Production of Recombinant Zika Virus Envelope Protein by Airlift Bioreactor as a New Subunit Vaccine Platform.

The Zika Virus (ZIKV) is an emerging arbovirus of great public health concern, particularly in the Americas after its last outbreak in 2015. There are still major challenges regarding disease control, and there is no ZIKV vaccine currently approved for human use. Among many different vaccine platforms currently under study, the recombinant envelope protein from Zika Virus (rEZIKV) constitutes an alternative option for vaccine development and has great potential for monitoring ZIKV infection and antibody response. This study describes a method to obtain a bioactive and functional rEZIKV using an E. coli expression system, with the aid of a 5-L airlift bioreactor and following an automated fast protein liquid chromatography (FPLC) protocol, capable of obtaining high yields of approximately 20 mg of recombinant protein per liter of bacterium cultures. The purified rEZIKV presented preserved antigenicity and immunogenicity. Our results show that the use of an airlift bioreactor for the production of rEZIKV is ideal for establishing protocols and further research on ZIKV vaccines bioprocess, representing a promising system for the production of a ZIKV envelope recombinant protein-based vaccine candidate.

Production of recombinant Zika virus envelope protein by airlift bioreactor as a new subunit vaccine platform

The Zika Virus (ZIKV) is an emerging arbovirus of great public health concern, particularly in the Americas after its last outbreak in 2015. There are still major challenges regarding disease control, and there is no ZIKV vaccine currently approved for human use. Among many different vaccine platforms currently under study, the recombinant envelope protein from Zika Virus (rEZIKV) constitutes an alternative option for vaccine development and has great potential for monitoring ZIKV infection and antibody response. This study describes a method to obtain a bioactive and functional rEZIKV using an E. coli expression system, with the aid of a 5-L airlift bioreactor and following an automated fast protein liquid chromatography (FPLC) protocol, capable of obtaining high yields of approximately 20 mg of recombinant protein per liter of bacterium cultures. The purified rEZIKV presented preserved antigenicity and immunogenicity. Our results show that the use of an airlift bioreactor for the production of rEZIKV is ideal for establishing protocols and further research on ZIKV vaccines bioprocess, representing a promising system for the production of a ZIKV envelope recombinant protein-based vaccine candidate.

Mutational profile confers increased stability of SARS-CoV-2 spike protein in Brazilian isolates.

Spike (S) protein has been recognized as a promising molecular target for diagnostic, vaccines and antiviral drugs development for COVID-19. In this study, we analyzed the most predominant mutations in the S protein of Brazilian isolates and predicted the effect of these amino acid alterations to protein conformation. A total of 25,924 sequences were obtained from GISAID for five regions of Brazilian territory (Midwest, North, Northeast, South, and Southeast), according to exclusion criteria. Most of the SARS-CoV-2 isolates belongs to the G clade and showed a large occurrence of D614G, N501Y and L18F substitutions. Prediction effects of these amino acid substitutions on the structure dynamics of the spike protein indicated a positive ΔΔG values and negative ΔΔSVib in most cases which is associated to structural stabilization and flexibility reduction of the S protein. Mutations E484K, N501Y and K417N belong to several SARS-CoV-2 variants of concern such as Alpha, Beta, Gamma and Delta, and showed high incidence among Brazilian isolates. These mutations have been described to increase RBD affinity to ACE-2 host and abolishment of RBD affinity to potent neutralizing ant-RBD. The increase in rates of infection and reinfection requires continuous genomic surveillance studies in order to characterize emerging mutations and monitor vaccine efficacy, and thus consideration structural data and dynamics in the observed phenotypes.Communicated by Ramaswamy H. Sarma.

Changes in blood lactate concentrations during taekwondo combat simulation.

The aim of this study was to analyze blood lactate response before, during and after simulated taekwondo fight in young male athletes. The experiment was composed of simulated official taekwondo fight. During the experiment a total of 7 blood samples (25 µL) were collected that following: at rest, after 1st, 2nd, and 3rd rounds, and 3, 5, and 10 min after the end of combat. The results showed that blood lactate concentrations [Lac]B increased significantly after 1st, 2nd, and 3rd rounds of the combat compared to the rested values. The [Lac]B after 3rd round was higher when compared to 3, 5, and 10 min of recovery. After 10 min of passive recovery, the [Lac]B was significantly lesser than 3 and 5 min of recovery, and 2nd round. These data showed that taekwondo requires high activation of anaerobic lactic metabolism, and improves the ability to rapidly remove the lactate from blood.

Liver overload in Brazilian triathletes after half-ironman competition is related muscle fatigue.

UNLABELLED: Triathlon competition is dependent on the athletes' ability to perform each discipline at optimal time, without excessive fatigue influencing the next one. OBJECTIVES: Determine the effects of a long distance triathlon on biochemistry parameters related to liver function. DESIGN AND METHODS: Blood samples from six athletes were collected before (T = 0) and immediately after the triathlon competition (T = 1). AST, ALT and alkaline phosphatase (ALP) values were assessed. RESULTS: Significant changes after triathlon competition were found for AST and ALP and no significant changes were found for ALT over time. CONCLUSIONS: A series of metabolically alterations, mainly related to energy production and also to muscle and skeletal adaptations occurs during and after strenuous exercise. The altered status of those metabolical changes cannot directly reflect the intensity of any possible muscular or hepatic damage or overload and elevated AST/ALT ratio is better associated to skeletal muscle lesion during competition.

In vivo inhibition of gastric acid secretion by the aqueous extract of Scoparia dulcis L. in rodents.

The freeze-dried aqueous extract (AE) from the aerial parts of Scoparia dulcis was tested for its effects on experimental gastric hypersecretion and ulcer in rodents. Administration of AE to animals with 4h pylorus ligature potently reduced the gastric secretion with ED(50)s of 195 mg/kg (rats) and 306 mg/kg (mice). The AE also inhibited the histamine- or bethanechol-stimulated gastric secretion in pylorus-ligated mice with similar potency suggesting inhibition of the proton pump. Bio-guided purification of the AE yielded a flavonoid-rich fraction (BuF), with a specific activity 4-8 times higher than the AE in the pylorus ligature model. BuF also inhibited the hydrolysis of ATP by H(+),K(+)-ATPase with an IC(50) of 500 microg/ml, indicating that the inhibition of gastric acid secretion of Scoparia dulcis is related to the inhibition of the proton pump. Furthermore, the AE inhibited the establishment of acute gastric lesions induced in rats by indomethacin (ED(50)=313 mg/kg, p.o.) and ethanol (ED(50)=490 mg/kg, p.o.). No influence of the AE on gastrointestinal transit allowed discarding a possible CNS or a cholinergic interaction in the inhibition of gastric secretion by the AE. Collectively, the present data pharmacologically validates the popular use of Scoparia dulcis in gastric disturbances.

Arginine increases growth hormone gene expression in rat pituitary and GH3 cells.

The effect of arginine (Arg) and Ornitargin (OT) [a compound containing the aminoacids Arg, citrulline (Cit) and ornithine (Orn)] administration upon growth hormone (GH) gene expression was studied both in vivo and in vitro (hemipituitaries and GH3 cells) by Northern blot analysis. For in vivo studies, adult male Wistar rats were anesthetized, subjected to i.v. infusion of 200 microl of 150 mM NaCl (control group), Arg (15 or 150 mg) or OT (15 mg of Arg, 1 mg of Cit and 4 mg of Orn) at a rate of 20 microl/min, and killed 50 min thereafter. For the in vitro studies, hemipituitaries or GH3 cells were incubated in 1 ml of appropriate medium containing Arg (15 or 150 mg) or OT (15 mg of Arg, 1 mg of Cit and 4 mg of Orn) for 60 min. The pituitaries of the in vivo and in vitro studies and GH3 cells were subsequently processed for RNA extraction. Total RNA was subjected to electrophoresis in agarose (1%)/formaldehyde gel, transferred to a nylon membrane and subjected to hybridization with a rat GH (32)P-cDNA, and (32)P-18S rRNA probe to correct for the variability in RNA loading. After autoradiography of the membrane, the abundance of GH mRNA and 18S rRNA bands was quantified by densitometry. The in vivo study demonstrated that Arg and OT infusion induced a 2.3-fold increase in GH mRNA expression, which could result from the Arg-mediated inhibition of somatostatin release. In addition, in vitro Arg, but not OT, induced GH gene expression in hemipituitaries and GH3 cells, indicating that the aminoacid can act per se at the pituitary somatotrope level. In conclusion, our data show for the first time that arginine stimulates GH gene expression in parallel to its recognized GH-releasing activity.