Type 1 T helper (Th1) cells are critical for the defense against pathogens by inducing an inflammation response, however, the T-cell inflammation response must be controlled to prevent excess tissue damage. Th1 cells have been implicated in the tissue destruction that occurs during many autoimmune diseases and negative regulators have evolved to keep the immune response in check. T-cell immunoglobulin mucin (TIM-3) protein negatively regulates Th1 cells through interaction with its ligand, the ß-galactoside-binding protein, Galectin-9 (Gal-9). The TIM-3/Gal-9 interaction elicits a complex response, which both limits tissue inflammation and stimulates immunity. These proteins have recently become strong candidates as therapeutic targets.
Straightforward, robust assays to search for antibodies or small molecules that interfere with TIM-3/Gal-9 binding are highly desirable. In this application note, we show how to develop a fast and easy method for screening inhibitors of the TIM-3 and Gal9 interaction using AlphaLISA® technology.