ABSTRACT
The Receptor-Binding Domain (RBD) of the Spike (S) protein from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has glycosylation sites which can limit the production of reliable antigens expressed in prokaryotic platforms, due to glycan-mediated evasion of the host immune response. However, protein regions without glycosylated residues capable of inducing neutralizing antibodies could be useful for antigen production in systems that do not carry the glycosylation machinery. To test this hypothesis, the potential antigens NG06 and NG19, located within the non-glycosylated S-RBD region, were selected and expressed in Escherichia coli, purified by FPLC and employed to determine their immunogenic potential through detection of antibodies in serum from immunized rabbits, mice, and COVID-19 patients. IgG antibodies from sera of COVID-19-recovered patients detected the recombinant antigens NG06 and NG19 (A450 nm = 0.80 ± 0.33; 1.13 ± 0.33; and 0.11 ± 0.08 for and negatives controls, respectively). Also, the purified antigens were able to raise polyclonal antibodies in animal models evoking a strong immune response with neutralizing activity in mice model. This research highlights the usefulness of antigens based on the non-N-glycosylated region of RBD from SARS-CoV-2 for candidate vaccine development.
ABSTRACT
The term "folate" is a generic way to name the different forms derived from folic acid, one of the B vitamins (specifically B9 vitamin). They are essential in the metabolism when they act as cofactors in the transfer reactions of one carbon. However, only plants and microorganisms are able to synthesize them de novo, in such a way that both animals and human beings have to intake them through their diet. Folic acid is widely spread in nature, mainly in vegetables, liver ans cereals. However, nowadays, the lack of folates in the diet is one of the most common nutritional deficiencies in the world, and it has serious consequences on human health. There is evidence that even in developed countries folate intake is usually low; and even, is some cases, below optima levels. The authorities in several countries have adapted different norms related to folic acid, fortifying staple food such as dairy products or cereals, mandatory (U.S.A., Canada or Chile) or voluntary (most of the European countries).
Subject(s)
Folic Acid Deficiency/prevention & control , Folic Acid/administration & dosage , Food, Fortified , Vitamin B Complex/administration & dosage , Adolescent , Adult , Animals , Canada , Child , Child, Preschool , Chile , Diet Records , Edible Grain/chemistry , Europe , Female , Folic Acid/metabolism , Humans , Infant , Infant, Newborn , Male , Middle Aged , Neural Tube Defects/prevention & control , Nutrition Policy , Nutritional Requirements , Pregnancy , United States , Vegetables/chemistry , Vitamin B Complex/analysisABSTRACT
El término folato se utiliza de forma genérica para denominar las distintas formas químicas derivadas del ácido fólico, una de las vitaminas del grupo B (concretamente la vitamina B). Son esenciales en el metabolismo al actuar como cofactores en las reacciones de transferencia de un carbono. No obstante, solamente las plantas y los microorganismos son capaces de sintetizarlos de novo, de tal forma que tanto los animales como el hombre necesitan ingerirlos a tráves de los alimentos de la dieta. se encuentra ampliamente extendido en la naturaleza, presentándose en mayor cantidad en las verduras de hoja ancha, en hígado y en cereales Aún así, en la actualidad es una de las deficiencias nutricionales más comunes en todo el mundo, y tiene graves consecuencias sobre la salud humana. Existe evidencia de que incluso en países desarrollados la ingesta de folatos es generalmente baja, e incluso en algunos casos por debajo de los niveles óptimos. Las autoridades competentes de numerosos países están tomando medidas a este respecto, de tal forma que se está realizando la fortificación, de numerosos alimentos considerados de consumo diario, tales como leche o cereales, ya sea de forma obligatoria (Estados Unidos, Canadá o Chile) o voluntaria (la mayoría de los países de Europa)
