Objective

Immunotherapy against cancer has proven clinical efficacy and tremendous potential in multiple tumor entities. Syngeneic mouse tumor models represent the gold standard to analyze effects of immunotherapy due to their fully competent immune-repertoire. However, the amount and composition of tumor infiltrating leukocytes (TIL) is highly variable, complicating the targeted analysis of subpopulations. In particular, small subpopulations cannot be analyzed properly but may be lost in the background noise.  

We have established an automated workflow combining tissue dissociation with TIL-specific isolation to improve and accelerate downstream analysis. Tumor dissociation was automated using the gentleMACS Octo Dissociator, and isolation of TIL was improved using new CD45-specific MicroBeads for separation from dissociated tumor tissue.

To address the need for parallel cell separation, the fully automated MultiMACS X was developed to process 24 separations in one run. Using this method TILs from syngeneic mouse tumors were enriched from under 4% to purities above 80% at high yields above 95%. Importantly, the composition of infiltrating immune cells was not affected.

In summary, we have developed an automated workflow for the isolation of TIL from mouse tumors, reducing time and costs of downstream analysis while standardizing and enhancing the detection and quantification of immune cell subpopulations.