The inhibitory checkpoint, PD-L2, is a target for effector T cells: Novel possibilities for immune therapy

TY - JOUR

T1 - The inhibitory checkpoint, PD-L2, is a target for effector T cells

T2 - Novel possibilities for immune therapy

AU - Ahmad, Shamaila Munir

AU - Martinenaite, Evelina

AU - Holmström, Morten

AU - Jørgensen, Mia Aaboe

AU - Met, Özcan

AU - Nastasi, Claudia

AU - Klausen, Uffe

AU - Donia, Marco

AU - Pedersen, Lars Møller

AU - Munksgaard, Lars

AU - Ødum, Niels

AU - Woetmann, Anders

AU - Svane, Inge Marie

AU - Andersen, Mads Hald

PY - 2018/2/1

Y1 - 2018/2/1

N2 - Cell surface molecules of the B7/CD28 family play an important role in T-cell activation and tolerance. The relevance of the PD-1/PD-L1 pathway in cancer has been extensively studied whereas PD-L2 has received less attention. However, recently the expression of PD-L2 was described to be independently associated with clinical response in anti-PD1-treated cancer patients. Here, we investigated whether PD-L2 might represent a natural target that induces specific T cells. We identified spontaneous specific T-cell reactivity against two epitopes located in the signal peptide of PD-L2 from samples from patients with cancer as well as healthy individuals ex vivo. We characterized both CD8+ and CD4+ PD-L2-specific T cells. Interestingly, the epitope in PD-L2 that elicited the strongest response was equivalent to a potent HLA-A2-restricted epitope in PD-L1. Importantly, PD-L1-specific and PD-L2-specific T cells did not cross-react; therefore, they represent different T-cell antigens. Moreover, PD-L2-specific T cells reacted to autologous target cells depending on PD-L2 expression. These results suggested that activating PD-L2 specific T cells (e.g., by vaccination) might be an attractive strategy for anti-cancer immunotherapy. Accordingly, PD-L2 specific T cells can directly support anti-cancer immunity by killing of target cells, as well as, indirectly, by releasing pro-inflammatory cytokines at the microenvironment in response to PD-L2-expressing immune supressive cells.

AB - Cell surface molecules of the B7/CD28 family play an important role in T-cell activation and tolerance. The relevance of the PD-1/PD-L1 pathway in cancer has been extensively studied whereas PD-L2 has received less attention. However, recently the expression of PD-L2 was described to be independently associated with clinical response in anti-PD1-treated cancer patients. Here, we investigated whether PD-L2 might represent a natural target that induces specific T cells. We identified spontaneous specific T-cell reactivity against two epitopes located in the signal peptide of PD-L2 from samples from patients with cancer as well as healthy individuals ex vivo. We characterized both CD8+ and CD4+ PD-L2-specific T cells. Interestingly, the epitope in PD-L2 that elicited the strongest response was equivalent to a potent HLA-A2-restricted epitope in PD-L1. Importantly, PD-L1-specific and PD-L2-specific T cells did not cross-react; therefore, they represent different T-cell antigens. Moreover, PD-L2-specific T cells reacted to autologous target cells depending on PD-L2 expression. These results suggested that activating PD-L2 specific T cells (e.g., by vaccination) might be an attractive strategy for anti-cancer immunotherapy. Accordingly, PD-L2 specific T cells can directly support anti-cancer immunity by killing of target cells, as well as, indirectly, by releasing pro-inflammatory cytokines at the microenvironment in response to PD-L2-expressing immune supressive cells.

U2 - 10.1080/2162402x.2017.1390641

DO - 10.1080/2162402x.2017.1390641

M3 - Journal article

C2 - 29308318

SN - 2162-4011

VL - 7

JO - OncoImmunology

JF - OncoImmunology

IS - 2

M1 - e1390641

ER -