Background: Ovarian cancer (OC) is the 8th most diagnosed cancer in women and displays poor prognosis with a 5-year survival rate of 17% for advanced stage patients. Given that 75% of cases are diagnosed at late stages, there is a need to develop better OC treatments.
T cell receptor T cell therapy (TCR-T) is emerging as a safe, alternative, and efficacious cell-based immunotherapy against solid tumours. It is based on a pre-existing mechanism by which CD8+ T cells (CTL), via their TCR, target and destroy cancer cells. CTLs achieve this by binding to specific tumour neoantigen (TNA) presented on human leukocyte antigen (HLA). Given this, precision TCR-T can be developed using CTLs engineered with neoantigen-specific TCR.
To develop TCR-T, a HLA-restricted TNA and the corresponding high-affinity TCR are required. We have identified a HLA restricted TNA specific for ovarian cancer (OC); Neuropeptide W E100Q (NPW E100Q), which is being used to explore high-affinity TCRs for engineering OC TCR-T.
Methods: To expand NPW E100Q-specific CTLs, DCs presenting NPW E100Q and CTLs from healthy, HLA-matched donor blood were co-cultured. Culture conditions were optimised to produce the highest yield of NPW E100Q CTLs by trialling differing concentrations of cytokines. Co-cultures were stained with proliferation dye and NPW E100Q dextramer to identify TNA-specific CTLs via flow cytometric analysis.
Results: CTLs cultured in cytokine cocktail (IL-7, IL-15, and IL-21) showed higher cell viability and expression of CD8 markers compared to co-cultures with IL-2 alone. Additionally, NPW E100Q stimulated co-cultures showed higher numbers of dextramer-specific CTLs compared to controls using cytokine cocktail conditions.
Conclusions: Using the aforementioned cytokine cocktail, we established a novel co-culture condition which allowed for the identification of NPW E100Q specific CTLs. This population can be used to discern a TCR sequence specific for NPW E100Q peptide and develop precision OC TCR-T.