Critical role of PD-L1 expression on non-tumor cells rather than on tumor cells for efective anti-PD-L1 immunotherapy in a transplantable mouse hematopoietic tumor model

[EN] The expression of PD-L1 on tumor cells or within the tumor microenvironment has been associated with good prognosis and sustained clinical responses in immunotherapeutic regimens based on PD-L1/PD-1/CD80 immune checkpoint blockade. To look into the current controversy in cancer immunotherapy of...

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Detalhes bibliográficos
Autores: Rodríguez Barbosa, José Ignacio, Azuma, Miyuki, Zelinskyy, Gennadiy, Pérez Simón, José Antonio, Río González, María Luisa del
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Recursos:Universidad Rey Juan Carlos
Repositorio:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:buleria.unileon.es:10612/17569
Acesso em linha:https://hdl.handle.net/10612/17569
Access Level:acceso abierto
Palavra-chave:Veterinaria
PD-1 (programmed death-1)
PD-L1 (programmed death-ligand
Immune checkpoint blockade
Hematological malignancies
CRISPR/Cas9
Descrição
Resumo:[EN] The expression of PD-L1 on tumor cells or within the tumor microenvironment has been associated with good prognosis and sustained clinical responses in immunotherapeutic regimens based on PD-L1/PD-1/CD80 immune checkpoint blockade. To look into the current controversy in cancer immunotherapy of the relative importance of PD-L1 expression on tumor cells versus non-tumor cells of the tumor microenvironment, a hematological mouse tumor model was chosen. By combining a genetic CRISPR/Cas9 and immunotherapeutic approach and using a syngeneic hematopoietic transplantable tumor model (E.G7-cOVA tumor cells), we demonstrated that dual blockade of PD-L1 interaction with PD-1 and CD80 enhanced anti-tumor immune responses that either delayed tumor growth or led to its complete eradication. PD-L1 expression on non-tumor cells of the tumor microenvironment was required for the promotion of tumor immune escape and its blockade elicited potent anti-tumor responses to PD-L1 WT and to PD-L1-defcient tumor cells. PD-L1+ tumors implanted in PDL1-defcient mice exhibited delayed tumor growth independently of PD-L1 blockade. These fndings emphasize that PD-L1 expression on non-tumor cells plays a major role in this tumor model. These observations should turn our attention to the tumor microenvironment in hematological malignancies because of its unappreciated contribution to create a conditioned niche for the tumor to grow and evade the anti-tumor immune response.