Single-cell transcriptomics reveals T-cell heterogeneity and immunomodulatory role of CD4^(+) T native cells in Candida albicans infection

Objective:Candida albicans is a common fungal pathogen that triggers complex host defense mechanisms,including coordinated innate and adaptive immune responses,to neutralize invading fungi effectively.Exploring the immune microenvironment has the potential to inform the development of therapeutic strategies for fungal infections.Methods:The study analyzed individual immune cell profiles in peripheral blood mononuclear cells from Candida albicans-infected mice and healthy control mice using single-cell transcriptomics,fluorescence quantitative PCR,and Western blotting.We investigated intergroup differences in the dynamics of immune cell subpopulation infiltration,pathway enrichment,and differentiation during Candida albicans infection.Results:Our findings indicate that infiltration of CD4^(+)naive cells,regulatory T(Treg)cells,and Microtubules(MT)-associated cells increased after infection,along with impaired T cell activity.Notably,CD4^(+) T cells and plasma cells were enhanced after infection,suggesting that antibody production is dependent on T cells.In addition,we screened 6 hub genes,transcription factor forkhead box protein 3(Foxp3),cytotoxic T-lymphocyte associated protein 4(CTLA4),Interleukin 2 Receptor Subunit Beta(Il2rb),Cd28,C-C Motif Chemokine Ligand 5(Ccl5),and Cd27 for alterations associated with CD4^(+) T cell differentiation.Conclusions:These results provide a comprehensive immunological landscape of the mechanisms of Candida albicans infection and greatly advance our understanding of adaptive immunity in fungal infections.

Effects of Combined Treatment with Sansanmycin and Macrolides on Pseudomonas aeruginosa and Formation of Biofilm

Objective To observe the effects of combined treatment with sansanmycin and macrolides on Pseudomonas aeruginosa and formation of biofilm. Methods Micro-dilution method was used to determine the minimal inhibitory concentrations （MICs） of sansanmycin, gentamycin, carbenicillin, polymyxin B, roxithromycin, piperacillin, and tazobactam. PAl and PA27853 biofilms were observed under optical microscope after staining and under SEM after treatment with sansanmycin at different dosages and combined treatment with sansanmycin and roxithromycin. Viable bacteria in PAl and PA27853 biofilms were counted after treatment with sansanmycin at different dosages or combined treatment with sansanmycin and roxithromycin. Results The MIC of sansanmycin was lower than that of gentamycin and polymyxin B, but was higher than that of carbenicillin. Roxithromycin enhanced the penetration of sansanmycin to PAl and PA27853 strains through biofilms. PAl and PA27853 biofilms were gradually cleared with the increased dosages of sansanmycin or with the combined sansanmycin and roxithromycin. Conclusion Sub-MIC levels of roxithromycin and sansanmycin substantially inhibit the generation of biofilms and proliferation of bacteria. Therefore, combined antibiotics can be used in treatment of intractable bacterial infection.

Cloning, Expression, Purification, and Crystallization of <i>P. aeruginosa </i>ICMP

Pseudomonas aeruginosa (P. aeruginosa) is a common opportunistic human pathogen that can lead to severe diseases in immunocompromised patients. The insulin-cleaving membrane protease (ICMP) of P. aeruginosa plays a vital role in the pathogenesis of the bacterium and is therefore characterized as an important bacterial virulence factor. In addition, ICMP also serves as a founding member of the M75 peptidase family and represents a prototype of the imelysin/imelysin-like proteins. Despite of its functional importance in the pathogenesis of P. aeruginosa and of a root position as the prototypic imelysin/imelysin-like member, the structural features of the protein remain uninvestigated. Since preparation of homogeneous and crystallizable protein species is the prerequisite for structural studies by crystallography, we reported the successful expression, purification, and crystallization of P. aeruginosa ICMP in this study. The protein was over-expressed in Escherichia coli as a GST-fusion protein, cleaved to remove the fusion tag, and then purified to homogeneity. Diffractable crystals were obtained using the sitting-drop vapour-diffusion method. The crystals diffracted to 2.5 &#197;?resolution and belonged to space group P212121, with unit-cell parameters a = 54.47, b = 158.98, c = 162.84 &#197;, α = β = γ = 90°. Preliminary analysis of the diffraction data revealed high-quality crystallographic statistics with a Matthews coefficient of about 2.61 &#197;3.Da-1 and a solvent content of about 52.58%, indicating the presence of three ICMP molecules in the asymmetric unit. The current work therefore paved the way for future studies aiming to delineate the characteristics of ICMP at the atomic level.

Developing a conceptual framework for the health protection of United Nations peacekeepers against the COVID-19 pandemic from global health perspectives

The coronavirus disease 2019(COVID-19)pandemic has posed particular health risks to United Nations peacekeepers,which require prompt responses and global attention.Since the health protection of United Nations peacekeepers against the COVID-19 pandemic is a typical global health problem,strategies from global health perspectives may help address it.From global health perspectives,and referring to the successful health protection of the Chinese Anti-Ebola medical team in Liberia,a conceptual framework was developed for the health protection of United Nations peacekeepers against the COVID-19 pandemic.Within this framework,the features include multiple cross-borders(cross-border risk factors,impact,and actions);multiple risk factors(Social Determinants of Health),multiple disciplines(public health,medicine,politics,diplomacy,and others),and extensive interdepartmental cooperation.These strategies include multiple phases(before-deployment,during-deployment,and post-deployment),multi-level cooperation networks(the United Nations,host countries,troop-contributing countries,the United Nations peacekeeping team,and United Nations peacekeepers),and concerted efforts from various dimensions(medical,psychological,and social).

Diagnosis and treatment of Helicobacter pylori infections in children and elderly populations

Helicobacter pylori(H.pylori)infection is associated with various gastric and extra-gastric diseases.Importantly,this infection is the strongest known risk factor for gastric cancer(GC).H.pylori eradication can effectively prevent H.pylori infectionassociated diseases in H.pylori-positive patients,including children and elderly subjects.However,a limited selection of antibiotics,a higher reinfection rate,and certain spontaneous clearance rates,to some extent,restrict the choice of H.pylori treatments in pediatrics.In addition,it is imperative to perform an accurate diagnosis of H.pylori infection in children by determining the presence of the H.pylori infection and the underlying cause of symptoms.In elderly patients,poor tolerance to drugs and higher sensitivity to adverse effects are major concerns during H.pylori therapy.Recent studies have demonstrated that H.pylori eradication could significantly lower the GC risk in the elderly population.The benefit and risk of H.pylori eradication in elderly patients should be comprehensively considered and balanced.If available,susceptibility-based tailored therapies may be preferable in eradicating H.pylori.In addition,to increase the eradication rate and reduce adverse effects,new therapeutic strategies(e.g.,probiotic supplementation,berberine supplementation,dual therapy)for H.pylori infection are being extensively investigated.The impact of H.pylori eradication with antibiotics on the microbiota in children has been explored,but further high-quality studies are crucial to delineate the extent of H.pylori eradication affecting the microbial community in children.In this review,we summarize the current understanding of H.pylori diagnosis and treatment in children and the elderly population and aim to provide insights into the efficient management and treatment implementation in these populations.

Tubulointerstitial nephritis antigen-like 1 is a novel matricellular protein that promotes gastric bacterial colonization and gastritis in the setting of Helicobacter pylori infection

The interaction between the gastric epithelium and immune cells plays key roles in H. pylori-associated pathology. Here, we demonstrate a procolonization and proinflammatory role of tubulointerstitial nephritis antigen-like 1 (TINAGL1), a newly discovered matricellular protein, in H. pylori infection. Increased TINAGL1 production by gastric epithelial cells (GECs) in the infected gastric mucosa was synergistically induced by H. pylori and IL-1β via the ERK-SP1 pathway in a cagA-dependent manner. Elevated human gastric TINAGL1 correlated with H. pylori colonization and the severity of gastritis, and mouse TINAGL1 derived from non-bone marrow-derived cells promoted bacterial colonization and inflammation. Importantly, H. pylori colonization and inflammation were attenuated in Tinagl1−/− and Tinagl1ΔGEC mice and were increased in mice injected with mouse TINAGL1. Mechanistically, TINAGL1 suppressed CCL21 expression and promoted CCL2 production in GECs by directly binding to integrin α5β1 to inhibit ERK and activate the NF-κB pathway, respectively, which not only led to decreased gastric influx of moDCs via CCL21-CCR7-dependent migration and, as a direct consequence, reduced the bacterial clearance capacity of the H. pylori-specific Th1 response, thereby promoting H. pylori colonization, but also resulted in increased gastric influx of Ly6Chigh monocytes via CCL2-CCR2-dependent migration. In turn, TINAGL1 induced the production of the proinflammatory protein S100A11 by Ly6Chigh monocytes, promoting H. pylori-associated gastritis. In summary, we identified a model in which TINAGL1 collectively ensures H. pylori persistence and promotes gastritis.

Pioneer of burn medicine in China: Professor Li Ao and “Li Ao spirit”

The 2019 marks twenty years since Professor Ao Li(黎鳌)passed away.Although he has left us,the"Li Ao Spirit"has lived on and continuously encourages us to climb higher in scientific research and make more contributions to our people and country(Fig.1).Professor Li is a well-known Chinese expert in burn surgery and a member of the Chinese Academy of Engineering.Mr.Li,also named Shengxu Li(黎升旭),was bom in Changsha,Hunan Province in May 1917.He graduated from the National Shanghai Medical College in 1941,and had a long and distinguished career in medicine.

High-throughput screening and evaluation of repurposed drugs targeting the SARS-CoV-2 main protease

Dear editor,To date,a number of clinically approved drugs have been evaluated for potential to treat coronavirus disease 2019(COVID-19),such as lopinavir/ritonavir,hydroxychloroquine,cobicistat,and darunavir.Some of these drugs have been proven to be effective in vitro;however,clinical trials showed that none of these compounds led to a significant improvement in symptoms or length of hospitalization.Thus,it is essential and more reliable to start from a defined target to ide ntify can didate drugs.

The efficacy assessment of convalescent plasma therapy for COVID-19 patients:a multi-center case series

Convalescent plasma(CP)transfusion has been indicated as a promising therapy in the treatment for other emerging viral infections.However,the quality control of CP and individual variation in patients in different studies make it rather difficult to evaluate the efficacy and risk of CP therapy for coronavirus disease 2019(COVID-19).We aimed to explore the potential efficacy of CP therapy,and to assess the possible factors associated with its efficacy.We enrolled eight critical or severe COVID-19 patients from four centers.Each patient was transfused with 200–400mL of CP from seven recovered donors.The primary indicators for clinical efficacy assessment were the changes of clinical symptoms,laboratory parameters,and radiological image after CP transfusion.CP donors had a wide range of antibody levels measured by serology tests which were to some degree correlated with the neutralizing antibody(NAb)level.No adverse events were observed during and after CP transfusion.Following CP transfusion,six out of eight patients showed improved oxygen support status;chest CT indicated varying degrees of absorption of pulmonary lesions in six patients within 8 days;the viral load was decreased to a negative level in five patients who had the previous viremia;other laboratory parameters also tended to improve,including increased lymphocyte counts,decreased C-reactive protein,procalcitonin,and indicators for liver function.The clinical efficacy might be associated with CP transfusion time,transfused dose,and the NAb levels of CP.This study indicated that CP might be a potential therapy for severe patients with COVID-19.

HIV-1 Vif suppresses antiviral immunity by targeting STING

HIV-1 infection-induced cGAS–STING–TBK1–IRF3 signaling activates innate immunity to produce type I interferon(IFN).The HIV-1 nonstructural protein viral infectivity factor(Vif)is essential in HIV-1 replication,as it degrades the host restriction factor APOBEC3G.However,whether and how it regulates the host immune response remains to be determined.In this study,we found that Vif inhibited the production of type I IFN to promote immune evasion.HIV-1 infection induced the activation of the host tyrosine kinase FRK,which subsequently phosphorylated the immunoreceptor tyrosine-based inhibitory motif(ITIM)of Vif and enhanced the interaction between Vif and the cellular tyrosine phosphatase SHP-1 to inhibit type I IFN.Mechanistically,the association of Vif with SHP-1 facilitated SHP-1 recruitment to STING and inhibited the K63-linked ubiquitination of STING at Lys337 by dephosphorylating STING at Tyr162.However,the FRK inhibitor D-65495 counteracted the phosphorylation of Vif to block the immune evasion of HIV-1 and antagonize infection.These findings reveal a previously unknown mechanism through which HIV-1 evades antiviral immunity via the ITIM-containing protein to inhibit the posttranslational modification of STING.These results provide a molecular basis for the development of new therapeutic strategies to treat HIV-1 infection.

DNAzyme@CuSNPs dual mimic enzyme probe-amplified chemiluminescent imaging array immunosensor for multiple chicken cytokines detection

The detection of cytokines plays an important role in clinical diagnosis and immune mechanism research of chicken diseases.In this work,a novel and ultrasensitive chemiluminescent(CL)imaging array immunosensor was proposed to detect multiple chicken cytokines based on DNAzyme@CuS nanoparticles(DNAzyme@CuSNPs)dual mimic enzyme signal amplification strategy.DNAzyme@CuSNPs owns excellent peroxidase property,which was modified with second antibody(Ab_(2))to prepare DNAzyme@CusNPs detection probe,and demonstrated high catalysis CL imaging signal due to synergistic catalysis.Chicken interleukin-4(ChIL-4)and chicken interferon-y(ChIFN-y)were used as model analysis samples,the DNAzyme@CusSNPs-based CL imaging immunosensor achieved simultaneous and high-throughput detection of ChIL-4 and ChIFN-y with wide linear range of 10^(-3)-10^(2) ng/mL,and the detection limits are 0.41 pg/mL and 0.36 pg/mL,respectively.The multiplex chicken cytokines CL imaging array immunosensor shows a high sensitivity,wide linear range,excellent specificity and acceptable stability.This research opens dual mimic enzyme signal-amplified strategy to develop sensitive CL imaging immunoassay for chicken diseases detection application.