FcgRIIa –an attractive target to control immune response

MCT Research Talks

Our group is a drug discovery lab currently working on the development of a novel Fc gamma receptor IIa inhibitors. FcgRIIa is a low affinity receptor for Fc portion of immunoglobulin G (IgG) and is implicated in a variety of conditions that are still mainly untreatable, such as rheumatoid arthritis, lupus, immune thrombocytopenia, sepsis. FcgRIIa is widely expressed by human innate immune cells, and is the only Fc gamma receptor found on human platelets.

Mainly over-stimulation of the FcgRIIa receptor in these conditions that leads to the progression of the disease. For example, in sepsis the platelets get activated via FcgRIIa in response to bacteria present in the blood, which results in thrombocytopenia and disseminated immune coagulopathy. This causes, not only internal haemorrhage but also formation of blood clots that block peripheral blood vessels leading to sepsis-associated limb loss, heart attacks and/or strokes. Using a targeted approach, such as pharmacophore modelling, our group has developed a small molecule compound that effectively blocks FcgRIIa-mediated platelet aggregation in vitro. In agreement with the chosen targeted approach, this compound was shown to bind to the FcgRIIa directly and possesses specificity for the FcgRII subgroup of the Fcg receptors.

Ultimately, this compound has a great potential to be used for treatment of other FcgRIIa-mediated auto-immune conditions, such as rheumatoid arthritis, lupus and an array of immune thrombocytopenia conditions.

Prof Dermot Cox, Dr Tatiana Devine and Padraig Norton