An animal model system for the immunotherapy of lung carcinoma using sensitized lymphocytes: a preliminary study

An animal model system was established for immunotherapy of lung cancer using line-1 lung carcinoma in Balb/cR mice and xenogeneic lymphocytes from New Zealand white (N2W) rabbits. The immunization schedule consisted of footpad and subcutaneous injections of 1 X 10(8) viable line-1 cells into two rabbits, twice at a weekly interval. Two other rabbits were maintained as source of unsensitized lymphocytes. All rabbits were bled on day 14 at which time 45 mice were divided into three groups of 15 for both transplantation of 1 X 10(4) viable line-1 cell (subcutaneously) and treatment with 1) control saline, 2) 2.5 X 10(6) unsensitized lymphocytes, and 3) 2.5 X 10(6) sensitized lymphocytes. These treatments were repeated twice at weekly intervals. Results were evaluated four weeks after transplant and initial treatment. Tumor developed in 13/15 control mice, 15/15 treated with unsensitized lymphocytes, and 7/15 with sensitized-lymphocyte injection. The mean tumor weight for group 1 (control mice) was 1.38 +/- 0.22 gm (SEM), group 2 was 2.09 +/- 0.25 gm, and 0.56 +/- 0.28 gm for group 3. There was a statistically significant difference between control and group 3 for both tumor appearance (P = 0.014) and tumor weight (P = 0.026).