ABSTRACT
Recent advances in immune checkpoint blockade (ICB) inhibiting programmed death-1 (PD-1) and cytotoxic T-
lymphocyte antigen-4 (CTLA-4) have revolutionized the standard of care for cancer treatment. However, the
limited response rates in head and neck squamous cell carcinomas (HNSCC) suggest that new approaches and
targets are clearly needed to fully elucidate the underlying biology of dysfunctional and exhausted CD8 T cells
in cancer and achieve durable responses (cure). G protein-coupled receptors (GPCRs) are the most intensively
studied drug targets since they play key roles in many physiological processes, and they have remained
longstanding favorable pharmacological targets. Here, we plan to target GPCRs that have been identified on
dysfunctional T cells using RNAseq to relieve the immunosuppressive tumor microenvironment in HNSCC.
Preliminary data shows an upregulation of Gas-coupled receptors, PTGER2, PTGER4, and ADRB2, on activated
and exhausted T cells in HNSCC patients, suggesting that these GPCRs that are coupled to the G protein Gas,
and their downstream signaling cascades may be dampening anti-tumor cytotoxicity of CD8 T cells, leading to
exhaustion. Our central hypothesis is that secretion of inflammatory and beta-adrenergic ligands in the tumor
microenvironment and their actions on CD8 T cells lead to Gas signaling and T cell dysfunction, which decreases
cytotoxic and migratory activity that nullifies the effectiveness of ICB. Altogether, Gas-coupled GPCRs may
represent candidates as immune checkpoints that can be targeted in combination with ICB as part of novel
multimodal precision immunotherapy approaches to reactive the immune system to destroy tumors. Using
bioinformatics, chemogenetic approaches, and translatable animal models, we aim to elucidate the role of Gas
signaling in T cell dysfunction and to target endogenous Gas-coupled receptors as a means to enhance existing
immunotherapies to generate favorable outcomes in HNSCC patients.
The proposed research will be conducted at UCSD’s Moores Cancer Center, an institution at the forefront of
translational oncology. This application details the applicant’s training plan including research mentorship,
advanced coursework, training in new techniques, and development of skills in scientific professionalism, writing,
and presentation of data. The research and training outlined in this application will prepare the applicant to
pursue a career in the conduct of academic research as an independent scientist.