T lymphocytes play a key role in the immune response and their functions are intimately linked to metabolic programs. During immune responses, T cells undergo a metabolic
reprogramming notably characterized by an increased aerobic
glycolysis. Using a quantitative phosphoproteomic approach, the inventors have identified a new
transcription factor called Foxk1 as being highly phosphorylated in T cells upon
T Cell Receptor (TCR) engagement. The results also indicate that Foxk1
phosphorylation and
nuclear translocation is dependent of the AKT-mTOR
kinase activities. Using T-
cell specific Foxk1 deficient mice (Foxk1- / -), we demonstrated that Foxk1 is required for full
T cell activation. Foxk1-deficient T cells exhibited reduced proliferation and
cytokine secretion following TCR stimulation. Furthermore, T cells from Foxk1- / - mice were less prone to acquire an
effector like
phenotype than wild-type cells when challenged
in vivo. Conversely, Foxk1 overexpression in T cells enhanced their
effector functions in a TCR-
dependent manner. In CD8+ T cells, this effect also results into enhanced
cancer cell killing capacity
in vitro, and improved tumor rejection
in vivo. Altogether, these results indicated that Foxk1 is a major
regulator of
T cell metabolism and thus, of
T cell effector functions. Thus, the present invention relates to host immune cells engineered to overexpress a Foxk1 polypeptide and their use of the treatment of
cancer.