Tumour-associated antigenic peptides are present in the HLA class I ligandome of cancer cell line derived extracellular vesicles.

ABSTRACT: The recent success of monoclonal antibody checkpoint inhibitor therapies that enhance the ability of CD8+ T cells to detect cancer-related antigenic peptides has refocused the need to fully understand the repertoire of peptides being presented to the immune system. Whilst the peptide ligandome presented by cell surface HLA class I molecules on cancer cells has been studied extensively, the ligandome of extracellular vesicles remains poorly defined. Here we report the HLA class I ligandome of both cell surface and extracellular vesicles from eight breast cancer cell lines (MCF7, MDA-MB-231, MDA-MB-361, MDA-MB-415, MDA-MB-453, HCC 1806, HCC 1395, and HCC 1954), and additionally the melanoma cell line ESTDAB-056 and the multiple myeloma line RPMI 8226. Utilising HLA class I immunoisolation and mass spectrometry we detected a total of 6574 peptides from the cell surface and 2461 peptides from the extracellular vesicles of the cell lines studied. Within the extracellular vesicle HLA class I ligandome we identified 150 peptides derived from tumour associated antigenic proteins, of which 19 peptides have been shown to elicit T cell responses in previous studies. Our data thus confirms for the first time the presence of clinically relevant tumour-associated antigenic peptides in the HLA class I ligandome present on EV.

INSTRUMENT(S): TripleTOF 5600

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Cell, Cell Suspension Culture, Permanent Cell Line Cell, Cell Culture, Diploid Cell

DISEASE(S): Melanoma,Breast Cancer,Multiple Myeloma

SUBMITTER: Pankaj Kumar  

LAB HEAD: Simon J Powis

PROVIDER: PXD025345 | Pride | 2022-04-01

REPOSITORIES: Pride