T cell homing to nasopharyngeal carcinoma

Undifferentiated nasopharyngeal carcinoma (NPC) is a very good candidate disease for treatment with adoptive T cell transfer. Uniformly Epstein-Barr virus (EBV)+, these tumours reportedly have functional antigen processing and presentation machinery and express viral proteins that contain known cytolytic T cell target epitopes. This raises the possibility that boosting relevant EBV-specific T cell immunity in NPC patients might defeat the tumour. The persistent nature of EBV infection may also encourage the long-term survival of therapeutically administered virus-specific cells. However, efficient delivery of tumour-specific T cells from the circulation to solid tumour tissue is a clear requirement for effective cellular therapy, yet the mechanisms by which T cells gain entry to NPC tumours have not yet been determined. The malignant cells of NPC are usually associated with a substantial lymphoid infiltrate mainly consisting of T cells. Using unmanipulated diagnostic biopsy samples, we have characterised chemokine receptor expression (CR) on tumour-infiltrating T cells, and established whether specific chemokine ligands are detectable at the NPC tumour site. We found that functional CXCR6 and CCR5 were expressed on tumour infiltrating T cells, consistent with the presence of specific ligands for these receptors at the tumour site. Furthermore, our data suggests that effector and regulatory cells may use shared homing mechanisms to gain entry to NPC tumours.