oa Mast Cell Proteases as Key Clinical Markers and New Targets for Drug Development in Allergic Disease: Implications for Anti-Doping Policy

There have been dramatic increases in the prevalence of allergic conditions throughout the world. Until recently conditions such as allergic asthma and rhinitis, and life-threatening anaphylaxis were relatively rare in Qatar and the Gulf states, but the proportion of the population affected now seem to be approaching the high levels of many Western countries. There is a pressing need for better means for effective diagnosis, for the prediction of those who are at risk of serious reactions and for new treatments.

Our studies focus on the mast cell, a cell type of pivotal importance in mediating allergic disease. Mast cells release a range of potent proteases and other mediators of inflammation. Three unique mast cell proteases, carboxypeptidase, tryptase and chymase may be valuable as markers for anaphylaxis; and even in asymptomatic subjects serum concentrations may be related to susceptibility to severe reactions. We propose to evaluate specific immunoassays for these enzymes as new laboratory tests.

These three genes encoding the three proteases have been codon optimized and synthesized for maximum expression in either E. coli or Pichia pastoris.

The carboxypeptidase A was sub cloned and overexpressed in E. coli using the pET28a. Two variants of human mast cell Tryptase and two variants of human mast cell Chymase were sub cloned into Pichia pasoris vectors pPIC9 or pPICZ alpha for expression.

Native proteases have also been produced from human lung mast cell.

Molecular characterizations of the three recombinant proteases are being done.

The potential for these three proteases as a novel target for therapeutic intervention in allergic disease will be carefully assessed. As drugs taken for allergic conditions are have attracted attention for their potential to lead to enhanced performance in athletes, the studies should be of relevance in the formulation of anti-doping policy.