[Characteristics of intestinal immune response of rats infected with Nippostrongylus brasiliensis].

After infection of rats with Nippostrongylus brasiliensis the response was a synthesis of hemagglutinating antibodies in intestinal secretions, the activity of which is mainly due to IgA. When rats were infected with 83 larvae (which is the smallest immunizing dose), local antibodies were evidenced just after parasite localization had occurred in the gut, whereas serum antibodies were not detected before a challenge infection. Some of these local antibodies were directed against two types of worm antigen which can induce immunity: sevretory antigens and phosphorylcholine. These experiments a role for local antibodies in mechanism of worn expulsion.