| 1. |
- Bergman, Peter, et al.
(författare)
-
Safety and efficacy of the mRNA BNT162b2 vaccine against SARS-CoV-2 in five groups of immunocompromised patients and healthy controls in a prospective open-label clinical trial
- 2021
-
Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 74
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with immunocompromised disorders have mainly been excluded from clinical trials of vaccination against COVID-19. Thus, the aim of this prospective clinical trial was to investigate safety and efficacy of BNT162b2 mRNA vaccination in five selected groups of immunocompromised patients and healthy controls.Methods: 539 study subjects (449 patients and 90 controls) were included. The patients had either primary (n=90), or secondary immunodeficiency disorders due to human immunodeficiency virus infection (n=90), allogeneic hematopoietic stem cell transplantation/CAR T cell therapy (n=90), solid organ transplantation (SOT) (n=89), or chronic lymphocytic leukemia (CLL) (n=90). The primary endpoint was seroconversion rate two weeks after the second dose. The secondary endpoints were safety and documented SARS-CoV-2 infection.Findings: Adverse events were generally mild, but one case of fatal suspected unexpected serious adverse reaction occurred. 72.2% of the immunocompromised patients seroconverted compared to 100% of the controls (p=0.004). Lowest seroconversion rates were found in the SOT (43.4%) and CLL (63.3%) patient groups with observed negative impact of treatment with mycophenolate mofetil and ibrutinib, respectively.Interpretation: The results showed that the mRNA BNT162b2 vaccine was safe in immunocompromised patients. Rate of seroconversion was substantially lower than in healthy controls, with a wide range of rates and antibody titres among predefined patient groups and subgroups. This clinical trial highlights the need for additional vaccine doses in certain immunocompromised patient groups to improve immunity.
|
|
| 2. |
- Blixt, Ola, et al.
(författare)
-
Anticarbohydrate antibody repertoires in patients transplanted with fetal pig islets revealed by glycan arrays
- 2009
-
Ingår i: American Journal of Transplantation. - 1600-6135 .- 1600-6143. ; 9, s. 83-90
-
Tidskriftsartikel (refereegranskat)abstract
- Ten patients with type I diabetes were transplanted with porcine fetal islet-like cell clusters (ICC) between 1990 and 1993. A significant rise in the anti-a -Gal antibody titers was seen posttransplant, but also nona -Gal-specific antibodies were detected in some patients. We have reanalyzed the carbohydrate specificity of antibodies in the sera from seven of these patients taken before transplantation, 1, 6 and 12 months posttransplantation using a glycan array with 200 structurally defined glycans. The main findings were: (i) prepig ICC transplantation patients had antibodies reactive with terminal a -GalNAc (e.g. the Forssman antigen, but not the blood group A determinant in blood group A patients), a -Gal (except blood group B determinants in B individuals), b 3-linked Gal especially Galb 1,3GlcNAc even if terminally sulfated or sialylated, b -GlcNAc except if b 1,3-linked and oligomannosyl compounds; (ii) the titers of all carbohydrate-specific antibodies detected before transplantation rose after transplantation; (iii) the kinetics of the antibody responses differed between patients; (iv) in some patients antibodies reacting with Gala 1,3Lex and several structures terminated with Neu5Gc appeared after transplantation. In conclusion, anti-a -Gal antibodies are the predominant anticarbohydrate antibodies detected after porcine ICC transplantation, with some patients also developing Neu5Gc-specific antibodies. Their clinical significance needs to be established.
|
|
| 3. |
- Blixt, Ola, et al.
(författare)
-
Pathogen specific carbohydrate antigen microarrays : a chip for detection of Salmonella O-antigen specific antibodies
- 2008
-
Ingår i: Glycoconjugate Journal. - : Springer. - 0282-0080 .- 1573-4986. ; 25:1, s. 27-36
-
Tidskriftsartikel (refereegranskat)abstract
- A Salmonella O-antigen microarray was developed by covalent coupling of oligosaccharide antigens specific for serogroups Salmonella enterica sv. Paratyphi (group A), Typhimurium (group B) and Enteritidis (group D). Antibodies were correctly detected in sera from patients with culture verified salmonellosis. High serogroup-specificity was seen with the disaccharide antigens. With the larger antigens, containing the backbone sequence Man alpha 1-2Rha alpha 1-2Gal (MRG), common backbone-specific antibodies (O-antigen 12) were also detected. This is "proof of principle" that pathogen-specific carbohydrate antigen microarrays constitute a novel technology for rapid and specific serological diagnosis in either individual patients or larger sero-epidemiological and vaccine studies.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Eriksson, Per, et al.
(författare)
-
Characterization of avian influenza virus attachment patterns to human and pig tissues
- 2018
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Wild birds of Anseriformes and Charadriiformes are natural reservoirs of influenza A viruses (IAVs). Occasionally, IAVs transmit and adapt to mammalian hosts, and are maintained as epidemic strains in their new hosts. Viral adaptions to mammalian hosts include altered receptor preference of host epithelial sialylated oligosaccharides from terminal alpha 2,3-linked sialic acid (SA) towards alpha 2,6-linked SA. However, alpha 2,3-linked SA has been found in human respiratory tract epithelium, and human infections by avian IAVs (AIVs) have been reported. To further explore the attachment properties of AIVs, four AIVs of different subtypes were investigated on human and pig tissues using virus histochemistry. Additionally, glycan array analysis was performed for further characterization of IAVs' receptor structure tropism. Generally, AIV attachment was more abundant to human tissues than to pig tissues. The attachment pattern was very strong to human conjunctiva and upper respiratory tract, but variable to the lower respiratory tract. AIVs mainly attached to alpha 2,3-linked SA, but also to combinations of alpha 2,3-and alpha 2,6-linked SA. The low attachment of these AIV isolates to pig tissues, but high attachment to human tissues, addresses the question whether AIVs in general require passage through pigs to obtain adaptions towards mammalian receptor structures.
|
|
| 7. |
- Goel, Suchi, et al.
(författare)
-
RIFINs are adhesins implicated in severe Plasmodium falciparum malaria
- 2015
-
Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 21:4, s. 314-317
-
Tidskriftsartikel (refereegranskat)abstract
- Rosetting is a virulent Plasmodium falciparum phenomenon associated with severe malaria. Here we demonstrate that P. falciparum-encoded repetitive interspersed families of polypeptides (RIFINs) are expressed on the surface of infected red blood cells (iRBCs), bind to RBCs-preferentially of blood group A-to form large rosettes and mediate microvascular binding of iRBCs. We suggest that RIFINs have a fundamental role in the development of severe malaria and thereby contribute to the varying global distribution of ABO blood groups in the human population.
|
|
| 8. |
- Henriksson, Sara, et al.
(författare)
-
Clinical isolates of Helicobacter pylori demonstrates alternative BabA-mediated adherence to human gastric mucosa
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Helicobacter pylori infection is life-long and can cause peptic ulcer disease and gastric cancer. The H. pylori BabA adhesin binds the ABO/Leb blood group (bg) antigens (Leb), which mediates attachment to the gastric epithelium. The prevalence of ABO binding is high worldwide and also in northern Europe. However, prevalence is reduced by 50% in Germany and is further reduced in Spain and Portugal. An inventory of strains from different European populations resulted in strains with high level of BabA expression but very little or no binding to Leb. The majority of such strains could not bind to human gastric mucosa in vitro. We further characterized a Spanish isolates, strain 812, that binds only weakly to soluble Leb-conjugate but still adheres firmly to gastric mucosa indicative of that it might bind to an alternative set of receptor. Receptor analysis by glycan arrays revealed higher binding of strain 812 to ALeb and Bleb glycans than to Leb, indicating that BabA from strain 812 has shifted its binding epitope somewhat away from the central Fuca1.2Gal bg domain and closer to the very terminal bg A and B determinants, i.e. GalNAca1.3Gal (bgA) or the Gala1.3Gal (bgB). By a colony screening approach we identified a subpopulation of 812 clones adapted for stronger Leb binding. Such affinity shifts comes from replacement of distinguishing amino acids by mechanisms of recombination with a BabA-related outer membrane protein.
|
|
| 9. |
- Hinkula, Jorma, et al.
(författare)
-
Immunization with DNA Plasmids Coding for Crimean-Congo Hemorrhagic Fever Virus Capsid and Envelope Proteins and/or Virus-Like Particles Induces Protection and Survival in Challenged Mice
- 2017
-
Ingår i: Journal of Virology. - : AMER SOC MICROBIOLOGY. - 0022-538X .- 1098-5514. ; 91:10
-
Tidskriftsartikel (refereegranskat)abstract
- Crimean-Congo hemorrhagic fever virus (CCHFV) is a bunyavirus causing severe hemorrhagic fever disease in humans, with high mortality rates. The requirement of a high-containment laboratory and the lack of an animal model hampered the study of the immune response and protection of vaccine candidates. Using the recently developed interferon alpha receptor knockout (IFNAR(- / -)) mouse model, which replicates human disease, we investigated the immunogenicity and protection of two novel CCHFV vaccine candidates: a DNA vaccine encoding a ubiquitin-linked version of CCHFV Gc, Gn, and N and one using transcriptionally competent virus-like particles (tc-VLPs). In contrast to most studies that focus on neutralizing antibodies, we measured both humoral and cellular immune responses. We demonstrated a clear and 100% efficient preventive immunity against lethal CCHFV challenge with the DNA vaccine. Interestingly, there was no correlation with the neutralizing antibody titers alone, which were higher in the tc-VLP-vaccinated mice. However, the animals with a lower neutralizing titer, but a dominant cell-mediated Th1 response and a balanced Th2 response, resisted the CCHFV challenge. Moreover, we found that in challenged mice with a Th1 response (immunized by DNA/DNA and boosted by tc-VLPs), the immune response changed to Th2 at day 9 postchallenge. In addition, we were able to identify new linear B-cell epitope regions that are highly conserved between CCHFV strains. Altogether, our results suggest that a predominantly Th1-type immune response provides the most efficient protective immunity against CCHFV challenge. However, we cannot exclude the importance of the neutralizing antibodies as the surviving immunized mice exhibited substantial amounts of them. IMPORTANCE Crimean-Congo hemorrhagic fever virus (CCHFV) is responsible for hemorrhagic diseases in humans, with a high mortality rate. There is no FDAapproved vaccine, and there are still gaps in our knowledge of the immune responses to infection. The recently developed mouse models mimic human CCHF disease and are useful to study the immunogenicity and the protection by vaccine candidates. Our study shows that mice vaccinated with a specific DNA vaccine were fully protected. Importantly, we show that neutralizing antibodies are not sufficient for protection against CCHFV challenge but that an extra Th1-specific cellular response is required. Moreover, we describe the identification of five conserved B-cell epitopes, of which only one was previously known, that could be of great importance for the development of diagnostics tools and the improvement of vaccine candidates.
|
|
| 10. |
|
|
| 11. |
- Kveton, Filip, et al.
(författare)
-
A graphene-based glycan biosensor for electrochemical label-free detection of a tumor-associated antibody
- 2019
-
Ingår i: Sensors (Switzerland). - : MDPI AG. - 1424-8220. ; 19:24
-
Tidskriftsartikel (refereegranskat)abstract
- The study describes development of a glycan biosensor for detection of a tumor-associated antibody. The glycan biosensor is built on an electrochemically activated/oxidized graphene screen-printed electrode (GSPE). Oxygen functionalities were subsequently applied for covalent immobilization of human serum albumin (HSA) as a natural nanoscaffold for covalent immobilization of Thomsen-nouvelle (Tn) antigen (GalNAc-O-Ser/Thr) to be fully available for affinity interaction with its analyte—a tumor-associated antibody. The step by step building process of glycan biosensor development was comprehensively characterized using a battery of techniques (scanning electron microscopy, atomic force microscopy, contact angle measurements, secondary ion mass spectrometry, surface plasmon resonance, Raman and energy-dispersive X-ray spectroscopy). Results suggest that electrochemical oxidation of graphene SPE preferentially oxidizes only the surface of graphene flakes within the graphene SPE. Optimization studies revealed the following optimal parameters: activation potential of +1.5 V vs. Ag/AgCl/3 M KCl, activation time of 60 s and concentration of HSA of 0.1 g L−1. Finally, the glycan biosensor was built up able to selectively and sensitively detect its analyte down to low aM concentration. The binding preference of the glycan biosensor was in an agreement with independent surface plasmon resonance analysis.
|
|
| 12. |
- Kveton, Filip, et al.
(författare)
-
Optimization of the Small Glycan Presentation for Binding a Tumor-Associated Antibody : Application to the Construction of an Ultrasensitive Glycan Biosensor
- 2017
-
Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 33:11, s. 2709-2716
-
Tidskriftsartikel (refereegranskat)abstract
- The main aim of the study was to optimize the interfacial presentation of a small antigen-a Tn antigen (N-acetylgalactosamine)-for binding to its analyte anti-Tn antibody. Three different methods for the interfacial display of a small glycan are compared here, including two methods based on the immobilization of the Tn antigen on a mixed self-assembled monolayer (SAM) (2D biosensor) and the third one utilizing a layer of a human serum albumin (HSA) for the immobilization of a glycan forming a 3D interface. Results showed that the 3D interface with the immobilized Tn antigen is the most effective bioreceptive surface for binding its analyte. The 3D impedimetric glycan biosensor exhibited a limit of detection of 1.4 aM, a wide linear range (6 orders of magnitude), and high assay reproducibility with an average relative standard deviation of 4%. The buildup of an interface was optimized using various techniques with the visualization of the glycans on the biosensor surface by atomic force microscopy. The study showed that the 3D biosensor is not only the most sensitive compared to other two biosensor platforms but that the Tn antigen on the 3D biosensor surface is more accessible for antibody binding with better kinetics of binding (t50% = 137 s, t50% = the time needed to attain 50% of a steady-state signal) compared to the 2D biosensor configuration with t50% = 354 s. The 3D glycan biosensor was finally applied for the analysis of a human serum sample spiked with an analyte.
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
- Luo, Zhengkang, 1994-
(författare)
-
Immunological strategies for counteracting type 1 diabetes focusing on IL-35 producing regulatory immune cells
- 2023
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Type 1 diabetes (T1D) is an autoimmune disease where pancreatic β-cells are attacked by immune cells. Regulatory T (Treg) cells play critical roles in suppressing immune responses and their involvement have been intensively studied in T1D. Low dose IL-2 has been proposed to selectively boost Treg cells in T1D, with only limited success. We thus further decreased the IL-2 dosage and treated multiple low dose streptozotocin (MLDSTZ) mice with an ultra-low dose IL-2, but it did not protect STZ mice from hyperglycemia. Similarly, low dose IL-2 only partially prevented diabetes. Treg cells’ phenotype was not protected by either dose. These data suggest that alternative IL-2 therapies might be considered. Regulatory B (Breg) cells suppress pro-inflammatory immune responses by producing anti-inflammatory cytokines IL-10 and IL-35. Decreased IL-35+ and increased IFN-γ+ Breg cell proportions were found in T1D patients, and in diabetic mice. IL-35 treatment prevented increased IFN-γ+ Breg cell proportions in STZ mice. These data illustrate Breg cells’ involvement in T1D, and IL-35 treatment prevents hyperglycemia by maintaining Breg cells’ phenotype.Treg cells’ involvement in diabetic nephropathy (DN) has not been studied. Lower plasma IL-35 was found in DN patients than in T1D patients without DN and healthy controls, and was strongly correlated with kidney function. Decreased IL-35+ and increased IL-17+ Treg cells were found in DN patients. Moreover, Foxp3+ cell infiltration was found in the kidneys of diabetic mice, but it failed to counteract mononuclear cell infiltration. IL-35 treatment prevented DN and Treg cells’ phenotypic shift in STZ mice by maintaining the transcription factor Eos. These results demonstrate that IL-35 may be used to prevent DN. Given the instability of IL-35, we explored the effect of IL-6 signaling blockade. Anti-IL-6R completely protected STZ mice from diabetes. Proteomics indicated enhanced metabolism and down-regulated pro-inflammatory pathways. It maintained Treg cells’ phenotype by increasing IL-35 and decreasing IFN-γ production. It also reduced the number of macrophages and conventional dendritic cells type 2 and their CD80 expression. STZ mice remained normoglycemic despite the discontinuation of anti-IL-6R treatment. Therefore, our results illustrate the outcomes of several potential T1D immunotherapies and highlight the involvement of IL-35 producing immune cells in controlling the disease.
|
|
| 16. |
- Luo, Zhengkang, et al.
(författare)
-
Interleukin-35 Prevents Development of Autoimmune Diabetes Possibly by Maintaining the Phenotype of Regulatory B Cells
- 2021
-
Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:23
-
Tidskriftsartikel (refereegranskat)abstract
- The anti-inflammatory role of regulatory B cells (Breg cells) has been associated with IL-35 based on studies of experimental autoimmune uveitis and encephalitis. The role of Breg cells and IL-35(+) Breg cells for type 1 diabetes (T1D) remains to be investigated. We studied PBMCs from T1D subjects and healthy controls (HC) and found lowered proportions of Breg cells and IL-35(+) Breg cells in T1D. To elucidate the role of Breg cells, the lymphoid organs of two mouse models of T1D were examined. Lower proportions of Breg cells and IL-35(+) Breg cells were found in the animal models of T1D compared with control mice. In addition, the systemic administration of recombinant mouse IL-35 prevented hyperglycemia after multiple low dose streptozotocin (MLDSTZ) injections and increased the proportions of Breg cells and IL-35(+) Breg cells. A higher proportion of IFN-gamma(+) cells among Breg cells were found in the PBMCs of the T1D subjects. In the MLDSTZ mice, IL-35 administration decreased the proportions of IFN-gamma(+) cells among the Breg cells. Our data illustrate that Breg cells may play an important role in the development of T1D and that IL-35 treatment prevents the development of hyperglycemia by maintaining the phenotype of the Breg cells under an experimental T1D condition.
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
- Norberg, Thomas, 1948-, et al.
(författare)
-
Reversible derivatization of sugars with carbobenzyloxy groups and use of the derivatives in solution-phase enzymatic oligosaccharide synthesis
- 2021
-
Ingår i: Carbohydrate Research. - : Elsevier. - 0008-6215 .- 1873-426X. ; 502
-
Tidskriftsartikel (refereegranskat)abstract
- Simple protocols for attaching and detaching carbobenzyloxy (Cbz) groups at the reducing end of sugars was developed. Briefly, lactose was converted into its glycosylamine, which was then acylated with carbobenzyloxy chloride in high overall yield. The obtained lactose Cbz derivative was used in sequential glycosylations using glycosyltransferases and nucleotide sugars in aqueous buffers. Isolation of the reaction products after each step was by simple C-18 solid-phase extraction. The Cbz group was removed by catalytic hydrogenolysis or catalytic transfer hydrogenation followed by in situ glycosylamine hydrolysis. In this way, a trisaccharide (GlcNAclactose), a human milk tetrasaccharide (LNnT), and a human milk pentasaccharide (LNFPIII) were prepared in a simple and efficient way.
|
|
| 20. |
- Olofsson, Sigvard, 1948, et al.
(författare)
-
Viral O-GalNAc peptide epitopes: a novel potential target in viral envelope glycoproteins.
- 2016
-
Ingår i: Reviews in medical virology. - : Wiley. - 1099-1654 .- 1052-9276. ; 26:1, s. 34-48
-
Tidskriftsartikel (refereegranskat)abstract
- Viral envelope glycoproteins are major targets for antibodies that bind to and inactivate viral particles. The capacity of a viral vaccine to induce virus-neutralizing antibodies is often used as a marker for vaccine efficacy. Yet the number of known neutralization target epitopes is restricted owing to various viral escape mechanisms. We expand the range of possible viral glycoprotein targets, by presenting a previously unknown type of viral glycoprotein epitope based on a short peptide stretch modified with small O-linked glycans. Besides being immunologically active, these epitopes have a high potential for antigenic variation. Thus, sera from patients infected with EBV develop individual IgG responses addressing the different possible glycopeptide glycoforms of one short peptide backbone that reflect individual variations in the course of virus infection. In contrast, in HSV type 2 meningitis patients, CSF antibodies are focussed to only one single glycoform peptide of a major viral glycoprotein. Thus, dependent on the viral disease, the serological response may be variable or constant with respect to the number of targeted peptide glycoforms. Mapping of these epitopes relies on a novel three-step procedure that identifies any reactive viral O-glycosyl peptide epitope with respect to (i) relevant peptide sequence, (ii) the reactive glycoform out of several possible glycopeptide isomers of that peptide sequence, and (iii) possibly tolerated carbohydrate or peptide structural variations at glycosylation sites. In conclusion, the viral O-glycosyl peptide epitopes may be of relevance for development of subunit vaccines and for improved serodiagnosis of viral diseases.
|
|
| 21. |
- Persson, Nina, et al.
(författare)
-
A combinatory antibody-antigen microarray assay for high-content screening of single-chain fragment variable clones from recombinant libraries
- 2016
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:12
-
Tidskriftsartikel (refereegranskat)abstract
- We have developed a combinatory antibody-antigen microarray for direct screening of multiple single-chain fragment variable (scFv) clones with no need for pre-purification or enrichment before screening. The straightforward workflow allows for early selection of binders to predefined peptide and glycopeptide targets. A capture antibody is contact printed on microarray slides, side by side with the antigens of interest. A large number of scFv clones, in supernatants, are printed on top of the capture antibody and the antigen in a "spot-on-spot" print. The printed scFv clones, which bind to the capture antibody, are detected using biotinylated antigen, while the binding of scFv clones to the printed antigen is detected through a mouse anti-tag antibody. Two different analyses are thus performed on the same slide, generating two kinds of information: one on the ability of an individual scFv clone to bind to the soluble form of the antigen, which may favour selection for higher affinity rather than avidity, while the other allows the identification of large numbers of clones, simultaneously, due to the binding of scFv clones to densely presented antigens, thus providing an overall increased hit rate. The functionality of the new screening approach was illustrated through the generation of antibodies against peptides from the chaperone complex Ku70/Ku80 and the GalNAcαserine/threonine epitope on the IgA1 alpha chain hinge region. In total, 659 scFv clones were screened with a hit rate of approximately 20%. This approach allowed the identification of functional antibodies in both cases, illustrating the usefulness and capacity of this combinatory microarray screening technique for efficient analysis and validation of antibodies at an early stage of antibody generation.
|
|
| 22. |
- Persson, Nina, et al.
(författare)
-
Epitope mapping of a new anti-Tn antibody detecting gastric cancer cells
- 2017
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 0959-6658 .- 1460-2423. ; 27:7, s. 635-645
-
Tidskriftsartikel (refereegranskat)abstract
- Here, we introduce a novel scFv antibody, G2-D11, specific for two adjacent Tn-antigens (GalNAc- Ser/Thr) binding equally to three dimeric forms of the epitope, Ser-Thr, Thr-Thr and Thr-Ser. Compared to other anti-Tn reagents, the binding of G2-D11 is minimally influenced by the peptide structure, which indicates a high degree of carbohydrate epitope dominance and a low influence from the protein backbone. With a high affinity (KDapp = 1.3 × 10-8 M) and no cross-reactivity to either sialyl-Tn epitope or blood group A antigens, scFv G2-D11 is an excellent candidate for a well-defined anti-Tn-antigen reagent. Detailed immunohistochemical evaluation of tissue sections from a cohort of 80 patients with gastric carcinoma showed in all cases positive tumor cells. The observed staining was localized to the cytoplasm and in some cases to the membrane, whereas the surrounding tissue was completely negative demonstrating the usefulness of the novel Tn-antigen binding antibody.
|
|
| 23. |
- Stowell, Sean R, et al.
(författare)
-
Galectins-1, -2 and -3 exhibit differential recognition of sialylated glycans and blood group antigens
- 2008
-
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 283:15, s. 10109-10123
-
Tidskriftsartikel (refereegranskat)abstract
- Human galectins have functionally divergent roles, although most of the members of the galectin family bind weakly to the simple disaccharide lactose (Galss1-4Glc). To assess galectin-glycan interactions in more detail, we explored the binding of several important galectins (Gal-1, Gal-2, and Gal-3) on a glycan microarray containing hundreds of structurally diverse glycans. All three galectins exhibited unique glycan binding characteristics. Only Gal-1 and Gal-2 bound complex-type N-glycans and extended core 1 O-glycans with high affinity, while Gal-2 and Gal-3, but not Gal-1, bound A and B blood group antigens. Gal-2 failed to recognize any sialylated glycans regardless of linkage, whereas Gal-1 and Gal-3 bound a2-3, but not a2-6 sialylated glycans. All galectins showed higher binding to sulfated glycans relative to unsulfated ones. Each galectin exhibited higher binding for glycans with poly-N-acetyllactosamine (PL) sequences (Galss1-4GlcNAc)n when compared to N-acetyllactosamine (Galss1-4GlcNAc) in the microarray. However, only Gal-3 preferred PL when assessed by solution-based surface plasmon resonance. Removal of the terminal galactose residue in PL abrogated its recognition by Gal-1 and Gal-2 while having no substantial effect on Gal-3 recognition, demonstrating that Gal-3 recognizes internal N-acetyllactosamine units. These results provide novel insights into the functional constraints of glycan recognition by each galectin and underscore the basis for differences in biological activity.
|
|
| 24. |
- Tobola, Felix, et al.
(författare)
-
Engineering the Ligand Specificity of the Human Galectin-1 by Incorporation of Tryptophan Analogues
- 2022
-
Ingår i: ChemBioChem. - : Wiley. - 1439-4227 .- 1439-7633. ; 23:5
-
Tidskriftsartikel (refereegranskat)abstract
- Galectin-1 is a β-galactoside-binding lectin with manifold biological functions. A single tryptophan residue (W68) in its carbohydrate binding site plays a major role in ligand binding and is highly conserved among galectins. To fine tune galectin-1 specificity, we introduced several non-canonical tryptophan analogues at this position of human galectin-1 and analyzed the resulting variants using glycan microarrays. Two variants containing 7-azatryptophan and 7-fluorotryptophan showed a reduced affinity for 3’-sulfated oligosaccharides. Their interaction with different ligands was further analyzed by fluorescence polarization competition assay. Using molecular modeling we provide structural clues that the change in affinities comes from modulated interactions and solvation patterns. Thus, we show that the introduction of subtle atomic mutations in the ligand binding site of galectin-1 is an attractive approach for fine-tuning its interactions with different ligands.
|
|
| 25. |
|
|
| 26. |
- Verhagen, Josanne H., et al.
(författare)
-
Host Range of Influenza A Virus H1 to H16 in Eurasian Ducks Based on Tissue and Receptor Binding Studies
- 2021
-
Ingår i: Journal of Virology. - : American Society of Microbiology. - 0022-538X .- 1098-5514. ; 95:6, s. 1-19
-
Tidskriftsartikel (refereegranskat)abstract
- Dabbling and diving ducks partly occupy shared habitats but have been reported to play different roles in wildlife infectious disease dynamics. Influenza A virus (IAV) epidemiology in wild birds has been based primarily on surveillance programs focused on dabbling duck species, particularly mallard (Anas platyrhynchos). Surveillance in Eurasia has shown that in mallards, some subtypes are commonly (H1 to H7 and H10), intermediately (H8, H9, H11, and H12), or rarely (H13 to H16) detected, contributing to discussions on virus host range and reservoir competence. An alternative to surveillance in determining IAV host range is to study virus attachment as a determinant for infection. Here, we investigated the attachment patterns of all avian IAV subtypes (H1 to H16) to the respiratory and intestinal tracts of four dabbling duck species (Mareca and Anas spp.), two diving duck species (Aythya spp.), and chicken, as well as to a panel of 65 synthetic glycan structures. We found that IAV subtypes generally showed abundant attachment to colon of the Anas duck species, mallard, and Eurasian teal (Anas crecca), supporting the fecal-oral transmission route in these species. The reported glycan attachment profile did not explain the virus attachment patterns to tissues but showed significant attachment of duck-originated viruses to fucosylated glycan structures and H7 virus tropism for Neu5Gc-LN. Our results suggest that Anas ducks play an important role in the ecology and epidemiology of IAV. Further knowledge on virus tissue attachment, receptor distribution, and receptor binding specificity is necessary to understand the mechanisms underlying host range and epidemiology of IAV. IMPORTANCE Influenza A viruses (IAVs) circulate in wild birds worldwide. From wild birds, the viruses can cause outbreaks in poultry and sporadically and indirectly infect humans. A high IAV diversity has been found in mallards (Anas platyrhynchos), which are most often sampled as part of surveillance programs; meanwhile, little is known about the role of other duck species in IAV ecology and epidemiology. In this study, we investigated the attachment of all avian IAV hemagglutinin (HA) subtypes (H1 to H16) to tissues of six different duck species and chicken as an indicator of virus host range. We demonstrated that the observed virus attachment patterns partially explained reported field prevalence. This study demonstrates that dabbling ducks of the Anas genus are potential hosts for most IAV subtypes, including those infecting poultry. This knowledge is useful to target the sampling of wild birds in nature and to further study the interaction between IAVs and birds.
|
|
| 27. |
- Welinder, Charlotte, et al.
(författare)
-
Intra-tumour IgA1 is common in cancer and is correlated with poor prognosis in bladder cancer.
- 2016
-
Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 2:8
-
Tidskriftsartikel (refereegranskat)abstract
- A high frequency of IgA1-positive tumour cells was found in tissue micro-arrays of oesophagus, colon, testis, lung, breast, bladder and ovarian cancer. IgA1 was observed in the cytoplasm and the plasma membrane. A correlation was found between intra-tumour IgA1 and poor overall survival in a large cohort of bladder cancer patients (n = 99, p = 0.011, log-rank test). The number of IgA1-positive tumour cells was also found to be higher in female than male bladder cancer patients. The presence of IgA1 was confirmed in formalin-fixed paraffin-embedded ovarian carcinoma samples using LC-MS/MS analysis. Uptake of IgA1 was also observed in breast cancer and melanoma cell lines when cultivated in the presence of serum from healthy individuals, indicating a possible origin of the IgA1 antibodies in cancer cells.
|
|
| 28. |
- Welinder, Charlotte, et al.
(författare)
-
Primary breast cancer tumours contain high amounts of IgA1 immunoglobulin: an immunohistochemical analysis of a possible carrier of the tumour-associated tn antigen.
- 2013
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:4
-
Tidskriftsartikel (refereegranskat)abstract
- The Tn antigen (GalNAc alpha-O-Ser/Thr) as defined by the binding of the lectin, helix pomatia agglutinin (HPA) or anti-Tn monoclonal antibodies, is known to be exposed in a majority of cancers, and it has also been shown to correlate positively with the metastatic capacity in breast carcinoma. The short O-glycan that forms the antigen is carried by a number of different proteins. One potential carrier of the Tn antigen is immunoglobulin A1 (IgA1), which we surprisingly found in tumour cells of the invasive parts of primary breast carcinoma. Conventional immunohistochemical analysis of paraffin-embedded sections from primary breast cancers showed IgA1 to be present in the cytoplasm and plasma membrane of 35 out of 36 individual primary tumours. The immunohistochemical staining of HPA and anti-Tn antibody (GOD3-2C4) did to some extent overlap with the presence of IgA1 in the tumours, but differences were seen in the percentage of stained cells and in the staining pattern in the different breast cancers analysed. Anti-Tn antibody and HPA were also shown to specifically bind to a number of possible constellations of the Tn antigen in the hinge region of IgA1. Both reagents could also detect the presence of Tn positive IgA in serum. On average 51% of the tumour cells in the individual breast cancer tumour sections showed staining for IgA1. The overall amount of staining in the invasive part of the tumour with the anti Tn antibody was 67%, and 93% with HPA. The intra-expression or uptake of IgA1 in breast cancer makes it a new potential carrier of the tumour associated and immunogenic Tn antigen.
|
|
| 29. |
- Wendel, Ulrika, et al.
(författare)
-
A novel monoclonal antibody targeting carboxymethyllysine, an advanced glycation end product in atherosclerosis and pancreatic cancer
- 2018
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:2
-
Tidskriftsartikel (refereegranskat)abstract
- Advanced glycation end products are formed by non-enzymatic reactions between proteins and carbohydrates, causing irreversible lysine and arginine alterations that severely affect protein structure and function. The resulting modifications induce inflammation by binding to scavenger receptors. An increase in advanced glycation end products is observed in a number of diseases e.g. atherosclerosis and cancer. Since advanced glycation end products also are present in healthy individuals, their detection and quantification are of great importance for usage as potential biomarkers. Current methods for advanced glycation end product detection are though limited and solely measure total glycation. This study describes a new epitope-mapped single chain variable fragment, D1-B2, against carboxymethyllysine, produced from a phage library that was constructed from mouse immunizations. The phage library was selected against advanced glycation end product targets using a phage display platform. Characterization of its binding pattern was performed using large synthetic glycated peptide and protein libraries displayed on microarray slides. D1-B2 showed a preference for an aspartic acid, three positions N-terminally from a carboxymethyllysine residue and also bound to a broad collection of glycated proteins. Positive immunohistochemical staining of mouse atherosclerotic plaques and of a tissue microarray of human pancreatic tumors confirmed the usability of the new scFv for advanced glycation end product detection in tissues. This study demonstrates a promising methodology for high-throughput generation of epitope-mapped monoclonal antibodies against AGE.
|
|
