Kutty Selva Nandakumar | Karolinska Institutet (original) (raw)
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Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the... more Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the population worldwide. Different environmental triggers initiate this complex multifactorial syndrome. Many individuals affected by Ps (6-26%) develop inflammatory disease in other organs, often in the joints as in psoriasis arthritis (PsA). Animal models that reflect the typical Ps syndrome, including both skin and joint pathology as in Ps and PsA, are valuable tools for dissecting disease pathways leading to clinical manifestations. In this context, we developed a new acute Ps and PsA-like disease model that appears after exposure to Saccharomyces cerevisiae mannan in certain mouse strains. The disease was found to be triggered by mannan-activated macrophages, leading to the activation of a pathogenic interleukin-17 pathway involving innate lymphocytes. Interestingly, the production of reactive oxygen species protected the mice from the triggering of this pathway and ameliorated Ps and PsA development.
Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), a... more Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), and anti-type II collagen (CII) antibodies are present in the serum, synovial fluid, and cartilage of RA patients. We had previously generated and characterized knock-in mice expressing a germline-encoded, CII-specific IgH (B10Q.ACB), which demonstrated positive selection of self-reactive B cells. Here, we show that despite the spontaneous production of CII-specific autoantibodies, B10Q.ACB mice are protected from collagen-induced arthritis. Introducing a mutation in the Ncf1 gene, leading to ROS deficiency, breaks this strong arthritis resistance. Disease development in Ncf1-mutated B10Q.ACB mice is associated with an enhanced germinal center formation but without somatic mutations of the auto-reactive B cells, increased T-cell responses and intramolecular epitope-spreading. Thus, ROS-mediated B-cell tolerance to a self-antigen could operate by limiting the expansion of the auto-reactive B-cell repertoire, which has important implications for the understanding of epitope spreading phenomena in rheumatoid arthritis and other autoimmune diseases.
PNAS, 2014
Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by un... more Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by γδ T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fcγ receptor III, mast cells, and histamine) and adaptive immune players (αβ T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-α secretion and stimulation of local γδ T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA.
Am J Pathol , 2014
Impairment of nerve conduction is common in neurodegenerative and neuroinflammatory diseases such... more Impairment of nerve conduction is common in neurodegenerative and neuroinflammatory diseases such as multiple sclerosis (MS), and measurement of evoked potentials (visual, motor, or sensory) has been widely used for diagnosis and recently also as a prognostic marker for MS. We used a classical genetic approach to identify novel genes controlling nerve conduction. First, we used quantitative trait mapping in F2 progeny of B10/SJL mice to identify EAE31, a locus controlling latency of motor evoked potentials (MEPs) and clinical onset of experimental autoimmune encephalomyelitis. Then, by combining congenic mapping, in silico haplotype analyses, and comparative genomics we identified inositol polyphosphate-4-phosphatase, type II (Inpp4b) as the quantitative trait gene for EAE31. Sequence variants of Inpp4b (C/A, exon 13; A/C, exon 14) were identified as differing among multiple mouse strains and correlated with individual cortical MEP latency differences. To evaluate the functional relevance of the amino acid exchanges at positions S474R and H548P, we generated transgenic mice carrying the longer-latency allele (Inpp4b(474R/548P)) in the C57BL/6J background. Inpp4b(474R/548P) mice exhibited significantly longer cortical MEP latencies (4.5 ± 0.22 ms versus 3.7 ± 0.13 ms; P = 1.04 × 10(-9)), indicating that INPP4B regulates nerve conduction velocity. An association of an INPP4B polymorphism (rs13102150) with MS was observed in German and Spanish MS cohorts (3676 controls and 911 cases) (P = 8.8 × 10(-3)).
Arthritis Res Ther , 2014
INTRODUCTION: A major subset of patients with rheumatoid arthritis (RA) is characterised by the ... more INTRODUCTION:
A major subset of patients with rheumatoid arthritis (RA) is characterised by the presence of circulating autoantibodies directed to citrullinated proteins/peptides (ACPA). These autoantibodies, which are commonly detected using an ELISA assay based on synthetic cyclic citrullinated peptides (CCP), predict clinical onset and a destructive disease course. In the present study, we have utilised plasma and synovial fluids from patients with RA, for the affinity purification and characterisation of anti-CCP2 reactive antibodies, with an aim to generate molecular tools that can be utilized in vitro and in vivo for future investigations into the pathobiology of the ACPA response. Specifically, this study aims to demonstrate that the surrogate marker CCP2 can capture ACPA that bind to autoantigens expressed in vivo, in the major inflammatory lesions of RA, i.e. in the rheumatoid joint.
METHODS:
Plasma (n = 16) and synovial fluid (n = 26) samples were collected from RA patients with anti-CCP2 IgG levels above 300 AU/ml. Total IgG was isolated on Protein G columns, and subsequently applied to CCP2 affinity columns. Purified anti-CCP2 IgG was analysed for reactivity and specificity using the CCPlus(R) ELISA assay, in-house peptide-ELISAs, western blot and immunohisto-/immunocytochemistry.
RESULTS:
Approximately 2% of the total IgG pool in both plasma and synovial fluid was CCP2-reactive. Purified anti-CCP2 reactive antibodies from different patients showed differences in binding to CCP2 and differences in binding to citrullinated peptides from alpha-enolase, vimentin, fibrinogen, and collagen type II, illustrating different ACPA fine-specificity profiles. Furthermore, the purified ACPA bound not only in vitro citrullinated proteins but more importantly, in vivo-generated epitopes on synovial fluid cells and synovial tissues from RA patients.
CONCLUSIONS:
We have isolated ACPA from plasma and synovial fluid, and demonstrated that the CCP2 peptides, frequently used in diagnostic ELISA assays, de facto act as surrogate antigens for at least four different, well-characterised, largely non cross-reactive, ACPA fine-specificities. Moreover, we have determined the concentration and proportion of CCP2-reactive IgG molecules in rheumatoid plasma and synovial fluid, and we have shown that the purified ACPA can be used to detect both in vitro- and in vivo-generated citrullinated epitopes by various techniques. We anticipate that these antibodies will provide us with new opportunities to investigate the potential pathogenic effects of human ACPAs.
Arthritis Res Ther , 2014
INTRODUCTION: Antibodies towards type II collagen (CII) are detected in patients with rheumatoid... more INTRODUCTION:
Antibodies towards type II collagen (CII) are detected in patients with rheumatoid arthritis (RA) and in non-human primates and rodents with collagen induced arthritis (CIA). We have previously shown that antibodies specific for several CII-epitopes are pathogenic using monoclonal antibodies from arthritic mice, although the role of different anti-CII epitopes has not been investigated in detail in other species. We therefore performed an inter-species comparative study of the autoantibody response to CII in patients with RA versus monkeys and mice with CIA.
METHODS:
Analysis of the full epitope repertoire along the disease course of CIA was performed using a library of CII triple-helical peptides. The antibody responses to the major CII epitopes were analyzed in sera and synovial fluid from RA patients, and in sera from rhesus monkeys (Macaca mulatta), common marmosets (Callithrix jacchus) and mice.
RESULTS:
Many CII epitopes including the major C1, U1, and J1 were associated with established CIA and arginine residues played an important role in the anti-CII antibody interactions. The major epitopes were also recognized in RA patients, both in sera and even more pronounced in synovial fluid: 77% of the patients had antibodies to the U1 epitope. The anti-CII immune response was not restricted to the anti-citrulline protein antibodies (ACPA) positive RA group.
CONCLUSION:
CII conformational dependent antibody responses are common in RA and are likely to originate from rheumatoid joints but did not show a correlation with ACPA response. Importantly, the fine specificity of the anti-CII response is similar with CIA in monkeys and rodents where the recognized epitopes are conserved and have a major pathogenic role. Thus, anti-CII antibodies may both contribute to, as well as be the consequence of, local joint inflammation.
Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different... more Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different applications. In linear form, these polymers supported growth of human kidney fibrosarcoma cells as confirmed by in vitro study and shown no visible toxic effects in mice when injected intradermally. However, polymers in linear form mixed with the cartilage protein, collagen type II (CII), induced significant anti-CII IgG response and arthritis in mice. Histological analysis of the arthritic paws showed massive infiltration of immune cells with extensive damage to joint tissues, similar to the classical arthritis induced with CII emulsified with the Freund's adjuvant. This adjuvant property of the linear polymers is not desirable for their use in tissue engineering. Interestingly, though chemical cross-linking of these polymers supported growth of human kidney fibrosarcoma cells, it completely abrogated their adjuvant property. Thus, cross-linking of polymers could be used as a strategy in biomedicine to avoid undesirable immune reactions induced or directed against polymers.
This is an author produced version of a paper published in Arthritis and Rheumatism. This paper h... more This is an author produced version of a paper published in Arthritis and Rheumatism. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.
Proceedings of The National Academy of Sciences, 2007
Environmental factors are thought to play a major role in the development of rheumatoid arthritis... more Environmental factors are thought to play a major role in the development of rheumatoid arthritis. Because the use of ethanol is widespread, we assessed the role of ethanol intake on the propensity to develop chronic arthritis. Collagen type II-immunized mice were given water or water containing 10% (vol/vol) ethanol or its metabolite acetaldehyde. Their development of arthritis was assessed, as well as the impact of ethanol on leukocyte migration and activation of intracellular transcription factors. Mice exposed daily to this dose of ethanol did not display any liver toxicity, and the development of erosive arthritis was almost totally abrogated. In contrast, the antibody-mediated effector phase of collageninduced arthritis was not influenced by ethanol exposure. Also, the major ethanol metabolite, acetaldehyde, prevented the development of arthritis. This antiinflammatory and antidestructive property of ethanol was mediated by (i) down-regulation of leukocyte migration and (ii) up-regulation of testosterone secretion, with the latter leading to decreased NF-B activation. We conclude that low but persistent ethanol consumption delays the onset and halts the progression of collagen-induced arthritis by interaction with innate immune responsiveness.
The Journal of experimental medicine, 2009
Trends in Immunology, 2008
Arthritis & Rheumatism , 2012
Objective. To identify genetic factors driving pathogenic autoantibody formation in collagen-indu... more Objective. To identify genetic factors driving pathogenic autoantibody formation in collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis (RA), in order to better understand the etiology of RA and identify possible new avenues for therapeutic intervention.
Arthritis research & therapy, 2012
Introduction: Cartilage oligomeric matrix protein (COMP) is a major non-collagenous component of ... more Introduction: Cartilage oligomeric matrix protein (COMP) is a major non-collagenous component of cartilage. Earlier, we developed a new mouse model for rheumatoid arthritis using COMP. This study was undertaken to investigate the epitope specificity and immunopathogenicity of COMP-specific monoclonal antibodies (mAbs). Methods: B cell immunodominant regions on the COMP molecule were measured with a novel enzyme-linked immunosorbent assay using mammalian expressed full-length mouse COMP as well as a panel of recombinant mouse COMP fragments. 18 mAbs specific to COMP were generated and the pathogenicity of mAbs was investigated by passive transfer experiments. Results: B cell immunodominant epitopes were localized within 4 antigenic domains of the COMP but with preferential response to the epidermal growth factor (EGF)-like domain. Some of our anti-COMP mAbs showed interactions with the native form of COMP, which is present in cartilage and synovium. Passive transfer of COMPspecific mAbs enhanced arthritis when co-administrated with a sub-arthritogenic dose of a mAb specific to collagen type II. Interestingly, we found that a combination of 5 COMP mAbs was capable of inducing arthritis in naive mice. Conclusions: We have identified the specificities of mAbs to COMP and their contribution to the development of arthritis. These findings will further improve our understanding of the autoantibody mediated immunopathologies occurring widely in rheumatoid arthritis (RA), as well as in other autoimmune disorders.
Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the... more Psoriasis (Ps) is a chronic, immune-mediated, skin inflammatory disease affecting up to 3% of the population worldwide. Different environmental triggers initiate this complex multifactorial syndrome. Many individuals affected by Ps (6-26%) develop inflammatory disease in other organs, often in the joints as in psoriasis arthritis (PsA). Animal models that reflect the typical Ps syndrome, including both skin and joint pathology as in Ps and PsA, are valuable tools for dissecting disease pathways leading to clinical manifestations. In this context, we developed a new acute Ps and PsA-like disease model that appears after exposure to Saccharomyces cerevisiae mannan in certain mouse strains. The disease was found to be triggered by mannan-activated macrophages, leading to the activation of a pathogenic interleukin-17 pathway involving innate lymphocytes. Interestingly, the production of reactive oxygen species protected the mice from the triggering of this pathway and ameliorated Ps and PsA development.
Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), a... more Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), and anti-type II collagen (CII) antibodies are present in the serum, synovial fluid, and cartilage of RA patients. We had previously generated and characterized knock-in mice expressing a germline-encoded, CII-specific IgH (B10Q.ACB), which demonstrated positive selection of self-reactive B cells. Here, we show that despite the spontaneous production of CII-specific autoantibodies, B10Q.ACB mice are protected from collagen-induced arthritis. Introducing a mutation in the Ncf1 gene, leading to ROS deficiency, breaks this strong arthritis resistance. Disease development in Ncf1-mutated B10Q.ACB mice is associated with an enhanced germinal center formation but without somatic mutations of the auto-reactive B cells, increased T-cell responses and intramolecular epitope-spreading. Thus, ROS-mediated B-cell tolerance to a self-antigen could operate by limiting the expansion of the auto-reactive B-cell repertoire, which has important implications for the understanding of epitope spreading phenomena in rheumatoid arthritis and other autoimmune diseases.
PNAS, 2014
Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by un... more Psoriasis (Ps) and psoriasis arthritis (PsA) are poorly understood common diseases, induced by unknown environmental factors, affecting skin and articular joints. A single i.p. exposure to mannan from Saccharomyces cerevisiae induced an acute inflammation in inbred mouse strains resembling human Ps and PsA-like disease, whereas multiple injections induced a relapsing disease. Exacerbation of disease severity was observed in mice deficient for generation of reactive oxygen species (ROS). Interestingly, restoration of ROS production, specifically in macrophages, ameliorated both skin and joint disease. Neutralization of IL-17A, mainly produced by γδ T cells, completely blocked disease symptoms. Furthermore, mice depleted of granulocytes were resistant to disease development. In contrast, certain acute inflammatory mediators (C5, Fcγ receptor III, mast cells, and histamine) and adaptive immune players (αβ T and B cells) were redundant in disease induction. Hence, we propose that mannan-induced activation of macrophages leads to TNF-α secretion and stimulation of local γδ T cells secreting IL-17A. The combined action of activated macrophages and IL-17A produced in situ drives neutrophil infiltration in the epidermis and dermis of the skin, leading to disease manifestations. Thus, our finding suggests a new mechanism triggered by exposure to exogenous microbial components, such as mannan, that can induce and exacerbate Ps and PsA.
Am J Pathol , 2014
Impairment of nerve conduction is common in neurodegenerative and neuroinflammatory diseases such... more Impairment of nerve conduction is common in neurodegenerative and neuroinflammatory diseases such as multiple sclerosis (MS), and measurement of evoked potentials (visual, motor, or sensory) has been widely used for diagnosis and recently also as a prognostic marker for MS. We used a classical genetic approach to identify novel genes controlling nerve conduction. First, we used quantitative trait mapping in F2 progeny of B10/SJL mice to identify EAE31, a locus controlling latency of motor evoked potentials (MEPs) and clinical onset of experimental autoimmune encephalomyelitis. Then, by combining congenic mapping, in silico haplotype analyses, and comparative genomics we identified inositol polyphosphate-4-phosphatase, type II (Inpp4b) as the quantitative trait gene for EAE31. Sequence variants of Inpp4b (C/A, exon 13; A/C, exon 14) were identified as differing among multiple mouse strains and correlated with individual cortical MEP latency differences. To evaluate the functional relevance of the amino acid exchanges at positions S474R and H548P, we generated transgenic mice carrying the longer-latency allele (Inpp4b(474R/548P)) in the C57BL/6J background. Inpp4b(474R/548P) mice exhibited significantly longer cortical MEP latencies (4.5 ± 0.22 ms versus 3.7 ± 0.13 ms; P = 1.04 × 10(-9)), indicating that INPP4B regulates nerve conduction velocity. An association of an INPP4B polymorphism (rs13102150) with MS was observed in German and Spanish MS cohorts (3676 controls and 911 cases) (P = 8.8 × 10(-3)).
Arthritis Res Ther , 2014
INTRODUCTION: A major subset of patients with rheumatoid arthritis (RA) is characterised by the ... more INTRODUCTION:
A major subset of patients with rheumatoid arthritis (RA) is characterised by the presence of circulating autoantibodies directed to citrullinated proteins/peptides (ACPA). These autoantibodies, which are commonly detected using an ELISA assay based on synthetic cyclic citrullinated peptides (CCP), predict clinical onset and a destructive disease course. In the present study, we have utilised plasma and synovial fluids from patients with RA, for the affinity purification and characterisation of anti-CCP2 reactive antibodies, with an aim to generate molecular tools that can be utilized in vitro and in vivo for future investigations into the pathobiology of the ACPA response. Specifically, this study aims to demonstrate that the surrogate marker CCP2 can capture ACPA that bind to autoantigens expressed in vivo, in the major inflammatory lesions of RA, i.e. in the rheumatoid joint.
METHODS:
Plasma (n = 16) and synovial fluid (n = 26) samples were collected from RA patients with anti-CCP2 IgG levels above 300 AU/ml. Total IgG was isolated on Protein G columns, and subsequently applied to CCP2 affinity columns. Purified anti-CCP2 IgG was analysed for reactivity and specificity using the CCPlus(R) ELISA assay, in-house peptide-ELISAs, western blot and immunohisto-/immunocytochemistry.
RESULTS:
Approximately 2% of the total IgG pool in both plasma and synovial fluid was CCP2-reactive. Purified anti-CCP2 reactive antibodies from different patients showed differences in binding to CCP2 and differences in binding to citrullinated peptides from alpha-enolase, vimentin, fibrinogen, and collagen type II, illustrating different ACPA fine-specificity profiles. Furthermore, the purified ACPA bound not only in vitro citrullinated proteins but more importantly, in vivo-generated epitopes on synovial fluid cells and synovial tissues from RA patients.
CONCLUSIONS:
We have isolated ACPA from plasma and synovial fluid, and demonstrated that the CCP2 peptides, frequently used in diagnostic ELISA assays, de facto act as surrogate antigens for at least four different, well-characterised, largely non cross-reactive, ACPA fine-specificities. Moreover, we have determined the concentration and proportion of CCP2-reactive IgG molecules in rheumatoid plasma and synovial fluid, and we have shown that the purified ACPA can be used to detect both in vitro- and in vivo-generated citrullinated epitopes by various techniques. We anticipate that these antibodies will provide us with new opportunities to investigate the potential pathogenic effects of human ACPAs.
Arthritis Res Ther , 2014
INTRODUCTION: Antibodies towards type II collagen (CII) are detected in patients with rheumatoid... more INTRODUCTION:
Antibodies towards type II collagen (CII) are detected in patients with rheumatoid arthritis (RA) and in non-human primates and rodents with collagen induced arthritis (CIA). We have previously shown that antibodies specific for several CII-epitopes are pathogenic using monoclonal antibodies from arthritic mice, although the role of different anti-CII epitopes has not been investigated in detail in other species. We therefore performed an inter-species comparative study of the autoantibody response to CII in patients with RA versus monkeys and mice with CIA.
METHODS:
Analysis of the full epitope repertoire along the disease course of CIA was performed using a library of CII triple-helical peptides. The antibody responses to the major CII epitopes were analyzed in sera and synovial fluid from RA patients, and in sera from rhesus monkeys (Macaca mulatta), common marmosets (Callithrix jacchus) and mice.
RESULTS:
Many CII epitopes including the major C1, U1, and J1 were associated with established CIA and arginine residues played an important role in the anti-CII antibody interactions. The major epitopes were also recognized in RA patients, both in sera and even more pronounced in synovial fluid: 77% of the patients had antibodies to the U1 epitope. The anti-CII immune response was not restricted to the anti-citrulline protein antibodies (ACPA) positive RA group.
CONCLUSION:
CII conformational dependent antibody responses are common in RA and are likely to originate from rheumatoid joints but did not show a correlation with ACPA response. Importantly, the fine specificity of the anti-CII response is similar with CIA in monkeys and rodents where the recognized epitopes are conserved and have a major pathogenic role. Thus, anti-CII antibodies may both contribute to, as well as be the consequence of, local joint inflammation.
Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different... more Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different applications. In linear form, these polymers supported growth of human kidney fibrosarcoma cells as confirmed by in vitro study and shown no visible toxic effects in mice when injected intradermally. However, polymers in linear form mixed with the cartilage protein, collagen type II (CII), induced significant anti-CII IgG response and arthritis in mice. Histological analysis of the arthritic paws showed massive infiltration of immune cells with extensive damage to joint tissues, similar to the classical arthritis induced with CII emulsified with the Freund's adjuvant. This adjuvant property of the linear polymers is not desirable for their use in tissue engineering. Interestingly, though chemical cross-linking of these polymers supported growth of human kidney fibrosarcoma cells, it completely abrogated their adjuvant property. Thus, cross-linking of polymers could be used as a strategy in biomedicine to avoid undesirable immune reactions induced or directed against polymers.
This is an author produced version of a paper published in Arthritis and Rheumatism. This paper h... more This is an author produced version of a paper published in Arthritis and Rheumatism. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.
Proceedings of The National Academy of Sciences, 2007
Environmental factors are thought to play a major role in the development of rheumatoid arthritis... more Environmental factors are thought to play a major role in the development of rheumatoid arthritis. Because the use of ethanol is widespread, we assessed the role of ethanol intake on the propensity to develop chronic arthritis. Collagen type II-immunized mice were given water or water containing 10% (vol/vol) ethanol or its metabolite acetaldehyde. Their development of arthritis was assessed, as well as the impact of ethanol on leukocyte migration and activation of intracellular transcription factors. Mice exposed daily to this dose of ethanol did not display any liver toxicity, and the development of erosive arthritis was almost totally abrogated. In contrast, the antibody-mediated effector phase of collageninduced arthritis was not influenced by ethanol exposure. Also, the major ethanol metabolite, acetaldehyde, prevented the development of arthritis. This antiinflammatory and antidestructive property of ethanol was mediated by (i) down-regulation of leukocyte migration and (ii) up-regulation of testosterone secretion, with the latter leading to decreased NF-B activation. We conclude that low but persistent ethanol consumption delays the onset and halts the progression of collagen-induced arthritis by interaction with innate immune responsiveness.
The Journal of experimental medicine, 2009
Trends in Immunology, 2008
Arthritis & Rheumatism , 2012
Objective. To identify genetic factors driving pathogenic autoantibody formation in collagen-indu... more Objective. To identify genetic factors driving pathogenic autoantibody formation in collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis (RA), in order to better understand the etiology of RA and identify possible new avenues for therapeutic intervention.
Arthritis research & therapy, 2012
Introduction: Cartilage oligomeric matrix protein (COMP) is a major non-collagenous component of ... more Introduction: Cartilage oligomeric matrix protein (COMP) is a major non-collagenous component of cartilage. Earlier, we developed a new mouse model for rheumatoid arthritis using COMP. This study was undertaken to investigate the epitope specificity and immunopathogenicity of COMP-specific monoclonal antibodies (mAbs). Methods: B cell immunodominant regions on the COMP molecule were measured with a novel enzyme-linked immunosorbent assay using mammalian expressed full-length mouse COMP as well as a panel of recombinant mouse COMP fragments. 18 mAbs specific to COMP were generated and the pathogenicity of mAbs was investigated by passive transfer experiments. Results: B cell immunodominant epitopes were localized within 4 antigenic domains of the COMP but with preferential response to the epidermal growth factor (EGF)-like domain. Some of our anti-COMP mAbs showed interactions with the native form of COMP, which is present in cartilage and synovium. Passive transfer of COMPspecific mAbs enhanced arthritis when co-administrated with a sub-arthritogenic dose of a mAb specific to collagen type II. Interestingly, we found that a combination of 5 COMP mAbs was capable of inducing arthritis in naive mice. Conclusions: We have identified the specificities of mAbs to COMP and their contribution to the development of arthritis. These findings will further improve our understanding of the autoantibody mediated immunopathologies occurring widely in rheumatoid arthritis (RA), as well as in other autoimmune disorders.
Frontiers in Immunology, 2022
Bone loss due to an increased osteoclast activity is common in osteoporosis and rheumatoid arthri... more Bone loss due to an increased osteoclast activity is common in osteoporosis and rheumatoid arthritis. For the first time, we observed an inhibition of osteoclast formation and bone resorption by outer-membrane vesicles (OMVs) from a Gram-negative, pathogenic bacterium, Proteus mirabilis (P.M). Gene ontogeny and KEGG enrichment analyses of miRNA and mRNA sequencing data demonstrated a significant effect of P.M OMVs on mitochondrial functions and apoptotic pathways. OMVs induced mitochondrial dysfunction through an increased level of intracellular ROS, collapse of mitochondrial membrane potential (ΔΨm), and modulation of Bax, Bcl-2, caspase-3, and cytochrome c expression. In addition, P.M OMVs strongly inhibited miR-96-5p expression, which caused an upregulation of ATP binding cassette subfamily A member 1 (Abca1) in osteoclasts leading to an increased level of mitochondria-dependent apoptosis. Moreover, treatment with P.M but not Escherichia coli OMVs attenuated bone loss in experime...
Viruses, 2022
Several countries have made unremitting efforts to develop an optimal vaccine in the fight agains... more Several countries have made unremitting efforts to develop an optimal vaccine in the fight against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing occurrence of SARS-CoV-2 variants, current vaccines show decreased neutralizing activities, especially towards the Omicron variant. In this context, adding appropriate adjuvants to COVID-19 vaccines can substantially reduce the number of required doses and improve efficacy or cross-neutralizing protection. We mainly focus on research progress and achievements associated with adjuvanted COVID-19 subunit and inactivated vaccines. We further compare the advantages and disadvantages of different adjuvant formulations in order to provide a scientific reference for designing an effective strategy for future vaccine development.
Journal of The Royal Society Interface, 2018
Recently, smart biocatalysts, where enzymes are conjugated to stimuli-responsive (smart) polymers... more Recently, smart biocatalysts, where enzymes are conjugated to stimuli-responsive (smart) polymers, have gained significant attention. Based on the presence or absence of external stimuli, the polymer attached to the enzyme changes its conformation to protect the enzyme from the external environment and regulate the enzyme activity, thus acting as a molecular switch. Owing to this behaviour, smart biocatalysts can be separated easily from a reaction mixture and re-used several times. Several such smart polymer-based biocatalysts have been developed for industrial and biomedical applications. In addition, they have been used in biosensors, biometrics and nano-electronic devices. This review article covers recent advances in developing different kinds of stimuli-responsive enzyme bioconjugates, including conjugation strategies, and their applications.
European journal of immunology, Jan 18, 2015
Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), a... more Autoantibody-mediated inflammation contributes to the development of rheumatoid arthritis (RA), and anti-type II collagen (CII) antibodies are present in the serum, synovial fluid, and cartilage of RA patients. We had previously generated and characterized knock-in mice expressing a germline-encoded, CII-specific IgH (B10Q.ACB), which demonstrated positive selection of self-reactive B cells. Here we show that despite the spontaneous production of CII-specific autoantibodies, B10Q.ACB mice are protected from collagen-induced arthritis. Introducing a mutation in the Ncf1 gene, leading to ROS deficiency, breaks this strong arthritis resistance. Disease development in Ncf1-mutated B10Q.ACB mice is associated with an enhanced germinal center (GC) formation but without somatic mutations of the auto-reactive B cells, increased T-cell responses and intramolecular epitope-spreading. Thus, ROS-mediated B-cell tolerance to a self-antigen could operate by limiting the expansion of the auto-reac...
A deficiency in C5 protects against arthritis development. However, there is currently no approac... more A deficiency in C5 protects against arthritis development. However, there is currently no approach successfully translating these findings into arthritis therapy, as by targeting the key component, C5a. The aim of this study was to develop a vaccination strategy targeting C5a as therapy for patients with rheumatoid arthritis. An anti-C5a vaccine was generated by incorporating the unnatural amino acid p-nitrophenylalanine (4NPA) into selected sites in the murine C5a molecule. C5a-4NPA variants were screened for their immunogenicity in mice on different arthritis-susceptible class II major histocompatibility complex (MHC) backgrounds. A candidate vaccine was tested for its impact on disease in a murine model of collagen-induced arthritis (CIA). Immunity toward endogenous C5a as well as type II collagen was monitored and characterized. Replacing a single tyrosine residue in position 35 (Y(35) ) with 4NPA allowed the generation of an anti-C5a vaccine, which partly protected mice against the development of CIA while strongly ameliorating the severity of clinical disease. Although differing in just 3 atoms from wild-type C5a (wtC5a), C5aY(35) 4NPA induced loss of T cell and B cell tolerance toward the endogenous protein in mice expressing class II MHC H-2(q) molecules. Despite differential B cell epitope recognition, antibodies induced by both wtC5a and C5aY(35) 4NPA neutralized C5a. Thus, anti-wtC5a IgG titers during arthritis priming were potentially of critical importance for disease protection, because high titers of C5a-neutralizing antibodies after disease onset were unable to reverse the course of arthritis. The results of this study suggest that the most effective anti-C5a treatment in arthritis can be accomplished using a preventive vaccination strategy, and that treatment using conventional biologic or small molecule strategies targeting the C5a/C5aR axis may miss the optimal window for therapeutic intervention during the subclinical priming phase of the disease.
Arthritis Research & Therapy, 2014
Current Protocols in Mouse Biology, 2014
Collagen-induced arthritis (CIA), the classical animal model for experimental arthritis, resemble... more Collagen-induced arthritis (CIA), the classical animal model for experimental arthritis, resembles human rheumatoid arthritis in several aspects. However, the most widely used method of inducing CIA utilizes Freund's adjuvants, which can skew the elicited immune responses and also pose toxicity problems. This unit describes a new method of inducing CIA using a well defined stimuli-responsive synthetic polymer, poly-N-isopropylacrylamide-based adjuvant, mixed with the joint cartilage protein collagen type II (CII). PNiPAAm as an adjuvant is biodegradable and biocompatible, and does not skew immune responses. Thus, it is helpful in the development of arthritis models for studying antigen and tissue -specific autoimmune responses in an unbiased manner. This model is valuable for analyzing disease pathways, positional identification of genes regulating arthritis, validation of existing therapies, and exploring new therapeutic targets. Furthermore, this newly developed PNiPAAm adjuvant allows investigation of disease induction using specific autoantigens in several autoimmune diseases independently of toll-like receptors, as well as optimization of vaccine delivery systems for infectious diseases. Curr. Protoc. Mouse Biol. 4:11-24 © 2014 by John Wiley & Sons, Inc.
RSC Advances, 2014
Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different... more Natural polymers like chitosan and alginic acid are extensively used in biomedicine for different applications.
Arthritis Research & Therapy, 2014
PLoS ONE, 2011
Copyright Public Library of Science. This is an open-access article distributed under the terms o... more Copyright Public Library of Science. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Journal of Experimental Medicine, 2014
Epitope-specific antibody responses recognized by germline-encoded structures are of significant ... more Epitope-specific antibody responses recognized by germline-encoded structures are of significant relevance for the development of autoantibody-mediated autoimmune diseases.
Journal of Biomedical Materials Research Part A, 2013
Polymers are used in several immunological applications, for example in designing new generation ... more Polymers are used in several immunological applications, for example in designing new generation vaccines, implantation studies, therapeutics and for the development of animal models that are mimicking human pathological conditions. Polymers can function as attenuators to modulate host immune responses in tissue transplantation, as suppressors to inhibit immune responses against therapeutics or as an adjuvant in the activation of immune responses. Among them, polymers as adjuvants are highly promising and are being developed in the vaccination and autoimmunity fields. As an adjuvant, polymers can efficiently deliver antigens and have the ability to modulate immune responses toward an antigen. Adjuvant properties of the polymers are mainly dependent on their extrinsic and intrinsic properties such as polymer chemistry, format, charge and a fine balance between hydrophobicity and hydrophilicity. Polymers can also be easily coupled with an antigen/immuno-modulator/ligand either physica...
Frontiers in Immunology
We identified abnormally methylated, differentially expressed genes (DEGs) and pathogenic mechani... more We identified abnormally methylated, differentially expressed genes (DEGs) and pathogenic mechanisms in different immune cells of RA and SLE by comprehensive bioinformatics analysis. Six microarray data sets of each immune cell (CD19+ B cells, CD4+ T cells and CD14+ monocytes) were integrated to screen DEGs and differentially methylated genes by using R package “limma.” Gene ontology annotations and KEGG analysis of aberrant methylome of DEGs were done using DAVID online database. Protein-protein interaction (PPI) network was generated to detect the hub genes and their methylation levels were compared using DiseaseMeth 2.0 database. Aberrantly methylated DEGs in CD19+ B cells (173 and 180), CD4+ T cells (184 and 417) and CD14+ monocytes (193 and 392) of RA and SLE patients were identified. We detected 30 hub genes in different immune cells of RA and SLE and confirmed their expression using FACS sorted immune cells by qPCR. Among them, 12 genes (BPTF, PHC2, JUN, KRAS, PTEN, FGFR2, AL...
Vaccines
Zika virus (ZIKV) is an arbovirus first discovered in the Americas. ZIKV infection is insidious b... more Zika virus (ZIKV) is an arbovirus first discovered in the Americas. ZIKV infection is insidious based on its mild clinical symptoms observed after infection. In Brazil, after 2015, ZIKV infection broke out on a large scale, and many infected pregnant women gave birth to babies with microcephaly. The teratogenic effects of the virus on the fetus and its effects on nerves and the immune system have attracted great attention. Currently, no specific prophylactics or therapeutics are clinically available to treat ZIKV infection. Development of a safe and effective vaccine is essential to prevent the rise of any potential pandemic. In this review, we summarize the latest research on Zika vaccine development based on different strategies, including DNA vaccines, subunit vaccines, live-attenuated vaccines, virus-vector-based vaccines, inactivated vaccines, virus-like particles (VLPs), mRNA-based vaccines, and others. We anticipate that this review will facilitate further progress toward the...
Molecular Therapy - Methods & Clinical Development
Mediators of Inflammation
Rheumatoid arthritis is a chronic autoimmune syndrome associated with several genetic, epigenetic... more Rheumatoid arthritis is a chronic autoimmune syndrome associated with several genetic, epigenetic, and environmental factors affecting the articular joints contributing to cartilage and bone damage. Although etiology of this disease is not clear, several immune pathways, involving immune (T cells, B cells, dendritic cells, macrophages, and neutrophils) and nonimmune (fibroblasts and chondrocytes) cells, participate in the secretion of many proinflammatory cytokines, chemokines, proteases (MMPs, ADAMTS), and other matrix lysing enzymes that could disturb the immune balance leading to cartilage and bone damage. The presence of autoantibodies preceding the clinical onset of arthritis and the induction of bone erosion early in the disease course clearly suggest that initiation events damaging the cartilage and bone start very early during the autoimmune phase of the arthritis development. During this process, several signaling molecules (RANKL-RANK, NF-κB, MAPK, NFATc1, and Src kinase) ...
Mediators of Inflammation
Rheumatoid arthritis is a systemic, polygenic, and multifactorial syndrome characterized by erosi... more Rheumatoid arthritis is a systemic, polygenic, and multifactorial syndrome characterized by erosive polyarthritis, damage to joint architecture, and presence of autoantibodies against several self-structures in the serum and synovial fluid. These autoantibodies (anticitrullinated protein/peptide antibodies (ACPAs), rheumatoid factors (RF), anticollagen type II antibodies, antiglucose-6 phosphate isomerase antibodies, anticarbamylated protein antibodies, and antiacetylated protein antibodies) have different characteristics, diagnostic/prognostic value, and pathological significance in RA patients. Some of these antibodies are present in the patients’ serum several years before the onset of clinical disease. Various genetic and environmental factors are associated with autoantibody production against different autoantigenic targets. Both the activating and inhibitory FcγRs and the activation of different complement cascades contribute to the downstream effector functions in the antibo...
International Journal of Molecular Sciences
Rheumatoid arthritis (RA) is a polygenic and multifactorial syndrome. Many complex immunological ... more Rheumatoid arthritis (RA) is a polygenic and multifactorial syndrome. Many complex immunological and genetic interactions are involved in the final outcome of the clinical disease. Autoantibodies (rheumatoid factors, anti-citrullinated peptide/protein antibodies) are present in RA patients' sera for a long time before the onset of clinical disease. Prior to arthritis onset, in the autoantibody response, epitope spreading, avidity maturation, and changes towards a pro-inflammatory Fc glycosylation phenotype occurs. Genetic association of epitope specific autoantibody responses and the induction of inflammation dependent and independent changes in the cartilage by pathogenic autoantibodies emphasize the crucial contribution of antibody-initiated inflammation in RA development. Targeting IgG by glyco-engineering, bacterial enzymes to specifically cleave IgG/alter N-linked Fc-glycans at Asn 297 or blocking the downstream effector pathways offers new avenues to develop novel therapeutics for arthritis treatment.
![Research paper thumbnail of {"__content__"=>"Streptococcal Endo-β--Acetylglucosaminidase Suppresses Antibody-Mediated Inflammation .", "i"=>[{"__content__"=>"N"}, {"__content__"=>"In Vivo"}]}](https://attachments.academia-assets.com/80489440/thumbnails/1.jpg)
](Frontiers in immunology, 2018
Endo-β--acetylglucosaminidase (EndoS) is a family 18 glycosyl hydrolase secreted by . Recombinant... more Endo-β--acetylglucosaminidase (EndoS) is a family 18 glycosyl hydrolase secreted by . Recombinant EndoS hydrolyzes the β-1,4-di--acetylchitobiose core of the N-linked complex type glycan on the asparagine 297 of the γ-chains of IgG. Here, we report that EndoS and IgG hydrolyzed by EndoS induced suppression of local immune complex (IC)-mediated arthritis. A small amount (1 µg given i.v. to a mouse) of EndoS was sufficient to inhibit IgG-mediated arthritis in mice. The presence of EndoS disturbed larger IC lattice formation both and , as visualized with anti-C3b staining. Neither complement binding nor antigen-antibody binding were affected. Thus, EndoS could potentially be used for treating patients with IC-mediated pathology.