The Study Of Photodynamic Induction And Enhancement Of Immune Response Under The Improvement Of Tumor Hypoxia

Photodynamic therapy(PDT)is a method of treating diseases by the action of oxygen and photosensitizer under the irradiation of light.Previous work has shown that some photodynamic therapy(PDT)can induce immunogenic cell death(ICD)and enhance anti-tumor immune response.In solid tumors,however,tissue hypoxia in the microenvironment not only reduces the efficacy of PDT,but also inhibits the expression of immune proteins associated with ICD.In order to study the effect of Hypoxia on the expression of immune protein induced by ICD,we used exogenous oxygen supply to hypoxic tumor cells during the course of PDT,in order to enhance the anti-tumor immune response.The main work is as follows:(1)Using hypericin(HY)as photosensitizer,PDT was carried out on MCF-7 cell line under 592 nm light.The effect of Hypoxia on the expression of ICD-associated immunoproteins after PDT was studied by Western blotting and immunofluorescence,although HY-PDT can produce immune response under Hypoxia,it can inhibit the expression of HSP70 and HSP90 protein,and up-regulate the expression of CD47 protein,so as to weaken the immune response of tumor cells.(2)Hollow Silicon Dioxide nanoparticles were prepared by reverse microemulsion method and etching,and then the controlled release oxygen-carrying nano-particles were prepared by loading perfluorocarbon with particle diameter of～70nm and releasing oxygen-carrying nano-particles under 808nm irradiation,the oxygen release capacity in water is up to 10.38 mg/L.(3)In this paper,HY-PDT was carried out on the MCF-7 cells under Hypoxia,nano-oxygen carrier system was added into the cells and photothermal release was carried out to carry oxygen,and immunoblotting was used to study the effect of Hypoxia on the expression of related immune proteins,it was found that exogenous oxygen supply significantly decreased the expression of Hypoxia inducible factor 1(HIF-1α)and increased the expression of HSP70 protein,but had little effect on the expression of HSP90 protein.