Echinococcus granulosus: changes in the transformational behaviour of murine lymph node cells during early infection.

Subcutaneous inoculation of living Echinococcus granulosus protoscolices (PSC) caused blastic transformation in local lymph node cells (LNC). The effect was maximal seven days post-infection (p.i.), had declined by day 21, and was prevented by killing the PSC prior to inoculation. LNC from inoculated mice also showed marked enhancement of blastogenesis in response to a secondary stimulation by live PSC in vitro. This secondary reaction occurred after exposure to living or killed PSC. There was generally enhanced reactivity to T- and B-cell mitogens at day 7. Phytohaemagglutinin was exceptional in that the killed parasite caused early changes in reactivity as above, but the live parasite induced a rise at 56 days p.i. It is concluded that E. granulosus may cause a determinate change in T-cell function.