1. Academic Validation
  2. Phenotypic Approaches to Identify Inhibitors of B Cell Activation

Phenotypic Approaches to Identify Inhibitors of B Cell Activation

  • J Biomol Screen. 2015 Aug;20(7):876-86. doi: 10.1177/1087057115585724.
Elizabeth B Rex 1 Suzie Kim 2 Jake Wiener 3 Navin L Rao 3 Marcos E Milla 2 Daniel DiSepio 2
Affiliations

Affiliations

  • 1 Discovery Sciences, Janssen Research and Development LLC, La Jolla, CA, USA erex@its.jnj.com.
  • 2 Discovery Sciences, Janssen Research and Development LLC, La Jolla, CA, USA.
  • 3 Immunology, Janssen Research and Development LLC, La Jolla, CA, USA.
Abstract

An EPIC label-free phenotypic platform was developed to explore B cell receptor (BCR) and CD40R-mediated B cell activation. The phenotypic assay measured the association of RL non-Hodgkin's lymphoma B cells expressing lymphocyte function-associated antigen 1 (LFA-1) to intercellular adhesion molecule 1 (ICAM-1)-coated EPIC plates. Anti-IgM (immunoglobulin M) mediated BCR activation elicited a response that was blocked by LFA-1/ICAM-1 specific inhibitors and a panel of Bruton's tyrosine kinase (Btk) inhibitors. LFA-1/ICAM-1 association was further increased on coapplication of anti-IgM and mega CD40L when compared to individual application of either. Anti-IgM, mega CD40L, or the combination of both displayed distinct kinetic profiles that were inhibited by treatment with a Btk Inhibitor. We also established a FLIPR-based assay to measure B cell activation in Ramos Burkitt's lymphoma B cells and an RL cell line. Anti-IgM-mediated BCR activation elicited a robust calcium response that was inhibited by a panel of Btk inhibitors. Conversely, CD40R activation did not elicit a calcium response in the FLIPR assay. Compared to the FLIPR, the EPIC assay has the propensity to identify inhibitors of both BCR and CD40R-mediated B cell activation and may provide more pharmacological depth or novel mechanisms of action for inhibition of B cell activation.

Keywords

EPIC; FLIPR; LFA-1/ICAM-1 adhesion; calcium flux; label free.

Figures
Products