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Schistosoma mansoni eggs trapped in the liver of an infected host cause the major pathological manifestations of schistosomiasis. Miracidia within the deposited eggs secrete soluble egg antigens (SEA) that induce periovular granuloma formation, which may lead to severe hepatic fibrosis. Several reports have highlighted the immunomodulatory capacities of carbohydrate determinants present in the glycoproteins of SEA. These glycans contain among others the immunogenic Galbeta1-4(Fucalpha1-3)GlcNAc (LewisX) and GalNAcbeta1-4(Fucalpha1-2Fucalpha1-3)GlcNAc (LDN-DF) elements. Due to cross-reactivity with schistosomal glycan antigens, keyhole limpet haemocyanin (KLH) has been used extensively for diagnostic and therapeutic studies on schistosomiasis. In the present study, a granulomatous response with numerous eosinophils towards SEA- and KLH-coated beads implanted in the liver by mesenteric injection was observed. Immunophenotyping of these experimentally induced granulomas for cellular recruitment, chemokines, adhesion and extracellular matrix proteins revealed very close resemblance with hepatic lesions evoked by native schistosome eggs, hence demonstrating the usefulness of the bead model, in general, as well as of KLH as a model antigen to study the immunopathological mechanisms of schistosome infections. While trypsin digestion of KLH did not alter its antigenic characteristics, beads coated with SEA or KLH treated with sodium periodate to destroy the immunological properties of their carbohydrate chains, yielded only a monolayer of macrophages similar to negative control beads. Up-regulation of ICAM-1, LFA-1 and fibronectin in SEA-induced granulomas and in native and trypsinised KLH-induced granulomas indicates a major role of the carbohydrate elements of SEA and KLH in the initiation and homeostasis of the inflammatory response. These data provide new insights in the complex and multifactorial carbohydrate-dependent host-parasite immunological interactions.  相似文献   

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Antibody levels against canine distemper virus were measured by means of an immunofluorescent antibody test prior to, and after, administration of a modified-live virus booster vaccine to seven African wild dogs (Lycaon pictus). Positive seroconversion with no harmful side-effects was seen in all the animals.  相似文献   

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The antibody response to viral haemorrhagic septicaemia virus proteins in rainbow trout surviving a disease outbreak under field conditions as well as animals immunised under laboratory conditions was analysed by immunoblotting, immunofluorescence and plaque neutralisation. No direct correlation between the serum reactivity in immunoblotting and the other serological tests was observed. Among sera from survivors from a disease outbreak in a farm, virus specific antibodies could be detected in most of the sera by immunofluorescence but only in a minority by immunoblotting. In fish injected with the individual viral proteins G, N, M1, or M2 under aquarium conditions, only the glycoprotein induced antibodies detectable by immunoblotting. Challenge of the fish with virulent virus indicated that only minor degrees of protective immunity had been induced. In sera from fish surviving the challenge, the neutralising activity was high. In immunoblotting however, a significant antibody reactivity was observed only in sera from fish primed with the glycoprotein. The results are discussed with respect to the immunogenicity of VHSV proteins in rainbow trout as well as the character of the epitopes recognised by antibodies induced in infected or immunised fish.  相似文献   

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A group of envelope proteins of human cytomegalovirus, gA protein (L. Pereira, M. Hoffman, M. Tatsuno, and D. Dondero, Virology 139:73-86, 1984; L. Pereira, p. 383-404, in B. Roizman, ed., The herpesviruses, vol. 3, 1985), and two protein mixtures (58,000-molecular-weight [58K]-66K and 130K-66K), separated by serial columns prepared with anti-gA immunoglobulin G from sera of immunized guinea pigs, induced neutralizing antibodies and a cellular immune response in the animals. The gA is a disulfide-linked protein complex consisting of high-molecular-weight (greater than 200K), 130K-150K, and 55K-58K proteins.  相似文献   

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Anti-phosphocholine (PC)-keyhole limpet hemacyanin hybridomas representative of a memory response that express the lambda 1 L chain isotype have a high reactivity to PC-protein. A common feature of these hybridomas possessing high affinity for PC-protein is the occurrence of somatic mutations resulting in replacement changes in three CDR2 positions of the lambda 1 L chain. The influence of each of these three positions on the Ag binding properties of these antibodies was examined by site-specific mutagenesis and expression of recombinant antibody molecules by transfected cells. Affinity measurements and fine specificity profile determinations demonstrated the importance of the three lambda 1 CDR2 positions in Ag binding. Compared to antibodies expressing germline lambda 1, including one with an additional junctional serine that is not encoded by V or J, those antibodies possessing critical changes in CDR2 would have a strong selective advantage based on affinity differences for Ag. Sequence analysis of a group of clonally related hybridomas expressing mutated lambda 1 genes allowed construction of a hypothetical genealogic tree that suggests selection based on changes in CDR2 of lambda 1 in the absence of H chain mutations. The results are consistent with stepwise acquisition of mutations and selection based on affinity constraints.  相似文献   

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Antibody formation by spleen cells isolated from adult, non-immunized donors and mixed withBrucella suis antigenin vitro was compared after transfer to young rabbits and to adult recipients irradiated with a dose of 450 r. It was found that this dose did not produce complete inhibition and that the recipients still responded actively to the given antigen. Only young animals, therefore, are a suitable experimental model in which to study antibody formation by transferred isolated cells. Development of the antibody reaction in young rabbits was studied by transferring cells isolated from the spleen of animals aged 8–30 days and mixed with antigenin vitro. Antibodies were formed after the transfer of these cells to X-irradiated recipients, but by the active response of the latter to the antigen. Antibody formation by cells of donors of different ages can be determined after transfer to young animals. The youngest donors whose cells form antibodies after transfer are three-week-old rabbits, but demonstration of antibodies requires the transfer of quite a large number of cells. The results are discussed in relation to the experiments of other authors on the transfer of cells to young animals.  相似文献   

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The existence of autoreactive B cells directed against a variety of self-antigens has been demonstrated by several investigations. However, no definitive evidence has been obtained for the existence of self-reactive B lymphocytes capable of reacting against soluble antigens circulating in high concentrations. The aim of the present investigation was to study whether such cells could be detected after in vitro activation of B cells with polyclonal B-cell activators. It was found that mouse spleen cells cultured for 3 days in the presence of the polyclonal B-cell activator LPS were capable of releasing antibodies with specificity for autologous serum- or albumin-coated sheep red blood cells (SRBC). This phenomenon was highly specific since the addition of autologous albumin in the agar during the plaque assay inhibited the number of plaques to control levels. These autoantibodies were found to belong to the IgM class. The implications of these findings for the understanding of the mechanism of self-tolerance are discussed.  相似文献   

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Characterization of serum proteins, which selectively bind estradiol for the regulation of its effective concentration, showed that the binding proteins differ in the normal and estradiol immunized rabbits. The estradiol binding protein in the control serum had a molecular weight of 65,000; Stokes radius 31 Å; frictional ratio 1.28 and sedimentation coefficient of 4.6 S while that in the immune serum had a molecular weight of 160,000; Stokes value 54 Å; frictional ratio 1.26 and sedimentation constant of 6.9 S. Binding affinity and binding capacity of the binding proteins in the sera of control and immunized rabbits showed that the former is a low affinity and high capacity protein with an association constant of 1.67 × 10−6 M−1 and the number of binding sites 1.125 × 10−5 mol/ml serum, while the latter had an association constant of 1.56 × 10−9 M−1 with 3 × 10−9 mol/ml serum binding sites. The difference in the nature of binding proteins was further authenticated by their relative mobilities on electrophoresis. The data suggested that estradiol binding serum proteins in the immunized rabbit are different from those in the control and this, in turn, has marked implications for the availability of hormone at the target site.  相似文献   

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A Mates  N A Hinton 《Microbios》1976,17(68-69):79-86
The primary antibody response of dogs and rabbits to both 'H' and 'O' antigens of Salmonella typhosa following intravenous injection with a formalin killed vaccine from 2.4 x 10(6) to 2.4 x 10(10) organisms/kg body weight was analysed. The animals were restimulated 80 days later with various vaccine concentrations. The lgM anti-'O' and lgG anti-'H' and 'O' antigens in the dogs, were significantly weaker in both primary and secondary response than the comparable rabbit group. Primary lgM anti-'H' response in the dog was found to be greater, equal, or less than that observed in the rabbit. A closer analysis of the primary response indicated that both animal species show the same latent period and doubling time in respect of anti-'H', and the differences observed are probably the result of the number of progenitor cells stimulated by the antigen. On the other hand the suppressed response of the dog to 'O'-antigen is the result of an overall weaker response of this animal to the antigen. The secondary anti-'H' lgM response was found to be greater than, equal to, or less than the primary response in the same animal. The significant inhibition of this response was observed in those animals which received a high primary dose of antigen.  相似文献   

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