Dr

Helen McGuire

Single cell analysis with Mass Cytometry; technology introduction and opportunities in clinical studies

Mass cytometry, or Cytometry by Time-Of-Flight (CyTOF), is a powerful platform for high-dimensional single-cell analysis of the immune system. It enables the simultaneous measurement of over 40 markers on individual cells through the use of monoclonal antibodies conjugated to rare-earth heavy metal isotopes. Coupled with our already extensive immunological knowledge of canonical immune subsets and an ability to delve into and describe subtle populations, mass cytometry presents an opportunity to investigate cumulative subtle changes across many specific immune subsets in a range of clinical cohorts.

Based on our previous studies in several autoimmune states, which revealed remarkably stable changes in the size of multiple peripheral blood cell subsets, we conducted a study of cell subsets in melanoma and lung cancer patients before and after therapy with the checkpoint inhibitor, anti-PD-1. We used a data analysis approach originally developed to analyse gene expression signatures in highly multiparametric datasets to analyse the cell subset distribution within samples. We identified an immune signature in baseline blood samples that robustly identified patients who would subsequently make clinical responses to anti-PD-1 therapy. Such an approach is well suited to machine learning, which will be used in future application of the predictive signature in clinical settings.