The development of immuno-oncology treatments requires an understanding of not only the quantity, but the exact localization of the immune cells present. We recently developed a panel of immune cell markers for detecting changes in the distribution of immune cells in response to treatment with immuno-oncology agents. The panel consists of a wide variety of stains for different immune cell sub-types and cancel cells in both mouse and human tissues and thus can be applied to a range of different programs depending on the chosen markers. Current markers include:
- T lymphocyte markers (CD3, CD4, and CD8)
- B lymphocyte markers (CD20 and CD45R)
- Macrophage markers (CD68, CD163, and CD206)
Additional markers are under development for FOXP3 to identify T regulatory cells as well as PD-1 and PD-L1 immune checkpoint inhibitors.
The panel was developed using immunohistochemistry, a valuable quantitative pathology tool that provides visual evidence of the distribution and locations of specific proteins or biomarkers within tissue. This technique is commonly used to identify specific subsets of cells within hematopoietic or tumor tissue based on the differential expression of well-defined surface or intracellular markers. Applying image analysis techniques such as stereology to the stained tissues provides further quantification of immune cell infiltration and statistical comparison of the number and area of infiltrating immune cell subtypes between treatment groups.
Both immunohistochemistry and these image analysis tools can be quite complex to perform so it is important to choose a partner who has vast experience and deep scientific knowledge of this technique in order to avoid compromised study design and delayed timelines.