Adoptive transfer of resistance to Nematospiroides dubius infections of mice and an assay to measure the in vitro proliferation of lymphocytes reactive with N. dubius antigen.

Spleen and mesenteric lymph node cells from Nematospiroides dubius-infected and normal control mice were cultured in vitro with N. dubius antigen. Proliferation of these cells in response to antigen was measured by the uptake of [3H]TdR. Cells harvested from mice during a primary infection did not proliferate in vitro; however, low levels of specific proliferation could be demonstrated if these mice were treated on Day 5 post-infection with 20 mg/kg of cyclophosphamide i.p. A strong cell proliferative response was measured 6 days following a challenge infection; spleen cells responded more strongly than cells from the mesenteric lymph nodes (MLN), but the addition of lymph node cells to spleen cell cultures did not suppress the latter response. Responsiveness of spleen cells to concanavalin A (Con A) was two-fold higher in infected mice than in normal controls, but the proliferation of MLN cells to Con A was similar in infected and uninfected mice. When N. dubius-resistant B10.M (H-2f) mice were compared to the susceptible B10.BR (H-2k) mice, no differences were observed in the spleen cell response to N. dubius adult antigen following challenge infections. However, after a tertiary infection, MLN cells from the resistant strain proliferated strongly in comparison to cells from susceptible mice. Spleen or MLN cells from resistant mice transferred immunity to naive recipients provided that the recipients had received a prior injection i.p. with adult N. dubius antigen. The injection alone, or cells in the absence of the injection, failed to protect the recipients from N. dubius challenge.