SARS-CoV-2-specific T cell memory with common TCRαβ motifs is established in unvaccinated children who seroconvert after infection
Louise C. Rowntree, Thi H. O. Nguyen, Łukasz Kedzierski, Melanie R. Neeland, Jan Petersen, Jeremy Chase Crawford, Lilith F. Allen, E. Bridie Clemens, Brendon Y. Chua, Hayley A. McQuilten, Anastasia A. Minervina, Mikhail V. Pogorelyy, Priyanka Chaurasia, Hyon‐Xhi Tan, Adam K. Wheatley, Xiaoxiao Jia, Fatima Amanat, Florian Krammer, E. Kaitlynn Allen, Sabrina Sonda, Katie L. Flanagan, Jaycee Jumarang, Pia S. Pannaraj, Paul V. Licciardi, Stephen J. Kent, Katherine Bond, Deborah A. Williamson, Jamie Rossjohn, Paul G. Thomas, Shidan Tosif, Nigel W. Crawford, Carolien E. van de Sandt, Katherine Kedzierska
Abstract
T cells prior to vaccination. We analyzed epitope-specific T cells directly ex vivo using seven HLA class I and class II tetramers presenting SARS-CoV-2 epitopes, together with Spike-specific B cells. Unvaccinated children who seroconverted had comparable Spike-specific but lower ORF1a- and N-specific memory T cell responses compared with adults. This agreed with our TCR sequencing data showing reduced clonal expansion in children. A strong stem cell memory phenotype and common T cell receptor motifs were detected within tetramer-specific T cells in seroconverted children. Conversely, children who did not seroconvert had tetramer-specific T cells of predominantly naive phenotypes and diverse TCRαβ repertoires. Our study demonstrates the generation of SARS-CoV-2-specific T cell memory with common TCRαβ motifs in unvaccinated seroconverted children after their first virus encounter.