Oncotarget

Research Papers:

Cell based functional assays for IDO1 inhibitor screening and characterization

Thomas Richards and Elena Brin _

PDF  |  HTML  |  How to cite  |  Order a Reprint

Oncotarget. 2018; 9:30814-30820. https://doi.org/10.18632/oncotarget.25720

Metrics: PDF 643 views  |   HTML 1245 views  |   ?  


Abstract

Thomas Richards1 and Elena Brin1

1Polaris Pharmaceuticals, San Diego, CA, USA

Correspondence to:

Elena Brin, email: ebrin@polarispharma.com

Keywords: IDO1; cell-based assay; epacadostat; BMS-986205

Received: May 15, 2018     Accepted: June 19, 2018     Published: July 20, 2018

ABSTRACT

Indoleamine 2,3-dioxygenase 1 (IDO1) is a new immune-oncology target and its inhibitors have shown promise in the clinic especially in combination with other immune-stimulating agents. Here we describe two robust cell-based assays for screening IDO1 inhibitors. Both assays can be easily adopted by most laboratories and utilized for screening of IDO1 inhibitors. Endogenous IDO1 expression is induced in a cancer cell line with interferon gamma and its activity is assessed by measuring kynurenine secreted into the media. The effect of cancer cell IDO1 induction and inhibition on T cell activation is evaluated in a co-culture assay using Jurkat T cell line. Additional readouts assessing cell viability are employed for early detection of false positive IDO1 inhibitors and toxic compounds. Clinical candidates epacadostat and BMS-986205 were evaluated in the assays as control compounds, the former can completely inhibit IDO1 activity while the maximum effect of the later is limited (to about 80% in our system) consistent with the differences in their interaction with IDO1. Nanomolar concentrations of both compounds rescued IDO1 mediated inhibition of T cell activation. However, treatment with micromolar concentrations of BMS-986205 blocked Jurkat T cell activation and after prolonged incubation induced cell death.


Creative Commons License All site content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 License.
PII: 25720