Comparative studies of inflammatory responses in susceptible and resistant mice infected with Giardia muris.

A comparative assessment of in-vivo and in-vitro inflammatory responses in mice which are susceptible (A/J) and resistant (B10.A) to Giardia muris was made. B10.A mice which have the ability to eliminate the parasites exhibited a greater capacity to recruit cells into the peritoneal cavity after thioglycollate injection, when compared to A/J mice. The recruitment of inflammatory cells into the peritoneal cavity by B10.A mice was higher on day 15 (acute phase) and on day 60 (elimination phase) of the infection. Quantitative differences in inflammatory responses of A/J and B10.A mice in vivo were related to the functional differences in macrophage phagocytosis and chemotaxis in vitro. Macrophages from the resistant B10.A mice were more phagocytically active and were more chemotactically responsive during both acute and elimination phases of the infection, compared to those from the susceptible A/J mice. There was a relationship between the capacity of A/J and B10.A mice to mount inflammatory responses and the ability of these strains of mice to control the infection with G. muris.