RESUMEN

Strategies to reprogram the tumor microenvironment are being explored to improve cancer immunotherapy. In one approach, we have targeted dendritic cells (DC) to improve their function with adjuvant vector cells (aAVC) that are engineered from NKT ligand-loaded CD1d(+) allogeneic cells transfected with tumor antigen mRNAs. Here, we report the finding that this approach also programs local immune responses by establishing tertiary lymphoid structures (TLS), which include expanded antigen-specific CD8(+) T-cell clones, mobilized DCs, and normalized tumor vasculature. aAVC therapy also expanded specific Vß-expressing antitumor T-cell clones, leading to the formation of long-term memory T cells. When combined with PD-1 blockade, aAVC infusion triggered regression of poorly immunogenic tumor cells that did not respond to PD-1 blockade alone, as well as expansion of antigen-specific CD8(+) T-cell clones in the tumor. The findings of this study help to inform a next-generation platform for the generation of efficacious cancer vaccines. Cancer Res; 76(13); 3756-66. ©2016 AACR.

Asunto(s)

Linfocitos T CD8-positivos/inmunología , Vacunas contra el Cáncer/inmunología , Células Dendríticas/inmunología , Memoria Inmunológica/inmunología , Melanoma Experimental/terapia , Microambiente Tumoral/inmunología , Adyuvantes Inmunológicos , Animales , Antígenos de Neoplasias , Femenino , Humanos , Inmunoterapia , Activación de Linfocitos , Masculino , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Phosphoglycerate mutase (PGAM) is an enzyme of intermediary metabolism that converts 3-phosphoglycerate to 2-phosphoglycerate in glycolysis. Here, we discovered PGAM5 that is anchored in the mitochondrial membrane lacks PGAM activity and instead associates with the MAP kinase kinase kinase ASK1 and acts as a specific protein Ser/Thr phosphatase that activates ASK1 by dephosphorylation of inhibitory sites. Mutation of an active site His-105 in PGAM5 abolished phosphatase activity with ASK1 and phospho-Thr peptides as substrates. The Drosophila and Caenorhabditis elegans orthologs of PGAM5 also exhibit specific Ser/Thr phosphatase activity and activate the corresponding Drosophila and C. elegans ASK1 kinases. PGAM5 is unrelated to the other known Ser/Thr phosphatases of the PPP, MPP, and FCP families, and our results suggest that this member of the PGAM family has crossed over from small molecules to protein substrates and been adapted to serve as a specialized activator of ASK1.

Asunto(s)

Proteínas Portadoras/metabolismo , Proteínas de Drosophila/metabolismo , MAP Quinasa Quinasa Quinasa 5/metabolismo , Proteínas Mitocondriales/metabolismo , Fosfoproteínas Fosfatasas/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas Portadoras/genética , Catálisis , Dominio Catalítico/genética , Línea Celular , Línea Celular Tumoral , Secuencia Conservada/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Activación Enzimática , Evolución Molecular , Humanos , Immunoblotting , Inmunoprecipitación , MAP Quinasa Quinasa Quinasa 5/genética , Proteínas Mitocondriales/genética , Datos de Secuencia Molecular , Mutación , Fosfoproteínas Fosfatasas/genética , Fosforilación , Homología de Secuencia de Aminoácido , Serina/metabolismo , Treonina/metabolismo

Asunto(s)

Apoptosis/genética , MAP Quinasa Quinasa Quinasa 5/fisiología , Proteínas 14-3-3/fisiología , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Proteínas Quinasas Dependientes de Calcio-Calmodulina/fisiología , Humanos , MAP Quinasa Quinasa Quinasa 5/metabolismo , Sistema de Señalización de MAP Quinasas/genética , Enfermedades Neurodegenerativas/etiología , Estrés Fisiológico/genética , Factor 2 Asociado a Receptor de TNF/fisiología , Tiorredoxinas