Mass Cytometry in Translational Research: Session I

Single-cell mass cytometry identifies mechanisms of resistance to immunotherapy in AML

6:30–7:00 am PDT

Presented By: Shelley Herbrich, PhD

The mechanisms of resistance to immunotherapies in patients with acute myeloid leukemia (AML) are not well-characterized, and biomarkers for improved immunotherapeutic strategies are critical. In this presentation, we characterize the baseline immune landscape and potential mechanisms of resistance using single-cell CyTOF mass cytometry profiling of serially collected samples from refractory/relapsed AML patients undergoing therapy with hypomethylating agents combined with PD-L1 inhibition. Single-cell characterization of these primary bone marrow samples reveals novel insights into the immune checkpoint distribution on AML cells while simultaneously allowing for the evaluation of T cell composition and fitness.

Understanding CD19 negative relapse following CAR T therapies in acute lymphoblastic leukemia

7:00–7:30 am PDT

Presented By: Kara Davis, DO

Chimeric antigen T (CAR T) cells have demonstrated impressive efficacy in refractory and relapsed B cell malignancies, including B cell lymphoblastic leukemia. However, loss of the target antigen, CD19, has been shown to be a mediator of relapse for some patients. We have used mass cytometry and single-cell RNA sequencing to understand whether rare CD19-negative cells exist for patients before they receive CAR T cells and to identify cell types and their features associated with relapse following CAR T therapy for relapsed acute lymphoblastic leukemia.

Mass cytometry reveals distinct immune signatures marking progression from mild to severe COVID-19

7:30–8:00 am PDT

Bernd Bodenmiller, PhD

Coronavirus disease 2019 (COVID-19) manifests with a range of severities, but immune signatures of mild and severe disease are still not fully understood. We used 40-plex mass cytometry and targeted serum proteomics to profile innate and adaptive immune cell populations from peripheral blood of patients with mild or severe COVID-19 and healthy controls. Our data provide new insights into the pathological immune responses that are likely key mechanism in severe COVID-19, further supporting investigation of targeted anti-inflammatory interventions in severe COVID-19.