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Query: EC:2.7.10.1 (ERK)
 95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have characterized the immunological behaviour of major histocompitibility complex (MHC) Class II molecule-deficient (Abeta(o)) mice after infection by Schistosoma mansoni. In Abeta(o) mice, morbidity developed dramatically 7 weeks after infection leading to death, despite the absence of an increase in parasite burden or of eggs trapped in the liver. Histological examination of the liver revealed the absence of a classical granulomatous reaction. Antibodies were produced only against schistosomulum antigens. Specific antibodies against adult worm (SWAP) or egg antigen (SEA) were not detected. Cytokine production (IFN-gamma and IL-4) was absent after in vitro restimulation of splenic cells from infected Abeta(o) mice with parasite antigens. Adoptive transfer of primed splenic cells (total, purified CD4+ or CD8+ T cells) failed to improve survival or to induce a granulomatous reaction in infected Abeta(o) mice. Survival, cellular and humoral responses in CD8+ T-cell-depleted Abeta(o) mice or MHC(o) mice (lacking MHC class I and II molecules) were similar to nondepleted Abeta(o) mice, suggesting that anti-schistosomula antibody production was thymo-independent. Our results demonstrate a high degree of susceptibility of Abeta(o) mice to infection and corroborate the importance of CD4+ T cells in the initiation of the granulomatous response. However, our results do not show evidence for the involvement of CD8+ T cells in response to S. mansoni infection.
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PMID:Immunological response of major histocompatibility complex class II-deficient (Abeta(o)) mice infected by the parasite Schistosoma mansoni. 971 7

Detailed parasitologic, serologic, clinical and histopathologic studies were conducted in owl monkeys (Aotus nancymai) exposed to varying numbers of cercariae of Schistosoma mansoni. All the experimental animals had clinical symptoms suggestive of infection (weight loss diarrhoea, mucus in stools, etc.) which were not seen in uninfected individuals. The only A. vociferans included in this study passed S. mansoni eggs 8 weeks after infection. None of the A. nancymai passed eggs in their faeces. No adult worms were recovered following perfusion of the sacrificed experimental monkeys, suggesting that they were early eliminated. Serological techniques (ELISA-SEA and COPT) allowed diagnosis of infection, starting 9 weeks post challenge, in all but one A. nancymai exposed to 100 cercariae. Granulomas containing eggs were observed predominantly in liver and less extensively in intestine, suggesting that adult worms were mainly lodged in the intrahepatic portal system. We conclude that A. nancymai is susceptible to infection with S. mansoi, with the worms reaching sexual maturity, but being eliminated shortly after oviposition.
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PMID:Schistosoma mansoni infection in owl monkeys (Aontus nancymai): evidence for the early elimination of adult worms. 977 12

Nitric oxide (NO) is an important effector molecule involved in immune regulation and defense. NO produced by cytokine-activated macrophages was reported to be cytotoxic against the helminth Schistosoma mansoni. Identification and characterization of S. mansoni antigens that can provide protective immunity is crucial for understanding the complex immunoregulatory events that modulate the immune response in schistosomiasis. It is, then, essential to have available defined, purified parasite antigens. Previous work by our laboratory identified a fraction of S. mansoni soluble adult worm antigenic preparation (SWAP), named PIII, able to elicit significant in vitro cell proliferation and at the same time lower in vitro and in vivo granuloma formation when compared either to SEA (soluble egg antigen) or to SWAP. In the present work we report the effect of different in vivo trials with mice on their spleen cells ability to produce NO. We demonstrate that PIII-immunization is able to significantly increase NO production by spleen cells after in vitro stimulation with LPS. These data suggest a possible role for NO on the protective immunity induced by PIII.
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PMID:Immunization with PIII, a fraction of Schistosoma mansoni soluble adult worm antigenic preparation, affects nitric oxide production by murine spleen cells. 992 44

TFG was discovered as a fusion partner of NTRK1 in human papillary thyroid carcinoma. We assembled the mouse TFG cDNA from EST sequences and 5' end RACE product, identified full coding length TFG EST clones in pig (c17b07) and Schistosoma mansoni (SMNAS62), and analyzed the genomic structure of TFG in Caenorhabditis elegans (Y63D3A). The protein sequences of mouse, pig, and S. mansoni TFG are highly homologous to human TFG. The C. elegans sequence has diverged, but its predicted secondary structure is remarkably conserved. Human, mouse, and C. elegans TFG contain a putative trimeric N-terminal coiled-coil domain, glycosylation, myristylation, and phosphorylation sites, and SH2- and SH3-binding motifs. The SH2-binding motif is absent in C. elegans TFG. The expression of TFG does not vary among 7, 11, 15, and 19 day mouse embryonal stages. In situ hybridization with a TFG probe in 10, 5-day whole mouse embryos showed preferential staining of the limb buds, branchial arches, nasal processes, and brain, and weak staining of the primitive spinal cord and dorsal root ganglia.
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PMID:Characterization of TFG in mus musculus and Caenorhabditis elegans. 1009 11

The contribution of IL-4 and IL-13 to inflammation and cytokine responses was compared in mice with types-1 or -2 pulmonary granulomas (GR) elicited by beads bound to antigens of Mycobacteria bovis (PPD) or Schistosoma mansoni eggs (SEA). Type-2 SEA-GR produced the most IL-4 and IL-13. Type-1 PPD-GR produced detectable IL-13, but not IL-4. Mice were treated with anti-IL4 or anti-IL-13 Abs, then lesion size/composition, cytokine/chemokine mRNA and lymph node cytokines were measured. Type-1 GRs resisted individual Abs, but combined Abs augmented lesions by 20%. In contrast, anti-IL-4 abrogated type-2 GR by 30-40% and eosinophil recruitment by 60%. Anti-IL-13 abrogated type-2 GR by 20-30% with no effect on eosinophils. Combined depletion reduced lesion area by 60% and eosinophils by more than 80%. In type-1 GR lungs, anti-IL-4 and anti-IL-13 augmented IFNgamma and TNFalpha mRNA. In type 2 lungs, anti-IL-13 did likewise, but anti-IL-4 decreased TNFalpha without affecting IFNgamma mRNA. In both responses, IL-4 promoted MCP-1 and MCP-5 mRNA, but IL-13 inhibited chemokines in type-1 GR. In lymph nodes, anti-IL-4, but not anti-IL-13, abrogated type-2 cytokines. In fact, IL-13 down-regulated itself and other type-2 cytokines. In summary, IL-4 and IL-13 have common and disparate regulatory functions in types 1 and 2 responses.
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PMID:Interleukin 4 and 13 participation in mycobacterial (type-1) and schistosomal (type-2) antigen-elicited pulmonary granuloma formation: multiparameter analysis of cellular recruitment, chemokine expression and cytokine networks. 1085 56

The selective accumulation of eosinophils in tissue is a characteristic feature of allergic diseases where there is a predominance of lymphocytes expressing a Th2 phenotype. In an attempt to define factors determining specific eosinophil accumulation in vivo, we have used a radiolabeled technique to assess the occurrence and the mechanisms underlying (111)In-eosinophil recruitment into Th1- and Th2-predominant, delayed-type hypersensitivity (DTH) reactions. Eosinophils were purified from the blood of IL-5 transgenic mice, labeled with (111)In and injected into nontransgenic CBA/Ca mice. Th1- and Th2-predominant, DTH reactions were induced in mice by immunization with methylated bovine serum albumin (MBSA) in Freund's complete adjuvant or with Schistosoma mansoni eggs, respectively. In these animals, (111)In-eosinophils were recruited in skin sites in an antigen-, time-, and concentration-dependent manner. Depletion of CD4+ lymphocytes abrogated (111)In-eosinophil recruitment in both reactions. Pretreatment of animals with anti-IFN-gamma mAb abrogated (111)In-eosinophil recruitment in MBSA-immunized and -challenged animals, whereas anti-IL-4 inhibited (111)In-eosinophil recruitment in both models. Local pretreatment with an anti-eotaxin polyclonal antibody inhibited the MBSA and SEA reactions by 51% and 39%, respectively. These results demonstrate that, although eosinophilia is not a feature of Th1-predominant, DTH reactions, these reactions produce the necessary chemoattractants and express the necessary cell adhesion molecules for eosinophil migration. The control of the circulating levels of eosinophils appears to be a most important strategy in determining tissue eosinophilia.
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PMID:Eosinophil recruitment into sites of delayed-type hypersensitivity reactions in mice. 1126 81

Allergic airway inflammation is characterized by peribronchial eosinophil accumulation within the submucosa surrounding the airway. The development of appropriate animal models to dissect the critical mechanisms involved in the deleterious responses is crucial for the evolution of proper therapeutic approaches. This article reviews several developed models of allergic airway inflammation induced by intratracheal challenge with parasite (Schistosoma mansoni egg antigen [SEA]), environmental (cockroach), and fungal (Aspergillus) allergens in presensitized mice. Use of these models to examine the eosinophil recruitment has identified key cytokines and adhesion molecules involved in the responses, which rely on several interacting events. These cytokines include interleukin 4 (IL-4), IL-13, and a number of chemokines, which appear to act as activating and recruitment
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PMID:Cytokine and Chemokine Interactions in Allergic Airway Inflammation. 1140 94

Activation of protein tyrosine kinases (PTKs) is a common step of T cell stimulation. However, the relationship between PTKs and activation of peripheral blood mononuclear cells (PBMC) from intestinal chronic schistosomiasis patients has not been explored yet. In this study, we investigated the participation of Lck and ZAP-70 protein tyrosine kinases (PTKs), as well as PLC-gamma1 and Shc proteins in PBMC activation by Schistosoma mansoni antigens. PBMC were stimulated with SEA (soluble egg antigen) or SWAP (soluble worm preparation), lysed, precipitated with specific antibodies and the level of tyrosine phosphorylation evaluated. Our results show that Lck and Shc were phosphorylated upon stimulation of the cells with SWAP, as well as with SEA. However, the phosphorylation level was more pronounced in SWAP than in SEA-stimulated cells. Phosphorylation of ZAP-70 was observed only in SWAP stimulated cells. Additionally, PLC-gamma1 phosphorylation was not observed in PBMC stimulated with SEA. Together, these results indicate that SEA and SWAP induce PBMC proliferation through distinct intracellular signaling pathways. Moreover, the weaker response of PBMC to SEA compared to SWAP stimulation suggests down-regulation of cells from intestinal chronic schistosomiasis patients to SEA, which may occur during immunomodulation to S. mansoni response.
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PMID:Signal transduction events in human peripheral blood mononuclear cells stimulated by Schistosoma mansoni antigens. 1160 Feb 25

In schistosomiasis endemic areas, antibody isotype responses against Schistosoma mansoni antigens vary with host age, sex and duration or intensity of infection, and are associated with susceptibility or resistance to infection. Identifying the quality and quantity of these responses is important to our understanding of the host-parasite relationship; however, the various host and parasite factors have a strong tendency to confound each other. We investigated the relationships and interactions between age, sex, faecal egg-counts and specific antibody isotype (IgA, IgG1, IgG2, IgG3, IgG4, IgE, IgM) responses to S. mansoni worm (SWA) and egg (SEA) antigens, amongst 380 individuals aged 5-59 from a fishing community from Uganda. This community was characterized by high levels of exposure, and high infection intensities, with higher infection intensities in males than in females. Multivariate anova was conducted with interaction terms between the three categorized explanatory variables. Most anti-SWA responses increased with age, whereas anti-SEA responses tended to decline with age, especially after puberty. IgG1-SWA, IgG4-SWA, IgG4-SEA, IgE-SWA responses increased with egg count, whereas IgG2-SEA decreased with egg count. IgG1-SWA, IgG4-SWA, IgE-SWA and IgG4-SEA responses were independently higher in males, whereas IgG2-SEA responses were independently higher in females. The significant effects of sex on isotype responses to adult worm antigens may be partly because of different levels of cumulative exposure. IgG4-SEA and IgG4-SWA were both strongly correlated with egg count. Patterns of IgE-SWA responses were qualitatively different to IgG4 responses, suggesting independent pathways of regulation.
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PMID:The relationship between age, sex, egg-count and specific antibody responses against Schistosoma mansoni antigens in a Ugandan fishing community. 1279 Oct 62

This experiment shows cellular and humoral immune responses induced by soluble egg antigen of Schistosoma mansoni, that is, change of the number of peripheral blood eosinophil, delayed hypersensitivity measured by the degree of ear swelling, granulomatous change of liver tissue and elevation of serum antibody titer by ELISA. SEA was given continuously by the insertion of a mini-pump into peritoneal cavity of mouse. In control group, same pump with HGG was inserted. New pump was exchanged once in two weeks and followed the result until 9 weeks after mini-pump insertion. 1. Highest peripheral blood eosinophil level was recorded at 2-3 weeks after SEA pump insertion. 2. Maximum ear swelling was observed at 2 weeks and then decreased gradually. 3. In liver tissue, several granulomas without egg were formed at 4 weeks. 4. Serum antibody titer was elevated from 4 weeks after SEA pump insertion.
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PMID:[Immunological Responses By Soluble Egg Antigen Of Schistosoma Mansoni In Mice] 1289 Oct 13


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