No abstract

No abstract

Limited T cell availability and proliferative exhaustion present major barriers to successful T cell-based immunotherapies and may potentially be overcome through the use of ''rejuvenated'' induced pluripotent stem cells derived from antigen-specific T cells (T-iPSCs). However, strict antigen specificity is essential for safe and efficient T cell immunotherapy. Here, we report that CD8ab T cells from human T-iPSCs lose their antigen specificity through additional rearrangement of the T cell receptor (TCR) a chain gene during the CD4/CD8 double positive stage of in vitro differentiation. CRISPR knockout of a recombinase gene in the T-iPSCs prevented this additional TCR rearrangement. Moreover, when CD8ab T cells were differentiated from monocyte-derived iPSCs that were transduced with an antigen-specific TCR, they showed monoclonal expression of the transduced TCR. TCR-stabilized, regenerated CD8ab T cells effectively inhibit tumor growth in xenograft cancer models. These approaches could contribute to safe and effective regenerative T cell immunotherapies.

BACKGROUND: The phosphatidylinositol 3 0 -kinase (PI3K) -AKT pathway is activated in many human cancers and plays a key role in cell proliferation and survival. A mutation (E17K) in the pleckstrin homology domain of the AKT1 results in constitutive AKT1 activation by means of localisation to the plasma membrane. The AKT1 (E17K) mutation has been reported in some tumour types (breast, colorectal, ovarian and lung cancers), and it is of interest which tumour types other than those possess the E17K mutation. METHODS: We analysed the presence of the AKT1 (E17K) mutation in 89 endometrial cancer tissue specimens and in 12 endometrial cancer cell lines by PCR and direct sequencing. RESULTS: We detected two AKT1 (E17K) mutations in the tissue samples (2 out of 89) and no mutations in the cell lines. These two AKT1 mutant tumours do not possess any mutations in PIK3CA, PTEN and K-Ras. INTERPRETATION: Our results and earlier reports suggest that AKT1 mutations might be mutually exclusive with other PI3K -AKTactivating alterations, although PIK3CA mutations frequently coexist with other alterations (such as HER2, K-Ras and PTEN) in several types of tumours.