{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T07:10:48Z","timestamp":1791443448070,"version":"4.3.3"},"reference-count":24,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,1,29]],"date-time":"2025-01-29T00:00:00Z","timestamp":1738108800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Transplant."],"abstract":"<jats:p>Mass Spectrometry allied with <jats:italic>in-vivo<\/jats:italic> generation of activated alloreactive T cell populations and tetramer screening facilitates the identification of endogenous peptides that are directly recognised in complex with allogeneic Major Histocompatibility class I (MHC I) molecules by alloreactive CD8<jats:sup>+<\/jats:sup> T cells. We had previously used this approach for the discovery of immunogenic self-peptides presented by the allomorph H-2K<jats:sup>b<\/jats:sup> (K<jats:sup>b<\/jats:sup>). In this study, we identified 22 highly immunogenic self-peptides presented by H-2K<jats:sup>d<\/jats:sup> (K<jats:sup>d<\/jats:sup>). Peptide abundance across skin, spleen and liver samples (estimated as the product of the spectral intensity obtained for these samples) was the principal factor influencing recognition of peptide-K<jats:sup>d<\/jats:sup> epitopes. Predicted binding affinity (BA score) and overall peptide hydrophobicity were also independently correlated with immunogenicity, while there was no significant correlation between the IEDB immunogenicity score and the proportion of T cells recognising a given epitope. Eight peptide-K<jats:sup>d<\/jats:sup> epitopes were selected for inclusion in a tetramer panel to detect directly alloreactive CD8<jats:sup>+<\/jats:sup> T cells. This panel bound over 30% of activated alloreactive CD8<jats:sup>+<\/jats:sup> T cells after a prime-boost against K<jats:sup>d<\/jats:sup>. Moreover, the panel identified alloreactive CD8<jats:sup>+<\/jats:sup> T cells within the graft infiltrate, spleen and draining lymph node during rejection of a K<jats:sup>d<\/jats:sup>-bearing heart graft. In conclusion, small animal studies have demonstrated the feasibility of high-throughput approaches for the discovery of pMHC epitopes recognised by directly alloreactive T cells. Translating this approach to the human setting is achievable and will yield both critical insights into the fundamental basis of alloreactivity and powerful tools for immune monitoring in transplantation.<\/jats:p>","DOI":"10.3389\/frtra.2025.1525003","type":"journal-article","created":{"date-parts":[[2025,1,29]],"date-time":"2025-01-29T07:00:11Z","timestamp":1738134011000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Discovery of conserved peptide-MHC epitopes for directly alloreactive CD8+ T cells"],"prefix":"10.3389","volume":"4","author":[{"given":"Alexandra E.","family":"Hill","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eric 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