Shunji Hattori

IgE reactivity to α1 and α2 chains of bovine type 1 collagen in children with bovine gelatin allergy

Abstract Background: Anaphylactic reactions to measles, mumps, and rubella vaccines, including gelatin as a stabilizer, have been reported. It had been found that most of these reactions to live vaccines are caused by the bovine gelatin included in these vaccines. Gelatin mainly includes denatured type I collagen, which consists of α1 and α2 chains. Objective: The current study was designed to investigate the IgE reactivity to α1 and α2 chains of bovine type I collagen in gelatin-sensitive children. Methods: Serum samples were taken from 10 children who had anaphylaxis to the vaccines and high levels of specific IgE to bovine gelatin. Bovine type I collagen was isolated from bovine skin and then separated to α1 and α2 chains by column chromatography. IgE reactivity to denatured type I collagen and its α1 and α2 chains was analyzed by immunoblotting, ELISA, and histamine release from the mast cells passive sensitized with IgE antibodies in pooled serum of the children. Results: All children had specific IgE to bovine type I collagen. Furthermore, IgE antibodies in their sera reacted with the alpha;2 chain but not with the α1 chain. Similarly, the mast cells sensitized with pooled sera in the children showed α2 chain-specific histamine release but not α1 chain–specific histamine release. Conclusion: In gelatin allergy denatured bovine type I collagen is a major allergen and IgE-binding sites exist in the α2 chain of type I collagen. (J Allergy Clin Immunol 1999;104:695-9.)

The complete cDNA coding sequence for the bovine Proα2(I) chain of type I procollagen

The complete sequence of the cDNA for the pro alpha2(I) chain of bovine type I procollagen is presented. The encoded amino acid sequence shows 92.0% identity to the human pro alpha2(I) collagen chain.

Regulation of polysome assembly on the endoplasmic reticulum by a coiled-coil protein, p180

A coiled-coil microtubule-bundling protein, p180, was originally identified as one of the ribosome receptor candidates on the rough endoplasmic reticulum (ER) and is highly expressed in secretory tissues. Recently, we reported that p180 plays crucial roles in upregulating collagen biosynthesis, mainly by facilitating ribosome association on the ER. Here, we provide evidence that p180 is required to form translationally active polysome/translocon complexes on the ER. Assembly of highly-developed polysomes on the ER was severely perturbed upon loss of p180. p180 associates with polysome/translocon complexes through multiple contact sites: it was coimmunoprecipitated with the translocon complex independently of ribosomes, while it can also bind to ribosomal large subunit specifically. The responsible domain of p180 for membrane polysome assembly was identified in the C-terminal coiled-coil region. The degree of ribosome occupation of collagen and fibronectin mRNAs was regulated in response to increased traffic demands. This effect appears to be exerted in a manner specific for a specified set of mRNAs. Collectively, our data suggest that p180 is required to form translationally active polysome/translocon complexes on the ER membrane, and plays a pivotal role in highly efficient biosynthesis on the ER membrane through facilitating polysome formation in professional secretory cells.

Analysis of collagen and elastin cross-links

Fibrillar collagens represent the most abundant extracellular matrix proteins in vertebrates providing tissues and organs with form, stability, and connectivity. For such mechanical functions, the formation of covalent intermolecular cross-linking between molecules is essential. This process, the final posttranslational modification during collagen biosynthesis, is initiated by conversion of specific lysine and hydroxylysine residues to the respective aldehydes by the action of lysyl oxidases. This conversion triggers a series of condensation reactions with the juxtaposed lysine-aldehyde, lysine, hydroxylysine, and histidine residues within the same and neighboring molecules resulting in di-, tri-, and tetravalent cross-links. Elastin, another class of extracellular matrix protein, is also stabilized by the lysyl oxidase-mediated mechanism but involving only lysine residues leading to the formation of unique tetravalent cross-links. This chapter presents an overview of fibrillar collagen cross-linking, and the analytical methods for collagen and elastin cross-links we have developed.

A Novel BSE screening kit with simplified preparation method for EIA

Introduction In Japan, all slaughtered and deceased bovine materials are tested for BSE infection. The primary screening test is undertaken by the meat inspection office or live stock hygiene service center in each prefecture. In these circumstances, BSE kits adapted for relatively small number of samples are required. Here we describe the development of a neŵ BSE screening system, which has simpler and safer protocol for sample preparation steps for EIA. This assay system has been named the NippIBL BSE Assay system.

Partial characterization of monoclonal antibodies which bind to disease-associated prion protein in immunoprecipitaion assay

Conformational conversion of cellular prion protein (PrPC) to scrapie-form prion protein (PrPSc) is thought to be the central event in prion pathogenesis. Several studies have shown that their distinct conformation should cause different immunogenic properties, however, almost all mAbs generated against PrP are unable to recognize each ones separately. Such characters of mAbs make it diffcult to study conformational difference between PrPC and PrPSc or mechanism of prion replication. Therefore the purpose of this study is to generate such mAbs that would react with PrPSc but not with PrPC.