Nanotechnology’s frontier in combatting infectious and inflammatory diseases:prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases,which continuously pose one of the most serious threats to human health,attributed to factors such as the emergence of new pathogens,increasing drug resistance,changes in living environments and lifestyles,and the aging population.Despite rapid advancements in mechanistic research and drug development for these diseases,current treatments often have limited efficacy and notable side effects,necessitating the development of more effective and targeted anti-inflammatory therapies.In recent years,the rapid development of nanotechnology has provided crucial technological support for the prevention,treatment,and detection of inflammation-associated diseases.Various types of nanoparticles(NPs)play significant roles,serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability.NPs can also directly combat pathogens and inflammation.In addition,nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases.This review categorizes and characterizes different types of NPs,summarizes their applications in the prevention,treatment,and detection of infectious and inflammatory diseases.It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects.In conclusion,nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Neoantigens:promising targets for cancer therapy

Recent advances in neoantigen research have accelerated the development and regulatory approval of tumor immunotherapies,including cancer vaccines,adoptive cell therapy and antibody-based therapies,especially for solid tumors.Neoantigens are newly formed antigens generated by tumor cells as a result of various tumor-specific alterations,such as genomic mutation,dysregulated RNA splicing,disordered post-translational modification,and integrated viral open reading frames.Neoantigens are recognized as non-self and trigger an immune response that is not subject to central and peripheral tolerance.The quick identification and prediction of tumor-specific neoantigens have been made possible by the advanced development of next-generation sequencing and bioinformatic technologies.Compared to tumor-associated antigens,the highly immunogenic and tumor-specific neoantigens provide emerging targets for personalized cancer immunotherapies,and serve as prospective predictors for tumor survival prognosis and immune checkpoint blockade responses.The development of cancer therapies will be aided by understanding the mechanism underlying neoantigen-induced anti-tumor immune response and by streamlining the process of neoantigen-based immunotherapies.This review provides an overview on the identification and characterization of neoantigens and outlines the clinical applications of prospective immunotherapeutic strategies based on neoantigens.We also explore their current status,inherent challenges,and clinical translation potential.

Low levels of neutralizing antibodies against XBB Omicron subvariants after BA.5 infection

The COVID-19 response strategies in Chinese mainland were recently adjusted due to the reduced pathogenicity and enhanced infectivity of Omicron subvariants.In Chengdu,China,an infection wave was predominantly induced by the BA.5 subvariant.It is crucial to determine whether the hybrid anti-SARS-CoV-2 immunity following BA.5 infection.

NAD+metabolism:pathophysiologic mechanisms and therapeutic potential

Nicotinamide adenine dinucleotide(NAD^(+))and its metabolites function as critical regulators to maintain physiologic processes,enabling the plastic cells to adapt to environmental changes including nutrient perturbation,genotoxic factors,circadian disorder,infection,inflammation and xenobiotics.These effects are mainly achieved by the driving effect of NAD^(+)on metabolic pathways as enzyme cofactors transferring hydrogen in oxidation-reduction reactions.Besides,multiple NAD^(+)-dependent enzymes are involved in physiology either by post-synthesis chemical modification of DNA,RNA and proteins,or releasing second messenger cyclic ADPribose(cADPR)and NAADP^(+).Prolonged disequilibrium of NAD^(+)metabolism disturbs the physiological functions,resulting in diseases including metabolic diseases,cancer,aging and neurodegeneration disorder.In this review,we summarize recent advances in our understanding of the molecular mechanisms of NAD^(+)-regulated physiological responses to stresses,the contribution of NAD^(+)deficiency to various diseases via manipulating cellular communication networks and the potential new avenues for therapeutic intervention.

Histones released by NETosis enhance the infectivity of SARS-CoV-2 by bridging the spike protein subunit 2 and sialic acid on host cells

Neutrophil extracellular traps(NETs)can capture and kill viruses,such as influenza viruses,human immunodeficiency virus(HIV),and respiratory syncytial virus(RSV),thus contributing to host defense.Contrary to our expectation,we show here that the histones released by NETosis enhance the infectivity of SARS-CoV-2,as found by using live SARS-CoV-2 and two pseudovirus systems as well as a mouse model.The histone H3 or H4 selectively binds to subunit 2 of the spike(S)protein,as shown by a biochemical binding assay,surface plasmon resonance and binding energy calculation as well as the construction of a mutant S protein by replacing four acidic amino acids.Sialic acid on the host cell surface is the key molecule to which histones bridge subunit 2 of the S protein.Moreover,histones enhance cell-cell fusion.Finally,treatment with an inhibitor of NETosis,histone H3 or H4,or sialic acid notably affected the levels of sgRNA copies and the number of apoptotic cells in a mouse model.These findings suggest that SARS-CoV-2 could hijack histones from neutrophil NETosis to promote its host cell attachment and entry process and may be important in exploring pathogenesis and possible strategies to develop new effective therapies for COVID-19.

Spike protein of SARS‐CoV‐2 Omicron(B.1.1.529)variant has a reduced ability to induce the immune response

Dear Editor,The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variant Omicron(B.1.1.529)has attracted great concerns since its identification in South Africa.Omicron is the fifth variant of concern(VOC)after Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1)and Delta(B.1.617.2),and set a record with the shortest duration from variants of interest(VOI)to VOC so far.Within 2 months after its first report,over 80%of global sequenced samples are verified as Omicron according to GISAID(https://cov-spectrum.org/explore/World/AllSamples/from=2021-12-15&to=2022-01-15/variants?pangoLineage=B.1.1.529*).

S19W,T27W,and N33OY mutations in ACE2 enhance SARS-CoV-2 S-RBD binding toward both wild-type and antibody-resistant viruses and its molecular basis

SARS-CoV-2 recognizes,via its spike receptor-binding domain(S-RBD),human angiotensin-converting enzyme 2(ACE2)to initiate infection.Ecto-domain protein of ACE2 can therefore function as a decoy.Here we show that mutations of S19W,T27W,and N330Y in ACE2 could individually enhance SARS-CoV-2 S-RBD binding.Y330 could be synergistically combined with either W19 or W27,whereas W19 and W27 are mutually unbeneficial.The structures of SARS-CoV-2S-RBD bound to the ACE2 mutants reveal that the enhan ced binding is mainly con tributed by the van der Waals interactio ns mediated by the aromatic side-chai ns from W19,W27,and Y330.While Y330 and W19/W27 are distantly located and devoid of any steric interference,W19 and W27 are shown to orient their side-chains toward each other and to cause steric conflicts,explai ning their in compatibility.Finally,using pseudotyped SARS-CoV-2 viruses,we dem on strate that these residue substitutions are associated with dramatically improved entry-inhibition efficacy toward both wild-type and antibody-resistant viruses.Taken together,our biochemical and structural data have delineated the basis for the elevated S-RBD binding associated with S19W,T27W,and N330Y mutations in ACE2,paving the way for potential application of these mutants in dinical treatment of COVID-19.