Rotation Estimation Based on Anisotropic Angular Radon Spectrum

In this letter, we present the anisotropic Angular Radon Spectrum (ARS), a novel feature for global estimation of rotation in a two dimension space. ARS effectively describes collinearity of points and has the properties of translation-invariance and shift-rotation. We derive the analytical expression of ARS for Gaussian Mixture Models (GMM) representing point clouds where the Gaussian kernels have arbitrary covariances. Furthermore, we developed a preliminary procedure for simplification of GMM suitable for efficient computation of ARS. Rotation between point clouds is estimated by searching of maximum of correlation between their spectra. Correlation is efficiently computed from Fourier series expansion of ARS. Experiments on datasets of distorted object shapes, laser scans and on robotic mapping datasets assess the accuracy and robustness to noise in global rotation estimation

Expression of rabies VLPs in adherence and suspension conditions: a flexible platform for rabies vaccine production

Rabies is a zoonotic viral disease with a mortality by close to 100%. As there is not an efficacious treatment available, post-exposure vaccination is recommended for individuals in contact with the virus. On the other hand, the most common source of virus transmission is saliva of infected animals, mostly dogs, whereby mass vaccination of pets is the most cost‑effective way to reduce human infections. In this context, availability of both human and veterinary vaccines is critical. In previous works1-2, our group developed immunogenic rabies VLPs, expressing the virus glycoprotein in HEK293 cells. We obtained a producer clone capable of growing in adherence (adhP2E5) and then adapted to suspension conditions (sP2E5). In this work, we analyzed the production of VLPs in both conditions, using two different platforms. On the one hand, adhP2E5 was cultured in 850 cm2 roller bottles (GBO) using medium with 5% FCS, that was exchanged every 48 h during the first 10 days and every 24 h during the last 5 days. RV-VLPs were continuously produced and the harvest obtained (2.5 L per bottle) was analyzed by sandwich ELISA, using the 6th International Standard for rabies vaccine that quantify the glycoprotein content (NIBSC), presenting a value of 19 IU.ml‑1 in average. On the other hand, we cultured sP2E5 in a 5 L bioreactor during 15 days, using EX‑CELL293 SFM (SAFC). The culture reached densities of 2x107 cel.ml-1 and VLPs were continuously secreted to the supernatant. The obtained harvest (28.5 L) presented a glycoprotein content of 28 IU.ml-1, a results that is comparable with the previous one taking into account the number of cells presents in both conditions. These results showed that our clone could be cultured in both platforms depending on the objectives and characteristics of the desired product. For the production of the rabies veterinary vaccine, RV-VLPs can be produced in adherent conditions using medium supplemented with FCS and, for human vaccine production, RV-VLPs can be produced in bioreactors using SFM. 1 Fontana et al. Rabies virus-like particles expressed in HEK293 cells. Vaccine 32 (2014) 2799-2804. 2 Fontana et al. Immunogenic virus-like particles continuously expressed in mammalian cells as a veterinary rabies vaccine candidate. Vaccine 33 (2015) 4238-4246

Rational design, expression and characterization of chimeric rabies VLPs displaying the major antigenic site of Foot and Mouth Disease Virus

Virus-like Particles (VLPs) are supramolecular arrangements of one or more viral proteins that resemble the structure of the native virus but are not infective, due the fact that they lack the viral genome. They have become very important in the field of novel recombinant vaccines, because of their biosafety and improved immunogenicity over subunit vaccines due to their particulate nature and highly repetitive epitope display. Moreover, they can elicit immune responses against heterologous antigens by the incorporation of epitopes by genic fusion to the viral proteins, constituting chimeric VLPs (cVLPs). In a previous work, by recombinant expression of the rabies G glycoprotein (RVG) in HEK293 cells, we stablished a platform to produce rabies VLPs as a new generation vaccine candidate 1–3. The main goal of this work was to generate a platform for heterologous antigen presentation based on RVG cVLPs. The heterologous epitope chosen for this study was the immunodominant site of Foot-and-Mouth Disease Virus (FMDV), named G-H loop (that is part of the capsid protein VP1), which is responsible of virus entry into the cell 4. Please click Download on the upper right corner to see the full abstract

Study of rabies VLPs expression in BHK-21 cell line for vaccine applications

In the last decades, virus-like particles (VLPs) have played an essential role in the development of novel vaccines due the fact that they trigger robust and balanced immune responses and, as they lack viral genome, are biosafe. Nowadays, several VLPs are commercially available for human use and one veterinary product was licensed. Besides, other VLP‑based vaccine candidates are in the stages of clinical trials or preclinical evaluation. Our group had previously developed a rabies glycoprotein based-VLP (RV-VLPs) expressed in HEK293 cells. These RV-VLPs were fully characterized and their capacity to induce a protective response and neutralizing antibodies production was confirmed. As inactivated veterinary vaccines for rabies are usually produced using BHK‑21, the goal of the present work was to develop a RV-VLPs expressing BHK‑21 cell line to analyze the characteristics of the VLPs produced using this cell substrate. Therefore, by lentivirus vector-mediated transduction, we generated a rabies virus glycoprotein expressing a stable cell line. The cellular expression of the recombinant protein was analyzed by flow cytometry and the membrane localization was confirmed by fluorescent microscopy. Later, RV-VLPs budding to the supernatant was analyzed by sandwich ELISA. After that, VLPs were purified by density gradient ultracentrifugation and the hydrodynamic diameter of the particles was analyzed by DLS. In a western blot assay, the particles were recognized by specific antibodies present in a rabies polyclonal serum. Finally, the recombinant cell line was cultured in 850 cm2 roller bottles producing RV-VLPs continuously during 25 days of culture. Thus, these results encourage further studies to confirm if BHK-21 is a good cell substrate for the production of RV-VLPs as a veterinary rabies vaccine candidate

Reproducción de Passer montanus y Passer domesticus en el término municipal de Huesca en los años 2015,2017,2020 y 2021

El Gorrión molinero (Passer montanus) y el Gorrión común (Passer domesticus) son dos aves passeriformes omnívoras y pueden habitar en diferentes hábitats. Ambas especies se pueden encontrar por toda la Península Ibérica y presentan similitudes en el período reproductor debido a que en su mayoría comienzan en el mes de abril y mayo y finalizan en los meses de julio y agosto. Este trabajo ha estudiado algunas variables reproductivas de las dos especies en Huesca en los años 2015, 2017, 2020 y 2021. La duración media de las puestas fue de 23,14 días para P. montanus y 28, 3 días para P. domesticus. En lo referente a número de huevos y pollos nacidos por pareja, P. domesticus cifró un mayor número de huevos y pollos, 5 y 3,97 respectivamente, en comparación a P. montanus que registró 4,1 y 3,32 mostrando una mayor capacidad reproductiva. Sin embargo, el éxito reproductivo y el porcentaje de eclosión se vieron favorecidos en P. montanus (ER = 55,74 % y %E = 71,22%) frente a los obtenidos por P. domesticus (ER = 50,81% y %E = 66,06%). Los factores ambientales, precipitación y temperatura, parecen no influir en la reproducción de las especies estudiadas.<br /

Chimeric VLPs Based on HIV-1 Gag and a Fusion Rabies Glycoprotein Induce Specific Antibodies against Rabies and Foot-and-Mouth Disease Virus

Foot and mouth disease is a livestock acute disease, causing economic losses in affected areas. Currently, control of this disease is performed by mandatory vaccination campaigns using inactivated viral vaccines. In this work, we describe the development of a chimeric VLP-based vaccine candidate for foot-and-mouth disease virus (FMDV), based on the co-expression of the HIV-1 Gag protein and a novel fusion rabies glycoprotein (RVG), which carries in its N-term the FMDV main antigen: the G-H loop. It is demonstrated by confocal microscopy that both Gag-GFP polyprotein and the G-H loop colocalize at the cell membrane and, that the Gag polyprotein of the HIV virus acts as a scaffold for enveloped VLPs that during the budding process acquires the proteins that are being expressed in the cell membrane. The obtained VLPs were spherical particles of 130 ± 40 nm in diameter (analyzed by TEM, Cryo-TEM and NTA) carrying an envelope membrane that efficiently display the GH-RVG on its surface (analyzed by gold immunolabeling). Immunostainings with a FMDV hyperimmune serum showed that the heterologous antigenic site, genetically fused to RVG, is recognized by specific G-H loop antibodies. Additionally, the cVLPs produced expose the G-H loop to the liquid surrounding (analyzed by specific ELISA). Finally, we confirmed that these FMD cVLPs are able to induce a specific humoral immune response, based on antibodies directed to the G-H loop in experimental animals

Optimized somatic embryogenesis and plant regeneration in elite Argentinian sugarcane (Saccharum spp.) cultivars

Background: Biotechnological breeding of elite sugarcane cultivars is currently limited because of the difficulty of regenerating plants by tissue culture. Here, we report that commercially elite sugarcane genotypes, which are adapted to Argentinian agro-ecological conditions, are capable of being regenerated via indirect somatic embryogenesis. Leaf rolls of five elite genotypes were cultured following two callus induction protocols using different concentrations of 2,4-D as the growth regulator. Embryogenic calluses were regenerated under light conditions. Regenerated plants were subsequently acclimatized in the greenhouse under two acclimatization procedures before being transplanted to the field. Results: Four of the five genotypes were able to form somatic embryos following the two induction protocols. The variables related to embryogenic callus production were influenced by the interaction between genotype and culture conditions. For plant regeneration, the embryogenic calluses were further cultured on an IBA-supplemented medium, where we observed a high genotype dependence. Calluses from the four cultivars regenerated a good number of plants. With the procedures described here, we obtained more than 90% of well-acclimatized plants both in the greenhouse and in the field. Conclusions: This protocol provides a simple way to regenerate sugarcane plants through indirect somatic embryogenesis. Also, the results confirm that tissue culture ability is highly genotype-dependent in sugarcane. Our findings suggest that these elite cultivars could be good candidates for biotechnological breeding.EEA FamailláFil: Di Pauli, Valentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Fontana, Paola Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Lewi, Dalia Marcela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Felipe, Arturo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Erazzú, Luis E. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina

Protein design and immunogenic analysis of COVID-19 vaccine candidates based on RBD/trimeric-spike antigens and chimeric VLPs antigens

Spike glycoprotein (S) and its Receptor Binding Domain region (RBD) are the main targets of neutralizing antibodies during an infection with SARS-CoV-2, the etiologic agent of COVID-19 pandemic viral disease. Thus, they are the chosen antigens for the development of diagnostic kits and vaccines candidates. Furthermore, Virus-like Particles (VLPs) constitute potent immunogens that have been engineered to obtain vaccine candidates through expression of SARS-CoV-2 S, M, E and N proteins. Although it might be a challenging platform, as multiple proteins must be expressed in order to assure VLP budding, they are able to induce stronger immune responses than soluble antigens due to their particulate nature and highly repetitive antigen display. Hence, we aimed to generate a serum-free platform to produce soluble SARS-CoV-2 antigens and design a novel chimeric VLP (cVLP) exposing the prefusion stabilized S ectodomain on its surface. Please click Download on the upper right corner to see the full abstract