COVID-19-like symptoms observed in Chinese tree shrews infected with SARS-CoV-2

Thecoronavirusdisease2019(COVID-19)pandemic continues to pose a global threat to the human population. Identifying animal species susceptible to infection with the SARS-CoV-2/HCoV-19 pathogen is essential for controlling the outbreak and for testing valid prophylactics or therapeutics based on animal model studies. Here,different aged Chinese tree shrews(adult group, 1 year old;old group, 5–6 years old), which are close relatives to primates, were infected with SARS-CoV-2. X-ray, viral shedding, laboratory, and histological analyses were performed on different days postinoculation(dpi). Results showed that Chinese tree shrews could be infected by SARS-CoV-2. Lung infiltrates were visible in X-ray radiographs in most infected animals. Viral RNA was consistently detected in lung tissues from infected animals at 3,5, and 7 dpi, along with alterations in related parameters from routine blood tests and serum biochemistry, including increased levels of aspartate aminotransferase(AST) and blood urea nitrogen(BUN). Histological analysis of lung tissues from animals at 3 dpi(adult group) and 7 dpi(old group) showed thickened alveolar septa and interstitial hemorrhage. Several differences were found between the two different aged groups in regard to viral shedding peak. Our results indicate that Chinese tree shrews have the potential to be used as animal models for SARS-CoV-2 infection.

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 SARSCoV-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.

Overexpression of Cdc25C predicts response to radiotherapy and survival in esophageal squamous cell carcinoma patients treated with radiotherapy followed by surgery

Biomarker identification is crucial for the selection of patients who might benefit from radiotherapy.To explore potential markers for response and prognosis in patients with locally advanced esophageal carcinoma treated with radiotherapy followed by surgery,we evaluated the expression of cell cycle checkpoint-related proteins Chk2,Cdc25C,and Cyclin D1.A total of 56 patients with locally advanced esophageal squamous cell carcinoma were treated with radiotherapy followed by surgery.Pretreatment tumor biopsy specimens were analyzed for Chk2,Cdc25C,and Cyclin D1 expression by immunohistochemistry.High expression of Chk2,Cyclin D1,and Cdc25C was observed in 44(78.6%),15(26.8%),and 27(48.2%) patients,respectively.The median survival was 16 months(range,3-154 months),with a 5-year overall survival rate of 19.6%.Overexpression of Chk2 was associated with smoking(P = 0.021),overexpression of Cdc25C was associated with patient age(P = 0.033) and tumor length(P = 0.001),and overexpression of Cdc25C was associated with pathologic complete response(P = 0.038).Univariate analysis demonstrated that overexpression of Cdc25C and pathologic complete response was associated with better survival.In multivariate analysis,Cdc25C was the most significant independent predictor of better survival(P = 0.014) for patients treated with radiotherapy followed by surgery.Overexpression of Cdc25C was significantly associated with pathologic complete response and better survival of patients with locally advanced esophageal cancer treated with radiotherapy followed by surgery.These results suggest that Cdc25C may be a biomarker of treatment response and good prognosis for esophageal carcinoma patients.Thus,immunohistochemical staining of Cdc25C in a pretreatment specimen may be a useful method of identifying optimal treatment for patients with esophageal carcinoma.

Northern pig-tailed macaques(Macaca leonina)infected with SARS-CoV-2 show rapid viral clearance and persistent immune response

Coronavirus disease 2019(COVID-19),which is caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2),has become an unprecedented global health emergency.At present,SARS-CoV-2-infected nonhuman primates are considered the gold standard animal model for COVID-19 research.Here,we showed that northern pig-tailed macaques(Macaca leonina,NPMs)supported SARS-CoV-2 replication.Furthermore,compared with rhesus macaques,NPMs showed rapid viral clearance in lung tissues,nose swabs,throat swabs,and rectal swabs,which may be due to higher expression of interferon(IFN)-αin lung tissue.However,the rapid viral clearance was not associated with good outcome.In the second week post infection,NPMs developed persistent or even more severe inflammation and body injury compared with rhesus macaques.These results suggest that viral clearance may have no relationship with COVID-19 progression and SARS-CoV-2-infected NPMs could be considered as a critically ill animal model in COVID-19 research.

Direct sunlight exposure reduces hair cortisol levels in rhesus monkeys(Macaca mulatta)

DEAR EDITOR,Major depressive disorder (MDD), commonly known as depression, is a mental disease characterized by a core symptom of low mood. It lasts at least two weeks (Badamasi et al., 2019;Wang et al., 2019) and is frequently accompanied by low self-esteem, loss of interest in routinely enjoyable activities, low energy, and unexplained pain (Huey et al., 2018;Park et al., 2012;Post & Warden, 2018;Rice et al., 2019;Xiao et al., 2018). Approximately 2%–8% of adults with MDD commit suicide (Richards & O'Hara, 2014;Strakowski & Nelson, 2015), and around half of suicidal individuals suffer depression or other mood disorders (Bachmann, 2018).

Lower respiratory tract samples are reliable for severe acute respiratory syndrome coronavirus 2 nucleic acid diagnosis and animal model study

Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2) and coronavirus disease 2019(COVID-19) continue to impact countries worldwide.At present, inadequate diagnosis and unreliable evaluation systems hinder the implementation and development of effective prevention and treatment strategies. Here, we conducted a horizontal and longitudinal study comparing the detection rates of SARS-Co V-2 nucleic acid in different types of samples collected from COVID-19 patients and SARS-Co V-2-infected monkeys. We also detected anti-SARS-Co V-2 antibodies in the above clinical and animal model samples to identify a reliable approach for the accurate diagnosis of SARS-Co V-2 infection. Results showed that, regardless of clinical symptoms, the highest detection levels of viral nucleic acid were found in sputum and tracheal brush samples, resulting in a high and stable diagnosis rate. Anti-SARS-Co V-2 immunoglobulin M(Ig M) and G(Ig G) antibodies were not detected in6.90% of COVID-19 patients. Furthermore,integration of nucleic acid detection results from the various sample types did not improve the diagnosis rate. Moreover, dynamic changes in SARS-Co V-2 viral load were more obvious in sputum and tracheal brushes than in nasal and throat swabs. Thus,SARS-Co V-2 nucleic acid detection in sputum and tracheal brushes was the least affected by infection route, disease progression, and individual differences. Therefore, SARS-Co V-2 nucleic acid detection using lower respiratory tract samples alone is reliable for COVID-19 diagnosis and study.

Emerging SARS-CoV-2 B.1.621/Mu variant is prominently resistant to inactivated vaccine-elicited antibodies

Although it first appeared almost two years ago,the COVID-19 pandemic continues to have an impact on a global scale,in part due to newly emerging SARS-CoV-2 variants such as Delta and Lambda.The B.1.621 variant,first identified in Colombia in January 2021,was classified as a variant of interest(VOI)and designated as Mu by the World Health Organization(WHO)in August 2021.However,its infectivity and resistance to neutralizing antibodies remain largely unknown.Here,in comparison to Delta,the Mu variant showed an unexpectedly enhanced immune resistance to inactivated vaccine-elicited antibodies.Nevertheless,Mu demonstrated less infectivity than Delta,implying a biological trade-off between viral transmission and immune escape.This study strongly calls for urgent evaluation of the protective efficacy of current COVID-19 vaccines against the Mu variant.Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are of concern regarding control of the global COVID-19 pandemic(Wang et al.,2021).The SARS-CoV-2 B.1.621 variant was first identified in Colombia in January 2021.Considering its epidemiological prevalence,the WHO defined B.1.621(named Mu)as a VOI on 30 August 2021.As of September 2021,the WHO has classified four variants of concern(VOC),i.e.,Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),and Delta(B.1.617.2),and two VOI,i.e.,Lambda(C.37)and Mu(B.1.621)(Supplementary Figure S1A).

Infectivity of SARS-CoV-2 and protection against reinfection in rats

DEAR EDITOR,The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) pandemic remains an important global public health issue. In this study, we unexpectedly found that wildtype Sprague-Dawley(SD) rats can be infected with the SARS-CoV-2 prototype. Our results showed direct experimental evidence of the infectivity of SARS-CoV-2 infection, subsequent pathogenicity, and protection against reinfection in rats.

Social rank and cortisol among female rhesus macaques(Macaca mulatta)

In animal societies,some stressful events can lead to higher levels of physiological stress.Such stressors,like social rank,also predict an increased vulnerability to an array of diseases.However,the physiological relationship between social rank and stress varies between different species,as well as within groups of a single species.For example,dominant individuals are more socially stressed at times,while at other times it is the subordinate ones who experience this stress.Together,these variations make it difficult to assess disease vulnerability as connected to social interactions.In order to learn more about how physiological rank relationships vary between groups of a single species,cortisol measurements from hair samples were used to evaluate the effects of dominance rank on long-term stress levels in despotic and less stringent female rhesus macaque hierarchal groups.In despotic groups,cortisol levels were found not to be correlated with social rank,but a negative correlation was found between social rank and cortisol levels in less stringent hierarchies.Low ranking monkeys in less stringent groups secreted elevated levels of cortisol compared to higher ranking animals.These data suggest that variations in the strictness of the dominance hierarchy are determining factors in rank related stress physiology.The further consideration of nonhuman primate social system diversity and the linear degree of their hierarchies may allow for the development of valid rank-related stress models that will help increase our understanding and guide the development of new therapeutics for diseases related to human socioeconomic status.

Social rank and cortisol among female rhesus macaques (Macaca mulatta)

In animal societies, some stressful events can lead to higher levels of physiological stress. Such stressors, like social rank, also predict an increased vulnerability to an array of diseases. However, the physiological relationship between social rank and stress varies between different species, as well as within groups of a single species. For example, dominant individuals are more socially stressed at times, while at other times it is the subordinate ones who experience this stress. Together, these variations make it difficult to assess disease vulnerability as connected to social interactions. In order to learn more about how physiological rank relationships vary between groups of a single species, cortisol measurements from hair samples were used to evaluate the effects of dominance rank on long-term stress levels in despotic and less stringent female rhesus macaque hierarchal groups. In despotic groups, cortisol levels were found not to be correlated with social rank, but a negative correlation was found between social rank and cortisol levels in less stringent hierarchies. Low ranking monkeys in less stringent groups secreted elevated levels of cortisol compared to higher ranking animals. These data suggest that variations in the strictness of the dominance hierarchy are determining factors in rank related stress physiology. The further consideration of nonhuman primate social system diversity and the linear degree of their hierarchies may allow for the development of valid rank-related stress models that will help increase our understanding and guide the development of new therapeutics for diseases related to human socioeconomic status.

HR121 targeting HR2 domain in S2 subunit of spike protein can serve as a broad-spectrum SARS-CoV-2 inhibitor via intranasal administration

The continuously emerging SARS-CoV-2 variants pose a great challenge to the efficacy of current drugs,this necessitates the development of broad-spectrum antiviral drugs.In the previous study,we designed a recombinant protein,heptad repeat(HR)121,as a variant-proof vaccine.Here,we found it can act as a fusion inhibitor and demonstrated broadly neutralizing activities against SARS-CoV-2 and its main variants.Structure analysis suggested that HR121 targets the HR2 domain in SARS-CoV-2 spike(S)2 subunit to block virus-cell fusion.Functional experiments demonstrated that HR121 can bind HR2 at serological-pH and endosomal-pH,highlighting its inhibition capacity when SARS-CoV-2 enters via either cellular membrane fusion or endosomal route.Importantly,HR121 can effectively inhibit SARS-CoV-2 and Omicron variant pseudoviruses entering the cells,as well as block authentic SARSCoV-2 and Omicron BA.2 replications in human pulmonary alveolar epithelial cells.After intranasal administration to Syrian golden hamsters,it can protect hamsters from SARS-CoV-2 and Omicron BA.2 infection.Together,our results suggest that HR121 is a potent drug candidate with broadly neutralizing activities against SARS-CoV-2 and its variants.

Preventive and therapeutic benefits of nelfinavir in rhesus macaques and human beings infected with SARS-CoV-2

Effective drugs with broad spectrum safety profile to all people are highly expected to combat COVID-19 caused by SARS-CoV-2.Here we report that nelfinavir,an FDA approved drug for the treatment of HIV infection,is effective against SARS-CoV-2 and COVID-19.Preincubation of nelfinavir could inhibit the activity of the main protease of the SARS-CoV-2(IC50=8.26μM),while its antiviral activity in Vero E6 cells against a clinical isolate of SARS-CoV-2 was determined to be 2.93μM(EC50).In comparison with vehicle-treated animals,rhesus macaque prophylactically treated with nelfinavir had significantly lower temperature and significantly reduced virus loads in the nasal and anal swabs of the animals.At necropsy,nelfinavir-treated animals had a significant reduction of the viral replication in the lungs by nearly three orders of magnitude.A prospective clinic study with 37 enrolled treatment-naive patients at Shanghai Public Health Clinical Center,which were randomized(1:1)to nelfinavir and control groups,showed that the nelfinavir treatment could shorten the duration of viral shedding by 5.5 days(9.0 vs.14.5 days,P=0.055)and the duration of fever time by 3.8 days(2.8 vs.6.6 days,P=0.014)in mild/moderate COVID-19 patients.The antiviral efficiency and clinical benefits in rhesus macaque model and in COVID-19 patients,together with its well-established good safety profile in almost all ages and during pregnancy,indicated that nelfinavir is a highly promising medication with the potential of preventative effect for the treatment of COVID-19.

agnetic Resonance Imaging Characteristics of Primary Central Nervous System T-cell Lymphoma

Primary central nervous system lymphomas （PCNSLs） are rare non-Hodgkin tumors defined as lymphomas of the central nervous system （CNS） without primary tumor elsewhere. It was reported that PCNSLs represented only 3-7% of primary brain tumors and 1-5% of all lymphomas. Most of PCNSLs are B-cell lymphomas, while T-cell PCNSL （T-PCNSL） is extremely rare, the majority of the reported T-PCNSL cases are clinically sporadic that focus on the treatment, and its imaging features have rarely been described. Herein, we report a case of T-PCNSL and comprehensively summarize its magnetic resonance imaging （MRI） characteristics. It is the first time in China to locus on the MRI diagnosis of T-PCNSL.

Characteristics of replication and pathogenicity of SARS-CoV-2 Alpha and Delta isolates

The continuously arising of SARS-CoV-2 variants has been posting a great threat to public health safety globally,from B.1.17(Alpha), B.1.351(Beta), P.1(Gamma), B.1.617.2(Delta) to B.1.1.529(Omicron). The emerging or reemerging of the SARS-CoV-2 variants of concern is calling for the constant monitoring of their epidemics,pathogenicity and immune escape. In this study, we aimed to characterize replication and pathogenicity of the Alpha and Delta variant strains isolated from patients infected in Laos. The amino acid mutations within the spike fragment of the isolates were determined via sequencing. The more efficient replication of the Alpha and Delta isolates was documented than the prototyped SARS-CoV-2 in Calu-3 and Caco-2 cells, while such features were not observed in Huh-7, Vero E6 and HPA-3 cells. We utilized both animal models of human ACE2(hACE2)transgenic mice and hamsters to evaluate the pathogenesis of the isolates. The Alpha and Delta can replicate well in multiple organs and cause moderate to severe lung pathology in these animals. In conclusion, the spike protein of the isolated Alpha and Delta variant strains was characterized, and the replication and pathogenicity of the strains in the cells and animal models were also evaluated.

Stability of SARS-CoV-2 on the Surfaces of Three Meats in the Setting That Simulates the Cold Chain Transportation

Dear Editor,The coronavirus disease 2019(COVID-19)pandemic presents a severe threat to public health and the global economy and the direct origin of the causative agent severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)remains unresolved(WHO 2020).The outbreak in China was successfully contained by the implementation of a strict quarantine strategy,however sporadic outbreaks still occurred and were associated with trade markets in Beijing and Dalian cities.The COVID-19 outbreak in Beijing was traced to contaminated salmon meat sold at the Xinfadi market,Beijing,China(Chinese CDC 2020)。

Synthetic Effect of Cr and Mo Elements on Microstructure and Properties of Laser Cladding NiCrxMoy Alloy Coatings

NiCrxMoy(x=1,1.5;y=0,0.1,0.3)alloy coatings were prepared on the Q235 substrate by laser cladding under the protection of argon.The phase composition,microstructure,corrosion behavior,and mechanical properties of the NiCrxMoy alloy coatings were investigated using X-ray diffraction,scanning electron microscopy,transmission electron microscopy,electrochemical tests,X-ray photoelectron spectroscopy,microhardness,and nanoindentation tests.As the Cr content increased,the phase composition of the coatings changed from a single face-centered cubic(FCC)structure to a dual-phase structure coexisting with body-centered cubic(BCC)and FCC structures,while the addition of Mo promoted the precipitation ofσphase.The appearance of a homogeneous dual-phase structure and some amount ofσphase played a positive role in the corrosion resistance of NiCrxMoy coatings.Cr^3+ ions and Mo^6+ ions in the passive film enhanced the stability of the coatings.The nanoindentation tests showed that the nanohardness(6.71 GPa)and elastic modulus(184.40 GPa)of BCC phase were higher than those of the FCC phase(5.19 GPa and 155.26 GPa,respectively).Overall,the BCC phase andσphase improved the mechanical properties of the coatings.

Pro-inflammatory microenvironment and systemic accumulation of CXCR3+cell exacerbate lung pathology of old rhesus macaques infected with SARS-CoV-2

Understanding the pathological features of severe acute respiratory syn drome coronavirus 2(SARS-CoV-2)infect io n in an animal model is crucial for the treatment of coronavirus disease 2019(COVID-19).Here,we compared imnnunopathological changes in young and old rhesus macaques(RMs)before and after SARS-CoV-2 infection at the tissue level.Quantitative analysis of multiplex immunofluoresce nee staining images of formali n-fixed paraffi n-embedded(FFPE)sections showed that SARS-CoV-2 infectio n specifically induced elevated levels of apoptosis,autophagy,and nuclear factor kappa-B(NF-kB)activation of angiotensirv convert!ng enzyme 2(ACE2)+cells,and increased interferon a(IFN-a)-and interleukin 6(IL-6)-secreting cells and C-X-C motif chemokine receptor 3(CXCR3)+cells in lung tissue of old RMs.This pathological pattern,which may be related to the age-related pro-inflammatory microenvironment in both lungs and spleens,was significantly correlated with the systemic accumulation of CXCR3+cells in lungs,spleens,and peripheral blood.Furthermore,the ratio of CXCR3+to T-box protein expression in T cell(T-bet)+(CXCR3+/T-bet+ratio)in CD8+cells may be used as a predictor of severe COVID-19.These findings uncovered the impact of aging on the immunopathology of early SARS-CoV-2 infection and demonstrated the potential application of CXCR3+cells in predicting severe COVID-19.

A recombinant receptor-binding domain in trimeric form generates protective immunity against SARSCoV-2 infection in nonhuman primates

A safe and effective vaccine is critical to combat the COVID-19 pandemic.Here,we developed a trimeric SARS-CoV-2 receptor-binding domain(RBD)subunit vaccine candidate that simulates the natural structure of the spike(S)trimer glycoprotein.Immunization with the RBD trimer-induced robust humoral and cellular immune responses,and a high level of neutralizing antibodies was maintained for at least 4.5 months.Moreover,the antibodies that were produced in response to the vaccine effectively cross-neutralized the SARS-CoV-2501Y.V2 variant(B.1.351).Of note,when the vaccine-induced antibodies dropped to a sufficiently low level,only one boost quickly activated the anamnestic immune response,conferring full protection against a SARSCoV-2 challenge in rhesus macaques without typical histopathological changes in the lung tissues.These results demonstrated that the SARS-CoV-2 RBD trimer vaccine candidate is highly immunogenic and safe,providing long-lasting,broad,and significant immunity protection in nonhuman primates,thereby offering an optimal vaccination strategy against COVID-19.

Correlation between the clinicopathological features and prognosis in patients with extranodal natural killer/T cell lymphoma

Objective: To investigate the correlation between the clinicopathological features and prognosis in patients with extranodal natural killer (NK)/T-cell lymphoma (ENKTCL). Methods: One hundred and four patients diagnosed with ENKTCL at the Department of Pathology, Cancer Hospital, Chinese Academy of Medical Sciences, Beijing, China from November 1991 to September 2011 were included in the study. The clini-copathological features and their correlations with disease prognosis were evaluated in these patients. Results: The number of effective follow-up cases was 56 (53.8％) by the end of last follow-up in October 2015. Univariate survival analysisshowedthatgranzymeB,perforin,andBcl-2expressionwassignificantlyassociatedwithapoorprognosisinENKTCL(P= 0.033, 0.004, and 0.034, respectively), whereas platelet-derived growth factor receptor-alpha (PDGFRA) expression was significantly associated withabetterprognosis(P= 0.034).Ki-67overexpression(≥50％)wassignificantlyassociatedwithapoorprognosis(P= 0.017).Different treatment approaches were also associated with prognosis (P = 0.014); specifically, the efficacies of combination treatments including chemotherapy and radiotherapy, and autologous hematopoietic stem cell transplantation were significantly better than those involving radiotherapy and chemotherapy alone. Patient gender, age, tumor location, staging, the presence of B symptoms, pretreatment lactate dehydrogenase levels, and β2-microglobulin levels were not associated with the prognosis of ENKTCL (P > 0.05). However, multivariate analyses showed that the treatment approach and all the immune markers were not independent prognostic factors for ENKTCL. Conclusion: Granzyme B, perforin, and Bcl-2 expression and Ki-67 overexpression (≥50％) might be adverse prognostic factors for ENKTCL, whereas PDGFRA-positivity suggested a better disease prognosis. In addition, different treatment approaches might be closely related to patient prognosis.