CD16+ lymphoblastic cell lines of crab-eating monkeys (Macaca fascicularis) shared U-5 antigen and expressed natural killer activity

The CD16+ lymphoblastic cell lines of crab-eating monkeys shared the U-5 antigen recognized by a monoclonal antibody. The CD16+U-5+ cell lines expressed high natural killer activity to K562 cells, whereas the CD16-U-5- control cell line had no significant natural killer activity. A possible involvement of the U-5 antigen in natural killer function was also suggested by reduction of the natural killer activity in peripheral blood mononuclear cells of Japanese monkeys after treatment with U-5 monoclonal antibody and complement.     

Possible apoptotic mechanism in epidermal cell acantholysis induced by pemphigus vulgaris autoimmunoglobulins

Through a still unclear mechanism, pemphigus vulgaris autoantibodies (PV-IgG) induce intra-epidermal acantholytic lesions responsible for severe to fatal skin wounding. We present evidence that PV lesions contain apoptotic keratinocytes, and that cell death is induced in the lesional tissue apparently before cell separation. These data suggest that apoptosis could be the cause of the acantholytic phenomenon. We show that PV-IgG and an antibody against Fas receptor (anti-FasR) induce lesions in vitro in a similar way, causing: (1) secretion of soluble FasL; (2) elevated cellular amounts of FasR, FasL (soluble and membranal), Bax and p53 proteins; (3) reduction in levels of cellular Bcl-2; (4) enrichment in caspase 8, and activation of caspases 1 and 3; (5) co-aggregation of FasL and FasR with caspase 8 in membranal death-inducing signaling complex (DISC). Hence, the Fas-mediated death signaling pathway seems to be involved in lesion formation. Moreover, we have shown that in skin organ cultures and in keratinocyte cultures, PV-IgG can induce caspase activation and DNA fragmentation, and caspase inhibitors can prevent the formation of PV-IgG-induced epidermal lesions. Altogether, these results suggest that PV-IgG-induced acantholysis may proceed through the death-signaling pathway. They highlight new perspectives on mechanisms of tissue damage in autoimmune diseases.     

Characterisation of a 34 kD protein from potato cyst nematodes, using monoclonal antibodies with potential for species diagnosis

Two monoclonal antibodies, which differentially recognise the two species of potato cyst nematodes (PCN), Globodera pallida and G. rostochiensis, are described. They have been shown to have potential for quantification of these two species, recognising proteins of the same molecular weight (34 kD) in both species. Further investigation showed these proteins to have isoelectric points at pH values of 5.7 in G. pallida and 5.9 in G. rostochiensis, in common with the proteins used by Fleming & Marks (1983) to differentiate the species of PCN. They are likely to be structurally very similar, with the same physiological function (and therefore similar concentrations) in the two species. In cross-reactivity tests with a wide range of soil nematode species, the antibodies reacted strongly only with species of the genus Globodera, and thereby confirmed their potential as the basis of a quantitative immunoassay likely to be useful in management of PCN populations.     

Serum levels of anti-heat shock protein 27 antibodies in patients with chronic liver disease

Heat shock protein 27 (HSP27), an intracellular molecular chaperone, is involved in the pathogenesis of cancer by promoting both tumor cell proliferation and resistance to therapy. HSP27 is also present in the circulation and circulating HSP27 (sHSP27) can elicit an autoimmune response with production of antibodies. Levels of sHSP27 are enhanced in patients with hepatocellular carcinoma (HCC); it is, however, unknown whether changes in HSP27 antibody levels occur in patients with HCC and can be exploited as a circulating biomarker of HCC. Our aim was to assess the potential association between newly diagnosed HCC and serum anti-HSP27 antibody levels. In this cross-sectional study, anti-HSP27 antibody levels were measured in serum samples from 71 HCC patients, 80 subjects with chronic liver disease, and 38 control subjects by immunoenzymatic assay. Anti-HSP27 antibody levels did not differ significantly among groups. However, in patients with chronic active hepatitis/cirrhosis, anti-HSP27 levels were significantly higher in subjects with a positive history of alcoholism (p = 0.03). Our data do not support the hypothesis that anti-HSP27 antibody levels may help identify patients with HCC among subjects with chronic liver disease. However, our finding that alcohol-related liver disease is associated with higher anti-HSP27 levels is novel and deserves further investigations.     

单域抗体与抗感染免疫

随着分子生物学技术的发展及抗体研究的不断深入,单域抗体(single domain antibodie,sdAb)的研究已成为肿瘤靶向治疗研究领域的热点之一。作为实验研究和治疗应用的重要工具与制剂,单域抗体在调节免疫功能,中和毒素和抗微生物感染等方面具有广阔的应用前景。     

Toxocara canis: Some characteristics of larval precipitating antibodies in rat serum

1972. Toxocara canis: Some characteristics of larval precipitating antibodies in rat serum. International Journal for Parasitology 2: 471–479. Serum from rats infected with 1000 T. canis eggs had larval precipitating antibodies present at least between 21 and 183 days post infection. The precipitating antibodies in whole serum were stable to heating at 60°C for 1 h and excretory pore precipitates developed in serum treated with 2-mercaptoethanol.

Fractionation of serum on G-200 and DEAE-cellulose and analysis of the fractions by immunoelectrophoresis indicated the fraction containing fast 7S globulin was primarily responsible for precipitating activity. Purified precipitating antibodies were stable to heating at 70°C for 15 min.

No skin fixing antibodies were detected in immune sera employing both a homologous and heterologous PCA text.     

The capsular polysaccharide of Haemophilus influenzae type B prevents killing by complement and antibodies against outer membrane protein a

Abstract The ability of antibodies, raised in rabbits against purified outer membrane protein a ( M _r 47 000) of Haemophilus influenzae type b, to promote complement-dependent killing of these encapsulated organisms was investigated. Killing of encapsulated strains was not induced by these antibodies in conjunction with either human, mouse, rabbit or guinea-pig complement. Acapsular mutants were effectively killed by complement in the presence of antibodies against protein a . Killing was dependent on the presence of the 47-kDa protein a and was not influenced by the outer membrane protein subtype or lipopolysaccharide serotype of the strain. The killing-promoting activity could be absorbed from the sera with cells of strains with the same protein a , purified protein a , but not by purified lipopolysaccharide and capsular polysaccharide. Binding experiments showed that the encapsulated strain and its acapsular mutant bound antibodies against protein a with the same rate and to the same extent, indicating that the capsule probably interferes with complement activation or insertion of the membrane attack complex into the bacterial cell.     

Interleukin-4 receptor signaling and its binding mechanism: A therapeutic insight from inhibitors tool box

Studies on Interlukin-4 (IL-4) disclosed great deal of information about its various physiological and pathological roles. All these roles depend upon its interaction and signaling through either type-I (IL-4Rα/common γ-chain) or type-II (IL-4Rα/IL-13Rα) receptors. Another cytokine, IL-13, shares some of the functions of IL-4, because both cytokines use a common receptor subunit, IL-4Rα. Here in this review, we discuss the structural details of IL-4 and IL-4Rα subunit and the structural similarities between IL-4 and IL-13. We also describe detailed chemistry of type-I and type-II receptor complexes and their signaling pathways. Furthermore, we elaborate the strength of type-II hetero dimer signals in response to IL-4 and IL-13. These cytokines are prime players in pathogenesis of allergic asthma, allergic hypersensitivity, different cancers, and HIV infection. Recent advances in the structural and binding chemistry of these cytokines various types of inhibitors were designed to block the interaction of IL-4 and IL-13 with their receptor, including several IL-4 mutant analogs and IL-4 antagonistic antibodies. Moreover, different targeted immunotoxins, which is a fusion of cytokine protein with a toxin or suicidal gene, are the new class of inhibitors to prevent cancer progression. In addition few small molecular inhibitors such as flavonoids have also been developed which are capable of binding with high affinity to IL-4Rα and, therefore, can be very effective in blocking IL-4-mediated responses.     

Monoclonal antibodies against alpha toxin of Clostridium perfringens

Ten distinct monoclonal antibodies (MAbs) against alpha toxin of Clostridium perfringens were produced by the fusion of SP2/O with spleen cells of mice immunized with alpha toxoid, and alpha toxin mixed with or without ethylenediamine-tetraacetate (EDTA). The antibody activity was evaluated by antigen-binding activity in an enzyme linked immunosorbent assay (ELISA), by phospholipase C (PLC)-neutralizing activity using both egg yolk lecithin and p-nitrophenylphosphoryl-choline (PNPPC) hydrolysis reactions and by anti-lethal activity in mice. Since the toxin-neutralizing activities of each MAb were not parallel, it has been suggested that the three biological activities may not be located in the same site in the toxin molecule. This report also describes the development of a simple purification of the toxin by affinity chromatography and a sensitive immunoassay for quantitation of the toxin using the monoclonal antibody.     

Barnase-barstar high affinity interaction phenomenon as the base for the heterogenous bioluminescence pseudorabies virus' immunoassay

The effective new variant of "sandwich" bioluminescent enzyme immunoassay (BEIA) for the sensitive detection of glycoprotein B (gB) of pseudorabies virus (PrV) was presently developed. The high affinity interaction of barnase-barstar protein pair and photoprotein obelin as bioluminescent marker were for the first time successfully applied to BEIA development. Preliminary the two monoclonal antibodies, 11/5 and 34/2, were raised against gB for ELISA PrV detection. Presently we used the same immuno-"sandwich" principle for BEIA. To do this the two different bioconjugates were elaborated. Recombinant barnase was chemically conjugated with monoclonal anti-PrV's gB IgG, and also barstar was fused in frame to obelin. The characteristics of BEIA method have been compared to ELISA PrV detection. We have shown the proposed here gB-BEIA was 40-fold more sensitive as opposed to gB-ELISA test. The construction might have a broad promise in multiple potential immunological applications.