In vitroinduction of lymph node cell proliferation by mouse bone marrow dendritic cells following stimulation with differentEchinococcus multilocularisantigens

Abstract

The immune response of mice experimentally infected with Echinococcus multilocularis metacestodes becomes impaired so as to allow parasite survival and proliferation. Our study tackled the question on how different classes of E. multilocularis antigens (crude vesicular fluid (VF); purified proteinic rec-14-3-3; purified carbohydrate Em2(G11)) are involved in the maturation process of bone-marrow-derived dendritic cells (BMDCs) and subsequent exposure to lymph node (LN) cells. In our experiments, we used BMDCs cultivated from either naïve (control) or alveolar echinococcosis (AE)-infected C57BL/6 mice. We then tested surface markers (CD80, CD86, MHC class II) and cytokine expression levels (interleukin (IL)-10, IL-12p40 and tumour necrosis factor (TNF)-a) of non-stimulated BMDCs versus BMDCs stimulated with different Em-antigens or lipopolysaccharide (LPS). While LPS and rec-14-3-3-antigen were able to induce CD80, CD86 and (to a lower extent) MHC class II surface expression, Em2(G11) and, strikingly, also VF-antigen failed to do so. Similarly, LPS and rec-14-3-3 yielded elevated IL-12, TNF-a and IL-10 expression levels, while Em2(G11) and VF-antigen didn't. When naïve BMDCs were loaded with VF-antigen, they induced a strong non-specific proliferation of uncommitted LN cells. For both, BMDCs or LN cells, isolated from AE-infected mice, proliferation was abrogated. The most striking difference, revealed by comparing naïve with AE-BMDCs, was the complete inability of LPS-stimulated AE-BMDCs to activate lymphocytes from any LN cell group. Overall, the presenting activity of BMDCs from AE-infected mice seemed to trigger unresponsiveness in T cells, especially in the case of VF-antigen stimulation, thus contributing to the suppression of clonal expansion during the chronic phase of AE infection.

Different protein of Echinococcus granulosus stimulates dendritic induced immune response

“…In this regard, ferritin is a more potent inducer of DC maturation, expression of co-stimulatory molecules and increasing migration capacity than is LPS. Our result is consistent with that of Jene (Jenne et al 2001) and Margos (Margos et al 2011). They found that DCs in presence of the Echinococcus multilocularis 14-3-3 antigen transform into mature DC that were slightly more effective inducers of T-cell proliferation than DC exposed to crude non-fractionated E. multilocularis antigen or Em2 (G11) antigen.…”

Dexamethasone attenuates echinococcosis-induced allergic reactions via regulatory T cells in mice

“…The mechanisms underlying this association may involve regulatory cells and cytokines. Our research found that the proportion of CD4 + CD25 + FOXP3+ Treg cells relative to CD4+ Treg cells increased after E. granulosus infection was consistent with previous studies [ 21 ] and significantly increased with preliminary treatment with DEX, which suggested their possible role to contributed to the maintenance of immune tolerance. However, the proportion of Treg cells relative to CD4+ cells was reduced in untreaded mice when allergic reaction happened,just as previously described [ 22 ].…”

Recent Advances in the Immunology and Serological Diagnosis of Echinococcosis

“…Similarly, LPS and Em14-3-3 yielded elevated IL-12, TNF-I+/-and IL-10 expression levels, while Em2(G11) did not. The proliferation of bone marrow DC isolated from AE-diseased mice was abrogated (Margos et al, 2011), indicating the E. multilocularis infection inhibited T cell responses.…”