Systemic and In Situ Natural Killer Activity in C57BL/6N and CBA/N Mice Bearing Murine Sarcoma Virus-Induced Regressor Tumors

Abstract

Both systemic and in situ natural killer (NK) activity was assessed in young and old C57BL/6N and CBA/N mice bearing primary murine sarcoma virus-induced tumors. Splenic NK activity was depressed in tumor-bearing mice relative to normal age-matched controls. In situ NK activity was detected in young mice, and the level paralleled that found in the spleens of the same mice. In older mice, in situ NK activity was not detected. Furthermore, the depressed levels of activity in the spleens of tumor-bearing mice seemed to reflect systemic effects rather than migration of NK cells from the spleen to the tumor site.