Intranasal boosting with RBD-HR protein vaccine elicits robust mucosal and systemic immune responses

The emergence of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants has decreased the efficacy of SARs-CoV-2 vaccines in containing coronavirus disease 2019(CoVID-19)over time,and booster vaccination strategies are urgently necessitated to achieve sufficient protection.Intranasal immunization can improvemucosal immunity,offer-ing protection against the infection and sustaining the spread of SARS-CoV-2.In this study,an intranasal booster of the RBD-HR vaccine after two doses of the mRNA vaccine significantly increased the levels of specific binding antibodies in serum,nasal lavage fluid,and bronchoal-veolar lavage fluid compared with only two doses of mRNA vaccine.After intranasal boosting with the RBD-HR vaccine,the levels of serum neutralizing antibodies against prototype and variant strains of SARS-Cov-2 pseudoviruses weremarkedly higher than those in mice receiving mRNA vaccine alone,and intranasal boosting with the RBD-HR vaccine also inhibited the bind-ing of RBD to hACE2 receptors.Furthermore,the heterologous intranasal immunization regimen promoted extensive memory T cell responses and activated CD103+dendritic cells in the respiratory mucosa,and potently enhanced the formation of T follicular helper cells and germinal center B cells in vital immune organs,including mediastinal lymph nodes,inguinal lymph nodes,and spleen.Collectively,these data infer that heterologous intranasal boosting with the RBD-HR vaccine elicited broad protective immunity against SARS-CoV-2 both locallyandsystemically.

Targeted therapy for head and neck cancer:signaling pathways and clinical studies

Head and neck cancer(HNC)is malignant,genetically complex and difficult to treat and is the sixth most frequent cancer,with tobacco,alcohol and human papillomavirus being major risk factors.Based on epigenetic data,HNC is remarkably heterogeneous,and treatment remains challenging.There is a lack of significant improvement in survival and quality of life in patients with HNC.Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy.In addition,resistance to chemotherapy,radiotherapy and some targeted therapies is common.Therefore,it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients.Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies.A well understanding of the pathogenesis of HNC contributes to learning more about its inner association,which provides novel insight into the development of small molecule inhibitors.In this review,we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC,as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy,which may contribute to a more favorable prognosis of HNC.Targeted therapy in combination with other therapies and its limitations were also discussed.

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.

The role of lysosome in regulated necrosis

Lysosome is a ubiquitous acidic organelle fundamental for the turnover of unwanted cellular molecules,particles,and organelles.Currently,the pivotal role of lysosome in regulating cell death is drawing great attention.Over the past decades,we largely focused on how lysosome influences apoptosis and autophagic cell death.However,extensive studies showed that lysosome is also prerequisite for the execution of regulated necrosis(RN).Different types of RN have been uncovered,among which,necroptosis,ferroptosis,and pyroptosis are under the most intensive investigation.It becomes a hot topic nowadays to target RN as a therapeutic intervention,since it is important in many patho/physiological settings and contributing to numerous diseases.It is promising to target lysosome to control the occurrence of RN thus altering the outcomes of diseases.Therefore,we aim to give an introduction about the common factors influencing lysosomal stability and then summarize the current knowledge on the role of lysosome in the execution of RN,especially in that of necroptosis,ferroptosis,and pyroptosis.

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.

Intranasal administration of a recombinant RBD vaccine induces long-term immunity against Omicron-included SARS-CoV-2 variants

The outbreak of coronavirus disease 2019(COVID-19)has posed great threats to global health and economy.Several effective vaccines are available now,but additional booster immunization is required to retain or increase the immune responses owing to waning immunity and the emergency of new variant strains.The deficiency of intramuscularly delivered vaccines to induce mucosal immunity urged the development of mucosal vaccines.Here,we developed an adjuvanted intranasal RBD vaccine and monitored its long-term immunogenicity against both wild-type and mutant strains of severe acute respiratory syndrome coronavirus-2(SARSCoV-2),including Omicron variants,in mice.Three-dose intranasal immunization with this vaccine induced and maintained high levels of neutralizing IgG antibodies in the sera for at least 1 year.Strong mucosal immunity was also provoked,including mucosal secretory IgA and lung-resident memory T cells(TRM).We also demonstrated that the long-term persistence of lung TRM cells is a consequence of local T-cell proliferation,rather than T-cell migration from lymph nodes.Our data suggested that the adjuvanted intranasal RBD vaccine is a promising vaccine candidate to establish robust,long-lasting,and broad protective immunity against SARS-CoV-2 both systemically and locally.

Biomaterial-assisted biotherapy:A brief review of biomaterials used in drug delivery,vaccine development,gene therapy,and stem cell therapy

Biotherapy has recently become a hotspot research topic with encouraging prospects in various fields due to a wide range of treatments applications,as demonstrated in preclinical and clinical studies.However,the broad applications of biotherapy have been limited by critical challenges,including the lack of safe and efficient de-livery systems and serious side effects.Due to the unique potentials of biomaterials,such as good biocompati-bility and bioactive properties,biomaterial-assisted biotherapy has been demonstrated to be an attractive strategy.The biomaterial-based delivery systems possess sufficient packaging capacity and versatile functions,enabling a sustained and localized release of drugs at the target sites.Furthermore,the biomaterials can provide a niche with specific extracellular conditions for the proliferation,differentiation,attachment,and migration of stem cells,leading to tissue regeneration.In this review,the state-of-the-art studies on the applications of bio-materials in biotherapy,including drug delivery,vaccine development,gene therapy,and stem cell therapy,have been summarized.The challenges and an outlook of biomaterial-assisted biotherapies have also been discussed.

Cationic nanocarriers as potent adjuvants for recombinant S-RBD vaccine of SARS-CoV-2

Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.Therefore,to improve the efficacy of the vaccine and seek a novel adjuvant that can stimulate both humoral and cellular immunity,we investigated the potential of series of cationic nanocarriers as adjuvants of the recombinant S-RBD vaccine for SARS-CoV-2.As the surface charge of a nanocarrier might dramatically affect the immunogenicity of a vaccine and enhance and/or shape antigen-specific immune responses,we also used anionic nanocarriers and neutral nanocarriers as controls(Supplementary Table S1).S-RBD vaccines with adjuvant candidates were administered intranasally or intramuscularly in the present study.

Cationic nanocarriers as potent adjuvants for recombinant S-RBD vaccine of SARS-CoV-2

Dear Editor,The worldwide outbreak of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection has urged the investigation of preventive vaccines.Recently,our team has developed a recombinant protein vaccine,targeting receptor binding domain(RBD)of the spike protein(S-RBD)of SARS-CoV-2,which could induce a potent antibody response and protect non-human primates from SARS-CoV-2 challenge.1 The recombinant RBD protein is proved as a potent antigen and a novel adjuvant is in demand for the effective stimulation of adaptive immunity.