Cellular immune responses to the murine nematode parasite <em>Trichuris muris</em>: II. DIFFERENTIAL INDUCTION OF TH-CELL SUBSETS IN RESISTANT VERSUS SUSCEPTIBLE MICE.

We have analysed the production of a wide variety of cytokines by in vitro concanavalin A (Con A) stimulated mesenteric lymph node cells (MLNC) from strains of mice experiencing chronic (B10.BR, AKR) venus acute (HALB/K) infection with the nematode parasite Trichuris muris. MLNC from infected BALB/K mice produced elevated levels of the Th2-specific cytokines interleukin-5 (IL-5) and IL-9. IL-3 and 11-4 remained at or just above normal. Interferon-gamma (IFN-γ) (a Th1-type cytokine) was secreted only in small amounts. MLNC from infected susceptible B10.BR and AKR mice produced large amounts of IFN-γ in the relative absence of IL-4 and IL-9. IL-5 levels failed to rise significantly above normal in H10.BR mice whilst in AKR mice high levels of IL-5 were detected early post-infection (p.i.) but levels decreased dramatically as the infection proceeded to reach normal levels by Day 34. IL-3 levels were depressed below normal. Our results are consistent with the polarization of the Th-cell response during T. muris infection to give predominantly IFN-γ-secreting Th1 cells in strains of mice unable to expel the parasite and mainly IL-4, 1L-5 and IL-9 producing Th2-type cells in resistant strains. [ABSTRACT FROM AUTHOR]