ALTERED EXPRESSION OF MAST-CELL PROTEASES IN THE RAT - QUANTITATIVE AND IMMUNOHISTOCHEMICAL ANALYSIS OF THE DISTRIBUTION OF RAT MAST-CELL PROTEASE-I AND PROTEASE-II DURING HELMINTH INFECTION

Expression of mast cell granule protease is regulated in a tissue-spec ific fashion in the rat. The granule chymases rat mast cell proteases I and II (RMCP I and II) predominate in non-mucosal and mucosal sites, respectively. Intestinal mastocytosis, a T cell-mediated phenomenon a ssociated with enteric nematodiasis, is accompanied by massive local e xpression of RMCP II and by release of this protease systemically into blood. The present observations, where both RMCP I and II have been q uantified by ELISA and immunolocalized by paired fluorescence, show th at the expression of both proteases in parasitized rats is profoundly altered at sites distant from infection. Thus, RMCP II-containing cell s are recruited to liver and thymus, and in the thymus there is a > 2- fold increase in concentration of RMCP I. The latter protease is deple ted from bone marrow and mesenteric lymph node early during infection, but concentrations of RMCP I in trachea/larynx, lung, and skeletal an d cardiac muscle are increased. Increased mast cell counts in intestin e, lung and liver are highly correlated with tissue concentrations of RMCP II.