Background information
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.1.427/B.1.429 lineage, also known as Epsilon variant, CAL.20C or GH/452R.V1, is a SARS-CoV-2 variant that was first discovered in Southern California, US in July 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 sequence EPI_ISL_648527. The B.1.427/B.1.429 lineage (Epsilon variant) has been found to evade a pre-existing antibody response and appears to be more infectious than other variants.
In total there are 4 mutations in surface or spike glycoprotein (“S”) of the B.1.427/B.1.429 lineage (Epsilon variant) compared to the Wuhan variant (reference genome GenBank MN908947.3): S13I, W152C, L452R and D614G.
The PepTivator SARS-CoV-2 Prot_S B.1.427/B.1.429 Mutation Pool covers selectively the mutated regions. It consists of 16 peptides of 15 aa length. The PepTivator SARS-CoV-2 Prot_S B.1.427/B.1.429 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.1.427/B.1.429 lineage (Epsilon 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.1.427/B.1.429 WT Reference Pool consists of the 16 homologous peptides of the Wuhan sequence and covers S13, W152, L452 and D614 of the Wuhan variant (reference genome GenBank MN908947.3). PepTivator SARS-CoV-2 Prot_S B.1.427/B.1.429 WT Reference Pool serves as a control for the SARS-CoV-2 Prot_S B.1.427/B.1.429 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.
