RESUMEN
The transcription factor B cell CLL/lymphoma 11B (BCL11B) is indispensable for T lineage development of lymphoid progenitors. Here, we show that chimeric antigen receptor (CAR) expression during early phases of ex vivo generation of lymphoid progenitors suppressed BCL11B, leading to suppression of T cell-associated gene expression and acquisition of NK cell-like properties. Upon adoptive transfer into hematopoietic stem cell transplant recipients, CAR-expressing lymphoid progenitors differentiated into CAR-induced killer (CARiK) cells that mediated potent antigen-directed antileukemic activity even across MHC barriers. CD28 and active immunoreceptor tyrosine-based activation motifs were critical for a functional CARiK phenotype. These results give important insights into differentiation of murine and human lymphoid progenitors driven by synthetic CAR transgene expression and encourage further evaluation of ex vivo-generated CARiK cells for targeted immunotherapy.
Asunto(s)
Antígenos CD28/metabolismo , Células Asesinas Naturales/citología , Linfocitos/citología , Receptores Quiméricos de Antígenos/metabolismo , Proteínas Represoras/metabolismo , Linfocitos T/citología , Proteínas Supresoras de Tumor/metabolismo , Animales , Antígenos CD19/metabolismo , Diferenciación Celular , Línea Celular Tumoral , Separación Celular , Citotoxicidad Inmunológica , Citometría de Flujo , Trasplante de Células Madre Hematopoyéticas , Humanos , Inmunoterapia , Inmunoterapia Adoptiva , Ratones , Análisis de Secuencia por Matrices de Oligonucleótidos , Fenotipo , Ingeniería de Proteínas , Células Madre/citología , TransgenesRESUMEN
The Philadelphia (Ph) chromosome, which occurs as a result of a translocation between chromosomes 9 and 22, generates a BCR-ABL fusion oncogene in leukaemia cells. The BCR-ABL fusion protein has constitutive tyrosine kinase activity. The development of imatinib mesylate (STI571, Gleevec®), a potent and selective BCR-ABL tyrosine kinase inhibitor, represents an important advance in cancer therapy. However, inherent mechanisms confer resistance to imatinib mesylate in some leukaemia patients. In order to identify the genes potentially related to these resistance mechanisms, we examined genes differentially expressed in BCR-ABL-positive cell lines resistant to imatinib mesylate. A comparison of global gene expression using the HG-U133 2.0 plus Gene Chip array was first performed. Twenty-three genes were shown to be overexpressed in an imatinib-resistant cell line. Among these, RUNX1T1 was shown to be overexpressed in another resistant cell line and in patients resistant to imatinib mesylate. This suggests that RUNX1T1 is a putative candidate for the further study of imatinib mesylate resistance.