SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) was first detected in December 2019 in Wuhan, China. Since that time the virus kept mutating, leading to new virus variants. The B.1.525 lineage, also known as Eta variant, G/484K.V3 or VUI-202102/03, is a SARS-CoV-2 variant that was first discovered in the UK and Nigeria in December 2020. The mutations of this variant affect also immune-relevant parts of structural SARS-CoV-2 proteins and the respective sequences are available in GISAID, a genome data base. The mutations listed below are taken from e.g. EPI_ISL_760883. The B.1.525 lineage (Eta variant) has been detected internationally.
In total there are 9 mutations in the surface or spike glycoprotein (“S”) of the B.1.525 lineage (Eta variant) compared to the Wuhan variant (reference genome GenBank MN908947.3): Q52R, A67V, deletion H69, deletion V70, deletion Y144, E484K, D614G, Q677H and F888L.
The PepTivator SARS-CoV-2 Prot_S B.1.525 Mutation Pool covers selectively the mutated regions. It consists of 28 peptides of 15 aa length. The PepTivator SARS-CoV-2 Prot_S B.1.525 Mutation Pool can be used to supplement PepTivators covering the sequence of the wild-type spike glycoprotein (“S”) in order to detect immune responses towards both variants, Wuhan (wild type) variant and B.1.525 lineage (Eta variant). PepTivator Peptide pools spanning the sequence of the spike glycoprotein (“S”) of the Wuhan (wild-type) variant are PepTivator SARS-CoV-2 Prot_S (predicted immunodominant sequence domains), Prot_S1 (N-terminal S1 domain), Prot_S+ (part of the C-terminal S2 domain) and Prot_S Complete (all functional domains).
The PepTivator SARS-CoV-2 Prot_S B.1.525 WT Reference Pool consists of the 28 homologous peptides of the Wuhan sequence and covers Q52, A67, H69, V70, Y144, E484, D614, Q677 and F888 of the Wuhan variant (reference genome GenBank MN908947.3. PepTivator SARS-CoV-2 Prot_S B.1.525 WT Reference Pool serves as a control for the SARS-CoV-2 Prot_S B.1.525 Mutation Pool. Comparison of the T cell immune response upon stimulation with mutation and reference pool can be used to analyze mutationspecific T cell responses.