Doorduijn EM, Sluijter M, Marijt KA, Querido BJ, van der Burg SH, van Hall T. T cells specific for a TAP-independent self-peptide remain naïve in tumor-bearing mice and are fully exploitable for therapy.
Oncoimmunology 2017;
7:e1382793. [PMID:
29399388 PMCID:
PMC5790395 DOI:
10.1080/2162402x.2017.1382793]
[Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 12/20/2022] Open
Abstract
Cancers frequently evade immune-recognition by lowering peptide:MHC-I complexes on their cell surface. Limited peptide supply due to TAP-deficiency results in such MHC-Ilow immune-escape variants. Previously, we reported on a category of TAP-independent self-peptides, called TEIPP, with selective presentation by these tumors. Here we demonstrate that in contrast to T cells specific for conventional tumor antigens, TEIPP-directed T cells remain naïve in mice bearing immune-escaped tumors. This unaffected state was caused by low levels of MHC-I on the tumors and the failure to cross-present low levels of antigenic protein by host APCs. Importantly, increased levels of MHC-I, antigen or co-stimulation resulted in potent activation of TEIPP-specific T cells via direct presentation. Genetic knockdown by CRISPR/Cas9 technology of the relevant MHC-I allele in tumor cells indeed abrogated T cell activation. Vaccine-mediated priming of TEIPP-specific T cells induced efficient homing to MHC-Ilow tumors and subsequently protected mice against outgrowth of their MHC-Ilow tumor. Thus, our data open up the search of TEIPP-specific T cells in cancer patients to explore their application against MHC-Ilow tumor cells.
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