Project description:We performed a study investigating donors previously infected with SARS-CoV-2 during the first wave of the COVID-19 pandemic to understand how vaccination may reshape T cell populations formed after infection. 10 donors were investigated using single-cell RNA-sequencing consisting of a) 3 mild non-hospitalised donors, b) 3 severe hospitalised donors, c) 1 mild recently vaccinated donor and d) 3 recently convalescent donors. For each of these groups we sampled at the following timepoints a) 6-9 months and 18 months after infection, b) 6-9 months and 18 months after infection, c) 13 months and 15 months after infection and d) 35 days after infection. All donors were unvaccinated at the first time point and vaccinated at the second time point. We stimulated PBMC with an overlapping peptide pool derived from the spike glycoprotein of the SARS-CoV-2 virus and sorted spike-specific CD4+ T cells (CD4+CD69+CD40L+) and spike-specific CD8+ T cells (CD8+CD69+4-1BB+) from every donor and time point using flow cytometry for 10X single-cell sequencing (5' protocol). Each time point from Dnr4868 was sequenced across two 10X reactions/libraries performed on the same day. Multiple samples were hashed and pooled together for sequencing using TotalSeq-C anti-human hashing antibodies from BioLegend. Individual library expression matrix files were generated using the CellRanger pipeline from 10X Genomics. The processed data file named immune.combined220929.rds is a Seurat Object containing all samples and generated using the Seurat package in R.