Abstract
The study was performed to determine whether local thoracic irradiation (LTI) causes accumulation of adoptively transferred peritoneal exudate (PE) cells in the lung and whether such treatment improves the response of tumor deposits in the lung to LTI. Tumors in the lung were generated by sarcoma SA-NH cells injected i.v. into syngeneic (C3Hf/Kam mice. Exposure of mice to a single dose of γ-rays ranging from 2 to 10 Gy caused a dose-dependent decrease in the number of alveolar exudate cells. Also, LTI caused a dose-dependent reduction in the number of lung tumor nodules in mice that were treated with tumor cells 4 days before irradiation. Adoptive i.v. transfer of syngeneic PE cells several hours or 2 days after LTI not only restored the radiation-depleted alveolar exudate cells to their normal levels but also led to an accumulation of transferred cells in the irradiated lung to a several-fold excess of the normal value. Maleic anhydride-divinyl ether-2-activated PE cells accumulated in the irradiated lung much more than normal PE cells and exerted antitumor activity in normal mice and in mice exposed to LTI. Their antitumor action, however, was much more pronounced in the latter, resulting in the augmentation of radioresponse of tumor nodules by a factor of 1.23. The better antitumor action of activated PE cells in mice given LTI can be ascribed to accumulation of these cells in the irradiated lung. Thus, these results show that the irradiation of the lung predisposes this tissue to accumulation of lymphoid cells, which can be beneficial in the therapy of malignant tumors by combinations of radiotherapy and adoptive immunotherapy.
Footnotes
-
↵1 This investigation was supported by NIH Research Grant CA-06294. Animals used in this study were maintained in facilities approved by the American Association for Accreditation of Laboratory Animal Care and in accordance with current regulations and standards of the United States Department of Agriculture and Department of Health and Human Services.
-
↵2 To whom requests for reprints should be addressed, at Department of Experimental Radiotherapy at The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030.
- Received March 31, 1989.
- Revision received June 8, 1989.
- Accepted June 14, 1989.
- ©1989 American Association for Cancer Research.