Measurement of interleukin 15

Area of Science:

• Immunology
• Cell Biology
• Biotechnology

Background:

• Interleukin 15 (IL-15) is a cytokine with diverse cellular activities, initially identified for its role in T cell proliferation.
• Accurate quantification of IL-15 is crucial for understanding its biological functions and involvement in various physiological and pathological processes.

Purpose of the Study:

• To describe and evaluate two distinct protocols for the measurement of IL-15 in biological matrices.
• To provide researchers with reliable methods for quantifying IL-15 in culture supernatants and serum samples.

Main Methods:

• Protocol 1: An enzyme-linked immunosorbent assay (ELISA) specifically designed for human IL-15, with cross-reactivity to simian IL-15.
• Protocol 2: A cell proliferation assay utilizing the CTLL-2 cell line, which relies on IL-15's ability to support their growth.

Main Results:

• The ELISA method provides specific detection of human and simian IL-15.
• The CTLL-2 assay demonstrates higher sensitivity compared to ELISA but lacks specificity, responding to IL-2 and IL-4 in addition to IL-15.
• The CTLL-2 assay is applicable for measuring IL-15 across human, simian, and murine species.

Conclusions:

• Both ELISA and CTLL-2 proliferation assays are valuable tools for IL-15 quantification, each with distinct advantages in specificity and sensitivity.
• The choice of method depends on the specific research question, sample type, and desired species-specific or broad detection of IL-15.