Monoclonal antibodies for equine IL-1β enable the quantification of mature IL-1β in horses.

The research article presents the development and testing of four monoclonal antibodies to improve the detection and measurement of the Interleukin-1β (IL-1β) protein in horses, a key contributor to inflammation responses and various diseases.

Study Context

• Interleukin-1β (IL-1β) is a vital protein in inflammation responses during innate immune responses. Essentially, it directs the body’s response and defense against infections and diseases. It plays a critical role in inflammatory diseases and certain degenerative diseases in horses.
• For immunological research, especially concerning inflammation and diseases in horses, precise and responsive assays for IL-1β are necessary. Assays are tools designed to analyze a component in a given sample.

Creation of Monoclonal Antibodies

• The researchers developed four monoclonal antibodies (mAbs) specific to equine IL-1β. Monoclonal antibodies are antibodies produced from a single clone of cells, which enable accurate targeting of a specific protein – in this case, IL-1β in horses.
• The antibodies produced were verified using a set of equine recombinant cytokines and chemokines. Their effectiveness in identifying IL-1β was confirmed.

Validation and Testing

• The research also includes testing and validating the monoclonal antibodies for detecting mature IL-1β using a fluorescent bead-based assay and staining of IL-1β-producing immune cells by flow cytometry.
• The bead-based assay had a linear quantification range of 60 pg/ml to 960 ng/ml, indicating its ability to accurately determine the quantity of IL-1β.
• The horse peripheral blood mononuclear cells (PBMC) were seen to produce IL-1β in response to lipopolysaccharide (LPS) stimulation. This was verified by the newly-developed bead-based assay for equine IL-1β.

Comparison with Commercial Assays

• When compared to two commercial equine IL-1β ELISA kits, the new bead-based assay showed higher efficiency in quantifying IL-1β produced by LPS-stimulated PBMC, producing high signals and a wide linear quantification range.
• The commercial ELISA kits displayed low signals and poor recognition of the native IL-1β signals, validating the new assay’s superiority.

Inflammatory Response and Effects of Caspase Inhibitor

• Flow cytometric analysis also identified CD14 monocytes as the main source of IL-1β in equine PBMC after LPS stimulation.
• The caspase inhibitor was observed to inhibit IL-1β secretion from PBMC but did not impact its protein translation within the cells. This demonstrates that, even without necessary proteolytic cleavage for IL-1β activation, pro-IL-1β accumulates within cells.
• This suggests the importance of specific mAbs in analyzing the biologically active, mature IL-1β in horses.