Selected in silico devised mutations endow TCR with superior antitumor function

T-cells can be genetically modified with tumor specific receptors such as CARs or TCRs, to provide them with the ability to recognize cancer cells. However, several factors may limit the effectiveness of this approach.

In this project, our goal was to increase the anti-cancer function of T-cells by increasing the stability of the constant region of the TCR and generating improved versions of several widely used TCRs. This can be achieved by modifying selected amino acids in the constant region. Using our modified TCRs in therapeutic settings will not require changing the well-established protocols currently in use.

Our method combines previously described modifications with an evolution-guided atomistic design to improve protein stability. The combination of several approaches resulted in an increased exogenous TCR expression, which directly correlated in co-cultures with tumor cells with an enhanced cytokine secretion that ranged from a three-fold increase to a sixteen-fold increase, depending on the TCR and the targeted cell line. Moreover, improved mutant TCRs mediated an increased in expression of activation-associated differentiation markers (e.g., 41BB, CD25 and CD69). Finally, T-cells expressing the mutated TCRs demonstrated an improved ability in targeting tumors in killing assays.

In conclusion, we demonstrate herein that it is feasible to generically devise in silico specific structural mutations applicable to multiple TCRs and can mediate superior anti-tumor activity.