| 1. |
- Carroll, Daniela J, et al.
(författare)
-
Interleukin-22 regulates B3GNT7 expression to induce fucosylation of glycoproteins in intestinal epithelial cells.
- 2021
-
Ingår i: The Journal of biological chemistry. - : Elsevier BV. - 1083-351X .- 0021-9258. ; 298:2
-
Tidskriftsartikel (refereegranskat)abstract
- Interleukin (IL)-22 is a cytokine that plays a critical role in intestinal epithelial homeostasis. Its downstream functions are mediated through interaction with the heterodimeric IL-22 receptor and subsequent activation of signal transducer and activator of transcription 3 (STAT3). IL-22 signaling can induce transcription of genes necessary for intestinal epithelial cell proliferation, tissue regeneration, tight junction fortification, and antimicrobial production. Recent studies have also implicated IL-22 signaling in the regulation of intestinal epithelial fucosylation in mice. However, whether IL-22 regulates intestinal fucosylation in human intestinal epithelial cells and the molecular mechanisms that govern this process are unknown. Here, in experiments performed in human cell lines and human-derived enteroids, we show that IL-22 signaling regulates expression of the B3GNT7 transcript, which encodes a β1-3-N-acetylglucosaminyltransferase that can participate in the synthesis of poly-N-acetyllactosamine (polyLacNAc) chains. Additionally, we find that IL-22 signaling regulates levels of the α1-3-fucosylated Lewis X (Lex) blood group antigen, and that this glycan epitope is primarily displayed on O-glycosylated intestinal epithelial glycoproteins. Moreover, we show that increased expression of B3GNT7 alone is sufficient to promote increased display of Lex-decorated carbohydrate glycan structures primarily on O-glycosylated intestinal epithelial glycoproteins. Together, these data identify B3GNT7 as an intermediary in IL-22-dependent induction of fucosylation of glycoproteins and uncover a novel role for B3GNT7 in intestinal glycosylation.
|
|
| 2. |
- Cervin, Jakob, et al.
(författare)
-
Fucose-Galactose Polymers Inhibit Cholera Toxin Binding to Fucosylated Structures and Galactose-Dependent Intoxication of Human Enteroids.
- 2020
-
Ingår i: ACS infectious diseases. - : American Chemical Society (ACS). - 2373-8227. ; 6:5, s. 1192-1203
-
Tidskriftsartikel (refereegranskat)abstract
- A promising strategy to limit cholera severity involves blockers mimicking the canonical cholera toxin ligand (CT) ganglioside GM1. However, to date the efficacies of most of these blockers have been evaluated in noncellular systems that lack ligands other than GM1. Importantly, the CT B subunit (CTB) has a noncanonical site that binds fucosylated structures, which in contrast to GM1 are highly expressed in the human intestine. Here we evaluate the capacity of norbornene polymers displaying galactose and/or fucose to block CTB binding to immobilized protein-linked glycan structures and also to primary human and murine small intestine epithelial cells (SI ECs). We show that the binding of CTB to human SI ECs is largely dependent on the noncanonical binding site, and interference with the canonical site has a limited effect while the opposite is observed with murine SI ECs. The galactose-fucose polymer blocks binding to fucosylated glycans but not to GM1. However, the preincubation of CT with the galactose-fucose polymer only partially blocks toxic effects on cultured human enteroid cells, while preincubation with GM1 completely blocks CT-mediated secretion. Our results support a model whereby the binding of fucose to the noncanonical site places CT in close proximity to scarcely expressed galactose receptors such as GM1 to enable binding via the canonical site leading to CT internalization and intoxication. Our finding also highlights the importance of complementing CTB binding studies with functional intoxication studies when assessing the efficacy inhibitors of CT.
|
|
| 3. |
|
|
| 4. |
- Mottram, Lynda, et al.
(författare)
-
A Systems Biology Approach Identifies B Cell Maturation Antigen (BCMA) as a Biomarker Reflecting Oral Vaccine Induced IgA Antibody Responses in Humans
- 2021
-
Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Vaccines against enteric diseases could improve global health. Despite this, only a few oral vaccines are currently available for human use. One way to facilitate such vaccine development could be to identify a practical and relatively low cost biomarker assay to assess oral vaccine induced primary and memory IgA immune responses in humans. Such an IgA biomarker assay could complement antigen-specific immune response measurements, enabling more oral vaccine candidates to be tested, whilst also reducing the work and costs associated with early oral vaccine development. With this in mind, we take a holistic systems biology approach to compare the transcriptional signatures of peripheral blood mononuclear cells isolated from volunteers, who following two oral priming doses with the oral cholera vaccine Dukoral (R), had either strong or no vaccine specific IgA responses. Using this bioinformatical method, we identify TNFRSF17, a gene encoding the B cell maturation antigen (BCMA), as a candidate biomarker of oral vaccine induced IgA immune responses. We then assess the ability of BCMA to reflect oral vaccine induced primary and memory IgA responses using an ELISA BCMA assay on a larger number of samples collected in clinical trials with Dukoral (R) and the oral enterotoxigenic Escherichia coli vaccine candidate ETVAX. We find significant correlations between levels of BCMA and vaccine antigen-specific IgA in antibodies in lymphocyte secretion (ALS) specimens, as well as with proportions of circulating plasmablasts detected by flow cytometry. Importantly, our results suggest that levels of BCMA detected early after primary mucosal vaccination may be a biomarker for induction of long-lived vaccine specific memory B cell responses, which are otherwise difficult to measure in clinical vaccine trials. In addition, we find that ALS-BCMA responses in individuals vaccinated with ETVAX plus the adjuvant double mutant heat-labile toxin (dmLT) are significantly higher than in subjects given ETVAX only. We therefore propose that as ALS-BCMA responses may reflect the total vaccine induced IgA responses to oral vaccination, this BCMA ELISA assay could also be used to estimate the total adjuvant effect on vaccine induced-antibody responses, independently of antigen specificity, further supporting the usefulness of the assay.
|
|
| 5. |
- Mottram, Lynda, et al.
(författare)
-
Booster vaccination with a fractional dose of an oral cholera vaccine induces comparable vaccine-specific antibody avidity as a full dose: A randomised clinical trial.
- 2020
-
Ingår i: Vaccine. - : Elsevier BV. - 1873-2518 .- 0264-410X. ; 38:3, s. 655-62
-
Tidskriftsartikel (refereegranskat)abstract
- Antibody avidity is an important measure of the quality of vaccine-induced immune responses. Murine and human studies suggest that antibody avidity may be augmented by limiting access to antigen. The primary objective of this study was to evaluate in primed Swedish adults if booster vaccination with fractional doses (1/5th and 1/25th) of a model oral vaccine, the cholera vaccine Dukoral®, results in higher avidity antibody responses compared to boosting with a full vaccine dose. We also evaluated if fractional booster vaccination elicited similar magnitudes of antibody response compared to a full dose, and if the previously observed increase in antibody avidity after booster vaccination 1-2years later occurred when boosting after a shorter interval. To this end, a randomised, open-label, exploratory Phase-II trial was performed. Swedish adults (n=44), primed with two full doses of Dukoral®, were randomised into three groups and given a booster dose at either full (n=14), 1/5th (n=17) or 1/25th (n=13) dose four months later. Antibody responses to cholera toxin B-subunit (CTB) were measured in serum and mucosal antibody in lymphocyte secretions (ALS). We found that the 1/5th and 1/25th booster doses had similar abilities as the full dose to induce significantly higher avidity anti-CTB antibody responses in both ALS and serum samples, as compared to after priming vaccination. There was a non-significant trend to lower magnitudes of ALS and serum IgA responses after the 1/5th compared to the full booster dose, and responses after the 1/25th dose were significantly lower. Our findings suggest fractional booster doses of Dukoral® four months after priming result in anti-toxoid mucosal antibody responses with increased antibody avidity compared to after priming vaccinations. ISRCTN registry identifier 11806026.
|
|
| 6. |
- Mottram, Lynda, et al.
(författare)
-
FUT2 non-secretor status is associated with altered susceptibility to symptomatic enterotoxigenic Escherichia coli infection in Bangladeshiw
- 2017
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Polymorphisms of the FUT2 gene alters glycan ABO(H) blood group and Lewis antigen expression (commonly known as non-secretor status) in the small intestinal mucosa. Whilst non-secretor status affects 20% of the population worldwide, it has been reported to be present in up to 40% of all Bangladeshis. Furthermore, Bangladeshi children are reportedly more susceptible to symptomatic enterotoxigenic Escherichia coli (ETEC) infection if they are non-secretors. Therefore, in an attempt to identify a non-secretor status genotypic biomarker of altered susceptibility to ETEC infection, we used the 1000 Genomes Project to identify three population related non-synonymous FUT2 single nucleotide polymorphisms (SNPs). We then assessed the genotypic frequency of these SNPs in Bangladeshi children who had been clinically monitored for ETEC infection. One novel missense FUT2 SNP, rs200157007-TT and the earlier established rs601338-AA SNP were shown to be causing non-secretor status, with these SNPs being associated with symptomatic but not asymptomatic ETEC infection. Moreover, rs200157007-TT and rs601338-AA were associated with symptomatic but not asymptomatic ETEC infection irrespective of the child's Lewis secretor status, suggesting FUT2, the regulator of Lewis and ABO(H) antigens in the intestinal mucosa, could be a host genotypic feature affecting susceptibility to ETEC infection.
|
|
| 7. |
- Mottram, Lynda, et al.
(författare)
-
Glyco-engineered cell line and computational docking studies reveals enterotoxigenic Escherichia coli CFA/I fimbriae bind to Lewis a glycans
- 2018
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- We have previously reported clinical data to suggest that colonization factor I (CFA/I) fimbriae of enterotoxigenic Escherichia coli (ETEC) can bind to Lewis a (Le(a)), a glycan epitope ubiquitous in the small intestinal mucosa of young children (< 2 years of age), and individuals with a genetic mutation of FUT2. To further elucidate the physiological binding properties of this interaction, we engineered Chinese Hamster Ovary (CHO-K1) cells to express Le(a) or Le(b) determinants on both N- and O-glycans. We used our glyco-engineered CHO-K1 cell lines to demonstrate that CfaB, the major subunit of ETEC CFA/I fimbriae, as well as four related ETEC fimbriae, bind more to our CHO-K1 cell-line expressing Le(a), compared to cells carrying Le(b) or the CHO-K1 wild-type glycan phenotype. Furthermore, using in-silico docking analysis, we predict up to three amino acids (Glu(25), Asn(27), Thr(29)) found in the immunoglobulin (Ig)-like groove region of CfaB of CFA/I and related fimbriae, could be important for the preferential and higher affinity binding of CFA/I fimbriae to the potentially structurally flexible Le(a) glycan. These findings may lead to a better molecular understanding of ETEC pathogenesis, aiding in the development of vaccines and/or anti-infection therapeutics.
|
|
| 8. |
- Mottram, Lynda, et al.
(författare)
-
How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions
- 2019
-
Ingår i: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 37:34, s. 4805-4810
-
Tidskriftsartikel (refereegranskat)abstract
- © 2019 The Authors Thanks to the modern sequencing era, the extent to which infectious disease imposes selective pressures on the worldwide human population is being revealed. This is aiding our understanding of the underlying immunological and host mechanistic defenses against these pathogens, as well as potentially assisting in the development of vaccines and therapeutics to control them. As a consequence, the workshop “How genomics can be used to understand host susceptibility to enteric infection, aiding in the development of vaccines and immunotherapeutic interventions” at the VASE 2018 meeting, aimed to discuss how genomics and related tools could be used to assist Shigella and ETEC vaccine development. The workshop featured four short presentations which highlighted how genomic applications can be used to assist in the identification of genetic patterns related to the virulence of disease, or host genetic factors that could contribute to immunity or successful vaccine responses. Following the presentations, there was an open debate with workshop attendees to discuss the best ways to utilise such genomic studies, to improve or accelerate the process of both Shigella and ETEC vaccine development. The workshop concluded by making specific recommendations on how genomic research methods could be strengthened and harmonised within the ETEC and Shigella research communities.
|
|
