Abstract
In solid malignancies, including head and neck squamous cell carcinoma (HNSCC), the immunosuppressive molecule adenosine, which accumulates in the tumor, suppresses cytotoxic CD8+ T cell functions including chemotaxis and tumor infiltration. Adenosine functions through binding to the adenosine A2A receptor (A2AR) present on T cells. In order to increase T cell migration into the tumor, the negative effect of adenosine must be abrogated. Systemic drug treatments targeting A2AR are available; however, they could lead to negative toxicities due to the broad expression of this receptor. Herein, we developed a lipid nanoparticle (NP)-based targeted delivery approach to knock down A2AR in T cells in order to increase their chemotaxis in the presence of adenosine. By using flow cytometry, immunofluorescence, qRT-PCR, and 3D-chemotaxis, we demonstrated that CD45RO-labeled nanoparticles delivering ADORA2A gene-silencing-RNAs decreased ADORA2A mRNA expression and rescued the chemotaxis of HNSCC CD8+ memory T cells. Overall, the data indicate that targeting the adenosine signaling pathway with lipid NPs is successful at suppressing the inhibitory effect of adenosine on the chemotaxis of HNSCC memory T cells, which could ultimately help increase T cell infiltration into the tumor.