEVANCE

Coronavirus and influenza virus infection seriously threaten human health. Cangma Huadu Granules (CMHD) is an in-hospital preparation composed of eight traditional Chinese medicines (TCM), which has been clinically used against COVID-19 in China and may be a promising candidate for the treatment of influenza. However, the role of its treatment urgently needs to be studied.

AIM OF THE STUDY

To evaluate the therapeutic effects of CMHD on pneumonia induced by coronavirus (HCoV-229E) and influenza A virus (H1N1/FM1) in mice and explore its mechanism of anti-infection.

MATERIALS AND METHODS

Mice were infected with HCoV-229E or H1N1/FM1 virus through the nasal cavity. CMHD (12.1, 6.05 and 3.03 g/kg/d) or the positive control drugs were administered intragastrically. The lung index and histopathological changes were used to evaluate the therapeutic effect of CMHD. The expression of TNF-α, IL-1β, IL-6 and IL-4 in Serum and the proportion of CD4+ and CD8+ T lymphocytes in peripheral blood were detected to evaluate the anti-inflammatory and immune regulation effects of CMHD, respectively. Furthermore, the levels of p-NF-κBp65/ NF-κB p65, which was the key targets of the NF-κB pathway was analyzed.

RESULTS

In HCoV-229E-induced pneumonia, the lung index was markedly reduced, and lung pathology was improved in mice that treated with CMHD (12.1, 6.05 g/kg/d). Meanwhile, the expression of TNF-α, IL-6 were obviously inhibited, but the expression of IL-4 was significantly increased in CMHD groups. Compared with the model group, CMHD could also markedly upregulate the level of CD4+ and CD8+. Furthermore, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung. In H1N1-induced pneumonia, the lung index of mice in the CMHD (12.1 g/kg/d) treatment group was lower than that in the model group, and less inflammatory infiltration could be seen in the lung pathological. Moreover, CMHD could also obviously decrease the expression of TNF-α, IL-1β, IL-6, but significantly increase the expression of IL-4. Except for that, CMHD could also markedly downregulate the level of CD4+ and upregulate the level of CD8+ compared with the model group. In addition, CMHD has a markedly effect on inhibit the expression of p-NF-κB p65/NF-κB p65 in the lung.

CONCLUSION

CMHD can significantly combats viral infections caused by HCoV-229E and H1N1, and the mechanism may be related to its multiple functions of anti-inflammatory, immunity regulating and inhibiting NF-κB signal transduction pathway.

Using Non-Pharmaceutical Interventions and High Isolation of Asymptomatic Carriers to Contain the Spread of SARS-CoV-2 in Nursing Homes

More than 40% of the deaths recorded in the first wave of the SARS-CoV-2 pandemic were linked to nursing homes. Not only are the residents of long-term care facilities (LTCFs) typically older and more susceptible to endemic infections, the facilities' high degree of connection to wider communities makes them especially vulnerable to local COVID-19 outbreaks. In 2008, in the wake of the SARS-CoV-1 and MERS epidemics and anticipating an influenza pandemic, we created a stochastic compartmental model to evaluate the deployment of non-pharmaceutical interventions (NPIs) in LTCFs during influenza epidemics. In that model, the most effective NPI by far was a staff schedule consisting of 5-day duty periods with onsite residence, followed by an 4-to-5 day off-duty period with a 3-day quarantine period just prior to the return to work. Unlike influenza, COVID-19 appears to have significant rates of pre-symptomatic transmission. In this study, we modified our prior modeling framework to include new parameters and a set of NPIs to identify and control the degree of pre-symptomatic transmission. We found that infections, deaths, hospitalizations, and ICU utilization were projected to be high and largely irreducible, even with rigorous application of all defined NPIs, unless pre-symptomatic carriers can be identified and isolated at high rates. We found that increasingly rigorous application of NPIs is likely to significantly decrease the peak of infections; but even with complete isolation of symptomatic persons, and a 50% reduction in silent transmission, the attack rate is projected to be nearly 95%.

Advanced Point-of-Care Testing Technologies for Human Acute Respiratory Virus Detection

The ever-growing global threats to human life caused by the human acute respiratory virus (RV) infections have cost billions of lives, created a significant economic burden, and shaped society for centuries. The timely response to emerging RVs could save human lives and reduce the medical care burden. The development of RV detection technologies is essential for potentially preventing RV pandemic and epidemics. However, commonly used detection technologies lack sensitivity, specificity, and speed, thus often failing to provide the rapid turnaround times. To address this problem, new technologies are devised to address the performance inadequacies of the traditional methods. These emerging technologies offer improvements in convenience, speed, flexibility, and portability of point-of-care test (POCT). Herein, recent developments in POCT are comprehensively reviewed for eight typical acute respiratory viruses. This review discusses the challenges and opportunities of various recognition and detection strategies and discusses these according to their detection principles, including nucleic acid amplification, optical POCT, electrochemistry, lateral flow assays, microfluidics, enzyme-linked immunosorbent assays, and microarrays. The importance of limits of detection, throughput, portability, and specificity when testing clinical samples in resource-limited settings is emphasized. Finally, the evaluation of commercial POCT kits for both essential RV diagnosis and clinical-oriented practices is included.

The future of zoonotic risk prediction

In the light of the urgency raised by the COVID-19 pandemic, global investment in wildlife virology is likely to increase, and new surveillance programmes will identify hundreds of novel viruses that might someday pose a threat to humans. To support the extensive task of laboratory characterization, scientists may increasingly rely on data-driven rubrics or machine learning models that learn from known zoonoses to identify which animal pathogens could someday pose a threat to global health. We synthesize the findings of an interdisciplinary workshop on zoonotic risk technologies to answer the following questions. What are the prerequisites, in terms of open data, equity and interdisciplinary collaboration, to the development and application of those tools? What effect could the technology have on global health? Who would control that technology, who would have access to it and who would benefit from it? Would it improve pandemic prevention? Could it create new challenges? This article is part of the theme issue 'Infectious disease macroecology: parasite diversity and dynamics across the globe'.

Association between supportive attitude and adoptive practice of control strategy against COVID-19 amosng college students in China: a cross-sectional study

Background

We investigated college students’ attitude and compliance towards a prevention strategy involving use of non-pharmaceutical interventions (NPIs) against coronavirus disease 2019 (COVID-19).

Methods

We conducted a cross-sectional online survey in four universities in Guangdong Province (China) based on purposive sampling. A self-administered questionnaire was given to College students (CSs) to measure the supportive attitude towards an outbreak control strategy and adoption of NPIs in respondents.

Results

A total of 44,446 CSs participated between 31 January and 10 February 2020; 92.7% of respondents supported the outbreak control strategy. The proportion of respondents who avoided public places, wore a facemask, avoid gatherings, and washed hands more frequently than usual was 94.8, 92.8, 91.2 and 86.9%. respectively. A total of 76.5% respondents adopted all four measures. A supportive attitude was associated with NPI adoption. Students who were female, postgraduate, anxious, and not depressed tended to have a higher supportive attitude and higher chance of NPI adoption.

Conclusions

Higher supportiveness towards the disease control strategy for the Chinese public may lead to higher adoption rate of NPIs. Psychosocial factors were related to a supportive attitude and adoption of the NPI. We believe that our findings could aid policymakers to create NPIs to prevent and control emerging infectious diseases such as COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10752-6.

Attenuating the Effects of Novel COVID-19 (SARS-CoV-2) Infection-Induced Cytokine Storm and the Implications

The COVID-19 pandemic constitutes an arduous global health challenge, and the increasing number of fatalities calls for the speedy pursuit of a remedy. This review emphasizes the changing aspects of the COVID-19 disease, featuring the cytokine storm's pathological processes. Furthermore, we briefly reviewed potential therapeutic agents that may modulate and alleviate cytokine storms. The literature exploration was made using PubMed, Embase, MEDLINE, Google scholar, and China National Knowledge Infrastructure databases to retrieve the most recent literature on the etiology, diagnostic markers, and the possible prophylactic and therapeutic options for the management of cytokine storm in patients hospitalized with COVID-19 disease. The causative agent, severe acute respiratory coronavirus-2 (SARS-CoV-2), continually threatens the efficiency of the immune system of the infected individuals. As the first responder, the innate immune system provides primary protection against COVID-19, affecting the disease's progression, clinical outcome, and prognosis. Evidence suggests that the fatalities associated with COVID-19 are primarily due to hyper-inflammation and an aberrant immune function. Accordingly, the magnitude of the release of pro-inflammatory cytokines such as interleukin (IL)-1, (IL-6), and tumor necrosis alpha (TNF-α) significantly differentiate between mild and severe cases of COVID-19. The early prediction of a cytokine storm is made possible by several serum chemistry and hematological markers. The prompt use of these markers for diagnosis and the aggressive prevention and management of a cytokine release syndrome is critical in determining the level of morbidity and fatality associated with COVID-19. The prophylaxis and the rapid treatment of cytokine storm by clinicians will significantly enhance the fight against the dreaded COVID-19 disease.

Relation between Cardiac Injury and Elevated Levels of Inflammatory Biomarkers in Patients with Severe COVID-19

Background: Since early December 2019, coronavirus disease 2019 (COVID-19) has emerged as a global pandemic and public health crisis. This study aims to explore the relationship between cardiac injury and inflammatory biomarkers in patients with severe COVID-19.Methods: We collected data on 91 patients with a confirmed diagnosis of severe COVID-19 from February 8 to March 31, 2020. Demographic characteristics, clinical data, and in-hospital outcomes were compared. The relationship between cardiac injury and inflammatory biomarkers was analyzed. Logistic regression was used to explore the independent risk factors for cardiac injury.Results: The mean age of all patients was 61 years±14 years. About half of the patients were male. Hypertension and coronary heart disease were more common in the cardiac injury group. The levels of inflammatory biomarkers in patients who experienced cardiac injury were generally higher than the levels of those without cardiac injury, including interleukin-6, interleukin-2 receptor (IL-2R), procalcitonin, and high-sensitivity C-reactive protein. There were positive correlations between the levels of high-sensitivity troponin I and N-terminal prohormone of brain natriuretic peptide and the levels of inflammatory biomarkers. Logistic regression shows that IL-2R (odds ratio 1.001, 95% confidence interval 1.000‐1.002, P=0.045) and comorbidities (odds ratio 4.909, 95% confidence interval 1.231‐19.579, P=0.024) are independent risk factors for cardiac injury in patients with severe COVID-19.Conclusion: High levels of inflammatory biomarkers are associated with higher risk of cardiac injury in patients with severe COVID-19. IL-2R and comorbidities are predictors of cardiac injury.

Non-pharmaceutical interventions used for COVID-19 had a major impact on reducing influenza in China in 2020

Stringent non-pharmaceutical measures to contain the COVID-19 outbreak in China also significantly reduced the spread of influenza in the winter season 2020.

Clinical Features and Risk Factors for Mortality in Children With Acute Encephalitis Who Present to the Emergency Department

Acute encephalitis is an important pediatric emergency that tends to be associated with neurological morbidity, critical illness, and mortality. Few data have specifically focused on evaluating various early clinical parameters in the pediatric emergency department as candidate predictors of mortality. The present retrospective study assessed the clinical, laboratory, and neuroimaging findings of children with acute encephalitis who presented to the emergency department. Of 158 patients diagnosed with encephalitis, 7 (4.4%) had mortality. Compared to the survivors, a multivariate analysis revealed that an initial Glasgow Coma Scale score ≤ 5 (odds ratio [OR]: 8.3, P = .022), acute necrotizing encephalitis (OR: 12.1, P = .01), white blood count level ≤ 5.2 × 10⁹ cells/L (OR: 28.7, P < .001), aspartate aminotransferase level > 35 U/L (OR: 14.3, P = .022), and influenza A infection (OR: 7.7, P = .027) were significantly associated with mortality. These results indicate that the early recognition of preliminary clinical features and the development of more specific etiologies for encephalitis are important for early treatment strategies.

The effects of COVID-19 on Physical Medicine and Rehabilitation in Turkey in the first month of pandemic

Objectives

The outbreak of novel coronavirus-2019 (COVID-19) has affected Turkey very seriously, as well as all around the world. Many urgent and radical measures were taken due to the high contagious risk and mortality rate of the outbreak. It is noteworthy that isolation recommendations and the provision of health services for pandemic have a negative impact on Physical Medicine and Rehabilitation (PMR) services. In this study, we aimed to evaluate the effects of COVID-19 on the PMR services and physiatrists immediately after the first month of pandemic in Turkey.

Patients and methods

An online survey consisting of 45 items was sent to the members of the Turkish Society of Physical Medicine and Rehabilitation. The main goal of the survey was to evaluate the changes in the provided service of PMR and conditions of physiatrists one month after the first reported COVID-19 case in Turkey.

Results

A total of 606 PMR specialists and residents responded to the survey. The mean number of the patients visited the outpatient clinics was 148.2±128.5 per week before the pandemic, it significantly decreased to 23.4±33.1 per week after the first month of the reported first COVID-19 case. Similarly, the mean number of the patients of inpatient service significantly decreased from 21.7±39.3 per week to 2.5±10.0 per week after the first month of the pandemic. Most of the residents (69%) reported that their training was seriously affected due to pandemic. From the economic aspect, 69.2% of the participants who were working at private hospitals reported a decrease in their monthly salary, and 21% of them were sent to an unpaid vacation. A total of 21.9% of private-practice institutions paused their services. During the first month, 46.9% of the participants were assigned to the different services such as COVID-19 inpatient service, emergency or COVID-19 outpatient clinics. According to the Republic of Turkey, Ministry of Health guideline and algorithm, 15.7% of the physicians were in the category of healthcare workers with suspected COVID-19.

Conclusion

The COVID-19 pandemic affected seriously both the services and the PMR physicians as early as the first month. This effect is expected to become worse, when the duration of pandemic prolongs. Proper arrangements and measures should be planned to ameliorate the negative effects of the pandemic on the patients and PMR physicians.

Coordinated responses of academic medical centres to pandemics: Sustaining medical education during COVID-19

Background: The Corona Virus Disease-19 (COVID-19) has been declared a pandemic by the World Health Organization (WHO). We state the consolidated and systematic approach for academic medical centres in response to the evolving pandemic outbreaks for sustaining medical education.Discussion: Academic medical centres need to establish a 'COVID-19 response team' in order to make time-sensitive decisions while managing pandemic threats. Major themes of medical education management include leveraging on remote or decentralised modes of medical education delivery, maintaining the integrity of formative and summative assessments while restructuring patient-contact components, and developing action plans for maintenance of essential activities based on pandemic risk alert levels. These core principles must be applied seamlessly across the various fraternities of academic centres: undergraduate education, residency training, continuous professional development and research. Key decisions from the pandemic response teams that help to minimise major disruptions in medical education and to control disease transmissions include: minimising inter-cluster cross contaminations and plans for segregation within and among cohorts; reshuffling academic calendars; postponing or restructuring assessments.Conclusions: While minimising the transmission of the pandemic outbreak within the healthcare establishments is paramount, medical education and research activities cannot come to a standstill each time there is a threat of one.

Covid-19: implications for prehospital, emergency and hospital care in patients with acute coronary syndromes

Hospitals play a critical role in providing communities with essential medical care during all types of disaster. Depending on their scope and nature, disasters can lead to a rapidly increasing service demand that can overwhelm the functional capacity and safety of hospitals and the healthcare system at large. Planning during the community outbreak of coronavirus disease 2019 (Covid-19) is critical for maintaining healthcare services during our response. This paper describes, besides general measures in times of a pandemic, also the necessary changes in the invasive diagnosis and treatment of patients presenting with different entities of acute coronary syndromes including structural adaptations (networks, spokes and hub centres) and therapeutic adjustments.

Influenza vaccination in early Alzheimer's disease rescues amyloidosis and ameliorates cognitive deficits in APP/PS1 mice by inhibiting regulatory T cells

Background

Alzheimer’s disease (AD) is a neurodegenerative disorder strongly correlated with a dysfunctional immune system. Our previous results demonstrated that inactivated influenza vaccine (IIV) facilitates hippocampal neurogenesis and blocks lipopolysaccharide (LPS)-induced cognitive impairment. However, whether IIV improves cognitive deficits in an AD mouse model remains unclear. In addition, early interventions in AD have been encouraged in recent years. Here, we investigated whether IIV immunization at the preclinical stage of AD alters the brain pathology and cognitive deficits in an APP/ PS1 mouse model.

Methods

We assessed spatial learning and memory using Morris water maze (MWM). The brain β-amyloid (Aβ) plaque burden and activated microglia were investigated by immunohistochemistry. Furthermore, flow cytometry was utilized to analyze the proportions of Treg cells in the spleen. A cytokine antibody array was performed to measure the alteration of cytokines in the brain and peripheral immune system.

Results

Five IIV immunizations activated microglia, reduced the Aβ burden and improved the cognitive impairment. Simultaneously, the IIV-induced immune response broke peripheral immunosuppression by reducing Foxp3⁺ regulatory T cell (Treg) activities, whereas the restoration of Treg level in the periphery using all-trans retinoic acid (ATRA) blunted the protective effects of IIV on Aβ burden and cognitive functions. Interestingly, IIV immunization might increase proinflammatory and anti-inflammatory cytokine expression in the brain of APP/PS1 mice, enhanced microglial activation, and enhanced the clustering and phagocytosis of Aβ, thereby creating new homeostasis in the disordered immune microenvironment.

Conclusions

Altogether, our results suggest that early multiple IIV immunizations exert a beneficial immunomodulatory effect in APP/PS1 mice by breaking Treg-mediated systemic immune tolerance, maintaining the activation of microglia and removing of Aβ plaques, eventually improving cognitive deficits.