tetano
Editor, Senior Moderator
Hum Vaccin Immunother
. 2021 Apr 13;1-11.
doi: 10.1080/21645515.2021.1901545. Online ahead of print.
SARS?CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice
Jeroen Pollet[SUP] 1 2 [/SUP], Wen-Hsiang Chen[SUP] 1 2 [/SUP], Leroy Versteeg[SUP] 1 [/SUP], Brian Keegan[SUP] 1 [/SUP], Bin Zhan[SUP] 1 2 [/SUP], Junfei Wei[SUP] 1 [/SUP], Zhuyun Liu[SUP] 1 [/SUP], Jungsoon Lee[SUP] 1 [/SUP], Rahki Kundu[SUP] 1 [/SUP], Rakesh Adhikari[SUP] 1 [/SUP], Cristina Poveda[SUP] 1 [/SUP], Maria Jose Villar[SUP] 1 [/SUP], Ana Carolina de Araujo Leao[SUP] 1 [/SUP], Joanne Altieri Rivera[SUP] 1 [/SUP], Zoha Momin[SUP] 3 [/SUP], Portia M Gillespie[SUP] 1 [/SUP], Jason T Kimata[SUP] 3 [/SUP], Ulrich Strych[SUP] 1 2 [/SUP], Peter J Hotez[SUP] 1 2 4 5 [/SUP], Maria Elena Bottazzi[SUP] 1 2 4 [/SUP]
Affiliations
Abstract
There is an urgent need for an accessible and low-cost COVID-19 vaccine suitable for low- and middle-income countries. Here, we report on the development of a SARS-CoV-2 receptor-binding domain (RBD) protein, expressed at high levels in yeast (Pichia pastoris), as a suitable vaccine candidate against COVID-19. After introducing two modifications into the wild-type RBD gene to reduce yeast-derived hyperglycosylation and improve stability during protein expression, we show that the recombinant protein, RBD219-N1C1, is equivalent to the wild-type RBD recombinant protein (RBD219-WT) in an in vitro ACE-2 binding assay. Immunogenicity studies of RBD219-N1C1 and RBD219-WT proteins formulated with Alhydrogel? were conducted in mice, and, after two doses, both the RBD219-WT and RBD219-N1C1 vaccines induced high levels of binding IgG antibodies. Using a SARS-CoV-2 pseudovirus, we further showed that sera obtained after a two-dose immunization schedule of the vaccines were sufficient to elicit strong neutralizing antibody titers in the 1:1,000 to 1:10,000 range, for both antigens tested. The vaccines induced IFN-? IL-6, and IL-10 secretion, among other cytokines. Overall, these data suggest that the RBD219-N1C1 recombinant protein, produced in yeast, is suitable for further evaluation as a human COVID-19 vaccine, in particular, in an Alhydrogel? containing formulation and possibly in combination with other immunostimulants.
Keywords: ACE-2; COVID-19; RBD; alum; coronavirus; pseudovirus.
. 2021 Apr 13;1-11.
doi: 10.1080/21645515.2021.1901545. Online ahead of print.
SARS?CoV-2 RBD219-N1C1: A yeast-expressed SARS-CoV-2 recombinant receptor-binding domain candidate vaccine stimulates virus neutralizing antibodies and T-cell immunity in mice
Jeroen Pollet[SUP] 1 2 [/SUP], Wen-Hsiang Chen[SUP] 1 2 [/SUP], Leroy Versteeg[SUP] 1 [/SUP], Brian Keegan[SUP] 1 [/SUP], Bin Zhan[SUP] 1 2 [/SUP], Junfei Wei[SUP] 1 [/SUP], Zhuyun Liu[SUP] 1 [/SUP], Jungsoon Lee[SUP] 1 [/SUP], Rahki Kundu[SUP] 1 [/SUP], Rakesh Adhikari[SUP] 1 [/SUP], Cristina Poveda[SUP] 1 [/SUP], Maria Jose Villar[SUP] 1 [/SUP], Ana Carolina de Araujo Leao[SUP] 1 [/SUP], Joanne Altieri Rivera[SUP] 1 [/SUP], Zoha Momin[SUP] 3 [/SUP], Portia M Gillespie[SUP] 1 [/SUP], Jason T Kimata[SUP] 3 [/SUP], Ulrich Strych[SUP] 1 2 [/SUP], Peter J Hotez[SUP] 1 2 4 5 [/SUP], Maria Elena Bottazzi[SUP] 1 2 4 [/SUP]
Affiliations
- PMID: 33847226
- DOI: 10.1080/21645515.2021.1901545
Abstract
There is an urgent need for an accessible and low-cost COVID-19 vaccine suitable for low- and middle-income countries. Here, we report on the development of a SARS-CoV-2 receptor-binding domain (RBD) protein, expressed at high levels in yeast (Pichia pastoris), as a suitable vaccine candidate against COVID-19. After introducing two modifications into the wild-type RBD gene to reduce yeast-derived hyperglycosylation and improve stability during protein expression, we show that the recombinant protein, RBD219-N1C1, is equivalent to the wild-type RBD recombinant protein (RBD219-WT) in an in vitro ACE-2 binding assay. Immunogenicity studies of RBD219-N1C1 and RBD219-WT proteins formulated with Alhydrogel? were conducted in mice, and, after two doses, both the RBD219-WT and RBD219-N1C1 vaccines induced high levels of binding IgG antibodies. Using a SARS-CoV-2 pseudovirus, we further showed that sera obtained after a two-dose immunization schedule of the vaccines were sufficient to elicit strong neutralizing antibody titers in the 1:1,000 to 1:10,000 range, for both antigens tested. The vaccines induced IFN-? IL-6, and IL-10 secretion, among other cytokines. Overall, these data suggest that the RBD219-N1C1 recombinant protein, produced in yeast, is suitable for further evaluation as a human COVID-19 vaccine, in particular, in an Alhydrogel? containing formulation and possibly in combination with other immunostimulants.
Keywords: ACE-2; COVID-19; RBD; alum; coronavirus; pseudovirus.