Cargando…
Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells
Autologous T cells engineered with T receptor genes (TCR) are being studied to treat cancers. We have recently identified a panel of mouse TCRs specific for the HLA-A0201/alpha fetoprotein epitope (AFP(158)) complex and have shown that human T cells engineered with these TCR genes (TCR-Ts) can eradi...
Autores principales: | , , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7196607/ https://www.ncbi.nlm.nih.gov/pubmed/32395117 http://dx.doi.org/10.3389/fimmu.2020.00607 |
_version_ | 1783528749620264960 |
---|---|
author | Cai, Lun Caraballo Galva, Leidy D. Peng, Yibing Luo, Xiaobing Zhu, Wei Yao, Yihong Ji, Yun He, Yukai |
author_facet | Cai, Lun Caraballo Galva, Leidy D. Peng, Yibing Luo, Xiaobing Zhu, Wei Yao, Yihong Ji, Yun He, Yukai |
author_sort | Cai, Lun |
collection | PubMed |
description | Autologous T cells engineered with T receptor genes (TCR) are being studied to treat cancers. We have recently identified a panel of mouse TCRs specific for the HLA-A0201/alpha fetoprotein epitope (AFP(158)) complex and have shown that human T cells engineered with these TCR genes (TCR-Ts) can eradicate hepatocellular carcinoma (HCC) xenografts in NSG mice. However, due to TCR’s promiscuity, their off-target cross-reactivity must be studied prior to conducting clinical trials. In this study, we conducted in vitro X-scan assay and in silico analysis to determine the off-target cross-reactivity of 3 AFP(158)-specific TCR-Ts. We found that the 3 AFP(158)-specific TCR-Ts could be cross-activated by ENPP1(436) peptide and that the TCR3-Ts could also be activated by another off-target peptide, RCL1(215). However, compared to AFP(158), it requires 250 times more ENPP1(436) and 10,000 times more RCL1(215) peptides to achieve the same level of activation. The EC(50) of ENPP1(436) peptide for activating TCR-Ts is approximately 17–33 times higher than AFP(158). Importantly, the ENPP1+ tumor cells did not activate TCR1-Ts and TCR2-Ts, and only weakly activated TCR3-Ts. The IFNγ produced by TCR3-Ts after ENPP1+ cell stimulation was >22x lower than that after HepG2 cells. And, all TCR-Ts did not kill ENPP1 + tumor cells. Furthermore, ectopic over-expression of ENPP1 protein in HLA-A2+ tumor cells did not activate TCR-Ts. In silico analysis showed that the ENPP1(436) peptide affinity for HLA-A0201 was ranked 40 times lower than AFP(158) and the chance of ENPP1(436) peptide being processed and presented by HLA-A0201 was 100 times less likely than AFP(158). In contrast, the two off-targets (Titin and MAGE-A3) that did cause severe toxicity in previous trials have the same or higher MHC-binding affinity and the same or higher chance of being processed and presented. In conclusion, our data shows that TCR-Ts can be activated by off-target ENPP1(436) peptide. But, compared to target AFP(158), it requires at least 250 times more ENPP1(436) to achieve the same level of activation. Importantly, ENPP1(436) peptide in human cells is not processed and presented to a sufficient level to activate the AFP(158)-specific TCR-Ts. Thus, these TCR-Ts, especially the TCR1-Ts and TCR2-Ts, will unlikely cause significant off-target toxicity. |
format | Online Article Text |
id | pubmed-7196607 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-71966072020-05-11 Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells Cai, Lun Caraballo Galva, Leidy D. Peng, Yibing Luo, Xiaobing Zhu, Wei Yao, Yihong Ji, Yun He, Yukai Front Immunol Immunology Autologous T cells engineered with T receptor genes (TCR) are being studied to treat cancers. We have recently identified a panel of mouse TCRs specific for the HLA-A0201/alpha fetoprotein epitope (AFP(158)) complex and have shown that human T cells engineered with these TCR genes (TCR-Ts) can eradicate hepatocellular carcinoma (HCC) xenografts in NSG mice. However, due to TCR’s promiscuity, their off-target cross-reactivity must be studied prior to conducting clinical trials. In this study, we conducted in vitro X-scan assay and in silico analysis to determine the off-target cross-reactivity of 3 AFP(158)-specific TCR-Ts. We found that the 3 AFP(158)-specific TCR-Ts could be cross-activated by ENPP1(436) peptide and that the TCR3-Ts could also be activated by another off-target peptide, RCL1(215). However, compared to AFP(158), it requires 250 times more ENPP1(436) and 10,000 times more RCL1(215) peptides to achieve the same level of activation. The EC(50) of ENPP1(436) peptide for activating TCR-Ts is approximately 17–33 times higher than AFP(158). Importantly, the ENPP1+ tumor cells did not activate TCR1-Ts and TCR2-Ts, and only weakly activated TCR3-Ts. The IFNγ produced by TCR3-Ts after ENPP1+ cell stimulation was >22x lower than that after HepG2 cells. And, all TCR-Ts did not kill ENPP1 + tumor cells. Furthermore, ectopic over-expression of ENPP1 protein in HLA-A2+ tumor cells did not activate TCR-Ts. In silico analysis showed that the ENPP1(436) peptide affinity for HLA-A0201 was ranked 40 times lower than AFP(158) and the chance of ENPP1(436) peptide being processed and presented by HLA-A0201 was 100 times less likely than AFP(158). In contrast, the two off-targets (Titin and MAGE-A3) that did cause severe toxicity in previous trials have the same or higher MHC-binding affinity and the same or higher chance of being processed and presented. In conclusion, our data shows that TCR-Ts can be activated by off-target ENPP1(436) peptide. But, compared to target AFP(158), it requires at least 250 times more ENPP1(436) to achieve the same level of activation. Importantly, ENPP1(436) peptide in human cells is not processed and presented to a sufficient level to activate the AFP(158)-specific TCR-Ts. Thus, these TCR-Ts, especially the TCR1-Ts and TCR2-Ts, will unlikely cause significant off-target toxicity. Frontiers Media S.A. 2020-04-27 /pmc/articles/PMC7196607/ /pubmed/32395117 http://dx.doi.org/10.3389/fimmu.2020.00607 Text en Copyright © 2020 Cai, Caraballo Galva, Peng, Luo, Zhu, Yao, Ji and He. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Immunology Cai, Lun Caraballo Galva, Leidy D. Peng, Yibing Luo, Xiaobing Zhu, Wei Yao, Yihong Ji, Yun He, Yukai Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title | Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title_full | Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title_fullStr | Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title_full_unstemmed | Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title_short | Preclinical Studies of the Off-Target Reactivity of AFP(158)-Specific TCR Engineered T Cells |
title_sort | preclinical studies of the off-target reactivity of afp(158)-specific tcr engineered t cells |
topic | Immunology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7196607/ https://www.ncbi.nlm.nih.gov/pubmed/32395117 http://dx.doi.org/10.3389/fimmu.2020.00607 |
work_keys_str_mv | AT cailun preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT caraballogalvaleidyd preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT pengyibing preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT luoxiaobing preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT zhuwei preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT yaoyihong preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT jiyun preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells AT heyukai preclinicalstudiesoftheofftargetreactivityofafp158specifictcrengineeredtcells |