Clonally expanded, stem cell-like melanomaantigen specific CD8 memory cells can be detected in healthy humans

Anna Przybyla; Ting Zhan; Ruliang Li; Diana R. Roen; Andrzej Mackiewicz; Paul V Lehmann

doi:10.21767/2471-304X-C1-009

Clonally expanded, stem cell-like melanomaantigen specific CD8 memory cells can be detected in healthy humans

16^th EuroSciCon Conference on Immunology
March 11-12, 2019 | Amsterdam, Netherlands

Anna Przybyla, Ting Zhan, Ruliang Li, Diana R. Roen,Andrzej Mackiewicz and Paul V Lehmann

Cellular Technology Ltd, USA Poznan University of Medical Sciences, Poland

Posters & Accepted Abstracts: J Clin Immunol Allergy

DOI: 10.21767/2471-304X-C1-009

Abstract

We used four-color ImmunoSpot® assays, in conjunction with peptide pools that cover the sequence of tyrosinase (Tyr), MAGE-3, Melan/MART-1, gp100, and NY-ESO-1 to charact erize the melanoma antigen (MA)-specific CD8 cell repertoire in PBMC of 40 healthy human donors (HD). Tyr triggered IFN-γ-secreting CD8 cells in 33% HD within 24h of antigen stimulation ex vivo. MAGE-3, Melan/MART-1, and gp100 also induced recall responses in 10%, 5%, and 5% of HD, respectively. At this time point, these CD8 cells did not yet produce GzB. However, they engaged in GzB production 72h after antigen stimulation. By this 72h time point ex vivo, 58% of the HD responded to at least one, and typically several, of the MA. A closer characterization of the Tyrspecific CD8 cell repertoire showed it to be of low affinity, and to entail primarily the stem cell-like subpopulation.