Immunotoxicant screening and prioritization in the twenty-first century

Area of Science:

• Toxicology and Pharmacology
• Immunology
• In vitro assay development

Background:

• Current immunotoxicity testing relies on resource-intensive animal models for evaluating immune system effects of drugs, chemicals, and pesticides.
• Existing animal assays for biomarkers (e.g., lymphoid organ indices) and immune function (e.g., pathogen response) require specialized expertise and significant resources.
• There is a need for more efficient and cost-effective methods to assess immunotoxicity, reducing reliance on animal testing.

Purpose of the Study:

• To explore the potential of alternative in vitro assays for detecting immunosuppression and allergic hypersensitivity.
• To evaluate how these alternative methods can reduce animal use and testing costs.
• To enhance the screening and prioritization of immunotoxic compounds.

Main Methods:

• In vitro assays targeting innate and adaptive immune cells and associated functional markers (gene expression, protein synthesis, proliferation) for immunosuppression.
• Alternative methods focusing on chemical properties and defined cell population activation for detecting skin sensitizers (allergic hypersensitivity).
• Development and validation of assays to assess specific modes of action for immune system modulation.

Main Results:

• Alternative in vitro assays demonstrate potential for detecting immunosuppression by assessing various immune cell functions and markers.
• Specific in vitro approaches effectively identify and estimate the potency of skin sensitizers, addressing allergic hypersensitivity.
• These alternative models show promise in reducing the need for animal-based immunotoxicity assessments.

Conclusions:

• Alternative in vitro assays provide a viable strategy to replace or supplement traditional animal testing for immunotoxicity.
• These methods offer increased efficiency, reduced costs, and improved screening capabilities for immunosuppression and allergic sensitization.
• Further development and validation of in vitro assays are crucial for their regulatory acceptance and widespread adoption in chemical safety assessments.