Size-Dependence and High Temperature Stability of Radial Vortex Magnetic Textures Imprinted by Superconductor Stray Fields.

Swirling spin textures, including topologically nontrivial states, such as skyrmions, chiral domain walls, and magnetic vortices, have garnered significant attention within the scientific community due to their appeal from both fundamental and applied points of view. However, their creation, controlled manipulation, and stability are typically constrained to certain systems with specific crystallographic symmetries, bulk or interface interactions, and/or a precise stacking sequence of materials. Recently, a new approach has shown potential for the imprint of magnetic radial vortices in soft ferromagnetic compounds making use of the stray field of YBa2Cu3O7-δ superconducting microstructures in ferromagnet/superconductor (FM/SC) hybrids at temperatures below the superconducting transition temperature (TC). Here, we explore the lower size limit for the imprint of magnetic radial vortices in square and disc shaped structures as well as the persistence of these spin textures above TC, with magnetic domains retaining partial memory. Structures with circular geometry and with FM patterned to smaller radius than the superconductor island facilitate the imprinting of magnetic radial vortices and improve their stability above TC, in contrast to square structures where the presence of magnetic domains increases the dipolar energy. Micromagnetic modeling coupled with a SC field model reveals that the stabilization mechanism above TC is mediated by microstructural defects. Superconducting control of swirling spin textures, and their stabilization above the superconducting transition temperature by means of defect engineering holds promising prospects for shaping superconducting spintronics based on magnetic textures.

Efficacy and safety of a SOD1-targeting artificial miRNA delivered by AAV9 in mice are impacted by miRNA scaffold selection.

Toxic gain-of-function mutations in superoxide dismutase 1 (SOD1) contribute to approximately 2%-3% of all amyotrophic lateral sclerosis (ALS) cases. Artificial microRNAs (amiRs) delivered by adeno-associated virus (AAV) have been proposed as a potential treatment option to silence SOD1 expression and mitigate disease progression. Primary microRNA (pri-miRNA) scaffolds are used in amiRs to shuttle a hairpin RNA into the endogenous miRNA pathway, but it is unclear whether different primary miRNA (pri-miRNA) scaffolds impact the potency and safety profile of the expressed amiR in vivo. In our process to develop an AAV amiR targeting SOD1, we performed a preclinical characterization of two pri-miRNA scaffolds, miR155 and miR30a, sharing the same guide strand sequence. We report that, while the miR155-based vector, compared with the miR30a-based vector, leads to a higher level of the amiR and more robust suppression of SOD1 in vitro and in vivo, it also presents significantly greater risks for CNS-related toxicities in vivo. Despite miR30a-based vector showing relatively lower potency, it can significantly delay the development of ALS-like phenotypes in SOD1-G93A mice and increase survival in a dose-dependent manner. These data highlight the importance of scaffold selection in the pursuit of highly efficacious and safe amiRs for RNA interference gene therapy.

Identification and molecular characterization of Orfvirus infection in occupationally exposed women inSouth America

Abstract Contagious Ecthyma (CE) is a severe exanthematous dermatitis caused by the Orf virus (ORFV) that mainly affects domestic small ruminants such as sheep and goats. It is a worldwide-distributed occupational zoonosis, particularly infecting those in close contact with animals or animal products such as shepherds, farmers and veterinarians, among others. In the present work, we report the first human CE case confirmed in Argentina. A phylogenetic analysis based on four gene sequences of the isolated strain responsible for the disease showed that this isolate grouped with other ORFV sequences that caused reported CE cases in sheep from the same Argentine province. We also sequenced a sample from a Chilean human case reported in 2017, whose phylogenetic analysis showed that it groups together with other Argentine isolates from locations close to the border with Chile. Keywords: Contagious Ecthyma; Dermatitis; Human Orf; Zoonosis; Molecular characterization.

Resumen El ectima contagioso (EC) es una dermatitis exantemática grave causada por el virus Orf (ORFV), que afecta mayormente a pequeños rumiantes domésticos, como ovinos y caprinos. Es una zoonosis ocupacional con distribución mundial, infecta a humanos en estrecho contacto con animales o sus productos, como granjeros, esquiladores y veterinarios, entre otros. En este trabajo se informa el primer caso humano de EC confirmado en Argentina. Un análisis filogenético basado en cuatro genes de la cepa responsable de este caso mostró que el aislamiento agrupa con otras secuencias de ORFV que causaron casos en ovinos en la misma provincia argentina. También se secuenció una muestra del caso de ectima humano reportado en Chile en 2017 y el análisis filogenético mostró que dicho aislamiento forma un grupo con otros aislamientos argentinos de localidades cercanas a la frontera con Chile. Palabras clave: Ectima contagioso; Dermatitis; Orf en humanos; Zoonosis; Caracterización molecular.

Large Magnetoresistance of Isolated Domain Walls in La2/3 Sr1/3 MnO3 Nanowires.

Generation, manipulation, and sensing of magnetic domain walls are cornerstones in the design of efficient spintronic devices. Half-metals are amenable for this purpose as large low field magnetoresistance signals can be expected from spin accumulation at spin textures. Among half metals, La1- x Srx MnO3 (LSMO) manganites are considered as promising candidates for their robust half-metallic ground state, Curie temperature above room temperature (Tc = 360 K, for x = 1/3), and chemical stability. Yet domain wall magnetoresistance is poorly understood, with large discrepancies in the reported values and conflicting interpretation of experimental data due to the entanglement of various source of magnetoresistance, namely, spin accumulation, anisotropic magnetoresistance, and colossal magnetoresistance. In this work, the domain wall magnetoresistance is measured in LSMO cross-shape nanowires with single-domain walls nucleated across the current path. Magnetoresistance values above 10% are found to be originating at the spin accumulation caused by the mistracking effect of the spin texture of the domain wall by the conduction electrons. Fundamentally, this result shows the importance on non-adiabatic processes at spin textures despite the strong Hund coupling to the localized t2g electrons of the manganite. These large magnetoresistance values are high enough for encoding and reading magnetic bits in future oxide spintronic sensors.

Demographic and socioeconomic correlates to buprenorphine access in pharmacies.

BACKGROUND: Research has focused on buprenorphine prescribing with limited attention to the role of pharmacy access to buprenorphine for opioid use disorder. OBJECTIVE: This study examines demographic and socioeconomic correlates to buprenorphine access in Georgia pharmacies. METHODS: A 5-question (12 potential subqueries) telephone administered survey was used to investigate access and stocking patterns of specific dosages and formulations of buprenorphine in Georgia pharmacies (n = 119). Descriptive statistics characterized physician and pharmacy demographics and buprenorphine stocking practices. Correlations between various factors including buprenorphine stocking practices, geographic, and sociodemographic characteristics were identified using nonlinear regression models. RESULTS: The majority of pharmacies stocked the most commonly prescribed 8/2 mg dosage strength of buprenorphine/naloxone films and tablets (69.0% and 63.0%, respectively). Other strengths were less likely to be readily available. Pharmacies in Suburban Census tracts were 77.0% more likely to stock any type of buprenorphine monotherapy [odds ratio (OR) = 1.77, t = 2.37, P < 0.05] and 58.1% more likely to stock the 8 mg buprenorphine monotherapy formulation [OR = 1.58, t = 2.15, P < 0.05] than Urban tracts. Pharmacies in areas with above-average non-White populations were 29.6% more likely to stock a monotherapy product [OR = 1.30, t = 2.16, P < 0.05], and those in areas with above-average poverty rates were more likely to stock the 8 mg/2 mg buprenorphine/naloxone tablets [OR = 1.04, t = 2.02, P < 0.05]. There were no additional differences across the sample in formulation or dosage strengths. Pharmacists who endorsed challenges dispensing buprenorphine (23.3%) cited issues around insurance coverage, payment difficulty, prior authorization issues, and low stock of specific formulations. CONCLUSIONS: Results suggest that low availability of certain dosages or formulations of buprenorphine in local pharmacies could obstruct access for patients. Future research should address barriers to supplying buprenorphine and collaborative measures between pharmacists and prescribers to improve access.

Assessing the hidden diversity underlying consensus sequences of SARS-CoV-2 using VICOS, a novel bioinformatic pipeline for identification of mixed viral populations.

INTRODUCTION: Coinfection with two SARS-CoV-2 viruses is still a very understudied phenomenon. Although next generation sequencing methods are very sensitive to detect heterogeneous viral populations in a sample, there is no standardized method for their characterization, so their clinical and epidemiological importance is unknown. MATERIAL AND METHODS: We developed VICOS (Viral COinfection Surveillance), a new bioinformatic algorithm for variant calling, filtering and statistical analysis to identify samples suspected of being mixed SARS-CoV-2 populations from a large dataset in the framework of a community genomic surveillance. VICOS was used to detect SARS-CoV-2 coinfections in a dataset of 1,097 complete genomes collected between March 2020 and August 2021 in Argentina. RESULTS: We detected 23 cases (2%) of SARS-CoV-2 coinfections. Detailed study of VICOS's results together with additional phylogenetic analysis revealed 3 cases of coinfections by two viruses of the same lineage, 2 cases by viruses of different genetic lineages, 13 were compatible with both coinfection and intra-host evolution, and 5 cases were likely a product of laboratory contamination. DISCUSSION: Intra-sample viral diversity provides important information to understand the transmission dynamics of SARS-CoV-2. Advanced bioinformatics tools, such as VICOS, are a necessary resource to help unveil the hidden diversity of SARS-CoV-2.

Identification and molecular characterization of Orf virus infection in occupationally exposed women in South America.

Contagious Ecthyma (CE) is a severe exanthematous dermatitis caused by the Orf virus (ORFV) that mainly affects domestic small ruminants such as sheep and goats. It is a worldwide-distributed occupational zoonosis, particularly infecting those in close contact with animals or animal products such as shepherds, farmers and veterinarians, among others. In the present work, we report the first human CE case confirmed in Argentina. A phylogenetic analysis based on four gene sequences of the isolated strain responsible for the disease showed that this isolate grouped with other ORFV sequences that caused reported CE cases in sheep from the same Argentine province. We also sequenced a sample from a Chilean human case reported in 2017, whose phylogenetic analysis showed that it groups together with other Argentine isolates from locations close to the border with Chile.

Exceso de mortalidad en México en 2020: una estimación preliminar a nivel nacional y estatal / Excess mortality in Mexico 2020: a preliminary estimate at national and state level

Resumen Como consecuencia directa o indirecta de la pandemia de COVID-19, junto con otros problemas de salud pública preexistentes, México se ha posicionado como uno de los países más afectados en cuanto al exceso de mortalidad, la cual está prácticamente generalizada, pero es heterogénea según el estado. Por ello, se tiene por objetivo cuantificarla a nivel nacional y estatal por medio del porcentaje de exceso de mortalidad (% 𝐸𝑀) y de diferencias en esperanzas de vida (𝐸𝑀𝑒𝑥 ) por sexo. En particular, para 𝐸𝑀𝑒𝑥 , se construyeron tablas de mortalidad con tasas específicas que se suavizan de manera controlada y por segmentos, con un enfoque no paramétrico. Los resultados mostraron una demasía en la población masculina y en algunos estados del país. Asimismo, respecto a 𝐸𝑀𝑒𝑥 , se evidenciaron fuertes retrocesos en la esperanza de vida en ciertos casos, incluida la capital del país: la Ciudad de México.

Abstract As a direct or indirect consequence of the COVID-19 pandemic, joint other punlic health problems, Mexico is one of the most affected countries in terms of excess mortality, which is generalized and heterogeneous at the state level. That is why, the papers aim is to quantify it at national and subnational level both through the percentage of excess mortality (% 𝐸𝑀) and using differences in life expectancies (𝐸𝑀𝑒𝑥 ) by sex. For (𝐸𝑀𝑒𝑥 ), mortality tables are constructed with specific rates that are estimated through a non-parametric approach so-called controlled and segmented smoothing. The results show the greatest excesses in male population and for some states of the country. Likewise, regarding 𝐸𝑀𝑒𝑥 , strong setbacks in life expectancy can be observed including the Mexico City.

Anthropogenic Infection of Domestic Cats With SARS-CoV-2 Alpha Variant B.1.1.7 Lineage in Buenos Aires.

SARS-CoV-2 reverse zoonosis, particularly to domestic animals, and the potential role of infected animals in perpetuating the spread of the virus is an issue of increasing concern. In this case report, we identified the natural infection of two cats by SARS-CoV-2, in Argentina, whose owner had been previously infected by SARS-CoV-2. Viral genetic material was detected in feline oropharyngeal (OP) and rectal (R) swab by RT-qPCR, and sequence analysis revealed that the virus infecting the owner and one cat were genetically similar. The alpha variant (B.1.1.7 lineage) was identified with a unique additional mutation, strongly suggesting human-to-cat route of transmission. This study reinforces the One Health concept and the importance of integrating human, animal, and environmental perspectives to promptly address relevant health issues.

Detection and first molecular characterization of bovine papular stomatitis virus in dairy calves in Argentina.

Bovine papular stomatitis virus (BPSV) is a parapoxvirus associated with papular and erosive lesions on the muzzle, lips, and oral mucosa of cattle. BPSV infection occurs worldwide; however, it has still not been unequivocally diagnosed. The present report describes an outbreak of BPSV infection affecting dairy calves in northwestern Argentina and provides the first molecular characterization of this virus in the country. The disease was detected in a dairy farm, affecting 33 calves between 2 and 20 days of age. The signs included reddish papules, ulcers, and scabby proliferative lesions on muzzle, lips, and oral mucosa. The affected calves resisted to being fed due to severe local pain. Two necropsies were performed; papulas and ulcers were observed in ruminal and omasal mucosa. Histologically, the affected areas of the skin showed acanthosis, spongiosis, and parakeratotic hyperkeratosis with adjacent focally extensive ulcers and multifocal inflammatory infiltrate in the epidermis. Eosinophilic inclusion bodies were detected in the cytoplasm of epithelial cells. DNA extracted from scab samples was analyzed by PCR using pan-parapoxvirus primers for the B2L gene. The sequence analysis revealed 99%, 85%, and 84% similarity with BPSV, Pseudocowpox virus, and Orf virus, respectively. A phylogenetic tree constructed using the B2L sequence showed that the virus clustered with BPSV isolates. Although clinical cases compatible with BSPV infection have been frequently described in Argentina, the present report is the first to identify the agent associated with cattle disease in the country.

Rotavirus RNAs sponge host cell RNA binding proteins and interfere with their subcellular localization.

Cellular mRNAs cycle between translating and non-translating pools, polysomes compose the translating pool, while RNA granules contain translationally-silenced mRNAs, where the RNAs are either stored in stress granules, or accumulate in processing bodies (PBs) or GW-bodies, which have an important role in RNA degradation. Viruses have developed measures to prevent the deleterious effects of these structures during their replication. Rotavirus, the most common agent of viral gastroenteritis, is capable of establishing a successful infection by counteracting several of the antiviral responses of its host. Here, we describe that in rotavirus-infected cells the distribution of several RNA binding proteins is changed causing the disaggregation of PBs, the relocalization of GW-body proteins, and the cytoplasmic accumulation of HuR, a predominantly nuclear protein. We show that this redistribution of proteins is more likely caused by the accumulation of viral RNA in the cytoplasm of infected-cells, where it might be acting as an RBP sponge.

Phylogenetic Analysis of ORF Viruses From Five Contagious Ecthyma Outbreaks in Argentinian Goats.

Orf virus (ORFV) is the etiological agent of Contagious Ecthyma (CE) disease that mainly affects sheep, goats, wild ruminants, and humans with a worldwide distribution. To date, only two strains from Argentinian sheep have been characterized at the molecular level and there is little information on ORFV strains circulating in Argentina. Here we describe and analyze five outbreaks of CE in goats in three geographic regions of the country: Northwest, Center, and Southwest. The phylogenetic analysis based on four molecular markers of ORFV (orf011 partial sequence and orf020, orf109, and orf127 complete sequence genes) revealed that there are different strains circulating in Argentina and pointed out the importance of knowing the health status of animals traded between farms.

Synthesis and Binding Properties of Monohydroxycucurbit[7]uril: A Key Derivative for the Functionalization of Cucurbituril Hosts.

We present a simple, direct method to prepare monohydroxylated cucurbit[7]uril (CB7-OH) through the direct oxidation of its precursor host, cucurbit[7]uril (CB7). Although the conversion takes place in low yield (14%), the isolation of CB7-OH from the reaction mixture is straightforward, and the unreacted CB7 can be easily recovered. ITC measurements with several selected guests confirmed that CB7-OH binds all of them in aqueous solution with similar, albeit slightly lower, binding affinities than those observed with the unmodified CB7 host. ESI mass spectrometric competition experiments are consistent with the ITC measurements. A variety of spectroscopic and voltammetric measurements also verify that the CB7-OH complexes exhibit properties essentially identical to those of the CB7 complexes. DFT computational data also confirm the similar thermodynamic stabilities and structures of the CB7-OH and CB7 inclusion complexes. Finally, the high thermodynamic stability of the CB7-OH complexes was used to improve on the extraction efficiency of stir bar sorptive extraction methods after suitable modification of the active coating with CB7-OH.

Virus orf en humanos, confirmación molecular de un caso clínico en Chile / Orf virus in human, confirmation in case report from Chile

Resumen La infección por el virus orf, también conocida como ectima contagioso, es reconocida una zoonosis ocupacional. Se diagnostica por lesiones cutáneas que evolu cionan rápidamente desde máculas a pápulas, vesículas y pústulas. Se presenta el caso clínico de una estudiante de medicina veterinaria que había tenido contacto con caprinos, clínicamente sanos y sin lesiones aparentes, hacía 19 días. Presentó dos lesiones vesiculares que coalescieron hasta formar una lesión de mayor tamaño rodeada por un halo eritematoso. Las lesiones fueron compatibles con la presentación clásica de las producidas por el virus orf en humanos. Se confirmó la presencia del virus orf mediante una RPC anidada del tejido de biopsia. Es uno de los primeros casos confirmados mediante técnicas moleculares en seres humanos en Chile.

Infection with the orf virus, also known as contagious ecthyma, is recognized as an occupational zoonosis worldwide. It is diagnosed by cutaneous lesions that progress rapidly from macules to papules, vesicles and pustules. The clinical case of a student of veterinary medicine who had had contact with goats, clinically healthy and without apparent lesions, which occured 19 days ago, is reported. She presented two vesicular lesions that coalesced to form a larger lesion surrounded by an erythematous halo. The lesions were compatible with the classical presentation of those produced by the orf virus in humans. The presence of the orf virus was confirmed by a nested PCR from biopsy tissue. It is one of the first cases confirmed by molecular techniques in humans in Chile.

The localization of a heterologous displayed antigen in the baculovirus-budded virion determines the type and strength of induced adaptive immune response.

In the search of strategies of presentation of heterologous antigens to elicit humoral or cellular immune responses that modulate and properly potentiate each type of response, researchers have been studying baculovirus (BV) as vaccine vectors with promising results. For some years, several research groups explored different antigen presentation approaches using the BV AcNPV by expressing polypeptides on the surface of budded virions or by de novo synthesis of heterologous antigens by transduction of mammalian cells. In the case of expression on the surface of budded virions, for example, researchers have expressed polypeptides in peplomers as GP64 glycoprotein fusions or distributed throughout the entire surface by fusions to portions of the G protein of vesicular stomatitis virus, VSV. Recently, our group developed the strategy of cross-presentation of antigens by fusions of GP64 to the capsid protein VP39 (capsid display) for the generation of cytotoxic responses. While the different strategies showed to be effective in raising immune responses, the individuality of each analysis makes difficult the comparison of the results. Here, by comparing the different strategies, we show that localization of the model antigen ovalbumin (OVA) strongly determined the quality and intensity of the adaptive response to the heterologous antigen. Furthermore, surface display favored humoral responses, whereas capsid display favored cytotoxic responses. Finally, capsid display showed a much more efficient strategy to activate CD8-mediated responses than transduction. The incorporation of adjuvants in baculovirus formulations dramatically diminished the immunostimulatory properties of baculovirus.

[Orf virus in human, confirmation in case report from Chile]. / Virus orf en humanos, confirmación molecular de un caso clínico en Chile.

Infection with the orf virus, also known as contagious ecthyma, is recognized as an occupational zoonosis worldwide. It is diagnosed by cutaneous lesions that progress rapidly from macules to papules, vesicles and pustules. The clinical case of a student of veterinary medicine who had had contact with goats, clinically healthy and without apparent lesions, which occured 19 days ago, is reported. She presented two vesicular lesions that coalesced to form a larger lesion surrounded by an erythematous halo. The lesions were compatible with the classical presentation of those produced by the orf virus in humans. The presence of the orf virus was confirmed by a nested PCR from biopsy tissue. It is one of the first cases confirmed by molecular techniques in humans in Chile.

Morfología craneofacial en niños con apnea obstructiva del sueño craneofacial / Craniofacial morphology in children with obstructive sleep apnea

Antecedentes: La apnea obstructiva del sueño (AOS) es un trastorno respiratorio asociado con alteraciones faciales y esqueléticas. Objetivo: Identificar las características craneofaciales asociadas a AOS en niños colombianos. Métodos: Se seleccionaron 43 niños entre 6 y 13 años con estudio polisomnográfico para trastornos del sueño. Los niños seleccionados se distribuyeron en grupo caso (19 niños con AOS) y grupo control (24 sin AOS), y se les tomaron radiografías laterales. Las variables cefalométricas analizadas fueron: longitud anteroposterior del cráneo (SN), clasificación esquelética (ANB), longitud efectiva mandibular (Co-Pg) y maxilar (Co-A), posición sagital maxilar (N┴A) y mandibular (N┴Pg), ángulo del plano mandibular (FH-PM), eje de crecimiento facial de Ricketts (Ba-N / PTM-Gn), espacios faríngeo superior e inferior y posición del hueso hioides (HPM). Resultados: El 84,2% de niños con AOS mostró una disminución de la longitud de la base de cráneo, en comparación con el 58,3% de niños sin AOS (p = 0,067 y OR =3,81, IC: 0,87-16,7). La posición superior del hueso hioides estuvo asociada con la ausencia de AOS (OR = 0,26 IC: 0,87-16,7). Conclusiones : Los resultados de esta investigación, a pesar de que no fueron estadísticamente significativos, muestran una tendencia que sugiere una relación entre la longitud de la base del cráneo y la posición del hioides con la presencia de AOS en niños.

Background: Obstructive sleep apnea (OSA) is a Sleep breathing disorder in children associated with facial and skeletal features. Purpose: to identify craniofacial features associated with OSA in Colombian children. Method: 43 children from 6-13 years old were selected for cephalometric measurements. All patients had been studied trough polysomnography. Cases were represented for 19 children with OSA and 24 children without OSA were grouped as controls, and lateral radiographs were taken. Cephalometric variables analyzed were: anteroposterior cranial length (SN), skeletal classification (ANB), effective mandibular and maxillary length (Co-Pg) (Co-A), sagittal position of maxillary and mandible (N┴A) (N┴Pg), mandibular plane angle (FH-PM), Ricketts growth axis angle (Ba-N/Ptm-Gn), upper and lower pharynx and hyoid Bone position (HPM). Results: 84.2% of children with OSA showed a decrease in the length of cranial base compared with 58.3% of children without OSA (p = 0.067; OR = 3.81 95% CI 0.87- 16.7). The superior bone hyoid position is associated with absence of OSA (OR = 0.26 95% CI 0.87 to 16.7.) Conclusions: these results suggest trends to relation between length of cranial base and bone hyoid position e and the presence of OSA in children.

Identification and molecular characterization of Orf virus in Argentina.

Orf virus (ORFV) is the etiological agent of contagious ecthyma (CE), a pustular dermatitis of sheep and goats. Outbreaks of ORFV have been observed in all geographical regions of the world, including Argentina. The origin and identity of Argentinian ORFVs are unknown, and no comparative or phylogenetic studies of these viruses have been performed. In this study, we described the sequencing and analysis of five ORFV molecular markers: a partial B2L gene (ORF011), VIR (ORF020), an envelope mature protein (ORF109), vIL10 (ORF127), and GIF (ORF117) from two particular Argentinian outbreaks of CE.

Functional and biochemical properties of Mal de Río Cuarto virus (Fijivirus, Reoviridae) P9-1 viroplasm protein show further similarities to animal reovirus counterparts.

Mal de Río Cuarto virus (MRCV) is a plant virus of the genus Fijivirus within the family Reoviridae that infects several monocotyledonous species and is transmitted by planthoppers in a persistent and propagative manner. Other members of the family replicate in viral inclusion bodies (VIBs) termed viroplasms that are formed in the cytoplasm of infected plant and insect cells. In this study, the protein coded by the first ORF of MRCV segment S9 (P9-1) was shown to establish cytoplasmic inclusion bodies resembling viroplasms after transfection of Spodoptera frugiperda insect cells. In accordance, MRCV P9-1 self-associates giving rise to high molecular weight complexes when expressed in bacteria. Strong self-interaction was also evidenced by yeast two-hybrid assays. Furthermore, biochemical characterization showed that MRCV P9-1 bound single stranded RNA and had ATPase activity. Finally, the MRCV P9-1 region required for the formation of VIB-like structures was mapped to the protein carboxy-terminal half. This extensive functional and biochemical characterization of MRCV P9-1 revealed further similarities between plant and animal reovirus viroplasm proteins.

Chimeric recombinant rotavirus-like particles as a vehicle for the display of heterologous epitopes.

In order to improve the presentation and immunogenicity of single epitopes, virus-like particles (VLPs) are being used as platforms for the display of foreing epitopes on their surface. The rotavirus major capsid protein VP6 has the ability to self-assemble into empty non-infectious VLPs. In the present study, we analyzed the use of double layered VLPs (made up of VP2 and VP6 rotavirus proteins) as carriers to display a 14 amino acid epitope fused to three different aminoacidic regions of VP6 exposed on the surface of VLPs. Although all chimeric protein were correctly expressed in insect cells, only one of them resulted in spontaneous assembly of VLPs displaying the heterologous epitope on their surface, confirmed by sandwich ELISA and electron microscopy. Furthermore, the injection of chimeric VLPs into mice elicited higher antibody titers than the monomeric chimeric protein. Our results identify an specific amino acid region of VP6 which allows the insertion of at least a 14 amino acid heterolgous epitope and demonstrate its potential as immunogenic carrier.