Mixed Lymphocyte Reaction for novel cancer immunotherapy testing

10 / 18 / 2018

The immunological synapse that occurs between T lymphocytes and Dendritic cells (DCs) is a key component of an effective immune response and is controlled by a combination of stimulatory and inhibitory signals – also called immune checkpoints. As to trigger a better anti-tumor immune response, interventions through a fine-tuning of these control signals within the immunological synapse represent one of the most promising cancer immunotherapy strategies.
The immunological synapse that occurs between T lymphocytes and Dendritic cells (DCs) is a key component of an effective immune response and is controlled by a combination of stimulatory and inhibitory signals – also called immune checkpoints. As to trigger a better anti-tumor immune response, interventions through a fine-tuning of these control signals within the immunological synapse represent one of the most promising cancer immunotherapy strategies.

In order to investigate novel immunotherapeutics capable of enhancing DC-mediated T cell activation, Explicyte set up and validated a robust and high throughput human allogeneic mixed lymphocyte reaction (MLR) assay, which consists in a co-culture of CD4+ T cells (responder) with monocyte-derived DCs (stimulator) and in the HTRF-based quantitation of IFNγ, a relevant surrogate of T cell activation. Our assay is a well-suited system for biologics and small molecules assessment either as single agents and/or forcombination therapies, including e.g. immune checkpoint inhibitors, and can thus be ran in various types of studies spanning from screening to potency profiling and functional characterization of candidate compounds.















 

Highlighting of robust and optimizable MLR response in different human allogeneic T-DC donor pairs.

(A) While displaying an expected response amplitude varying from a donor pair to another one, the MLR response is robust and is further optimized following PD1 blockade. Isolated peripheral blood monocyte-derived DCs from six human donors are mixed with CD4+ T cells each isolated from different donors. IFNγ levels released in the supernatants are measured after 72h using a specific HTRF-based specific kit.

(B) PD1/PDL1 blockade characterization in an allogeneic MLR assay. Isolated peripheral blood monocyte-derived DCs from a human donor are mixed with CD4+ T cells isolated from a second donor. IFNγ levels released in the supernatants are measured after 72h using a specific HTRF-based specific kit. Anti-PD1 (Nivolumab and Pembrolizumab) and anti-PDL1 (Atezolizumab) antibodies potentiate DC-mediated T cell activation as highlighted by IFNg increase in the MLR assay.