Specific immunoglobulin E antibodies to saprophytic yeasts in sera of atopic patients allergic to house dust mites.

BACKGROUND: Atopic dermatitis (AD) is a complex disease caused by genetic and environmental interactions. AD impairs skin barrier function, enabling microorganisms to penetrate and interact with the immune system. OBJECTIVES: This study aimed to investigate the presence of specific immunoglobulin (Ig) E antibodies to the yeast species Candida pelliculosa, Candida guilliermondii, Candida famata, and Rhodotorula rubra in the sera of AD patients and to evaluate possible cross-reactivity between yeasts and allergens of Dermatophagoides pteronyssinus (D1) and Dermatophagoides farinae (D2). METHODS: We analyzed serum samples from 14 healthy individuals and 34 AD patients: 19 were positive to D1 and D2 (Immulite) and 15 were negative. Determinations were made using enzyme-linked immunosorbent assay (ELISA), competitive ELISA, and the Immulite inhibition assay. RESULTS: The results of ELISA showed that all house dust mite-positive sera had specific IgE antibodies to the yeast species tested: 42% of these sera reacted with all 4 yeast species. The inhibition study demonstrated partial cross-reactivity between IgE class antibodies with the yeast species. This finding indicates that different Candida species and R rubra have species-specific and cross-reactive antigens with partially overlapping epitopes, thus suggesting cross-reactivity with mite allergens. C pelliculosa protein extract inhibited IgE binding to D1 (63.4%) and D2 (71%) allergens. The inhibition value for D1 showed a significant correlation with the inhibition value for D2 (r = 0.669, P = .03; Spearman rank correlation). CONCLUSION: The results of the present study suggest that C pelliculosa and house dust mites share common antigens.

The K2-type killer toxin- and immunity-encoding region from Saccharomyces cerevisiae: structure and expression in yeast.

The cDNA copies of M2-1, the larger heat-cleavage product of M2 double-stranded (ds) RNA, have been synthesized, cloned, sequenced and expressed in yeast. This sequence, in combination with the known terminal sequence of M2-1 dsRNA, identifies a translation reading frame for a 362-amino-acid protein of 38.7 kDa, similar in size to the one of several protein species produced from M2-1 dsRNA in vitro translation. The expression of this cDNA clone in yeast confers both killer and immunity phenotypes.

'Red pigment' from ADE-2 mutants of S. cerevisiae prevents DNA cleavage by restriction endonucleases.

Protection of DNA from cleavage by restriction endonucleases EcoRI, HindIII, BamHI, and Bg/II with red pigment, produced by ADE-2 mutants of Saccharomyces cerevisiae is demonstrated. Purification of yeast DNA from pigment can be achieved by chromatography on hydroxyapatite columns.