RESUMO
The increase in the incidence of dementia over the last century correlates strongly with the increases in post-reproductive lifespan during this time. As post-reproductive lifespan continues to increase it is likely that the incidence of dementia will also increase unless therapies are developed to prevent, slow or cure dementia. A growing body of evidence implicates age-related endocrine dyscrasia and the length of time that the brain is subjected to this endocrine dyscrasia, as a key causal event leading to the cognitive decline associated with aging and Alzheimer's disease (AD), the major form of dementia in our society. In particular, the elevations in circulating gonadotropins, resulting from the loss of gonadal sex hormone production with menopause and andropause, appear central to the development of AD neuropathology and cognitive decline. This is supported by numerous cell biology, preclinical animal, and epidemiological studies, as well as human clinical studies where suppression of circulating luteinizing hormone and/or follicle-stimulating hormone with either gonadotropin-releasing hormone analogues, or via physiological hormone replacement therapy, has been demonstrated to halt or significantly slow cognitive decline in those with AD. This review provides an overview of past and present studies demonstrating the importance of hypothalamic-pituitary-gonadal hormone balance for normal cognitive functioning, and how targeting age-related endocrine dyscrasia with hormone rebalancing strategies provides an alternative treatment route for those with AD.
Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/terapia , Doença de Alzheimer/etiologia , Animais , Doenças do Sistema Endócrino/terapia , Doenças do Sistema Endócrino/etiologiaRESUMO
Feral swine are invasive in the United States and a reservoir for infectious diseases. The increase in feral swine population and the geographic range are a concern for the spread of zoonotic diseases to humans and livestock. Feral swine could contribute to the spread of Coxiella burnetii, the causative agent of human Q fever. In this study, we characterized the seroprevalence of C. burnetii in feral swine populations of Hawai'i and Texas, which have low and high rates of human Q fever, respectively. Seropositivity rates were as high as 0.19% and 6.03% in Hawai'i and Texas, respectively, indicating that feral swine cannot be ruled out as a potential reservoir for disease transmission and spread. In Texas, we identified the overlap between seropositivity of feral swine and human Q fever incidence. These results indicate that there is a potentially low but detectable risk of C. burnetii exposure associated with feral swine populations in Hawai'i and Texas.
Assuntos
Coxiella burnetii , Febre Q , Doenças dos Suínos , Animais , Texas/epidemiologia , Coxiella burnetii/imunologia , Coxiella burnetii/isolamento & purificação , Coxiella burnetii/genética , Havaí/epidemiologia , Febre Q/epidemiologia , Febre Q/veterinária , Febre Q/microbiologia , Estudos Soroepidemiológicos , Humanos , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/microbiologia , Incidência , Anticorpos Antibacterianos/sangueRESUMO
Initial transmission of severe acute respiratory syndrome virus-2 (SARS-CoV-2) was highest in densely populated regions of Kenya. Transmission gradually trickled down to the less densely populated, remote and underserved regions such as the pastoral regions of Kajiado County which are characterized by poor healthcare systems. Molecular assays that were pivotal for COVID-19 diagnosis were not available in these regions. Serology is an alternative method for retrospectively tracking the transmission of SARS-CoV-2 in such populations. Dry blood spots (DBS) were prepared from consenting patients attending six health facilities in Kajiado County from March 2020 to March 2022. Upon elution, we conducted an enzyme-linked immunosorbent assay (ELISA) for the detection of SARS-Cov-2 IgG antibodies. Of the 908 DBSs we analyzed, 706 (78%) were from female participants. The overall seropositivity to SARS-Cov-2 antibodies was 7.3% (95% CI 5.7-9.1). The elderly (over 60 years) and male participants had a high likelihood of testing positive for SAR-CoV-2 infections. Mashuru (15.6%, 14/90) and Meto (15%, 19/127) health facilities registered the highest proportion of seropositive participants. Evidence of SARS-CoV-2 transmission among pastoralists in the remote and underserved regions of Kajiado County was established by DBS sampling and serologic testing.
Assuntos
Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/diagnóstico , Feminino , Masculino , Quênia/epidemiologia , Adulto , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Adolescente , Anticorpos Antivirais/sangue , Adulto Jovem , Imunoglobulina G/sangue , Criança , Idoso , Pré-Escolar , Estudos Retrospectivos , Ensaio de Imunoadsorção Enzimática , LactenteRESUMO
Chronic wasting disease (CWD) has become a major concern among those involved in managing wild and captive cervid populations. CWD is a fatal, highly transmissible spongiform encephalopathy caused by an abnormally folded protein, called a prion. Prions are present in a number of tissues, including feces and urine in CWD infected animals, suggesting multiple modes of transmission, including animal-to-animal, environmental, and by fomite. CWD management is complicated by the lack of practical, non-invasive, live-animal screening tests. Recently, there has been a focus on how the volatile odors of feces and urine can be used to discriminate between infected and noninfected animals in several different species. Such a tool may prove useful in identifying potentially infected live animals, carcasses, urine, feces, and contaminated environments. Toward this goal, dogs were trained to detect and discriminate CWD infected individuals from non-infected deer in a laboratory setting. Dogs were tested with novel panels of fecal samples demonstrating the dogs' ability to generalize a learned odor profile to novel odor samples based on infection status. Additionally, dogs were transitioned from alerting to fecal samples to an odor profile that consisted of CWD infection status with a different odor background using different sections of gastrointestinal tracts. These results indicated that canine biodetectors can discriminate the specific odors emitted from the feces of non-infected versus CWD infected white-tailed deer as well as generalizing the learned response to other tissues collected from infected individuals. These findings suggest that the health status of wild and farmed cervids can be evaluated non-invasively for CWD infection via monitoring of volatile metabolites thereby providing an effective tool for rapid CWD surveillance.
Assuntos
Cervos , Fezes , Odorantes , Doença de Emaciação Crônica , Animais , Doença de Emaciação Crônica/diagnóstico , Doença de Emaciação Crônica/transmissão , Doença de Emaciação Crônica/urina , Odorantes/análise , Fezes/química , Príons/análise , CãesRESUMO
Arthropod-borne viruses represent a crucial public health threat. Current arboviral serology assays are either labor intensive or incapable of distinguishing closely related viruses, and many zoonotic arboviruses that may transition to humans lack any serologic assays. In this study, we present a programmable phage display platform, ArboScan, that evaluates antibody binding to overlapping peptides that represent the proteomes of 691 human and zoonotic arboviruses. We confirm that ArboScan provides detailed antibody binding information from animal sera, human sera, and an arthropod blood meal. ArboScan identifies distinguishing features of antibody responses based on exposure history in a Colombian cohort of Zika patients. Finally, ArboScan details epitope level information that rapidly identifies candidate epitopes with potential protective significance. ArboScan thus represents a resource for characterizing human and animal arbovirus antibody responses at cohort scale.
Assuntos
Anticorpos Antivirais , Arbovírus , Humanos , Arbovírus/imunologia , Arbovírus/isolamento & purificação , Animais , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/sangue , Peptídeos/imunologia , Peptídeos/química , Infecção por Zika virus/virologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/sangue , Zika virus/imunologia , Epitopos/imunologia , Testes Sorológicos/métodos , Infecções por Arbovirus/virologia , Infecções por Arbovirus/imunologia , Proteoma , Colômbia , Feminino , Biblioteca de Peptídeos , Técnicas de Visualização da Superfície Celular , MasculinoRESUMO
The COVID-19 pandemic has highlighted the need for mucosal vaccines as breakthrough infections, short-lived immune responses and emergence of new variants have challenged the efficacy provided by the first generation of vaccines against SARS-CoV-2 viruses. M2SR SARS-CoV-2, an M2-deleted single-replication influenza virus vector modified to encode the SARS-CoV-2 receptor binding domain, was evaluated following intranasal delivery in a hamster challenge model for protection against Wuhan SARS-CoV-2. An adjuvanted inactivated SARS-CoV-2 whole virus vaccine administered intramuscularly was also evaluated. The intranasal M2SR SARS-CoV-2 was more effective than the intramuscular adjuvanted inactivated whole virus vaccine in providing protection against SARS-CoV-2 challenge. M2SR SARS-CoV-2 elicited neutralizing serum antibodies against Wuhan and Omicron SARS-CoV-2 viruses in addition to cross-reactive mucosal antibodies. Furthermore, M2SR SARS-CoV-2 generated serum HAI and mucosal antibody responses against influenza similar to an H3N2 M2SR influenza vaccine. The intranasal dual influenza/COVID M2SR SARS-CoV-2 vaccine has the potential to provide protection against both influenza and COVID.
Assuntos
COVID-19 , Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Cricetinae , Influenza Humana/prevenção & controle , Vacinas contra COVID-19 , SARS-CoV-2 , Infecções por Orthomyxoviridae/prevenção & controle , Vírus da Influenza A Subtipo H3N2 , Pandemias/prevenção & controle , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinação , Anticorpos Neutralizantes , Adjuvantes ImunológicosRESUMO
Melioidosis, caused by the intracellular bacterial pathogen and Tier 1 select agent Burkholderia pseudomallei (Bp), is a highly fatal disease endemic in tropical areas. No licensed vaccine against melioidosis exists. In preclinical vaccine studies, demonstrating protection against respiratory infection in the highly sensitive BALB/c mouse has been especially challenging. To address this challenge, we have used a safe yet potent live attenuated platform vector, LVS ΔcapB, previously used successfully to develop vaccines against the Tier 1 select agents of tularemia, anthrax, and plague, to develop a melioidosis vaccine. We have engineered melioidosis vaccines (rLVS ΔcapB/Bp) expressing multiple immunoprotective Bp antigens among type VI secretion system proteins Hcp1, Hcp2, and Hcp6, and membrane protein LolC. Administered intradermally, rLVS ΔcapB/Bp vaccines strongly protect highly sensitive BALB/c mice against lethal respiratory Bp challenge, but protection is overwhelmed at very high challenge doses. In contrast, administered intranasally, rLVS ΔcapB/Bp vaccines remain strongly protective against even very high challenge doses. Under some conditions, the LVS ΔcapB vector itself provides significant protection against Bp challenge, and consistent with this, both the vector and vaccines induce humoral immune responses to Bp antigens. Three-antigen vaccines expressing Hcp6-Hcp1-Hcp2 or Hcp6-Hcp1-LolC are among the most potent and provide long-term protection and protection even with a single intranasal immunization. Protection via the intranasal route was either comparable to or statistically significantly better than the single-deletional Bp mutant Bp82, which served as a positive control. Thus, rLVS ΔcapB/Bp vaccines are exceptionally promising safe and potent melioidosis vaccines. IMPORTANCE: Melioidosis, a major neglected disease caused by the intracellular bacterial pathogen Burkholderia pseudomallei, is endemic in many tropical areas of the world and causes an estimated 165,000 cases and 89,000 deaths in humans annually. Moreover, B. pseudomallei is categorized as a Tier 1 select agent of bioterrorism, largely because inhalation of low doses can cause rapidly fatal pneumonia. No licensed vaccine is available to prevent melioidosis. Here, we describe a safe and potent melioidosis vaccine that protects against lethal respiratory challenge with B. pseudomallei in a highly sensitive small animal model-even a single immunization is highly protective, and the vaccine gives long-term protection. The vaccine utilizes a highly attenuated replicating intracellular bacterium as a vector to express multiple key proteins of B. pseudomallei; this vector platform has previously been used successfully to develop potent vaccines against other Tier 1 select agent diseases including tularemia, anthrax, and plague.
Assuntos
Antraz , Burkholderia pseudomallei , Melioidose , Peste , Tularemia , Humanos , Animais , Camundongos , Burkholderia pseudomallei/genética , Melioidose/prevenção & controle , Camundongos Endogâmicos BALB C , Vacinas Bacterianas , Vacinas Atenuadas , Antígenos de Bactérias/genéticaRESUMO
The continued emergence of highly pathogenic viruses, which either thwart immune- and small molecule-based therapies or lack interventions entirely, mandates alternative approaches, particularly for prompt and facile pre- and post-exposure prophylaxis. Many highly pathogenic viruses, including coronaviruses, employ the six-helix bundle heptad repeat membrane fusion mechanism to achieve infection. Although heptad-repeat-2 decoys can inhibit viral entry by blocking six-helix bundle assembly, the biophysical and pharmacologic liabilities of peptides have hindered their clinical development. Here, we develop a chemically stapled lipopeptide inhibitor of SARS-CoV-2 as proof-of-concept for the platform. We show that our lead compound blocks infection by a spectrum of SARS-CoV-2 variants, exhibits mucosal persistence upon nasal administration, demonstrates enhanced stability compared to prior analogs, and mitigates infection in hamsters. We further demonstrate that our stapled lipopeptide platform yields nanomolar inhibitors of respiratory syncytial, Ebola, and Nipah viruses by targeting heptad-repeat-1 domains, which exhibit strikingly low mutation rates, enabling on-demand therapeutic intervention to combat viral outbreaks.
Assuntos
Infecções por Coronavirus , Lipopeptídeos , Humanos , Lipopeptídeos/farmacologia , Lipopeptídeos/uso terapêutico , Lipopeptídeos/química , Pandemias/prevenção & controleRESUMO
Gallic acid (GA) is a naturally occurring polyphenol with a strong antioxidant capacity. GA stimulates the apoptosis of cancer cells, thereby suppressing cancer cell invasion. However, the low oral permeability of GA limits its therapeutic use. In order to enhance the antioxidant capacity and oral permeability of GA, a series of compounds analogous to GA were synthesized: 4-methoxybenzenesulfonamide (MBS), 3,4-dimethoxybenzenesulfonamide (DMBS) and 3,4,5-trimethoxybenzenesulfonamide (TMBS). In the new compounds, hydroxyl groups were replaced with various numbers of methoxy groups (stronger electron-donating groups), to increase hydrophobicity and oral permeability compared to GA. In addition, the carboxylic group was replaced with a sulfonyl group (a stronger electron-withdrawing group), to increase the molecular polarity and antioxidative activities of the compounds. The cell counting kit-8 (CCK-8) assay was used to detect the effect of GA, MBS, DMBS, and TMBS on cell proliferation and apoptosis in peripheral blood mononuclear cells (PBMCs) from healthy individuals and non-small cell lung carcinoma A549 cells. Additionally, the comet assay was used to assess the genotoxicity of these compounds in PBMCs from healthy individuals, lung cancer patients, and A549 cells. Compared to untreated cells, TMBS reduced DNA damage more effectively than GA in PBMCs from lung cancer patients and healthy donors. Furthermore, in comparison to GA, TMBS was more cytotoxic in A549 cells. Moreover, TMBS was not cytotoxic in healthy PBMCs, suggesting that TMBS demonstrates therapeutic potential in cancer.
Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Células A549 , Ácido Gálico/farmacologia , Ácido Gálico/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Leucócitos Mononucleares , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêuticoRESUMO
The ongoing evolution of SARS-CoV-2 variants emphasizes the need for vaccines providing broad cross-protective immunity. This study was undertaken to assess the ability of Advax-CpG55.2 adjuvanted monovalent recombinant spike protein (Wuhan, Beta, Gamma) vaccines or a trivalent formulation to protect hamsters againstBeta or Delta virus infection. The ability of vaccines to block virus transmission to naïve co-housed animals was also assessed. In naïve hosts, the Beta variant induced higher virus loads than the Delta variant, and conversely the Delta variant caused more severe disease and was more likely to be associated with virus transmission. The trivalent vaccine formulation provided the best protection against both Beta and Delta infection and also completely prevented virus transmission. The next best performing vaccine was the original monovalent Wuhan-based vaccine. Notably, hamsters that received the monovalent Gamma spike vaccine had the highest viral loads and clinical disease of all the vaccine groups, a potential signal of antibody dependent-enhancement (ADE). These hamsters were also the most likely to transmit Delta virus to naïve recipients. In murine studies, the Gamma spike vaccine induced the highest total spike protein to RBD IgG ratio and the lowest levels of neutralizing antibody, a context that could predispose to ADE. Overall, the study results confirmed that the current SpikoGen® vaccine based on Wuhan spike protein was still able to protect against clinical disease caused by either the Beta or Delta virus variants but suggested additional protection may be obtained by combining it with extra variant spike proteins to make a multivalent formulation. This study highlights the complexity of optimizing vaccine protection against multiple SARS-CoV-2 variants and stresses the need to continue to pursue new and improved COVID-19 vaccines able to provide robust, long-lasting, and broadly cross-protective immunity against constantly evolving SARS-CoV-2 variants.
Assuntos
COVID-19 , Vacinas , Cricetinae , Animais , Humanos , Camundongos , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Adjuvantes Imunológicos , Anticorpos Neutralizantes , Anticorpos AntiviraisRESUMO
BACKGROUND: Surgical treatment options of discoid lateral meniscus in pediatric patients consist of saucerization with or without meniscal repair, meniscocapular stabilization, and, less often, subtotal meniscectomy. PURPOSE: To describe a large, prospectively collected multicenter cohort of discoid menisci undergoing surgical intervention, and further investigate corresponding treatment of discoid menisci. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A multicenter quality improvement registry (16 institutions, 26 surgeons), Sports Cohort Outcomes Registry, was queried. Patient characteristics, discoid type, presence and type of intrasubstance meniscal tear, peripheral rim instability, repair technique, and partial meniscectomy/debridement beyond saucerization were reviewed. Discoid meniscus characteristics were compared between age groups (<14 and >14 years old), based on receiver operating characteristic curve, and discoid morphology (complete and incomplete). RESULTS: In total, 274 patients were identified (mean age, 12.4 years; range, 3-18 years), of whom 55.6% had complete discoid. Meniscal repairs were performed in 55.1% of patients. Overall, 48.5% of patients had rim instability and 36.8% had >1 location of peripheral rim instability. Of the patients, 21.5% underwent meniscal debridement beyond saucerization, with 8.4% undergoing a subtotal meniscectomy. Patients <14 years of age were more likely to have a complete discoid meniscus (P < .001), peripheral rim instability (P = .005), and longitudinal tears (P = .015) and require a meniscal repair (P < .001). Patients ≥14 years of age were more likely to have a radial/oblique tear (P = .015) and require additional debridement beyond the physiologic rim (P = .003). Overall, 70% of patients <14 years of age were found to have a complete discoid meniscus necessitating saucerization, and >50% in this young age group required peripheral stabilization/repair. CONCLUSION: To preserve physiological "normal" meniscus, a repair may be indicated in >50% of patients <14 years of age but occurred in <50% of those >14 years. Additional resection beyond the physiological rim may be needed in 15% of younger patients and 30% of those aged >14 years.
Assuntos
Doenças das Cartilagens , Artropatias , Lesões do Menisco Tibial , Humanos , Criança , Adolescente , Meniscos Tibiais/cirurgia , Meniscos Tibiais/patologia , Estudos de Coortes , Artroscopia/métodos , Lesões do Menisco Tibial/cirurgia , Artropatias/cirurgia , Estudos RetrospectivosRESUMO
A convenient method of applying competition experiments to devise a Hammett correlation in the dissociation by α-cleavage of 17 ionised 3- and 4-substituted benzophenones, YC6H4COC6H5 [Y=F, Cl, Br, CH3, CH3O, NH2, CF3, OH, NO2, CN and N(CH3)2] is reported and discussed. The results given by this approach, which rely on the relative abundance of [M-C6H5]+ and [M-C6H4Y]+ ions in the electron ionisation spectra of the substituted benzophenones, are compared with those obtained by previous methods. Various refinements of the method are considered, including reducing the ionising electron energy, making allowance for the relative abundance of ions such as C6H5+ and C6H4Y+, which may be formed to some extent by secondary fragmentation, and using substituent constants other than the standard σ constants. The reaction constant, ρ, of 1.08, which is in good agreement with that deduced previously, is consistent with a considerable reduction in electron density (corresponding to an increase in positive charge) at the carbon of the carbonyl group during fragmentation. This method has been successfully extended to the corresponding cleavage of 12 ionised substituted dibenzylideneacetones, YC6H4CH=CHCOCH=CHC6H5 (Y=F, Cl, CH3, OCH3, CF3, and NO2), which may fragment to form either a substituted cinnamoyl cation, [YC6H4CH=CHCO]+, or the cinnamoyl cation, [C6H5CH=CHCO]+. The derived ρ value of 0.76 indicates that the substituent, Y, influences the stability of the cinnamoyl cation somewhat less strongly than it does the analogous benzoyl cation.
RESUMO
Current SARS-CoV-2 vaccines provide protection for COVID-19-associated hospitalization and death, but remain inefficient at inhibiting initial infection and transmission. Despite updated booster formulations, breakthrough infections and reinfections from emerging SARS-CoV-2 variants are common. Intranasal vaccination to elicit mucosal immunity at the site of infection can improve the performance of respiratory virus vaccines. We developed SARS-CoV-2 M2SR, a dual SARS-CoV-2 and influenza vaccine candidate, employing our live intranasal M2-deficient single replication (M2SR) influenza vector expressing the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein of the prototype strain, first reported in January 2020. The intranasal vaccination of mice with this dual vaccine elicits both high serum IgG and mucosal IgA titers to RBD. Sera from inoculated mice show that vaccinated mice develop neutralizing SARS-CoV-2 antibody titers against the prototype and Delta virus strains, which are considered to be sufficient to protect against viral infection. Moreover, SARS-CoV-2 M2SR elicited cross-reactive serum and mucosal antibodies to the Omicron BA.4/BA.5 variant. The SARS-CoV-2 M2SR vaccine also maintained strong immune responses to influenza A with high titers of anti H3 serum IgG and hemagglutination inhibition (HAI) antibody titers corresponding to those seen from the control M2SR vector alone. With a proven safety record and robust immunological profile in humans that includes mucosal immunity, the M2SR influenza viral vector expressing key SARS-CoV-2 antigens could provide more efficient protection against influenza and SARS-CoV-2 variants.
RESUMO
Invasive feral swine (Sus scrofa) are one of the most important wildlife species for disease surveillance in the United States, serving as a reservoir for various diseases of concern for the health of humans and domestic animals. Brucella suis, the causative agent of swine brucellosis, is one such pathogen carried and transmitted by feral swine. Serology assays are the preferred field diagnostic for B. suis infection, as whole blood can be readily collected and antibodies are highly stable. However, serological assays frequently have lower sensitivity and specificity, and few studies have validated serological assays for B. suis in feral swine. We conducted an experimental infection of Ossabaw Island Hogs (a breed re-domesticated from feral animals) as a disease-free proxy for feral swine to (1) improve understanding of bacterial dissemination and antibody response following B. suis infection and (2) evaluate potential changes in the performance of serological diagnostic assays over the course of infection. Animals were inoculated with B. suis and serially euthanized across a 16-week period, with samples collected at the time of euthanasia. The 8% card agglutination test performed best, whereas the fluorescence polarization assay demonstrated no capacity to differentiate true positive from true negative animals. From a disease surveillance perspective, using the 8% card agglutination test in parallel with either the buffered acidified plate antigen test or the Brucella abortus/suis complement fixation test provided the best performance with the highest probability of a positive assay result. Application of these combinations of diagnostic assays for B. suis surveillance among feral swine would improve understanding of spillover risks at the national level.
RESUMO
BACKGROUND: The SARS-CoV-2 global pandemic has fuelled the generation of vaccines at an unprecedented pace and scale. However, many challenges remain, including: the emergence of vaccine-resistant mutant viruses, vaccine stability during storage and transport, waning vaccine-induced immunity, and concerns about infrequent adverse events associated with existing vaccines. METHODS: We report on a protein subunit vaccine comprising the receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein, dimerised with an immunoglobulin IgG1 Fc domain. These were tested in conjunction with three different adjuvants: a TLR2 agonist R4-Pam2Cys, an NKT cell agonist glycolipid α-Galactosylceramide, or MF59® squalene oil-in-water adjuvant, using mice, rats and hamsters. We also developed an RBD-human IgG1 Fc vaccine with an RBD sequence of the immuno-evasive beta variant (N501Y, E484K, K417N). These vaccines were also tested as a heterologous third dose booster in mice, following priming with whole spike vaccine. FINDINGS: Each formulation of the RBD-Fc vaccines drove strong neutralising antibody (nAb) responses and provided durable and highly protective immunity against lower and upper airway infection in mouse models of COVID-19. The 'beta variant' RBD vaccine, combined with MF59® adjuvant, induced strong protection in mice against the beta strain as well as the ancestral strain. Furthermore, when used as a heterologous third dose booster, the RBD-Fc vaccines combined with MF59® increased titres of nAb against other variants including alpha, delta, delta+, gamma, lambda, mu, and omicron BA.1, BA.2 and BA.5. INTERPRETATION: These results demonstrated that an RBD-Fc protein subunit/MF59® adjuvanted vaccine can induce high levels of broadly reactive nAbs, including when used as a booster following prior immunisation of mice with whole ancestral-strain spike vaccines. This vaccine platform offers a potential approach to augment some of the currently approved vaccines in the face of emerging variants of concern, and it has now entered a phase I clinical trial. FUNDING: This work was supported by grants from the Medical Research Future Fund (MRFF) (2005846), The Jack Ma Foundation, National Health and Medical Research Council of Australia (NHMRC; 1113293) and Singapore National Medical Research Council (MOH-COVID19RF-003). Individual researchers were supported by an NHMRC Senior Principal Research Fellowship (1117766), NHMRC Investigator Awards (2008913 and 1173871), Australian Research Council Discovery Early Career Research Award (ARC DECRA; DE210100705) and philanthropic awards from IFM investors and the A2 Milk Company.
Assuntos
COVID-19 , Proteínas de Transporte , Cricetinae , Humanos , Camundongos , Ratos , Animais , Vacinas contra COVID-19 , SARS-CoV-2 , Subunidades Proteicas , COVID-19/prevenção & controle , Austrália , Adjuvantes Imunológicos , Anticorpos Neutralizantes , Anticorpos AntiviraisRESUMO
Anthrax is a disease that affects livestock, wildlife, and humans worldwide; however, its relative impacts on these populations remain underappreciated. Feral swine (Sus scrofa) are relatively resistant to developing anthrax, and past serosurveys have alluded to their utility as sentinels, yet empirical data to support this are lacking. Moreover, whether feral swine may assist in the dissemination of infectious spores is unknown. To address these knowledge gaps, we intranasally inoculated 15 feral swine with varying quantities of Bacillus anthracis Sterne 34F2 spores and measured the seroconversion and bacterial shedding over time. The animals also were inoculated either one or three times. The sera were evaluated by enzyme-linked immunosorbent assay (ELISA) for antibodies against B. anthracis, and nasal swabs were cultured to detect bacterial shedding from the nasal passages. We report that the feral swine developed antibody responses to B. anthracis and that the strength of the response correlated with the inoculum dose and the number of exposure events experienced. Isolation of viable bacteria from the nasal passages of the animals throughout the study period suggests that feral swine may assist in the spread of infectious spores on the landscape and have implications for the identification of environments contaminated with B. anthracis as well as the exposure risk to more susceptible hosts.
RESUMO
Oral delivery of an inexpensive COVID-19 (coronavirus disease 2019) vaccine could dramatically improve immunization rates, especially in low- and middle-income countries. Previously, we described a potential universal COVID-19 vaccine, rLVS ΔcapB/MN, comprising a replicating bacterial vector, LVS (live vaccine strain) ΔcapB, expressing the highly conserved SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) membrane and nucleocapsid (N) proteins, which, when administered intradermally or intranasally, protects hamsters from severe COVID-19-like disease after high-dose SARS-CoV-2 respiratory challenge. Here, we show that oral administration of the vaccine also protects against high-dose SARS-CoV-2 respiratory challenge; its protection is comparable to that of intradermal, intranasal, or subcutaneous administration. Hamsters were protected against severe weight loss and lung pathology and had reduced oropharyngeal and lung virus titers. Protection against weight loss and histopathology by the vaccine, which in mice induces splenic and lung cell interferon gamma in response to N protein stimulation, was correlated in hamsters with pre-challenge serum anti-N TH1-biased IgG (IgG2/3). Thus, rLVS ΔcapB/MN has potential as an oral universal COVID-19 vaccine. IMPORTANCE The COVID-19 pandemic continues to rage into its fourth year worldwide. To protect the world's population most effectively from severe disease, hospitalization, and death, a vaccine is needed that is resistant to rapidly emerging viral variants of the causative agent SARS-CoV-2, inexpensive to manufacture, store, and transport, and easy to administer. Ideally, such a vaccine would be capable of oral administration, especially in resource-poor countries of the world where there are shortages of needles, syringes and trained personnel to administer injectable vaccines. Here, we show that oral administration of a bacterium-vectored vaccine meeting all these criteria protects naturally susceptible Syrian hamsters from severe COVID-19-like disease, including severe weight loss and lung pathology, after high-dose SARS-CoV-2 respiratory challenge. As the vaccine is based upon inducing immunity to highly conserved SARS-CoV-2 membrane and nucleocapsid proteins, as opposed to the rapidly mutating Spike protein, it should remain resistant to newly emerging SARS-CoV-2 variants.
RESUMO
Interfaces in heavy metal (HM) - antiferromagnetic insulator (AFI) heterostructures have recently become highly investigated and debated systems in the effort to create spintronic devices that function at terahertz frequencies. Such heterostructures have great technological potential because AFIs can generate sub-picosecond spin currents which the HMs can convert into charge signals. In this work we demonstrate an optically induced picosecond spin transfer at the interface between AFIs and Pt using time-domain THz emission spectroscopy. We select two antiferromagnets in the same family of fluoride cubic perovskites, KCoF3 and KNiF3, whose magnon frequencies at the centre of the Brillouin zone differ by an order of magnitude. By studying their behaviour with temperature, we correlate changes in the spin transfer efficiency across the interface to the opening of a gap in the magnon density of states below the Néel temperature. Our observations are reproduced in a model based on the spin exchange between the localized electrons in the antiferromagnet and the free electrons in Pt. Through this comparative study of selected materials, we are able to shine light on the microscopy of spin transfer at picosecond timescales between antiferromagnets and heavy metals and identify a key figure of merit for its efficiency: the magnon gap. Our results are important for progressing in the fundamental understanding of the highly discussed physics of the HM/AFI interfaces, which is the necessary cornerstone for the designing of femtosecond antiferromagnetic spintronics devices with optimized characteristics.
RESUMO
The electron ionisation mass spectra of an extensive set of 53 ionised monosubstituted and disubstituted cinnamamides [XC6H4CH=CHCONH2, X = H, F, Cl, Br, I, CH3, CH3O, CF3, NO2, CH3CH2, (CH3)2CH and (CH3)3C; and XYC6H3CH=CHCONH2, X = Y = Cl; and X, Y = F, Cl or Br] are reported and discussed. Particular attention is paid to the significance of loss of the substituent, X, from the 2-position, via a rearrangement that is sometimes known as a proximity effect, which has been reported for a range of radical-cations, but is shown in this work to be especially important for ionised cinnamamides. When X is in the 2-position of the aromatic ring, [M - X]+ is formed to a far greater extent than [M - H]+; in contrast, when X is in the 3-position or 4-position, [M - H]+ is generally much more important than [M - X]+. Parallel trends are found in the spectra of XYC6H3CH=CHCONH2: the signal for [M - X]+ dominates that for [M - Y]+ when X is in the 2-position and Y in the 4-position or 5-position, irrespective of the nature of X and Y. Further insight is obtained by studying the competition between expulsion of X· and alternative fragmentations that may be described as simple cleavages. Loss of ·NH2 results in the formation of a substituted cinnamoyl cation, [XC6H4CH=CHCO]+ or [XYC6H3CH=CHCO]+; this process competes far less effectively with the proximity effect when X is in the 2-position than when it is in the 3-position or 4-position. Additional information has been obtained by investigating the competition between formation of [M - H]+ by the proximity effect and loss of CH3· by cleavage of a 4-alkyl group to give a benzylic cation, [R1R2CC6H4CH=CHCONH2]+ (R1, R2 = H, CH3).
RESUMO
BACKGROUND: Monkeypox virus has recently emerged from endemic foci in Africa and, since October 20, 2022, more than 73,000 human infections have been reported by the CDC from over 100 countries that historically have not reported monkeypox cases. The detection of virus in skin lesions, blood, semen, and saliva of infected patients with monkeypox infections raises the potential for disease transmission via routes that have not been previously documented, including by blood and plasma transfusions. Methods for protecting the blood supply against the threats of newly emerging disease agents exist and include Pathogen Reduction Technologies (PRT) which utilize photochemical treatment processes to inactivate pathogens in blood while preserving the integrity of plasma and cellular components. Such methods have been employed broadly for over 15 years, but effectiveness of these methods under routine use conditions against monkeypox virus has not been reported. STUDY DESIGN AND METHODS: Monkeypox virus (strain USA_2003) was used to inoculate plasma and whole blood units that were then treated with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of monkeypox virus in the samples before and after riboflavin + UV treatment were determined by plaque assay on Vero cells. RESULTS: The levels of spiked virus present in whole blood and plasma samples exceeded 103 infectious particles per dose, corresponding to greater than 105 DNA copies per mL. Treatment of whole blood and plasma units under standard operating procedures for the Mirasol PRT System resulted in complete inactivation of infectivity to the limits of detection. This is equivalent to a reduction of ≥ 2.86 +/- 0.73 log10 pfu/mL of infectivity in whole blood and ≥ 3.47 +/-0.19 log10 pfu/mL of infectivity in plasma under standard operating conditions for those products. CONCLUSION: Based on this data and corresponding studies on infectivity in patients with monkeypox infections, use of Mirasol PRT would be expected to significantly reduce the risk of transfusion transmission of monkeypox.