Assessing the immunomodulatory potential of therapeutic agents in cynomolgus macaque cytotoxic T lymphocytes.

Abstract

Abstract The preclinical evaluation of therapeutic agents contributes to the understanding of associated risks and benefits. The non-human primate, and notably the cynomolgus macaque, is often a species of choice for such pharmacological and toxicological assessments. The degree of immunomodulation associated with these agents, intended or not, is a critical point to consider in that context. While there are tools to immunophenotype and enumerate effector T cells, the knowledge gap surrounding the functional characterization of cytotoxic T lymphocytes (CTL) persists. Here we present a multi-parametric cynomolgus macaque CTL functional assay. By using an EGFR expressing target cell line co-cultured with cynomolgus peripheral blood mononuclear cells (PBMC) and an EGFR Bispecific T Cell Engager (BiTE®), we were able to redirect lysis in a target-specific manner. In this assay we simultaneously monitored cytolytic potential (CD107a) and cytokine secretion (IFN-γ and TNF-α) of effector CTL against target cell growth. Overall our results demonstrate the ability to assess cynomolgus CTL function under known immunosuppressive agents, thereby enabling a multi-parametric approach of monitoring the impact of investigational drugs on an important component of the immune system.