Novel neutralizing chicken IgY antibodies targeting 17 potent conserved peptides identified by SARS-CoV-2 proteome microarray, and future prospects

Abstract

Introduction: An approach toward novel neutralizing IgY polyclonal antibodies (N-IgY-pAb) against SARS-CoV-2 S-ECD was developed.

Material and methods: The novel N-IgY-pAb and its intranasal spray response against the wild type ("'WH-Human 1") SARS-CoV-2 virus, variants of Delta or Omicron were up to 98%. Unique virus peptides binding to N-IgY-pAb were screened by a SARS-CoV-2 proteome microarray.

Results: Seventeen mutation-free peptides with a Z-score > 3.0 were identified as potent targets from a total of 966 peptides. The new findings show that one is in the RBM domain (⁴⁶¹LKPFERDISTEIYQA⁴⁷⁵ ), two are in the NTD domain (²¹RTQLPPAYTNSFTRG³⁵, ²⁹¹CALDPLSETKCTLKS³⁰⁵) four are in the C1/2-terminal (⁵⁶¹PFQQFGRDIADTTDA⁵⁷⁵,⁵⁷¹DTTDAVRDPQTLEIL⁵⁸⁵,⁵⁸¹TLEILDITPCSFGGV⁵⁹⁵, ⁶⁶¹ECDIPIGAGICASYQ⁶⁷⁵ ), three are in the S1/S2 border (⁷⁴¹YICGDSTECSNLLLQ⁷⁵⁵, ⁸¹¹KPSKRSFIEDLLFNK⁸²⁵, ⁸²¹LLFNKVTLADAGFIK⁸³⁵) one target is in HR2 (¹¹⁶¹SPDVDLGDISGINAS¹¹⁷⁵) and one is in HR2-TM (¹²⁰¹QELGKYEQYIKWPWY¹²¹⁵). Moreover, five potential peptides were in the NSP domain: nsp3-55 (¹³⁶¹SNEKQEILGTVSWNL¹³⁷⁵), nsp14-50 (⁶¹⁴HHANEYRLYLDAYNM⁶⁴², ORF10-3 (²¹MNSRNYIAQVDVVNFNLT³⁸, ORF7a-1(¹MKIILFLALITLATC¹⁵) and ORF7a-12 (¹¹¹⁶TLCFTLKRKTE¹²¹).

Discussion and conclusion: We concluded that the N-IgY-pAb could effectively neutralize the SARS-CoV-2. The new findings of seventeen potent conserved peptides are extremely important for developing new vaccines and "cocktails" of neutralizing Abs for efficient treatments for patients infected with SARS-CoV-2.

Keywords: SARS-CoV-2; SARS-CoV-2 extracellular domain of the S-protein (S-ECD); chicken egg yolk immunoglobulin (IgY); neutralizing IgY polyclonal antibodies (N-IgY-pAb); neutralizing antibodies (NAbs); residue mutations (RMs).