REDUCED AMOUNT OF INTESTINAL MUCUS BY TREATMENT WITH ANTI-CD4 ANTIBODY INTERFERES WITH THE SPONTANEOUS CURE OF NIPPOSTRONGYLUS BRASILIENSIS-INFECTION IN MICE

Mechanism of spontaneous cure was studied in mice infected with mouse- nonadaptive Nippostrongylus brasiliensis. Adult BALB/c mice were cured spontaneously of infection with this strain of N. brasiliensis by Day 7 post-infection. Expulsion of intestinal worms was delayed dose-depe ndently by a treatment with anti-CD4 antibody. However, the treatment had no significant effect on larval recovery from the lungs. Treatment of mice with anti-IL-5 antibody suppressed intestinal tissue eosinoph ilia induced by the infection, but did not affect intestinal worm reco very. Antigen specific IgE antibody was not detected in the sera obtai ned from Days 5 to 15. Therefore, IL-5 and specific IgE antibody are p robably not important in the spontaneous cure. Treatment of mice with anti-CD4 antibody had no significant effect on number of intestinal go blet cells or on expression of terminal sugars of goblet cell mucins. However, histological and quantitative analyses revealed that signific antly less intestinal mucus was released in anti-CD4 antibody treated mice than in control mice. These results suggest that CD4(+) lymphocyt es control the amount of intestinal mucus and consequently the reduced mucus interferes with the spontaneous cure. Quantity of mucus release d in the intestinal lumen may have an essential role in the spontaneou s cure of N. brasiliensis-infection of mice.