OriginalArticle ssr 2 TumorInoculation is a ImmuneUseful Model for Response in SHRStudying the Anti - Tumor Rats

Objective: The purpose of the present study was to investigate the relation between the dose of tumor cel[ inoculation (especiatly the doses tess than minimum required to evoke tumor growth) itnd the anti-tumor immune system, particularty lymphoblast format;on and cytotoxic actiyity of lyrnphcytes. Method: We inoculated rats with various doses of SSTL2 tumor cells and examined naturaE kitter (NK) cell activity and lymphoblast formation in vitro. Result: The results showed that the cytotoxicities against SSTL2 celts and lymphoblast fonmation of lymphocytes were enhanced by small dose inoculation of tumor cells that could not induce tumor grewth. Conclusion: It was suggested that was lymphocutes play an important role as an anti-tumor immune system at smal) doses of tumor inoculation, which appears to reflect an early stage of tumor growth in vivo. It was also suggested that SS[[L2 tumer inecutation might be a useful model for stLgdying the anti-tumor immune response in SHR rats.