Phototherapy together with it triggered immunological response for Anti-HPV treatment of oropharyngeal cancer: Removing tumor and pathogenic virus simultaneously

Abstract

Oropharyngeal squamous cell carcinoma (OPSCC) is one of most common cancers that often brings lots of inconvenience to the patient in swallowing and phonation even after the operation. Moreover, OPSCC is typically as nodal metastases and high recurrence rate due to the high-risk human papillomavirus (HPV) infection for 90% of patients. Obviously, completely curing OPSCC requires simultaneous removal of solid tumor and related pathogenic virus, which is very indispensable but never be realized by any kind of clinical therapy up to now. In this work, we selected the ZrC nanoparticles as difunctional photoactive substance for synchronous generation of hyperthermia and reactive oxygen species (ROS) under NIR excitation. The resultant synergistic photothermal and photodynamic treatment outcome contributed to an excellent anti-tumor effect. The phototherapy of this work was found not only to be able to damage cancer cells directly, but also could trigger the host immunity for further tumor removal and desirable HPV inactivation. An immunologic mechanism of this work was reasonable proposed by monitoring level of shock protein (HSP), calreticulin (CRT), T lymphocytes and dendritic cells (DCs) and immune check point of B7H3, B7H4 and PD-L1 post phototherapy. It was found that tumor-associated antigens of CRT ("eat-me" signal), HSPs and cell debris were released as cancer cell damage, and then the adaptive immune system and the congenital immunity were triggered to activate DCs maturity, antigen presentation to T cells, proliferation of CD4⁺ and CD8⁺ T cells, recruiting macrophages and NK cells and so forth immune responses. Being the first example of using phototherapy for virus-related cancer study, this work opens the door for photo-immunotherapy.

Keywords: Antitumor immunity; HPV; Immunotherapy; Oropharyngeal cancer; Phototherapy.