The cellular transfer to immunity to Nippostrongylus brasiliensis in inbred rats (Lewis strain).

Mesenteric lymph node cells obtained from highly inbred donor rats (Lewis strain), resistant to Nippostrongylus brasiliensis infection, were syngeneically transferred by intravenous injection into previously uninfected recipients. The adoptively immunized recipients were then challenged with either 1500 or 3000 third stage N. brasiliensis larvae on the day of cell transfer. The degree of resistance transferred was assessed by monitoring daily faecal egg output, differential worm burdens on days 6 and 10 of infection and the number of eggs per uterus in gravid worms. The syngeneic transfer of 100 × 106 immune mesenteric lymph node cells invariably resulted in suppression of egg production, a two- to four-fold reduction in the number of eggs per uterus in gravid females and rejection of at least 75 per cent of adult worms by days 6 and 10 of infection. It was also noted that mesenteric lymph node cells obtained from donors on day 15 of a primary infection were more effective than those obtained from donors immunized by multiple infections. Immune cells transferred from donors on day 4 of infection were equally effective with those transferred on day 0. However, immune cells transferred on or after day 10 of infection had little or no effect and this shows that the parasite is less susceptible to an attack mounted by the transferred cells during the later stages of infection.