Vaccination of interleukin-4 (IL-4) receptor (IL-4R) chain-deficient BALB/c mice with urease and cholera toxin or with urease-expressing, live attenuated serovar Typhimurium cells revealed that protection against infection is independent of IL-4- or IL-13-mediated signals. genetic lesions, heat-labile enterotoxin (5, 13). Infection with also induces specific CD4+ T cells commonly classified as type 1 effector cells characterized based on their secretion of gamma interferon (IFN-) (9, 10, 15; for a review of clinical data see references 17 and 18). This response is not effective in reducing the bacterial burden. In contrast, results of vaccination studies with mice suggest a role for type 2 CD4+ T cells and the secretion of cytokines such as interleukin-4 (IL-4) and IL-10 by these cells in protection against infection (2, 7, 10, 15). In line with these findings, mice deficient in IFN- expression were successfully vaccinated with antigens and CT (16), while vaccination in IL-4 gene-defective mice was quoted to be less efficient (14). These studies further supported the hypothesis that type 2 CD4+ T cells and IL-4 in particular play a role in protection but did not distinguish between its relevance for the induction of serovar Typhimurium in IL-4-deficient mice was similar to that for wild-type mice (12). We aimed to assess the importance of IL-4 and also IL-13 (which overlap in function and use the same IL-4 receptor (IL-4R) chain for signaling [11]) for induction of immunity and protection against afforded by vaccination with either CT in combination with urease or with recombinant urease-expressing, attenuated live serovar Typhimurium SL3261/pYZ97 cells (6). For this purpose, IL-4R chain-deficient BALB/c ES cell-derived mice (IL-4R?/?) (11), which are not able to respond to IL-4 or IL-13, and normal female BALB/c mice were vaccinated at weekly intervals with four intragastric applications of 10 g of CT (Sigma) mixed with 5 g of native urease purified from strain 26695 as previously described (4). The animals were challenged a week later on with 109 CFU of mouse-adapted intragastrically, streptomycin-resistant P76 (a sort present from H. Kleanthous; OraVax) cultivated to past due log stage at 37C with shaking at 200 rpm within an atmosphere of 5% O2, 85% N2, and 10% CO2 in mind center infusion broth (Becton Dickinson) including 10% fetal leg serum (Gibco), supplemented with 400 g of streptomycin/ml. Three weeks later NU7026 kinase inhibitor on, mice had been wiped out and bled, and their stomachs had been removed. Stomachs had been cut in two to determine in parallel tissue-associated urease activity and burdens as referred to previously (6). To be able to assess an over-all parameter from CD178 the immunogenicity from the vaccine, comparative titers of urease-specific immunoglobulin (Ig) in serum had been dependant on enzyme-linked immunosorbent assay using plate-bound urease-positive or -adverse lysates (6). Immunized and challenged IL-4R?/? mice had Ig titers particular NU7026 kinase inhibitor for urease than BALB/c mice ( 0 fivefold-lower.003 inside a check), confirming that IL-4 and IL-13 are essential factors in the induction of the defense response by CT and urease (Fig. ?(Fig.1A).1A). This is also shown in lower proliferation by spleen cells from vaccinated IL-4R?/? mice than by those from wild-type animals in the presence NU7026 kinase inhibitor of urease-containing lysates (not shown). However, in our hands IL-4R?/? mice could still be protected from challenge infection with this treatment since no tissue-associated urease activity was detected in their stomachs (Fig. ?(Fig.1B).1B). Open in a separate window FIG. 1 Vaccination with purified urease in combination with CT is less immunogenic but still protective against infection in IL-4R?/? BALB/c mice. Groups of eight BALB/c and IL-4R?/? mice were immunized with purified native urease in combination with CT and challenged with = 8). OD420nm, optical density at 420 nm. Next, IL-4R?/? and BALB/c female mice were vaccinated orally with 107 or 109 CFU of SL3261/pYZ97 as described previously (6). Five weeks later vaccinated and control animals were challenged intragastrically with 109 CFU of P76. In contrast to immunization with CT, vaccination with SL3261/pYZ97 induced similar levels of urease-specific serum Ig in.