pubmed.ncbi.nlm.nih.gov

The spectrum of resistance in SR/CR mice: the critical role of chemoattraction in the cancer/leukocyte interaction - PubMed

  • ️Fri Jan 01 2010

The spectrum of resistance in SR/CR mice: the critical role of chemoattraction in the cancer/leukocyte interaction

Gregory Riedlinger et al. BMC Cancer. 2010.

Abstract

Background: Spontaneous regression/complete resistance (SR/CR) mice are a unique colony of mice that possess an inheritable, natural cancer resistance mediated primarily by innate cellular immunity. This resistance is effective against sarcoma 180 (S180) at exceptionally high doses and these mice remain healthy.

Methods: In this study, we challenged SR/CR mice with additional lethal transplantable mouse cancer cell lines to determine their resistance spectrum. The ability of these transplantable cancer cell lines to induce leukocyte infiltration was quantified and the percentage of different populations of responding immune cells was determined using flow cytometry.

Results: In comparison to wild type (WT) mice, SR/CR mice showed significantly higher resistance to all cancer cell lines tested. However, SR/CR mice were more sensitive to MethA sarcoma (MethA), B16 melanoma (B16), LL/2 lung carcinoma (LL/2) and J774 lymphoma (J774) than to sarcoma 180 (S180) and EL-4 lymphoma (EL-4). Further mechanistic studies revealed that this lower resistance to MethA and LL/2 was due to the inability of these cancer cells to attract SR/CR leukocytes, leading to tumor cell escape from resistance mechanism. This escape mechanism was overcome by co-injection with S180, which could attract SR/CR leukocytes allowing the mice to resist higher doses of MethA and LL/2. S180-induced cell-free ascites fluid (CFAF) co-injection recapitulated the results obtained with live S180 cells, suggesting that this chemoattraction by cancer cells is mediated by diffusible molecules. We also tested for the first time whether SR/CR mice were able to resist additional cancer cell lines prior to S180 exposure. We found that SR/CR mice had an innate resistance against EL-4 and J774.

Conclusions: Our results suggest that the cancer resistance in SR/CR mice is based on at least two separate processes: leukocyte migration/infiltration to the site of cancer cells and recognition of common surface properties on cancer cells. The infiltration of SR/CR leukocytes was based on both the innate ability of leukocytes to respond to chemotactic signals produced by cancer cells and on whether cancer cells produced these chemotactic signals. We found that some cancer cells could escape from SR/CR resistance because they did not induce infiltration of SR/CR leukocytes. However, if infiltration of leukocytes was induced by co-injection with chemotactic factors, these same cancer cells could be effectively recognized and killed by SR/CR leukocytes.

PubMed Disclaimer

Figures

Figure 1
Figure 1

SR/CR mice resist a broad range of lethal cancer cell lines at different doses. The percentage of SR/CR mice that were able to survive challenge with J774, MethA, EL-4, S180, B16, or LL/2 was determined empirically. Mice were monitored for at least 60 days after challenge. SR/CR C57BL/6 mice were challenged with 10e3 or 5 × 10e4 B16 or LL/2. SR/CR C57BL/6 mice were also challenged with 0.8 × 10e7, 1.6 × 10e8, 2.2 × 10e8, or 3.2 × 10e8 S180 or 2.5 × 10e7, 5 × 10e7, 10e8, or 2 × 10e8 EL-4. SR/CR BALB/c mice were challenged with 10e5, 2 × 10e5, 4 × 10e5, or 10e6 MethA or 5 × 10e4, 10e6, or 10e7 J774. WT mice uniformly died at all doses with all cell lines tested. At least 5 mice were tested for any given dose of tumor cells injected.

Figure 2
Figure 2

Naïve SR/CR pups resist the initial challenge with EL-4 and J774. Pups from an SR/CR × WT cross were challenged with 10e6 EL-4 prior to being challenged with any other cancer cell line and 22 out of 35 pups survived. Pups from an SR/CR × WT cross that were challenged with 5 × 10e5 and a second challenge with 5 × 10e6 S180 have a historical survival rate of ~30% [1,2]. When nine pups from an SR/CR × WT cross were challenged with 5 × 10e4 J774 prior to being challenged with any other cell line, one mouse survived. All WT mice challenged with EL-4, S180, and J774 at the indicated doses uniformly died. Mice were monitored for at least 60 days after challenge.

Figure 3
Figure 3

S180 or cell free ascites fluid (CFAF) enhances SR/CR resistance. SR/CR or WT mice were challenged with 2 × 10e5 LL/2 (upper panel) or 10e6 MethA (lower panel) i.p. either alone or with 10e6 S180, 10e6 irradiated S180, or weekly injections of CFAF and survival curves were generated. The number of mice in each group is indicated in the figure.

Figure 4
Figure 4

S180 only enhances SR/CR resistance locally. SR/CR mice were challenged with 2 × 10e5 LL/2 i.p. either alone or with 10e6 S180, either i.p. or s.c., and the survival of mice was monitored. The number of mice in each group is indicated in the figure.

Figure 5
Figure 5

Leukocyte subset composition during challenge with different cancer cell lines. A) SR/CR and WT mice were challenged with 10e5 cells of the indicated cancer cell line, CFAF, or PBS and responding leukocytes were washed out at six hours, quantitated, stained with Ly6 g (PMN), F4/80 (Mac), and CD19 (B-cell) and profiled by flow cytometry. B) Composition of infiltrating immune cells. SR/CR mice were injected with 10e5 cells of the indicated cancer cell line or PBS and six hours later the peritoneal cavity was washed out. The peritoneal infiltrate was stained with Ly6 g (PMN), F4/80 (Mac), NK1.1 (NK cell), CD11c (dendritic cell), CD19 (B-cell), CD4, and CD8 and profiled by flow cytometry. The total value for these seven markers was arbitrarily set at 100% for each sample to allow comparison between groups. Values represent the mean +/- SEM. For each injection group, n >= 4. C) Immune infiltration in response to cancer cell lines and CFAF. SR/CR or WT mice were injected i.p. with 10e5 cells of the indicated cancer cell line or CFAF and six hours later the peritoneal cavity was washed out and the number of cells was quantitated using a cytometer. Values represent the mean +/- SEM. For each injection group, n >= 4. D) SR/CR immune infiltration in response to CFAF, heat inactivated CFAF, and small (<5 kD) or large (>5 kD) molecules found in CFAF fluid. SR/CR mice were injected as indicated and six hours later the peritoneal cavity was washed out and the number of cells was quantitated using a cytometer. Values represent the mean +/- SEM. For each injection group, n >= 4.

Figure 6
Figure 6

SR/CR leukocyte migration and cancer destruction. A proposed model for SR/CR mediated cancer cell killing. S180 secretes chemotactic factors that attract SR/CR leukocytes (SR) to the site of the cancer, allowing tight contact between the leukocytes and cancer cells to be made which facilitates tumor destruction. LL/2 and MethA produce little or no chemoattractant and are, therefore, not efficiently killed by SR/CR leukocytes. Co-injection of MethA or LL/2 with S180 results in attraction of SR/CR leukocytes to the site of the cancer and efficient cell killing of these cancer cell lines. This suggests that some cancer cells may escape from SR/CR resistance because they do not induce SR/CR leukocyte infiltration and demonstrates the importance of leukocyte infiltration in the SR/CR resistance mechanism.

Similar articles

Cited by

References

    1. Koch J, Boschian A, Hau J, Rieneck K. Frequency of the cancer-resistant phenotype in SR/CR mice and the effect of litter seriation. In Vivo. 2008;22:565–569. - PubMed
    1. Cui Z, Willingham MC, Hicks AM, Alexander-Miller MA, Howard TD, Hawkins GA, Miller MS, Weir HM, Du W, DeLong CJ. Spontaneous regression of advanced cancer: identification of a unique genetically determined, age-dependent trait in mice. Proc Natl Acad Sci USA. 2003;100:6682–6687. doi: 10.1073/pnas.1031601100. - DOI - PMC - PubMed
    1. Cui Z. The winding road to the discovery of the SR/CR mice. Cancer Immun. 2003;3:14. - PubMed
    1. Hicks AM, Riedlinger G, Willingham MC, Alexander-Miller MA, Von Kap-Herr C, Pettenati MJ, Sanders AM, Weir HM, Du W, Kim J. Transferable anticancer innate immunity in spontaneous regression/complete resistance mice. Proc Natl Acad Sci USA. 2006;103:7753–7758. doi: 10.1073/pnas.0602382103. - DOI - PMC - PubMed
    1. Hicks AM, Willingham MC, Du W, Pang CS, Old LJ, Cui Z. Effector mechanisms of the anti-cancer immune responses of macrophages in SR/CR mice. Cancer Immun. 2006;6:11. - PubMed

Publication types

MeSH terms