Cross resistance between Ascaris suum and Nippostrongylus brasiliensis in mice.

The present study shows that N. brasiliensis infection in thymus-bearing mice results in resistance against a subsequent A. suum infection. In contrast thymus-deficient mice do not develop this heterologous resistance. Thymus-deficient mice, on the other hand, develop resistance to homologous challenge although to a lesser degree than thymus-bearing mice. Further, it is shown that A. suum infection in thymus-bearing mice yields resistance against a subsequent N. brasiliensis infection. The underlying mechanism of the cross resistance between A. suum and N. brasiliensis in mice may be both shared antigens and tissue reactions such as fibrosis and macrophage activation.