Testing of immunomodulatory properties in vitro

Area of Science:

• Immunology
• Toxicology
• Cell Biology

Background:

• Species-specific immune responses necessitate human cell models for accurate immunomodulatory compound evaluation.
• In vitro models are crucial for studying immune responses and inflammation.
• Human whole blood and liver cell systems offer advantages for studying immune mediator release and cellular interactions.

Purpose of the Study:

• To establish and validate in vitro models using human whole blood and liver cells for assessing immunomodulatory and inflammatory properties of test compounds.
• To investigate the release of immune mediators in response to various stimuli in human whole blood.
• To explore the mechanisms of inflammation and cell death in co-culture systems involving macrophages, hepatocytes, and neutrophils.

Main Methods:

• Human whole blood incubations with ten different immune stimuli to measure leukocyte mediator release.
• Co-culture experiments using primary rat and human liver cells (hepatocytes) with liver macrophages.
• Addition of human neutrophil granulocytes to co-cultures to study synergistic effects on hepatocyte toxicity.

Main Results:

• Each immune stimulus in whole blood induced a unique pattern of mediator release with distinct kinetics and concentrations.
• Over-activated macrophages in a liver cell model released toxic factors that killed co-cultured hepatocytes.
• Neutrophils synergized with macrophages to enhance hepatocyte killing, mimicking in vivo cellular interactions.

Conclusions:

• Human whole blood incubations provide a robust model for studying immune mediator release.
• In vitro co-culture systems of liver cells, macrophages, and neutrophils effectively model inflammatory mechanisms and cell death.
• These developed in vitro models are suitable for evaluating the pro- and anti-inflammatory potential of test compounds.