Engineering a robust and scalable platforn for the production of IEILC1-like NK cells, a novel solid tumor immunothereapeutic modality

While surgery, radiation, and chemotherapy have been the gold standards of cancer treatment for decades, they are severely limited in certain aspects -- not all tumors are operable, and chemotherapy and radiotherapy can damage healthy tissues as well as the cancer cells. Targeted therapy and immunotherapy were hailed as solutions to this, but they also have drawbacks of their own. The first is that they can be extremely expensive, which leads to financial toxicity, and the second is that they can sometimes cause cytotoxicity to healthy tissues or even occasionally kill the patients they are meant to treat. Natural killer (NK) cell-based therapies solve both issues as they exhibit an optimal safety profile and can be given off-the-shelf to lower the cost of production, but their success has been mostly restricted to liquid tumors. Solid tumors account for 90% of all cancer diagnoses and are significantly more difficult to treat due to a variety of factors such as tumor heterogeneity, the immunosuppressive tumor microenvironment (TME), and poor immune cell trafficking. Here, I present our work designing NK cells with optimized functionalities for solid tumor indications. We have previously identified a novel population of NK cells within head and neck squamous cell carcinoma (SCC) patients that maintain an activated and highly proliferative phenotype within the TME and resemble intraepithelial group 1 innate lymphoid cells (ieILC1s) due to their expression of CD49a and CD103. In earlier work, we were able to induce moderate levels of CD49a and CD103 expression on peripheral blood NK cells through injection of the NK cells into subcutaneous tumors or co-culture with live tumor cells -- but these cells were not thoroughly studied in vitro or in vitro, and this functional evaluation is critical for designing solid tumor therapeutics. We designed cell culture systems that can reliably differentiate peripheral blood NK cells into highly pure, clinically relevant doses of ieILC1-like NK cells. This platform design involved comparing media conditions, cytokine exposure, feeder cell ratios, seeding density, and many other variables. We then assessed the ability of these ieILC1-like NK cells to kill target cells, produce inflammatory cytokines, interact with tumor-targeting antibodies and chimeric antigen receptors, and infiltrate solid tumors. Our results show that ieILC1-like NK cells exhibit high cytotoxicity, high production of cytokines, and tumor infiltration rates up to ten times higher than other NK cell products that are currently being tested in the clinic. This cytotoxicity can be enhanced by using antibodies or chimeric antigen receptors in manners similar to conventional NK cells. Furthermore, we established the role of the surface integrin CD103 as a critical molecular regulator of tumor invasion by NK cells. This work represents an important step forward in the design of affordable and accessible cell therapeutics for solid tumors

Keywords: Bioengineering.
Advisor: Sunwoo John B.
Barron Annelise E.
Engleman Edgar G.