Allergic diseases affect many individuals world-wide and are dependent on the interaction between... more Allergic diseases affect many individuals world-wide and are dependent on the interaction between allergens and antibodies of the IgE isotype. Allergen-specific immunotherapy (AIT) can alter the development of the disease, e.g., through induction of allergen-specific IgG that block allergen-IgE interactions. The knowledge of epitopes recognized by allergy-causing and protective antibodies are limited. Therefore, we developed an allergome-wide peptide microarray, aiming to track linear epitope binding patterns in allergic diseases and during AIT. Here, we focused on immune responses to grass pollen allergens and found that such epitopes were commonly recognized before initiation of AIT and that AIT commonly resulted in increased antibody production against additional epitopes already after 1 year of treatment. The linear epitope binding patterns were highly individual, both for subjects subjected to and for individuals not subjected to AIT. Still, antibodies against some linear epito...
Engineering of novel carbohydrate-binding proteins that can be utilized in various biochemical an... more Engineering of novel carbohydrate-binding proteins that can be utilized in various biochemical and biotechnical applications would benefit from a deeper understanding of the biochemical interactions that determine protein-carbohydrate specificity. In an effort to understand further the basis for specificity we present the crystal structure of the multi-specific carbohydrate-binding module (CBM) X-2 L110F bound to a branched oligomer of xyloglucan (XXXG). X-2 L110F is an engineered CBM that can recognize xyloglucan, xylans and β-glucans. The structural observations of the present study compared with previously reported structures of X-2 L110F in complex with linear oligomers, show that the π-surface of a phenylalanine, F110, allows for interactions with hydrogen atoms on both linear (xylopentaose and cellopentaose) and branched ligands (XXXG). Furthermore, X-2 L110F is shown to have a relatively flexible binding cleft, as illustrated in binding to XXXG. This branched ligand requires ...
IgE is a key mediator in allergic diseases. However, in strong contrast to other antibody isotype... more IgE is a key mediator in allergic diseases. However, in strong contrast to other antibody isotypes, many details of the composition of the human IgE repertoire are poorly defined. The low levels of human IgE in the circulation and the rarity of IgE-producing B cells are important reasons for this lack of knowledge. In this review, we summarize the current knowledge on these repertoires both in terms of their complexity and activity, i.e. knowledge which despite the difficulties encountered when studying the molecular details of human IgE has been acquired in recent years. We also take a look at likely future developments, for instance through improvements in sequencing technology and methodology that allow the isolation of additional allergen-specific human antibodies mimicking IgE, as this certainly will support our understanding of human IgE in the context of human disease in the years to come.
Clinical and diagnostic laboratory immunology, 1995
The lower matrix protein (pp65) is a major product of many laboratory strains of cytomegalovirus ... more The lower matrix protein (pp65) is a major product of many laboratory strains of cytomegalovirus (CMV). It is thus an integral part of many CMV serological assays based on native antigen. Recombinant fragments of pp65 have previously been investigated for their usefulness in more-defined assays. The latter antigens have, however, failed to develop a positive response with serum samples derived from a substantial number of infected individuals. Here we show that the human humoral immune response to CMV pp65 is highly diverse and recognizes at least seven distinct but in some cases partly overlapping epitopes. Most of these epitopes could not be mimicked by any of the investigated recombinant or synthetic antigens. Furthermore, when we investigated the ability of human CMV-seropositive serum samples to block the reactivity of pp65-specific antibodies recognizing five different epitopes within pp65, it was evident that several sera did not contain significant levels of antibodies again...
Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focuse... more Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization seems to affect the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies c...
&NA; Inference of antibody gene repertoires using transcriptome data has emerged as an altern... more &NA; Inference of antibody gene repertoires using transcriptome data has emerged as an alternative approach to the complex process of sequencing of adaptive immune receptor germline gene loci. The diversity introduced during rearrangement of immunoglobulin heavy chain variable (IGHV), diversity, and joining genes has however been identified as potentially affecting inference specificity. In this study, we have addressed this issue by analysing the nucleotide composition of unmutated human immunoglobulin heavy chains‐encoding transcripts, focusing on the 3ö most bases of 47 IGHV germline genes. Although transcripts derived from some of the germline genes predominately incorporated the germline encoded base even at position 320, the last base of most IGHV genes, transcripts originating in other genes presented other nucleotides to the same extent at this position. In transcripts derived from two of the germline genes, IGHV3‐13*01 and IGHV4‐30‐2*01, the predominating nucleotide (G) was in fact not that of the gene (A). Hence, we suggest that inference of IGHV genes should be limited to bases preceding nucleotide 320, as inference beyond this would jeopardize the specificity of the inference process. The different degree of incorporation of the final base of the IGHV gene directly influences the distribution of amino acids of the ascending strand of the third complementarity determining region of the heavy chain. Thereby it influences the nature of this specificity‐determining part of the antibody population. In addition, we also present data that indicate the existence of a common so far un‐recognized allelic variant of IGHV3‐7 that carries an A318G difference in relation to IGHV3‐7*02. Graphical abstract Figure. No caption available. HighlightsIGHV genes to different extent incorporate their last base into rearrangements.Inference of bases of IGHV genes beyond codon 105 requires particular attention.Inference of bases of IGHV genes beyond position 319 should be avoided.Evidence of a currently un‐recognized allelic variant of IGHV3‐7 is presented.
Lignocellulose-acting enzymes play a central role in the biorefinery of plant biomass to make fue... more Lignocellulose-acting enzymes play a central role in the biorefinery of plant biomass to make fuels, chemicals and materials. These enzymes are often appended to carbohydrate binding modules (CBMs) that promote substrate targeting. When used in plant materials, which are complex assemblies of polymers, the binding properties of CBMs can be difficult to understand and predict, thus limiting the efficiency of enzymes. In order to gain more information on the binding properties of CBMs, some bioinspired model assemblies that contain some of the polymers and covalent interactions found in the plant cell walls have been designed. The mobility of three engineered CBMs has been investigated by FRAP in these assemblies, while varying the parameters related to the polymer concentration, the physical state of assemblies and the oligomerization state of CBMs. The features controlling the mobility of the CBMs in the assemblies have been quantified and hierarchized. We demonstrate that the parameters can have additional or opposite effects on mobility, depending on the CBM tested. We also find evidence of a relationship between the mobility of CBMs and their binding strength. Overall, bioinspired assemblies are able to reveal the unique features of affinity of CBMs. In particular, the results show that oligomerization of CBMs and the presence of ferulic acid motifs in the assemblies play an important role in the binding affinity of CBMs. Thus we propose that these features should be finely tuned when CBMs are used in plant cell walls to optimise bioprocesses.
Allergic diseases affect many individuals world-wide and are dependent on the interaction between... more Allergic diseases affect many individuals world-wide and are dependent on the interaction between allergens and antibodies of the IgE isotype. Allergen-specific immunotherapy (AIT) can alter the development of the disease, e.g., through induction of allergen-specific IgG that block allergen-IgE interactions. The knowledge of epitopes recognized by allergy-causing and protective antibodies are limited. Therefore, we developed an allergome-wide peptide microarray, aiming to track linear epitope binding patterns in allergic diseases and during AIT. Here, we focused on immune responses to grass pollen allergens and found that such epitopes were commonly recognized before initiation of AIT and that AIT commonly resulted in increased antibody production against additional epitopes already after 1 year of treatment. The linear epitope binding patterns were highly individual, both for subjects subjected to and for individuals not subjected to AIT. Still, antibodies against some linear epito...
Engineering of novel carbohydrate-binding proteins that can be utilized in various biochemical an... more Engineering of novel carbohydrate-binding proteins that can be utilized in various biochemical and biotechnical applications would benefit from a deeper understanding of the biochemical interactions that determine protein-carbohydrate specificity. In an effort to understand further the basis for specificity we present the crystal structure of the multi-specific carbohydrate-binding module (CBM) X-2 L110F bound to a branched oligomer of xyloglucan (XXXG). X-2 L110F is an engineered CBM that can recognize xyloglucan, xylans and β-glucans. The structural observations of the present study compared with previously reported structures of X-2 L110F in complex with linear oligomers, show that the π-surface of a phenylalanine, F110, allows for interactions with hydrogen atoms on both linear (xylopentaose and cellopentaose) and branched ligands (XXXG). Furthermore, X-2 L110F is shown to have a relatively flexible binding cleft, as illustrated in binding to XXXG. This branched ligand requires ...
IgE is a key mediator in allergic diseases. However, in strong contrast to other antibody isotype... more IgE is a key mediator in allergic diseases. However, in strong contrast to other antibody isotypes, many details of the composition of the human IgE repertoire are poorly defined. The low levels of human IgE in the circulation and the rarity of IgE-producing B cells are important reasons for this lack of knowledge. In this review, we summarize the current knowledge on these repertoires both in terms of their complexity and activity, i.e. knowledge which despite the difficulties encountered when studying the molecular details of human IgE has been acquired in recent years. We also take a look at likely future developments, for instance through improvements in sequencing technology and methodology that allow the isolation of additional allergen-specific human antibodies mimicking IgE, as this certainly will support our understanding of human IgE in the context of human disease in the years to come.
Clinical and diagnostic laboratory immunology, 1995
The lower matrix protein (pp65) is a major product of many laboratory strains of cytomegalovirus ... more The lower matrix protein (pp65) is a major product of many laboratory strains of cytomegalovirus (CMV). It is thus an integral part of many CMV serological assays based on native antigen. Recombinant fragments of pp65 have previously been investigated for their usefulness in more-defined assays. The latter antigens have, however, failed to develop a positive response with serum samples derived from a substantial number of infected individuals. Here we show that the human humoral immune response to CMV pp65 is highly diverse and recognizes at least seven distinct but in some cases partly overlapping epitopes. Most of these epitopes could not be mimicked by any of the investigated recombinant or synthetic antigens. Furthermore, when we investigated the ability of human CMV-seropositive serum samples to block the reactivity of pp65-specific antibodies recognizing five different epitopes within pp65, it was evident that several sera did not contain significant levels of antibodies again...
Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focuse... more Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization seems to affect the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies c...
&NA; Inference of antibody gene repertoires using transcriptome data has emerged as an altern... more &NA; Inference of antibody gene repertoires using transcriptome data has emerged as an alternative approach to the complex process of sequencing of adaptive immune receptor germline gene loci. The diversity introduced during rearrangement of immunoglobulin heavy chain variable (IGHV), diversity, and joining genes has however been identified as potentially affecting inference specificity. In this study, we have addressed this issue by analysing the nucleotide composition of unmutated human immunoglobulin heavy chains‐encoding transcripts, focusing on the 3ö most bases of 47 IGHV germline genes. Although transcripts derived from some of the germline genes predominately incorporated the germline encoded base even at position 320, the last base of most IGHV genes, transcripts originating in other genes presented other nucleotides to the same extent at this position. In transcripts derived from two of the germline genes, IGHV3‐13*01 and IGHV4‐30‐2*01, the predominating nucleotide (G) was in fact not that of the gene (A). Hence, we suggest that inference of IGHV genes should be limited to bases preceding nucleotide 320, as inference beyond this would jeopardize the specificity of the inference process. The different degree of incorporation of the final base of the IGHV gene directly influences the distribution of amino acids of the ascending strand of the third complementarity determining region of the heavy chain. Thereby it influences the nature of this specificity‐determining part of the antibody population. In addition, we also present data that indicate the existence of a common so far un‐recognized allelic variant of IGHV3‐7 that carries an A318G difference in relation to IGHV3‐7*02. Graphical abstract Figure. No caption available. HighlightsIGHV genes to different extent incorporate their last base into rearrangements.Inference of bases of IGHV genes beyond codon 105 requires particular attention.Inference of bases of IGHV genes beyond position 319 should be avoided.Evidence of a currently un‐recognized allelic variant of IGHV3‐7 is presented.
Lignocellulose-acting enzymes play a central role in the biorefinery of plant biomass to make fue... more Lignocellulose-acting enzymes play a central role in the biorefinery of plant biomass to make fuels, chemicals and materials. These enzymes are often appended to carbohydrate binding modules (CBMs) that promote substrate targeting. When used in plant materials, which are complex assemblies of polymers, the binding properties of CBMs can be difficult to understand and predict, thus limiting the efficiency of enzymes. In order to gain more information on the binding properties of CBMs, some bioinspired model assemblies that contain some of the polymers and covalent interactions found in the plant cell walls have been designed. The mobility of three engineered CBMs has been investigated by FRAP in these assemblies, while varying the parameters related to the polymer concentration, the physical state of assemblies and the oligomerization state of CBMs. The features controlling the mobility of the CBMs in the assemblies have been quantified and hierarchized. We demonstrate that the parameters can have additional or opposite effects on mobility, depending on the CBM tested. We also find evidence of a relationship between the mobility of CBMs and their binding strength. Overall, bioinspired assemblies are able to reveal the unique features of affinity of CBMs. In particular, the results show that oligomerization of CBMs and the presence of ferulic acid motifs in the assemblies play an important role in the binding affinity of CBMs. Thus we propose that these features should be finely tuned when CBMs are used in plant cell walls to optimise bioprocesses.
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