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.
Dr Helen McGuire
Senior Research Fellow, Discipline of Pathology and Ramaciotti Facility for Human Systems Biology, Charles Perkins Centre, University of Sydney
Dr Helen McGuire is a Senior Research Officer at the Ramaciotti Facility for Human Systems Biology, Charles Perkins Centre, an initiative established in 2013 to support the development of mass cytometry and wider systems biology analysis across the University of Sydney campus and wider collaborative links. Her research focus and interest lies in the clinical application of immunological studies to a range of human diseases, including cardiovascular disease and cancer.