Aak1 to increase infiltration of adoptively transferred cells into solid tumors

PROJECT SUMMARY/ABSTRACT Insufficient T cell infiltration is a major challenge in adoptive transfer therapies like CAR-T. Therefore, one strategy to improve therapy is to enhance T cell trafficking into tumors. However, current therapies targeting T cell activities largely consist of immune checkpoint modulators, and very little innovation has occurred in therapeutic design targeting T cell intrinsic regulators of intratumoral accumulation. This is due, in part, to an incomplete understanding of the regulatory pathways involved in T cell trafficking. We recently identified Adapter protein 2 associated kinase 1 (Aak1) as an important regulator of T cell chemotaxis into tumors in an in vivo forward genetic screen. The primary objective of this project is to measure the translational potential of AAK1 as a therapeutic target in cancer to augment adoptive transfer therapies, with the additional goal of better understanding molecular functions of Aak1 as a regulator of chemokine receptor Cxcr3 internalization. These goals will be accomplished in three aims. Aim 1 will quantify the impact of genetic modification of Aak1 on tumor infiltration of adoptively transferred T cells in a preclinical solid tumor model. Aim 2 will determine whether Aak1 kinase activity is required for chemokine-induced internalization of Cxcr3 in primary T cells. Aim 3 will measure the degree to which Aak1 modification impacts therapeutic efficacy in adoptive transfer therapies. This proposal has several innovative aspects, including characterization of a novel, T cell specific Aak1 knockout mouse, functional and mechanistic testing of a novel Aak1 mutant construct, and evaluation of Aak1 as a novel therapeutic target to limit T cell chemotaxis into inflamed tissue. Successful completion of this project will benefit development of novel treatment strategies for solid tumors, and findings can broadly be applied to any T cell adoptive transfer approach and is not limited to individual CAR or TCR engineered platforms.