[HTML][HTML] Identification of non-mutated neoantigens presented by TAP-deficient tumors

KA Marijt, L Blijleven, EME Verdegaal… - Journal of Experimental …, 2018 - rupress.org
KA Marijt, L Blijleven, EME Verdegaal, MG Kester, DJ Kowalewski, HG Rammensee
Journal of Experimental Medicine, 2018rupress.org
Most T cell–based immunotherapies of cancer depend on intact antigen presentation by
HLA class I molecules (HLA-I). However, defects in the antigen-processing machinery can
cause downregulation of HLA-I, rendering tumor cells resistant to CD8+ T cells. Previously,
we demonstrated that a unique category of cancer antigens is selectively presented by
tumor cells deficient for the peptide transporter TAP, enabling a specific attack of such
tumors without causing immunopathology in mouse models. With a novel combinatorial …
Most T cell–based immunotherapies of cancer depend on intact antigen presentation by HLA class I molecules (HLA-I). However, defects in the antigen-processing machinery can cause downregulation of HLA-I, rendering tumor cells resistant to CD8+ T cells. Previously, we demonstrated that a unique category of cancer antigens is selectively presented by tumor cells deficient for the peptide transporter TAP, enabling a specific attack of such tumors without causing immunopathology in mouse models. With a novel combinatorial screening approach, we now identify 16 antigens of this category in humans. These HLA-A* 02: 01 presented peptides do not derive from the mutanome of cancers, but are of “self” origin and therefore constitute universal neoantigens. Indeed, CD8+ T cells specific for the leader peptide of the ubiquitously expressed LRPAP1 protein recognized TAP-deficient, HLA-I low lymphomas, melanomas, and renal and colon carcinomas, but not healthy counterparts. In contrast to personalized mutanome-targeted therapies, these conserved neoantigens and their cognate receptors can be exploited for immune-escaped cancers across diverse histological origins.
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