| 1. |
- Adlerberth, Ingegerd, 1959, et al.
(författare)
-
Interaction of P-fimbriated Escherichia coli with human meconium.
- 1991
-
Ingår i: FEMS microbiology letters. - 0378-1097. ; 68:1, s. 57-62
-
Tidskriftsartikel (refereegranskat)abstract
- The ability of Escherichia coli with different receptor specificities to interact with meconium was studied. E. coli strains expressing P-fimbriae, specific for Gal alpha 1-4Gal beta-containing receptors, were agglutinated by meconium at high titres. This reaction was inhibited by globotetraosylceramide. The attachment of P-fimbriated E. coli to human colonic epithelial cells of the HT-29 cell line was inhibited by meconium. Some type 1 fimbriated strains were agglutinated by meconium, but the agglutination was rarely blocked by methyl alpha-D-mannoside. The attachment by type 1 fimbriated strains to HT-29 cells was reduced by meconium only in some cases. These results suggest that meconium interacts with the P-fimbriae of E. coli, in a way that may influence bacterial colonization of the neonatal intestine.
|
|
| 2. |
- Adlerberth, Ingegerd, 1959, et al.
(författare)
-
Intestinal colonization with Enterobacteriaceae in Pakistani and Swedish hospital-delivered infants.
- 1991
-
Ingår i: Acta paediatrica Scandinavica. - 0001-656X. ; 80:6-7, s. 602-10
-
Tidskriftsartikel (refereegranskat)abstract
- Rectal cultures from Swedish and Pakistani hospital-delivered newborn infants were analysed regarding the early acquisition of enterobacteria. Swedish infants were delivered vaginally, Pakistani infants were delivered either vaginally or by caesarean section. The Swedish infants were all breast-fed, whereas breastfeeding was incomplete and often started late among the Pakistani infants. Both groups of Pakistani infants were more rapidly colonized with enterobacteria than were the Swedish infants. Cultures from Swedish infants seldom yielded more than one kind of enterobacteria; E. coli and Klebsiella were most frequently isolated. E. coli dominated in both Pakistani groups, but especially caesarean section delivered infants were in addition often colonized with Proteus, Klebsiella, Enterobacter or Citrobacter species. Breastfeeding from the first day of life reduced colonization with Klebsiella/Enterobacter/Citrobacter. The results suggest that environmental exposure, delivery mode and early feeding habits all influence the early intestinal colonization with enterobacteria.
|
|
| 3. |
- Dahlgren, Ulf, 1953, et al.
(författare)
-
Expression of a dietary protein in E. coli renders it strongly antigenic to gut lymphoid tissue.
- 1991
-
Ingår i: Immunology. - 0019-2805. ; 73:4, s. 394-7
-
Tidskriftsartikel (refereegranskat)abstract
- Bacteria that colonize the intestinal mucosa elicit a strong mucosal immune response, whereas food antigens such as ovalbumin are very weakly immunogenic to the gut-associated lymphoid tissue. This may either be due to special physico-chemical properties of bacterial substances versus proteins from animals and plants, or to stimulating properties of the bacteria on, e.g., antigen presentation, rendering all substances contained within bacteria antigenic. To test these hypotheses, ovalbumin was expressed in wild-type Escherichia coli and germ-free female rats were colonized with this strain. The systemic and mucosal antibody response of these rats was compared with that of rats given large amounts of dietary ovalbumin. Biliary IgA antibodies, which reflect the local IgA antibody production in the intestine, were only found in the rats colonized with ovalbumin-synthesizing E. coli. IgG antibodies in the bile were also only seen in these rats. We conclude that mucosal immunogenicity depends on the context in which a protein is presented to the gut-associated lymphoid tissue, rather than to special antigenic characteristics of the protein in itself.
|
|
| 4. |
- Dahlgren, Ulf, 1953, et al.
(författare)
-
The secretory antibody response in milk and bile against fimbriae and LPS in rats monocolonized or immunized in the Peyer's patches with Escherichia coli.
- 1990
-
Ingår i: Immunology. - 0019-2805. ; 71:2, s. 295-300
-
Tidskriftsartikel (refereegranskat)abstract
- The homing of lymphoid cells to mucosa-associated lymphoid tissue is, amongst other factors, influenced by the nature of the antigen used to induce an immune response. To study this phenomenon we have monocolonized rats with a type 1 fimbriated Escherichia coli O6K13H1 strain and compared the secretory antibody response to colonization with the primary and secondary response obtained in rats immunized in the Peyer's patches (PP). Samples were tested with respect to the titres of antibodies against two antigens present on the E. coli strain: O6 lipopolysaccharide (LPS) and type 1 fimbrial antigen. In the primary immunized animals, IgA anti-fimbrial antibodies were mainly seen in milk and IgA anti-LPS antibodies mostly found in bile. In the booster immunized, and in the monocolonized, animals there was a shift of the antibody response towards the bile. Thus anti-fimbrial antibodies appeared in milk at approximately the same or at a lower level than in bile and the IgA anti-LPS antibodies were almost completely absent in the milk. The IgG antibody response of the animals immunized in the PP was primarily confined to milk for both anti-LPS and anti-fimbrial antibodies, while the colonized animals responded with higher levels in bile than in milk. IgM antibodies were only seen in the milk, except in primary immunized animals in which biliary IgM antibodies also were found. The data illustrate that: (i) primary stimulated cells predestined to produce IgA anti-LPS antibodies home mainly to the intestine, while cells predestined to anti-fimbrial antibody production have a greater tendency to populate the mammary gland; (ii) after repeated antigen stimulation and maturation of the immune response the cells are directed from the mammary gland to the intestine. We thus conclude that the nature of the antigen and the stage of lymphocyte maturation influences the homing of the cells and the appearance of various antibodies in different secretions.
|
|
| 5. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
-
Immune response against ovalbumin in rats colonized with an ovalbumin-producing Escherichia coli and the influence of feeding ovalbumin.
- 1994
-
Ingår i: International archives of allergy and immunology. - 1018-2438. ; 105:4, s. 381-5
-
Tidskriftsartikel (refereegranskat)abstract
- The influence of feeding ovalbumin (OA) on the development of IgE/IgG antibodies and delayed-type hypersensitivity (DTH) against OA was studied in rats colonized from birth with an Escherichia coli genetically manipulated to produce OA. At 21 days of age, colonized pups and pups with a normal intestinal flora were weaned onto either an OA-containing or a conventional diet without OA. At 2 months of age the colonized rats showed an increased DTH reaction to OA, but they did not have any anti-OA antibodies in serum. The rats were then immunized intracutaneously with OA in Freund's complete adjuvant. After immunization the colonized rats fed the conventional diet had a significantly higher DTH reaction to OA and significantly higher serum levels of IgE anti-OA antibodies than the uncolonized rats on the same diet. The colonized rats eating the OA-containing diet showed a 73% decrease in the DTH reaction to OA and also significantly lower levels of IgE and IgG antibodies against OA compared with the colonized rats fed conventional diet. The dams colonized as adults by the OA-producing E. coli developed IgE anti-lipopolysaccharide antibodies in serum while the pups colonized via the dams at birth did not. Neonatal colonization with an E. coli strain producing OA resulted in increased DTH reactivity against OA and priming for secondary IgE anti-OA response. Feeding the animals an OA-containing diet from weaning abrogated this intestinally induced hypersensitivity and rendered the animals orally tolerant to OA.
|
|
| 6. |
- Dahlman-Höglund, Anna, 1964, et al.
(författare)
-
Induction of IgE antibodies and T-cell reactivity to ovalbumin in rats colonized with Escherichia coli genetically manipulated to produce ovalbumin.
- 1992
-
Ingår i: Immunology. - 0019-2805. ; 76:2, s. 225-8
-
Tidskriftsartikel (refereegranskat)abstract
- The immune response to ovalbumin (OA) and the bacterial antigens, lipopolysaccharide (LPS) and fimbriae were studied in conventional rats colonized from birth with an Escherichia coli strain producing OA. The colonized rats had developed IgE antibodies against OA, but not against the fimbrial or the LPS antigens from the E. coli at 2 months of age. At this time all rats were primed with OA given intracutaneously in Freund's complete adjuvant. Two weeks later the colonized rats showed a 35% greater delayed-type hypersensitivity (DTH) reaction to OA, measured as ear swelling, than the controls. Thus bacteria carrying antigens resembling potential allergens might aggravate, or participate in the induction of allergic symptoms. In addition such bacteria could be efficient vaccine vectors in protection against parasites. The study illustrates the importance of the mode of antigen presentation for the subsequent immune response.
|
|
| 7. |
- Lodinová-Zádníková, R, et al.
(författare)
-
The antibody response in breast-fed and non-breast-fed infants after artificial colonization of the intestine with Escherichia coli O83.
- 1991
-
Ingår i: Pediatric research. - : Springer Science and Business Media LLC. - 0031-3998 .- 1530-0447. ; 29:4 Pt 1, s. 396-9
-
Tidskriftsartikel (refereegranskat)abstract
- The local and systemic antibody response after oral administration of a nonenteropathogenic type 1 fimbriated Escherichia coli O83 strain was followed in nine breast-fed and eight formula-fed infants during their first 15 wk of life. Five breast-fed and six formula-fed infants were followed as controls. E. coli O83 was detected in the stools of colonized infants from d 2 after colonization and persisted in the intestine for up to 26 wk. The percentage of children successfully colonized with E. coli O83 was higher among breast-fed than among formula-fed colonized infants. Also, the O83 bacteria isolated from the breast-fed children had a higher capacity to attach to colonic epithelial cells of the HT-29 cell line than those isolated from bottle-fed infants. E. coli O83 IgA and IgM antibodies estimated by ELISA were significantly elevated in the saliva of colonized as compared with control infants 2-7 wk after colonization. IgA antibodies against O83 were also higher in the stool of colonized formula-fed infants than in formula-fed controls. The results suggest that the mucosal immune system of the newborn infant can be triggered early to produce specific antibodies against bacteria colonizing the intestine.
|
|
