a Growth of s.c. MC-C tumor initiated (on day 0) with 5 × 105 MC-C tumor cells. Each point represents the mean ± standard error (SE) of 12 mice. b Concomitant immunity expressed, in the ordinate, as the ratio between TD50 of secondary MC-C tumor in MC-C tumor-bearing mice/TD50 in control mice. Abscissa indicates the primary tumor volume at the day of the second challenge. Each point represents the mean ± SE of five experiments. *
P < 0.002 as compared with control mice and mice bearing MC-C tumors measuring 1,500 and 2,000 mm3; P < 0.05 as compared with mice bearing MC-C tumors measuring 800 mm3. **
P < 0.001 as compared with control mice and mice bearing MC-C tumors measuring 800, 1,500 and 2,000 mm3; P < 0.02 and P < 0.05 as compared with mice bearing MC-C tumors measuring 600 mm3 and 100 mm3, respectively. c In the adoptive transference assay, normal mice received 1 × 108 spleen cells by the i.p. route, from normal mice or mice bearing MC-C tumors with different sizes; 2 h later mice were challenged with 5 × 105 MC-C tumor cells by the s.c. route. Each bar represents the mean ± SE of six experiments. Ordinate: Survival index of recipient mice = survival time/t/n, where t = number of mice that died of tumor and n = number of mice inoculated. *
P < 0.01 as compared with normal mice and mice bearing tumors measuring 1,100 and >2,000 mm3. **
P < 0.001 as compared with normal mice and mice bearing tumors measuring 1,100 and >2,000. d In the Winn test, 50 × 106 spleen cells from normal mice or mice bearing MC-C tumors with different sizes were mixed in vitro with 5 × 105 MC-C tumor cells and then the mixture was s.c. inoculated in naive mice. Each bar represents the mean ± SE of five experiments. Ordinate Survival index of mice inoculated. *
P < 0.001 as compared with normal mice and mice bearing MC-C tumors measuring 1,500 and >2,000 mm3. **
P < 0.001 as compared with normal mice and mice bearing MC-C tumors measuring 1,500 and >2,000 mm3; P < 0.002 and P < 0.01 as compared with mice bearing tumors measuring 300 mm3 and 800 mm3, respectively. e Cytotoxic activity of 2 × 106 spleen cells from normal mice or mice bearing MC-C tumors with different sizes against 2 × 104
51Cr-labeled MC-C tumor cells. Each bar represents the mean ± SE of four experiments. *
P < 0.01 as compared with normal mice and mice bearing MC-C tumors >2,000 mm3. **
P < 0.001 as compared with normal mice and mice bearing MC-C tumors >2,000 mm3 and P < 0.05 as compared with mouse bearing MC-C tumor measuring 100 and 800 mm3. f Levels of p56lck in T splenocytes throughout MC-C tumor growth. Cell lysates from enriched T cells (4 × 106 cell equivalent/lane) were separated on a 10% SDS-PAGE gel, transferred to a polyvinylidene difluoride membrane and immunoblotted with an anti-p56lck antibody, followed by a secondary antibody conjugated to peroxidase and developed via enhanced chemiluminescence. These results are representative of those obtained in two similar experiments. Lanes: M markers of molecular weight in Kilo Daltons, J Jurkat cells (positive control of p56lck expression), N, T splenocytes from normal mice, ST, T splenocytes from mice bearing small tumors (<500 mm3), LT T splenocytes from mice bearing large tumors (1,500–2,000 mm3)