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Daniele Sblattero

Publications and source records attributed to Daniele Sblattero.

6 recordsLinked to original sources

Antibodies in proteomics I: generating antibodies.

The explosion in genome sequencing, and in subsequent DNA array experiments, has provided extensive information on gene sequence, organization and expression. This has resulted in a desire to perform similarly broad experiments on all the proteins encoded by a genome. Panels of specific antibodies, or other binding ligands, will be essential tools in this endeavour. Because traditional immunization will be unlikely to generate antibodies in sufficient quantity, and of the required quality and reproducibility, in vitro selection methods will probably be used. This review--the first of two--examines the strategies available for in vitro antibody selection. The second review discusses the adaptation of these methods to high throughput and the uses to which antibodies, once derived, can be put.

Animals↗

Antibodies in proteomics II: screening, high-throughput characterization and downstream applications.

There are many ways in which the use of antibodies and antibody selection can be improved and developed for high-throughput characterization. Standard protocols, such as immunoprecipitation, western blotting and immunofluorescence, can be used with antibody fragments generated by display technologies. Together with novel approaches, such as antibody chips and intracellular immunization, these methods will yield useful proteomic data following adaptation of the protocols for increased reliability and robustness. To date, most work has focused on the use of standard, well-characterized commercial antibodies. Such protocols need to be adapted for broader use, for example, with antibody fragments or other binders generated by display technologies, because it is unlikely that traditional approaches will provide the required throughput.

Antibodies↗

Celiac disease in patients with sporadic and inherited cardiomyopathies and in their relatives.

AIMS: To investigate celiac disease (CD) and related co-morbidity in patients with familial and sporadic cardiomyopathy and in their relatives. METHODS AND RESULTS: We screened anti-human-tissue-transglutaminase (IgA and IgG anti-h-tTG) and anti-endomysial antibodies (AEAs) in 238 consecutive adult patients with inherited or sporadic dilated cardiomyopathy (DCM), 418 relatives, and 2000 healthy blood donors. HLADQ2-DQ8 was tested in tTG-positive subjects. The IgA-tTG-positive patients with cardiomyopathy underwent duodenal biopsy. Twenty-six subjects were tTG-positive: five DCM patients (2.1%), two of 28 (7.1%) and three of 390 (0.7%) relatives with and without echocardiographic abnormalities respectively, and 16 controls (0.8%). Twenty-two of 26 subjects were AEA-positive, and 25 HLA-positive. Of the five patients with cardiomyopathy and biopsy-proven CD, four suffered iron-deficiency anaemia. Two CD-positive DCM patients and two tTG-positive relatives were from families with inherited disease in which CD did not co-segregate with DCM. CONCLUSIONS; The higher prevalence of CD in patients with sporadic or inherited DCM, and of tTG-positive serology in relatives with echocardiographic abnormalities, suggests that immune-mediated mechanisms are active in subsets of patients/families. However, gluten intolerance cannot be considered causative since CD seems to be associated but not co-segregated with DCM in familial cases.

Adolescent↗

Selecting open reading frames from DNA.

We describe a method to select DNA encoding functional open reading frames (ORFs) from noncoding DNA within the context of a specific vector. Phage display has been used as an example, but any system requiring DNA encoding protein fragments, for example, the yeast two-hybrid system, could be used. By cloning DNA fragments upstream of a fusion gene, consisting of the beta-lactamase gene flanked by lox recombination sites, which is, in turn, upstream of gene 3 from fd phage, only those clones containing DNA fragments encoding ORFs confer ampicillin resistance and survive. After selection, the beta-lactamase gene can be removed by Cre recombinase, leaving a standard phage display vector with ORFs fused to gene 3. This vector has been tested on a plasmid containing tissue transglutaminase. All surviving clones analyzed by sequencing were found to contain ORFs, of which 83% were localized to known genes, and at least 80% produced immunologically detectable polypeptides. Use of a specific anti-tTG monoclonal antibody allowed the identification of clones containing the correct epitope. This approach could be applicable to the efficient selection of random ORFs representing the coding potential of whole organisms, and their subsequent downstream use in a number of different systems.

Antibodies, Monoclonal↗

The cleavage site of C5 from man and animals as a common target for neutralizing human monoclonal antibodies: in vitro and in vivo studies.

The isolation of an anti-C5 single-chain fragment variable (scFv) antibody, TS-A12/22, from a human phage display library, is described. This antibody inhibits the activation of C5 and the assembly of the terminal complement complex implicated in cell and tissue damage. Using antibody-sensitized sheep erythrocytes and rabbit red cells as target cells in hemolytic assays, we found that TS-A12/22 inhibited the activation of C5 by the convertases of both classical and alternative pathways. Western blot analysis and competition experiments with synthetic peptides showed that TS-A12/22 reacted with the alpha chain of C5 and recognized the cleavage site of this complement component by the C5 convertase. As a result, the antibody prevented splitting of C5 and inhibited the generation of C5a and of the terminal complement complex. The identification of the TS-A12/22 recognition site as a conserved sequence in man, mouse, rat and rabbit enabled the demonstration of in vitro inhibition of complement activity in these species. The scFv TS-A12/22 was tested in a rat model of antigen-induced arthritis and proved to be effective in preventing influx of polymorphonuclear cells into the knee joint and C9 deposition on synovial tissue.

Animals↗

The analysis of the fine specificity of celiac disease antibodies using tissue transglutaminase fragments.

Celiac disease is an intestinal malabsorption characterized by an intolerance to cereal proteins accompanied by immunological responses to dietary gliadins and an autoantigen located in the endomysium. The latter has been identified as the enzyme tissue transglutaminase which belongs to a family of enzymes that catalyze protein cross-linking reactions and is constitutively expressed in many tissues as well as being activated during apoptosis. In a recent paper, we described the selection and characterization of anti-transglutaminase Igs from phage antibody libraries created from intestinal lymphocytes from celiac disease patients. In this work, using transglutaminase gene fragments, we identify a region of tissue transglutaminase recognized by these antibodies as being conformational and located in the core domain of the enzyme. This is identical to the region recognized by anti-transglutaminase Igs found in the serum of celiac disease patients.

Antibody Specificity↗