Adaptive immunity-centered primary immune cell in vitro bioassay

Acquired (adaptive) immunity is demonstrated through the immune function of T lymphocytes and B lymphocytes, including CD8+ cytotoxic T cells that are the effector cells that can destroy tumor cells, CD4+ helper T cells that regulate CD8+ T-cell and B-cell function, and B cells that present antigen and can become plasma cells which produce antibodies.

Immune checkpoints are mostly expressed on T cells. A good experimental approach to assess the function of anti-immune checkpoint antibodies is via stimulation of primary T cells or PBMCs. Blocking the binding between inhibitory immune checkpoints and their ligands can activate the immune response of T cells. Stimulation of co-stimulatory immune checkpoints by agonist antibodies can enhance the immune response of the T cells. To date, GenScript Probio has successfully developed a primary cell-based in vitro bioassay platform for anti-immune checkpoint antibodies.

Immune checkpoint-centered primary cell bioassay service

Immune cell stimulation assay

GenScript Probio provides a variety of immune cell stimulation assays to accommodate your research needs. There are many types of stimuli for this assay to choose from, including non-specific ones such as PHA, PMA, bacterial lipopolysaccharide (LPS), staphylococcal enterotoxin (SEA, SEB, SEE, etc.), anti-CD3 antibody, and anti-CD3/CD28 beads, as well as specific stimuli such as cytokines. By assessing immune cell proliferation, single or multiplex cytokine release, or expression of immune cell activation markers, the potency and efficacy of the antibody drug candidates can be evaluated.

	Service details
Target	Inhibitory or co-stimulatory immune checkpoint targets
Stimulation	anti-CD3 antibody, CD3/CD28 beads, various superantigen (SEA-SEE), PMA/ionomycin, LPS, TNF-α, IL-1β etc.
Cell	PBMC, CD3+ T cell, CD4+ T cell, CD8+ T cell, Treg cell
Assessment	Proliferation, Cytokines (single or multiple), cell surface marker expression
Species	Human, Cyno, Murine, Canine etc.

Mechanism of Action

Figure: Mechanism of actions for immune co-stimulatory and inhibitory immune checkpoints in tumor microenvironment

Key Features

• High QC standards and controllable project turnaround time
• Extensive experience in customized projects

Mixed Lymphocyte Reaction

Mixed lymphocyte reaction (MLR) uses PBMCs from two different donors and co-culture them in vitro. Because the HLA-II antigen D and DP on the cell surface from two donors are different, they may stimulate each other's lymphocyte to proliferate or to release cytokines such as IL-2 and IFN-γ. We can evaluate the function of anti-immune checkpoint antibody drugs by assessing the amount of cytokines being released.

Figure: Mechanism of Action of MLR

Service type	Target	Deliverables	Lead-time
Multiple donors MLR	PD-1, PD-L1, TIM-3, LAG-3, CD73, TIGIT	Final reports including raw data (8 concentrations), analyzed data and DC differentiation and maturation QC data; Data include: EC50, dose-response curves (DRC) for the samples and internal control	4 weeks
Two single donors MLR

Key features of services

• Extensive experience
• Free positive and negative controls
• Stringent documentation standard suitable for IND-filing

Please download the project evaluation form, fill it and send it to us for an evaluation

Case

Figure 1.: Reproducibility of MLR assay data (Pembrolizumab as positive control, human IgG4 and murine IgG1 as negative controls)

Figure 2.: Bioactivity comparison of anti-PD-1 antibody (Pembrolizumab, Nivolumab) and anti-PD-L1 antibody (MPDL3280A) in MLR assay