Loci on murine chromosomes 7 and 13 that modify the phenotype of the NOA mouse, an animal model of atopic dermatitis.

The NOA (Naruto Research Institute Otsuka Atrichia) mouse is an animal model of allergic or atopic dermatitis, a condition characterized by ulcerative skin lesions with accumulation of mast cells and increased serum IgE. We reported earlier that a major gene responsible for dermatitis in the NOA mouse lay in the middle of chromosome 14, and that the incidence of disease clearly differed according to parental strain; the mode of inheritance was autosomal recessive with incomplete penetrance. In the study reported here, we searched for genes that might modify the NOA phenotype, and we identified two candidate loci that appeared to contain genes capable of modifying atopic or allergic dermatitis, one in the middle of chromosome 7 (chi2 = 14.66; P = 0.00013 for D7Mit62) and the other in the telomeric region of chromosome 13 (chi2 = 15.352; P = 0.000089 for D13Mit147). These loci correspond to regions of synteny in human chromosomes where linkages to asthma, atopy, or related phenotypes, such as serum IgE levels, have been documented.

Mapping of a gene responsible for dermatitis in NOA (Naruto Research Institute Otsuka Atrichia) mice, an animal model of allergic dermatitis.

The NOA (Naruto Research Institute Otsuka Atrichia) mouse is an animal model of allergic or atopic dermatitis, a condition characterized by ulcerative skin lesions with accumulation of mast cells and increased serum IgE. These features of the murine disease closely resemble human atopy and atopic disorders. We performed linkage analysis in NOA back-cross progeny, as a step toward identifying and isolating a gene responsible for the NOA phenotype. We crossed NOA mice with five other murine strains (C57BL/6J, IQI, C3H/HeJ, DBA/2J, and BALB/cByJ) and then bred back-cross animals. Using microsatellite markers, we scanned the entire genomes of 559 N2 offspring from the five parental strains. Linkage analysis revealed a significant association between ulcerative skin lesions and markers on murine chromosome 14. Statistical analysis indicated that the critical region was assigned to the vicinity of D14Mit236 and D14Mit160.

Significantly elevated expression of PF4 (platelet factor 4) and eotaxin in the NOA mouse, a model for atopic dermatitis.

The NOA (Naruto Research Institute Otsuka Atrichia) mouse, an animal model of allergic or atopic dermatitis, exhibits ulcerative skin lesions associated with accumulation of mast cells and eosinophils, a significantly increased level of serum IgE, and scratching behavior. To investigate genetic contributors to the pathological process of dermatitis in this murine model, we looked for genes that were expressed differently in spleens of NOA mice compared with controls, by means of a differential display method. We cloned and characterized one gene that revealed a significantly higher expression in the NOA mouse than in control strains. Its cDNA consisted of 570 nucleotides, including 315 nucleotides of open reading frame encoding 105 amino acids. The deduced amino acid sequence identified this gene as the murine homologue of rat and human platelet factor (PF) 4s (89% identity and 64% identity in 105 amino acids, respectively). PF4 is a heparin-binding protein that is released from alpha-granules of activated platelets and belongs to the family of chemokine molecules that contain a CXC motif. Our results suggested that increased expression of PF4 may play an important role in the etiology of allergic dermatitis.

Quantitation by enzyme immunoassay of spirosin from Lactobacillus reuteri and Escherichia coli.

Three EIA methods (Direct, Indirect and Sandwich EIA) were studied to quantify spirosin in Lactobacillus reuteri and Escherichia coli cultured under various conditions in an attempt to get some insight into the function of spirosome. Both Direct and Indirect EIA were suited well for the quantitation of L. reuteri spirosin while Direct EIA was appropriate for spirosin of E. coli. Sandwich EIA could not be applied successfully in either case. By use of these methods, the amounts of spirosin produced by E. coli were determined to be 1.4, 36.2 and 46.5 micrograms per mg protein of the cell lysate under aerobic, standing and anaerobic culture conditions, respectively. Since the production profile of spirosin coincided entirely with that of alcohol dehydrogenase, these findings supported the identity of spirosin to alcohol dehydrogenase in E. coli. In the same way, L. reuteri spirosin was quantified to be 73.5 and 65.4 micrograms/ mg protein of the lysate in standing and anaerobic culture, respectively. The production pattern of spirosin did not parallel that of alcohol dehydrogenase among three strains of L. reuteri, suggesting that spirosin might not be identical to alcohol dehydrogenase.

Chromatographic study of spirosin by use of monoclonal antibodies to spirosin of Yersinia enterocolitica.

Two monoclonal antibodies (MAbs) reacting with spirosins from Enterobacteriaceae were obtained in a course of screening MAbs to spirosin from Yersinia enterocolitica SYT-11-72 (YE72). The antibodies were designated MAbs-S44 and S50. They were IgG2b and IgG2a, respectively, both with kappa light chains. On Western blotting after limited proteolysis of YE72 spirosin with Staphylococcus aureus V8 protease, they reacted markedly with peptide fragments of 27 and 35 kDa, suggesting the presence of an antigenic determinant on the fragments. When supernatant cell lysate from Escherichia coli K12 was chromatographed on DEAE-cellulose and Sepharose CL-6B columns successively, a 96-kDa protein with alcohol dehydrogenase (ADH) activity was always associated with reactivity to MAb-S50. These findings combined with N-terminal amino acid sequences clearly indicate the identity of spirosin to ADH in E. coli.