SCID mice show a similar susceptibility to Angiostrongylus cantonensis as do wild-type mice of the C.B-17 strain.

C.B-17-SCID/SCID (SCID) mice infected with Angiostrongylus cantonensis yielded a high percentage of worm recovery and did not show any body weight loss until day 24 postinfection. Unexpectedly, C.B-17-+/+(+/+) mice also produced a similar worm burden containing well-developed worms. This is probably attributable to the observation that +/+ mice failed to induce eosinophilia in cerebrospinal fluid (CSF) despite their production of antigen-specific IgA and IgGI; +/+ mice have defective bone-marrow eosinopoiesis, which in turn results in reduced blood and CSF eosinophilia. Interleukin 5 (IL-5) production in +/+ mice is similar to that in BALB/c and C57BL/6 mice. However, bone-marrow eosinopoiesis in response to IL-5 is markedly suppressed in +/+ mice. This is probably associated with impaired expression of common beta-chain mRNA in bone-marrow cells of +/+ mice, which leads to the failure of bone-marrow eosinopoiesis. Hence, +/+ mice may serve as a useful model for the elucidation of eosinophil production in the mouse and for determination of the relationship between parasite infection and the eosinophil.