A rapid method for assessment of natural killer cell function after multiple receptor crosslinking

Area of Science:

• Immunology
• Cellular Biology
• Flow Cytometry

Background:

• Natural Killer (NK) cell function relies on integrating signals from activating and inhibitory receptors.
• Studying these receptor interactions typically requires isolating NK cells, which can be challenging with limited samples.

Purpose of the Study:

• To develop and validate a novel assay for studying the combined effects of NK cell receptor co-crosslinking.
• To analyze NK cell degranulation and interferon-gamma (IFN-γ) production in response to paired receptor stimulation without cell purification.

Main Methods:

• Developed an assay using antibody-coated plates to co-crosslink NK cell receptors on unfractionated peripheral blood mononuclear cells (PBMCs).
• Measured NK cell degranulation via CD107a expression using flow cytometry.
• Assessed IFN-γ production through intracellular cytokine staining and supernatant analysis.

Main Results:

• Co-crosslinking activating receptors (CD16, NKG2D, NKp30, NKp46) enhanced NK cell degranulation compared to single receptor stimulation.
• The inhibitory receptor NKG2A significantly inhibited degranulation triggered by NKp30 or NKp46, but not CD16 or NKG2D.
• IFN-γ production patterns in cytokine-activated NK cells mirrored degranulation responses, with no IFN-γ detected from resting cells.

Conclusions:

• The developed assay effectively analyzes the impact of NK cell receptor co-crosslinking on degranulation and IFN-γ production.
• This method is suitable for studies with limited cell numbers, including those involving pathologic conditions.