Host cell infiltration into PDT-treated tumor

Publisher Website
Google Scholar
Abstract
C3H mice bearing SCCVII squamous cell carcinoma were treated with photodynamic therapy (PDT) 24 hours after receiving Photofrin (25 mg/kg, i.v.). Single cell suspensions obtained by the enzymatic digestion of tumors excised either 30 minutes or 4 hours after PDT were analyzed for the content of host immune cells and colony forming ability of malignant cells. The results were compared to the data obtained with non-treated tumors. It is shown that there is a marked increase in the content of cells expressing Mac-1 (monocytes/macrophages or granulocytes) in the tumor 30 minutes post PDT, while a high level of other leucocytes are found within the tumors by 4 hours after PDT. As elaborated in Discussion, the infiltration rate of host immune cells, dying of malignant tumor cells, and yet unknown death rate of host cells originally present in PDT treated tumor occurring concomitantly during this time period complicates this analysis. The results of this study suggest a massive infiltration of macrophages and other leucocytes in PDT treated SCCVII tumor, supporting the suggestion that a potent immune reaction is one of the main characteristics of PDT action in solid tumors. It remains to be determined to what extent is the activity of tumor infiltrating immune cells responsible for its eradication by PDT.

This publication has 0 references indexed in Scilit: