26-color flow cytometry to immunophenotype human lymphoid and myeloid cells in cancer patients undergoing immunotherapy
Huang Wang1*, James Gotley1*, Ahmed Mehdi1, Tasafin Hossain2, Ian Frazer1, Janin Chandra1
1 The University of Queensland Diamantina Institute, The University of Queensland, Woolloongabba, QLD 4102
2 Princess Alexandra Hospital, Annerley, QLD
* Equal Contribution
Immune checkpoint inhibitors aim to block inhibitory immune cell pathways and have shown promising therapeutic outcomes in cancer patients. However, this therapy only impacts on tumour regression in less than 20% of treated patients. Therefore, predictive biomarkers of long-term clinical response will significantly enhance the utility of this therapy. We designed a 26-colour antibody panel which will be used to phenotype peripheral blood mononuclear cells (PBMCs) of cancer patients before and shortly after commencement of immunotherapy. Additional to diverse lymphocyte subsets, the panel delineates the myeloid cell landscape at high resolution, allowing discrimination of multiple cell states within monocytes and dendritic cells, which are recognised as important players in the immune response to cancer. All cell populations will further be analysed for expression of multiple inhibitory and stimulatory features. Final optimization of the panel is currently ongoing. A clinical study which will utilize this panel to measure correlation of the peripheral immune composition with response to therapy is now underway.