Antigenic properties of porins fromYersinia outer membranes

Abstract

The pore-forming proteins porins isolated from Yersinia pseudotuberculosis and Y. enterocolitica outer membranes and purified were found, by means of enzyme-linked immunosorbent assays, to be genus-specific antigens. Antiporin antibodies were detected in rabbit antisera to the isolated proteins as well as to total outer membrane proteins and whole bacterial cells. Enzyme-linked immunosorbent and immunoblotting assays demonstrated an antigenic relatedness of porins from five Yersinia species. Key Words: Yersinia porins; antigenic relatedness; enzyme-linked irnmunosorbent assaysThe pore-forming proteins (porins) present in the outer membrane of gram-negative bacteria have pores allowing for transmembrane transfer of hydrophilic substances [8], and some also serve as receptors for bacteriophages [8]. Being among the major surface antigens of bacterial ceils, porins play an important role in the pathogenesis of infection by promoting adhesion of bacteria to (and possibly their invasion into) host cells [3] and affecting the immune response [5,9].Recent years have witnessed mounting interest in the immunochemical and immunobiological properties of outer membranes proteins, including porins, found in gram-negative bacteria. Porins from several members of the family Enterobacteriaceae have been shown to be antigenically related [6,13], and variations in biological activity among surface epitopes of outer membrane proteins have been reported [16]. However, information on the antigenic structures of porins in the genus Yersinia is scarce [2,10].Identification of antigenically related surface components on the outer cell membrane within Enterobacteriaceae genera may provide a basis for the MATERIALS AND METHODS

New genes involved in Yersinia pestis fraction I biosynthesis

“…Both proteins appeared to be non-speci®c for Y. pestis. They were also found in outer membranes of all yersiniae ± Y. pseudotuberculosis, Y. enterocolitica, Y. kristensenii, Y. frederiksenii and Y. intermedia [33] ± and many other representatives of the Brucellaceae and the Enterobacteriaceae [13]. The adhesive properties of these proteins probably explain the adhesive and lectin properties of Y. pestis FI [34] and FI haemagglutination activity [7].…”

“…The adhesive properties of these proteins probably explain the adhesive and lectin properties of Y. pestis FI [34] and FI haemagglutination activity [7]. Furthermore, synthesis of these proteins is independent of cultivation temperature (4±408C) [16,33] and probably provides psychrophility to Y. pseudotuberculosis [35] and Y. pestis [16]. However, they are synthesised in smaller quantities than caf1 product because Y. pestis pFra strains grown at 378C give a signi®cantly stronger positive reaction in immuno¯uorescence tests [13,14,25] or ELISA with MAb (data not shown) than pFra À strains grown at <288C which demonstrate only colour background [13,14,25].…”

“…It should be emphasised that high speci®city of the MAb is well proven [1, 9, 12±14, 16, 25]. At the same time, antibodies to these proteins revealed only homologous antigens in immunoblotting of Yersinia whole-cell lysates and reacted in ELISA to a high titre [33] with a wide spectrum of gram-negative bacteria probably, because both proteins with mol. wts of 28 and 43 kDa together with the 18-kDa protein (identi®ed as caf1 product) were isolated by the procedure of Baker et al [5] from capsulate (Klebsiella pneumoniae and Citrobacter freundii) and non-capsulate (Shigella dysenteriae, P. mirabilis, E. coli, Y. pseudotuberculosis, Y. enterocolitica) bacteria including plasmidless Y. pestis strains [13].…”

Prevention of experimental pseudotuberculosis infection by immunization with porin fromYersinia pseudotuberculosis

“…Here and in Table 2: the resistance index is given in parentheses. Y. pseudotuberculosis porin is a genus-specific Yersinia antigen [3], and therefore, we tested the protective effect of yersinin towards another representative of this genus, Y. pestis. However, repeated immunization of albino mice and guinea pigs with yersinin did not protect them from infection with the plague agent ( Table 2).…”

Morphological and immunological characterization of immunostimulatory complexes based on glycoglycerolipids from Laminaria japonica.

“…The pore-forming protein from Yersinia pseudotuberculosis, being a species-specific antigen of Yersinia (Novikova et al, 1996), was chosen as the antigen in ISCOM vaccines. The outer membrane porins of Gram-negative microorganisms are immunodominant antigens.…”