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Papers by Eric Claassen
Detection of genetic variants of alpha 1-antitrypsin with site-specific monoclonal antibodies
Clinical Chemistry, Sep 1, 1991
The serum protein alpha 1-antitrypsin (alpha 1-AT) serves as the major inhibitor of neutrophil el... more The serum protein alpha 1-antitrypsin (alpha 1-AT) serves as the major inhibitor of neutrophil elastase. The most common allele of the alpha 1-AT gene is designated as PiM. The Z mutation is a single-base substitution of the normal M allele, causing a Glu----Lys change at position 342 in the molecule. The ZZ phenotype is associated with a severe deficiency of alpha 1-AT, serum concentrations of the protein being 10% of normal. Individuals with an alpha 1-AT deficiency are at an increased risk of developing emphysema. To generate antibodies that specifically detect the 342 position in the context of the flanking sequences, we synthesized several peptides that included the 342 position for both the M and the Z variant. Immunization with variant-specific peptide-carrier conjugates elicited alpha 1-AT variant-specific responses, as determined in a direct enzyme-linked immunoassay. Monoclonal antibodies (MAbs) were selected with different specificity for the 342 region: MAbs F43 recognize only the alpha 1-AT sequence with 342Glu, i.e., all variant proteins that are non-Z, either from hetero- or homozygous individuals; MAbs F50 recognize only the sequence with 342Lys, i.e., all Z-variant proteins in ZZ or heterozygous individuals; MAbs F46 recognize alpha 1-AT with either 342Lys or 342Glu, all variant proteins with sequences as in the peptides used. Z homo- and heterozygotes were detected with our MAbs in a rapid and simple immunoblot assay. Other variants (M, S, and F) can also be assigned on the basis of the electrophoretic pattern. This sensitive detection method is very easy, rapid, and straightforward and provides a powerful tool for diagnosis of the alpha 1-AT deficiencies, allowing early treatment (augmentation of alpha 1-AT) and proper advice on lifestyle practices.
ABSTRACTThe SARS-CoV-2 variant B.1.1.7 lineage, also known as clade GR from Global Initiative on ... more ABSTRACTThe SARS-CoV-2 variant B.1.1.7 lineage, also known as clade GR from Global Initiative on Sharing All Influenza Data (GISAID), Nextstrain clade 20B, or Variant Under Investigation in December 2020 (VUI – 202012/01), appears to have an increased transmissability in comparison to other variants. Thus, to contain and study this variant of the SARS-CoV-2 virus, it is necessary to develop a specific molecular test to uniquely identify it. Using a completely automated pipeline involving deep learning techniques, we designed a primer set which is specific to SARS-CoV-2 variant B.1.1.7 with >99% accuracy, starting from 8,923 sequences from GISAID. The resulting primer set is in the region of the synonymous mutation C16176T in the ORF1ab gene, using the canonical sequence of the variant B.1.1.7 as a reference. Furtherin-silicotesting shows that the primer set’s sequences do not appear in different viruses, using 20,571 virus samples from the National Center for Biotechnology Inform...
International Journal of Clinical Trials, 2020
Background: Chlamydia infections in humans and animals pose a significant burden on health system... more Background: Chlamydia infections in humans and animals pose a significant burden on health systems worldwide. While widespread screening, adequate treatment, and prevention programs are helpful to increase awareness and improve screening rates, infection rates are rising. A vaccine is necessary to slow increasing rates, manage negative consequences, and prevent possible antibiotic resistance. We present the current landscape regarding the innovations for commercial vaccine development in a “one-health” context.Methods: We developed a unique dataset containing data of patent documents intended for human and veterinary use, and clinical trials in order to provide a detailed description of the global chlamydia vaccine developments.Results: Analysis of patents and clinical trials intended for human use presented a vaccine field that is underdeveloped, with no commercial human chlamydia vaccine available, and two potential candidates in a phase 1 clinical trial. Comparing innovations con...
PLOS Neglected Tropical Diseases, 2018
Background Despite the existence of safe and effective vaccines, rabies disease still causes an e... more Background Despite the existence of safe and effective vaccines, rabies disease still causes an estimated 59,000 human deaths a year in the endemic areas in Asia and Africa. These numbers reflect severe drawbacks regarding the implementation of PrEP and PEP in endemic settings, such as lack of political will and low priority given to rabies. Since these contextual factors have proven to be persistent, there is an urgency to improve current strategies or develop novel approaches in order to control rabies disease in the future. Methods/Findings This study aimed to identify and systematically prioritize the research needs, through interviews and questionnaires with key-opinion-leaders (KOLs). A total of 46 research needs were identified and prioritized. The top research needs are considered very high priority based on both importance for rabies control and need for improvement. KOLs agree that animal rabies control remains most important for rabies control, while research on human host, agent (rabies virus) and the environment should be prioritized in terms of need for improvement. A wide variety in perceptions is observed between and within the disciplines of virology, public health and veterinary health and between KOLs with more versus those with less experience in the field. Conclusion/Significance The results of this study give well-defined, prioritized issues that stress the drawbacks that are experienced by KOLs in daily practice. The most important research domains are: 1) cheap and scalable production system for RIG 2) efficacy of dog mass vaccination programs and 3) cheap human vaccines. Addressing these research needs should exist next to and may reinforce current awareness and mass vaccination campaigns. The differences in perspectives between actors revealed in this study are informative for effective execution of the One Health research agenda.
Critical Reviews in Food Science and Nutrition, 2017
and it is a condition of accessing publications that users recognise and abide by the legal requi... more and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Microbial biotechnology, Jul 27, 2016
Lactobacillus plantarum WCFS1 is one of the best studied Lactobacilli, notably as its genome was ... more Lactobacillus plantarum WCFS1 is one of the best studied Lactobacilli, notably as its genome was unravelled over 12 years ago. L. plantarum WCFS1 can be grown to high densities, is amenable to genetic transformation and highly robust with a relatively high survival rate during the gastrointestinal passage. In this review, we present and discuss the main insights provided by the functional genomics research on L. plantarum WCFS1 with specific attention for the molecular mechanisms related to its interaction with the human host and its potential to modify the immune system, and induce other health-related benefits. Whereas most insight has been gained in mouse and other model studies, only five human studies have been reported with L. plantarum WCFS1. Hence NCIMB 8826 (the parental strain of L. plantarum WCFS1) in human trials as to capitalize on the wealth of knowledge that is summarized here.
Enhancing Historical Consciousness and Democratic Citizenship: a Report about Quantitative Prioritization of Unmet Needs
ABSTRACT
Beneficial microbes, 2014
In this study, we systematically evaluated safety aspects in clinical trials with probiotics and ... more In this study, we systematically evaluated safety aspects in clinical trials with probiotics and synbiotics in young infants (0-2 years of age). This study is an update of earlier reports and covers the recent literature from 2008-2013. The safety evaluation is performed along the Common Terminology Clinical Adverse Events (CTCAE) version 4.0 scale, hereby also providing guidance for future studies. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. The results show a deficiency in the precise reporting and classification of adverse events in most studies. Analysis of 57 clinical trials with probiotics and synbiotics in combination with eight follow-up studies indicate that probiotic administration to infants between 0 and 24 months is safe with regard to the evaluated strains in infants with a particular health status or susceptibility. Most adverse events and seriou...
Knowledge diffusion in the European medical nutrition industry
PharmaNutrition, 2014
Bioscience and Microflora, 2002
Vaccine, 2003
Lactobacillus strains with probiotic activity are major constituents of numerous common food prod... more Lactobacillus strains with probiotic activity are major constituents of numerous common food products. Due to their 'generally regarded as safe'-status (GRAS-status), Lactobacillus strains can also be genetically engineered for use in oral immunotherapeutic applications, such as vaccination and T lymphocyte tolerance induction in autoimmune disease. In the current study, we demonstrate that the growth phase of orally administered individual Lactobacillus strains can differentially affect antigen-specific antibody subclasses IgG1 and IgG2a, which might reflect skewing of systemic activity of T helper cell type 2 (Th2) and T helper cell type 1 (Th1) pathways, respectively. Mice were orally fed different wild type Lactobacillus strains in log phase or stationary phase and immunized intraperitoneally with a T-cell dependent protein antigen. Sera were evaluated for the ratio of antigen-specific IgG1 and IgG2a antibodies. Stationary Lactobacillus murines and Lactobacillus casei cultures, but not two other Lactobacillus strains, evoked significantly higher IgG1/IgG2a ratios than log phase cultures, possibly relating to increased activity of the Th2-pathway. Despite normal variation in antibody responses against TNP-CGG among individual mice, a high correlation was found between the IgG1 and IgG2a responses of mice within experimental groups. This differential antibody response is likely due to growth phase-dependent differences in bacterial cell composition. Since Lactobacillus growth phase dependent skewing of antibody responses possibly reflecting T-cell pathways can inadvertently affect allergic and (auto)-immune responses, the current findings strongly caution against unidimensional views on the oral administration of individual Lactobacillus strains for probiotic or immunotherapeutic purposes, but also suggest additional possibilities for immune modulation.
Technology and Investment, 2013
During the past two decades the biopharmaceutical industry has been facing an innovation deficit,... more During the past two decades the biopharmaceutical industry has been facing an innovation deficit, characterized by increasing research & development costs and stagnant productivity. From its inception, biotechnology has been expected to counter this deficit by its revolutionary science-based approach to drug discovery. For this study we gathered patent and product data related to the technological development of the first two biotechnologies: recombinant DNA technology and monoclonal antibody technology. We studied the technological lifecycles of these technologies in terms of scientific discoveries and inventions as well as product innovations. Results indicate that over the years inventions related to these technologies have simultaneously become less radical and less valuable. Furthermore, our analysis shows that these biotechnologies have reached a stage of technological limit or saturation, which may be followed by an innovation cliff. Now, more than ever, it is crucial to examine new strategies and opportunities for value creation, capturing, and delivery, within the biopharmaceutical industry.
Vaccine, 2003
Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tole... more Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tolerance in autoimmune diseases like multiple sclerosis (MS). To increase the efficacy of oral tolerance induction and obviate the need for large-scale purification of human myelin proteins, we use genetically modified lactobacilli expressing myelin antigens. A panel of recombinant lactobacilli was constructed producing myelin proteins and peptides, including human and guinea pig myelin basic protein (MBP) and proteolipid protein peptide 139-151 (PLP 139-151). In this study we examined whether these Lactobacillus recombinants are able to induce oral and intranasal tolerance in an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Lewis rats received soluble cell extracts of Lactobacillus transformants intranasally three times prior to induction of EAE. For the induction of oral tolerance, rats were fed live transformed lactobacilli for 20 days. Ten days after the first oral administration EAE was induced. Intranasal administration of extracts containing guinea pig MBP (gpMBP) or MBP 72-85 significantly inhibited EAE in Lewis rats. Extracts of control transformants did not reduce EAE. Live lactobacilli expressing guinea pig MBP 72-85 fused to the marker enzyme -glucuronidase (-gluc) were also able to significantly reduce disease when administered orally. In conclusion, these experiments provide proof of principle that lactobacilli expressing myelin antigens reduce EAE after mucosal (intranasal and oral) administration. This novel method of mucosal tolerance induction by mucosal administration of recombinant lactobacilli expressing relevant autoantigens could find applications in autoimmune disease in general, such as multiple sclerosis, rheumatoid arthritis and uveitis.
Vaccine, 2012
As infectious diseases cause approximately 25% of the annual global mortality, vaccines are found... more As infectious diseases cause approximately 25% of the annual global mortality, vaccines are found to be a time proven and promising response to infectious disease need. However, like for pharmaceutical small molecules, vaccine development is lengthy, risky and resource demanding. Faced with an attrition rate estimated around 80%, key opinion leaders were interviewed with the question: is there a recipe for success?
Seminars in Immunology, 1994
The spleen is an important lymphoid organ. involved in immune responses against all types of anti... more The spleen is an important lymphoid organ. involved in immune responses against all types of antigen that appear in the circulation. Its complex anatomical organization. with distinct compartments containing specialized cell types. provides a microenvironment which allows different cell-cell interactions and determines the direction of developing immune responses. In this review we evaluate the vast amount of in virro data dealing with antigen presentation. cell-eel\ interactions, T and B cell activation, and the immunoregulatory role of cytokincs, as suggested to be involved in immune responses. As a basis for understanding of in rivo processes. these in vitro data will be related to discrete phenomena of in rivo immune responses. such as antigen localization/trapping. cell migration patterns of immunocompetent cells. cytokine production, and antibody formation in the different compartments of the spleen. Finally, we try to bring order to the sequence of events that occur in the spleen after antigenic challenge by presenting an in vivo model forT cell dependent and T cell independent immune responses.
Letters in Applied Microbiology, 2002
Various probiotic lactobacilli have been reported to modulate immunity. In this study we investig... more Various probiotic lactobacilli have been reported to modulate immunity. In this study we investigate the effects of viable indigenous Lactobacillus strains Utr-1, Utr-2 and Utr-3, on T cell-mediated immunological memory responses. Methods and Results: In Listeria monocytogenes infected rats it was demonstrated that shortterm daily ingestion of Lactobacillus strain Utr-3 significantly decreased delayed-type hypersensitivity (DTH) expression, whereas long-term, daily oral administration of Lactobacillus strain Utr-3 and Lactobacillus strain Utr-2 significantly enhanced acquired cellular resistance (ACR) towards Listeria re-infection. Conclusions: Our findings demonstrate that certain indigenous Lactobacillus strains are capable of modulating T cell-mediated immunity. Significance and Impact of the Study: Our results support the importance of indigenous microflora analysis in probiotic lactobacilli studies.
Characterization of polyclonal antibodies against the capsid proteins of Ljungan virus
Journal of Virological Methods, 2008
Ljungan virus (LV) is a suspected human pathogen isolated from voles in Sweden and North America.... more Ljungan virus (LV) is a suspected human pathogen isolated from voles in Sweden and North America. To enable virus detection and studies of localization and activity of virion proteins, polyclonal antibodies were produced against bacterially expressed capsid proteins of the LV strain, 87-012G. Specific detection of proteins corresponding to viral antigens in lysates of LV infected cells was demonstrated by immunoblotting using each one of the generated polyclonal antibodies. In addition, native viral antigens present in cell culture infected with LV strains 87-012G or 145SLG were detected in ELISA and by immunofluorescence using the antibodies against the VP0 and VP1 proteins. The anti-VP3 antibody did not react with native proteins of the LV virion, suggesting that the VP3 is less potent in evoking humoral response and may have a less exposed orientation in the virus capsid. No activity of the antibodies was observed against the closely related human parechovirus type 1. The polyclonal antibody against the VP1 protein was further used for detection of LV infected myocytes in a mouse model of LV-induced myocarditis. Thus, polyclonal antibodies against recombinant viral capsid proteins enabled detection of natural LV virions by several different immunological methods.
Journal of Neuroimmunology, 1994
Irrespective of the large body of literature on the putative role of antibodies in the developmen... more Irrespective of the large body of literature on the putative role of antibodies in the development of multiple sclerosis (MS), the detection of specific antibody-forming B cells (AFCs) in the central nervous system (CNS) tissues has not been described. In this study we show that autoantigen-specific AFCs can be found in CNS tissue sections of MS patients. Applying a newly developed myelin basic protein (MBP)-enzyme conjugate technique, we have detected MBP-specific AFCs in autopsy periventricular white matter and cerebellum tissue sections of MS patients. We demonstrated the presence of MBP-specific AFCs in CNS tissue sections in five out of 12 MS patients. No MBP-specific AFCs were detected in CNS tissue sections of 11 patients with other neurological diseases, such as Parkinson's and Alzheimer's disease, or in brain tissue sections of eight deceased persons without neurological diseases. In MS patients, anti-MBP AFCs were present in brain tissue sections both with and without plaques. The proportion of MBP-specific AFCs in some of the MS patient brain tissues reached over 50% of all AFCs. The high relative frequency of the anti-MBP AFCs and their localization in periventricular white matter and cerebellum of MS patients only, suggests that anti-MBP AFCs represent a cell population, which could play an important role in MS immunopathology.
The role of GP39 (CD40 ligand) in EAE and MS
Journal of Neuroimmunology, 1994
Journal of Immunological Methods, 1992
Detection of genetic variants of alpha 1-antitrypsin with site-specific monoclonal antibodies
Clinical Chemistry, Sep 1, 1991
The serum protein alpha 1-antitrypsin (alpha 1-AT) serves as the major inhibitor of neutrophil el... more The serum protein alpha 1-antitrypsin (alpha 1-AT) serves as the major inhibitor of neutrophil elastase. The most common allele of the alpha 1-AT gene is designated as PiM. The Z mutation is a single-base substitution of the normal M allele, causing a Glu----Lys change at position 342 in the molecule. The ZZ phenotype is associated with a severe deficiency of alpha 1-AT, serum concentrations of the protein being 10% of normal. Individuals with an alpha 1-AT deficiency are at an increased risk of developing emphysema. To generate antibodies that specifically detect the 342 position in the context of the flanking sequences, we synthesized several peptides that included the 342 position for both the M and the Z variant. Immunization with variant-specific peptide-carrier conjugates elicited alpha 1-AT variant-specific responses, as determined in a direct enzyme-linked immunoassay. Monoclonal antibodies (MAbs) were selected with different specificity for the 342 region: MAbs F43 recognize only the alpha 1-AT sequence with 342Glu, i.e., all variant proteins that are non-Z, either from hetero- or homozygous individuals; MAbs F50 recognize only the sequence with 342Lys, i.e., all Z-variant proteins in ZZ or heterozygous individuals; MAbs F46 recognize alpha 1-AT with either 342Lys or 342Glu, all variant proteins with sequences as in the peptides used. Z homo- and heterozygotes were detected with our MAbs in a rapid and simple immunoblot assay. Other variants (M, S, and F) can also be assigned on the basis of the electrophoretic pattern. This sensitive detection method is very easy, rapid, and straightforward and provides a powerful tool for diagnosis of the alpha 1-AT deficiencies, allowing early treatment (augmentation of alpha 1-AT) and proper advice on lifestyle practices.
ABSTRACTThe SARS-CoV-2 variant B.1.1.7 lineage, also known as clade GR from Global Initiative on ... more ABSTRACTThe SARS-CoV-2 variant B.1.1.7 lineage, also known as clade GR from Global Initiative on Sharing All Influenza Data (GISAID), Nextstrain clade 20B, or Variant Under Investigation in December 2020 (VUI – 202012/01), appears to have an increased transmissability in comparison to other variants. Thus, to contain and study this variant of the SARS-CoV-2 virus, it is necessary to develop a specific molecular test to uniquely identify it. Using a completely automated pipeline involving deep learning techniques, we designed a primer set which is specific to SARS-CoV-2 variant B.1.1.7 with >99% accuracy, starting from 8,923 sequences from GISAID. The resulting primer set is in the region of the synonymous mutation C16176T in the ORF1ab gene, using the canonical sequence of the variant B.1.1.7 as a reference. Furtherin-silicotesting shows that the primer set’s sequences do not appear in different viruses, using 20,571 virus samples from the National Center for Biotechnology Inform...
International Journal of Clinical Trials, 2020
Background: Chlamydia infections in humans and animals pose a significant burden on health system... more Background: Chlamydia infections in humans and animals pose a significant burden on health systems worldwide. While widespread screening, adequate treatment, and prevention programs are helpful to increase awareness and improve screening rates, infection rates are rising. A vaccine is necessary to slow increasing rates, manage negative consequences, and prevent possible antibiotic resistance. We present the current landscape regarding the innovations for commercial vaccine development in a “one-health” context.Methods: We developed a unique dataset containing data of patent documents intended for human and veterinary use, and clinical trials in order to provide a detailed description of the global chlamydia vaccine developments.Results: Analysis of patents and clinical trials intended for human use presented a vaccine field that is underdeveloped, with no commercial human chlamydia vaccine available, and two potential candidates in a phase 1 clinical trial. Comparing innovations con...
PLOS Neglected Tropical Diseases, 2018
Background Despite the existence of safe and effective vaccines, rabies disease still causes an e... more Background Despite the existence of safe and effective vaccines, rabies disease still causes an estimated 59,000 human deaths a year in the endemic areas in Asia and Africa. These numbers reflect severe drawbacks regarding the implementation of PrEP and PEP in endemic settings, such as lack of political will and low priority given to rabies. Since these contextual factors have proven to be persistent, there is an urgency to improve current strategies or develop novel approaches in order to control rabies disease in the future. Methods/Findings This study aimed to identify and systematically prioritize the research needs, through interviews and questionnaires with key-opinion-leaders (KOLs). A total of 46 research needs were identified and prioritized. The top research needs are considered very high priority based on both importance for rabies control and need for improvement. KOLs agree that animal rabies control remains most important for rabies control, while research on human host, agent (rabies virus) and the environment should be prioritized in terms of need for improvement. A wide variety in perceptions is observed between and within the disciplines of virology, public health and veterinary health and between KOLs with more versus those with less experience in the field. Conclusion/Significance The results of this study give well-defined, prioritized issues that stress the drawbacks that are experienced by KOLs in daily practice. The most important research domains are: 1) cheap and scalable production system for RIG 2) efficacy of dog mass vaccination programs and 3) cheap human vaccines. Addressing these research needs should exist next to and may reinforce current awareness and mass vaccination campaigns. The differences in perspectives between actors revealed in this study are informative for effective execution of the One Health research agenda.
Critical Reviews in Food Science and Nutrition, 2017
and it is a condition of accessing publications that users recognise and abide by the legal requi... more and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Microbial biotechnology, Jul 27, 2016
Lactobacillus plantarum WCFS1 is one of the best studied Lactobacilli, notably as its genome was ... more Lactobacillus plantarum WCFS1 is one of the best studied Lactobacilli, notably as its genome was unravelled over 12 years ago. L. plantarum WCFS1 can be grown to high densities, is amenable to genetic transformation and highly robust with a relatively high survival rate during the gastrointestinal passage. In this review, we present and discuss the main insights provided by the functional genomics research on L. plantarum WCFS1 with specific attention for the molecular mechanisms related to its interaction with the human host and its potential to modify the immune system, and induce other health-related benefits. Whereas most insight has been gained in mouse and other model studies, only five human studies have been reported with L. plantarum WCFS1. Hence NCIMB 8826 (the parental strain of L. plantarum WCFS1) in human trials as to capitalize on the wealth of knowledge that is summarized here.
Enhancing Historical Consciousness and Democratic Citizenship: a Report about Quantitative Prioritization of Unmet Needs
ABSTRACT
Beneficial microbes, 2014
In this study, we systematically evaluated safety aspects in clinical trials with probiotics and ... more In this study, we systematically evaluated safety aspects in clinical trials with probiotics and synbiotics in young infants (0-2 years of age). This study is an update of earlier reports and covers the recent literature from 2008-2013. The safety evaluation is performed along the Common Terminology Clinical Adverse Events (CTCAE) version 4.0 scale, hereby also providing guidance for future studies. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. The results show a deficiency in the precise reporting and classification of adverse events in most studies. Analysis of 57 clinical trials with probiotics and synbiotics in combination with eight follow-up studies indicate that probiotic administration to infants between 0 and 24 months is safe with regard to the evaluated strains in infants with a particular health status or susceptibility. Most adverse events and seriou...
Knowledge diffusion in the European medical nutrition industry
PharmaNutrition, 2014
Bioscience and Microflora, 2002
Vaccine, 2003
Lactobacillus strains with probiotic activity are major constituents of numerous common food prod... more Lactobacillus strains with probiotic activity are major constituents of numerous common food products. Due to their 'generally regarded as safe'-status (GRAS-status), Lactobacillus strains can also be genetically engineered for use in oral immunotherapeutic applications, such as vaccination and T lymphocyte tolerance induction in autoimmune disease. In the current study, we demonstrate that the growth phase of orally administered individual Lactobacillus strains can differentially affect antigen-specific antibody subclasses IgG1 and IgG2a, which might reflect skewing of systemic activity of T helper cell type 2 (Th2) and T helper cell type 1 (Th1) pathways, respectively. Mice were orally fed different wild type Lactobacillus strains in log phase or stationary phase and immunized intraperitoneally with a T-cell dependent protein antigen. Sera were evaluated for the ratio of antigen-specific IgG1 and IgG2a antibodies. Stationary Lactobacillus murines and Lactobacillus casei cultures, but not two other Lactobacillus strains, evoked significantly higher IgG1/IgG2a ratios than log phase cultures, possibly relating to increased activity of the Th2-pathway. Despite normal variation in antibody responses against TNP-CGG among individual mice, a high correlation was found between the IgG1 and IgG2a responses of mice within experimental groups. This differential antibody response is likely due to growth phase-dependent differences in bacterial cell composition. Since Lactobacillus growth phase dependent skewing of antibody responses possibly reflecting T-cell pathways can inadvertently affect allergic and (auto)-immune responses, the current findings strongly caution against unidimensional views on the oral administration of individual Lactobacillus strains for probiotic or immunotherapeutic purposes, but also suggest additional possibilities for immune modulation.
Technology and Investment, 2013
During the past two decades the biopharmaceutical industry has been facing an innovation deficit,... more During the past two decades the biopharmaceutical industry has been facing an innovation deficit, characterized by increasing research & development costs and stagnant productivity. From its inception, biotechnology has been expected to counter this deficit by its revolutionary science-based approach to drug discovery. For this study we gathered patent and product data related to the technological development of the first two biotechnologies: recombinant DNA technology and monoclonal antibody technology. We studied the technological lifecycles of these technologies in terms of scientific discoveries and inventions as well as product innovations. Results indicate that over the years inventions related to these technologies have simultaneously become less radical and less valuable. Furthermore, our analysis shows that these biotechnologies have reached a stage of technological limit or saturation, which may be followed by an innovation cliff. Now, more than ever, it is crucial to examine new strategies and opportunities for value creation, capturing, and delivery, within the biopharmaceutical industry.
Vaccine, 2003
Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tole... more Oral administration of autoantigens is a safe and convenient way to induce peripheral T-cell tolerance in autoimmune diseases like multiple sclerosis (MS). To increase the efficacy of oral tolerance induction and obviate the need for large-scale purification of human myelin proteins, we use genetically modified lactobacilli expressing myelin antigens. A panel of recombinant lactobacilli was constructed producing myelin proteins and peptides, including human and guinea pig myelin basic protein (MBP) and proteolipid protein peptide 139-151 (PLP 139-151). In this study we examined whether these Lactobacillus recombinants are able to induce oral and intranasal tolerance in an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). Lewis rats received soluble cell extracts of Lactobacillus transformants intranasally three times prior to induction of EAE. For the induction of oral tolerance, rats were fed live transformed lactobacilli for 20 days. Ten days after the first oral administration EAE was induced. Intranasal administration of extracts containing guinea pig MBP (gpMBP) or MBP 72-85 significantly inhibited EAE in Lewis rats. Extracts of control transformants did not reduce EAE. Live lactobacilli expressing guinea pig MBP 72-85 fused to the marker enzyme -glucuronidase (-gluc) were also able to significantly reduce disease when administered orally. In conclusion, these experiments provide proof of principle that lactobacilli expressing myelin antigens reduce EAE after mucosal (intranasal and oral) administration. This novel method of mucosal tolerance induction by mucosal administration of recombinant lactobacilli expressing relevant autoantigens could find applications in autoimmune disease in general, such as multiple sclerosis, rheumatoid arthritis and uveitis.
Vaccine, 2012
As infectious diseases cause approximately 25% of the annual global mortality, vaccines are found... more As infectious diseases cause approximately 25% of the annual global mortality, vaccines are found to be a time proven and promising response to infectious disease need. However, like for pharmaceutical small molecules, vaccine development is lengthy, risky and resource demanding. Faced with an attrition rate estimated around 80%, key opinion leaders were interviewed with the question: is there a recipe for success?
Seminars in Immunology, 1994
The spleen is an important lymphoid organ. involved in immune responses against all types of anti... more The spleen is an important lymphoid organ. involved in immune responses against all types of antigen that appear in the circulation. Its complex anatomical organization. with distinct compartments containing specialized cell types. provides a microenvironment which allows different cell-cell interactions and determines the direction of developing immune responses. In this review we evaluate the vast amount of in virro data dealing with antigen presentation. cell-eel\ interactions, T and B cell activation, and the immunoregulatory role of cytokincs, as suggested to be involved in immune responses. As a basis for understanding of in rivo processes. these in vitro data will be related to discrete phenomena of in rivo immune responses. such as antigen localization/trapping. cell migration patterns of immunocompetent cells. cytokine production, and antibody formation in the different compartments of the spleen. Finally, we try to bring order to the sequence of events that occur in the spleen after antigenic challenge by presenting an in vivo model forT cell dependent and T cell independent immune responses.
Letters in Applied Microbiology, 2002
Various probiotic lactobacilli have been reported to modulate immunity. In this study we investig... more Various probiotic lactobacilli have been reported to modulate immunity. In this study we investigate the effects of viable indigenous Lactobacillus strains Utr-1, Utr-2 and Utr-3, on T cell-mediated immunological memory responses. Methods and Results: In Listeria monocytogenes infected rats it was demonstrated that shortterm daily ingestion of Lactobacillus strain Utr-3 significantly decreased delayed-type hypersensitivity (DTH) expression, whereas long-term, daily oral administration of Lactobacillus strain Utr-3 and Lactobacillus strain Utr-2 significantly enhanced acquired cellular resistance (ACR) towards Listeria re-infection. Conclusions: Our findings demonstrate that certain indigenous Lactobacillus strains are capable of modulating T cell-mediated immunity. Significance and Impact of the Study: Our results support the importance of indigenous microflora analysis in probiotic lactobacilli studies.
Characterization of polyclonal antibodies against the capsid proteins of Ljungan virus
Journal of Virological Methods, 2008
Ljungan virus (LV) is a suspected human pathogen isolated from voles in Sweden and North America.... more Ljungan virus (LV) is a suspected human pathogen isolated from voles in Sweden and North America. To enable virus detection and studies of localization and activity of virion proteins, polyclonal antibodies were produced against bacterially expressed capsid proteins of the LV strain, 87-012G. Specific detection of proteins corresponding to viral antigens in lysates of LV infected cells was demonstrated by immunoblotting using each one of the generated polyclonal antibodies. In addition, native viral antigens present in cell culture infected with LV strains 87-012G or 145SLG were detected in ELISA and by immunofluorescence using the antibodies against the VP0 and VP1 proteins. The anti-VP3 antibody did not react with native proteins of the LV virion, suggesting that the VP3 is less potent in evoking humoral response and may have a less exposed orientation in the virus capsid. No activity of the antibodies was observed against the closely related human parechovirus type 1. The polyclonal antibody against the VP1 protein was further used for detection of LV infected myocytes in a mouse model of LV-induced myocarditis. Thus, polyclonal antibodies against recombinant viral capsid proteins enabled detection of natural LV virions by several different immunological methods.
Journal of Neuroimmunology, 1994
Irrespective of the large body of literature on the putative role of antibodies in the developmen... more Irrespective of the large body of literature on the putative role of antibodies in the development of multiple sclerosis (MS), the detection of specific antibody-forming B cells (AFCs) in the central nervous system (CNS) tissues has not been described. In this study we show that autoantigen-specific AFCs can be found in CNS tissue sections of MS patients. Applying a newly developed myelin basic protein (MBP)-enzyme conjugate technique, we have detected MBP-specific AFCs in autopsy periventricular white matter and cerebellum tissue sections of MS patients. We demonstrated the presence of MBP-specific AFCs in CNS tissue sections in five out of 12 MS patients. No MBP-specific AFCs were detected in CNS tissue sections of 11 patients with other neurological diseases, such as Parkinson's and Alzheimer's disease, or in brain tissue sections of eight deceased persons without neurological diseases. In MS patients, anti-MBP AFCs were present in brain tissue sections both with and without plaques. The proportion of MBP-specific AFCs in some of the MS patient brain tissues reached over 50% of all AFCs. The high relative frequency of the anti-MBP AFCs and their localization in periventricular white matter and cerebellum of MS patients only, suggests that anti-MBP AFCs represent a cell population, which could play an important role in MS immunopathology.
The role of GP39 (CD40 ligand) in EAE and MS
Journal of Neuroimmunology, 1994
Journal of Immunological Methods, 1992