Histological and morphological studies of immune responses induced by laser immunotherapy

Abstract

Laser energy can induce acute photothermal tissue damage, but without systemic effect in the treatment of tumors. However, it could serve as a precursor of immune responses if its photothermal actions could be used effectively as a means of producing tumor-specific antigens and other immunological stimulation elements. When used in a combination with immunoadjuvants, laser photothermal energy had been successfully applied in the treatment of metastatic tumors. Pre-clinical and preliminary clinical studies have demonstrated the systemic and immunological effects of the combination of laser irradiation and immunological stimulation through eradication of primary and secondary tumors, and through molecular and cellular anti-tumor immune activities. This study focuses on the histological and morphological aspects of laser immunotherapy induced immune responses, using glycated chitosan as the adjuvant and an 805-nm laser as the source of photothermal energy source. Cellular activities, such as tumor destruction and lymphocyte infiltration after the laser immunotherapy treatment were observed and analyzed. These cellular activities further support the hypothesis that induced immune activities are crucial outcome of laser immunotherapy.