A novel membrane-bound interleukin-2 promotes NK-92 cell persistence and anti-tumor activity

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• Limited persistence of natural killer (NK) cells in vivo is a major hurdle in NK cell immunotherapy.
• Interleukin-2 (IL-2) is crucial for NK cell proliferation and survival but causes toxicities when administered systemically.
• Existing methods struggle to balance NK cell enhancement with systemic toxicity.

Purpose of the Study:

• To engineer a cell-restricted form of IL-2 to improve NK cell persistence.
• To mitigate the adverse toxicities associated with systemic IL-2 administration.
• To enhance NK cell-mediated antitumor activity.

Main Methods:

• Construction of membrane-bound IL-2 (mbIL-2) by linking human IL-2 and human IL-2Rα.
• Activation and culture of NK-92 cells with mbIL-2 in vitro.
• Evaluation of NK-92 cell survival, proliferation, and antitumor activity in vitro and in vivo.

Main Results:

• mbIL-2-activated NK-92 cells demonstrated enhanced survival and proliferation in vitro and in vivo without exogenous IL-2.
• mbIL-2 expression on NK-92 cells did not promote bystander cell survival, indicating cell restriction.
• mbIL-2 improved NK-92 cell-mediated antitumor activity by modulating IL-2 receptor signaling and NK cell receptor expression.

Conclusions:

• The novel mbIL-2 effectively enhances NK-92 cell persistence and antitumor efficacy.
• mbIL-2 represents a promising strategy for improving NK cell immunotherapy by improving NK cell function and reducing systemic toxicity.
• Genetically modified NK-92 cells expressing mbIL-2 hold potential for clinical development.