A comparison of mucosal inflammatory responses to Giardia muris in resistant B10 and susceptible BALB/c mice.

In the first three weeks of primary Giardia muris infections B10 mice clear infection more rapidly than BALB/c mice. There is evidence that interferon-gamma contributes to the relative resistance of B10 mice. The nature of the functional contribution of interferon-gamma is unclear and does not relate to the secretory or serum antibody response. Mucosal inflammatory events in these strains have been studied. Apart from a small rise in both strains of goblet cell and mucosal mast cell numbers, associated with release of mast cell protease-1 in serum, no inflammatory infiltrate was observed at the time trophozoites were cleared from the intestinal lumen. Inhibition of mast cell products (5-hydroxytryptamine and histamine) by cyproheptadine enhanced the intensity of infection in both strains. The relative resistance of B10 mice could not be explained in terms of the mucosal inflammatory response.