Subject(s)
Complement System Proteins/immunology , Drug Development , Molecular Targeted Therapy , Animals , Complement Activation/drug effects , Complement Activation/immunology , Complement System Proteins/drug effects , Complement System Proteins/metabolism , Drug Development/methods , Humans , Immunomodulation/drug effectsABSTRACT
Sickle cell disease (SCD) is a common inherited clinical syndrome, characterized by the presence of hemoglobin S. Anemia, susceptibility to infections and episodes of vaso-occlusive crisis (VOC) are among its features. Since SCD complications (VOC or delayed hemolytic transfusion reaction/DHTR) lead to significant morbidity and mortality, a number of studies have addressed their pathophysiology Although SCD pathophysiology has been mainly attributed to the interaction between sickle cells and neutrophils, platelets or endothelial cells in small vessels leading to hemolysis, the role of complement activation has been increasingly investigated. Importantly, complement inhibition with eculizumab has shown beneficial effects in DHTR. Given the unmet clinical need of novel therapeutics in SCD, our review summarizes current understanding of (a) complement system for the clinician, (b) complement activation in SCD both in asymptomatic state and severe clinical manifestations, (c) probable underlying mechanisms of complement activation in SCD, and (d) new therapeutic perspective of complement inhibition.
Subject(s)
Anemia, Sickle Cell/drug therapy , Anemia, Sickle Cell/etiology , Complement System Proteins/drug effects , Complement System Proteins/immunology , Molecular Targeted Therapy , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Complement Activation/drug effects , Complement Activation/immunology , Complement Inactivating Agents/administration & dosage , Complement Inactivating Agents/adverse effects , Complement Inactivating Agents/therapeutic use , Disease Susceptibility , Humans , Molecular Targeted Therapy/methods , Transfusion Reaction/immunology , Treatment OutcomeABSTRACT
Because the liver plays a major role in metabolic homeostasis and secretion of clotting factors and inflammatory innate immune proteins, there is interest in understanding the mechanisms of hepatic cell activation under hyperglycaemia and whether this can be attenuated pharmacologically. We have previously shown that hyperglycaemia stimulates major changes in chromatin organization and metabolism in hepatocytes, and that the histone deacetylase inhibitor valproic acid (VPA) is able to reverse some of these metabolic changes. In this study, we have used RNA-sequencing (RNA-seq) to investigate how VPA influences gene expression in hepatocytes. Interesting, we observed that VPA attenuates hyperglycaemia-induced activation of complement and coagulation cascade genes. We also observe that many of the gene activation events coincide with changes to histone acetylation at the promoter of these genes indicating that epigenetic regulation is involved in VPA action.
Subject(s)
Blood Coagulation/genetics , Complement System Proteins/genetics , Gene Expression Regulation/drug effects , Hyperglycemia/blood , Hyperglycemia/genetics , Valproic Acid/pharmacology , Blood Coagulation/drug effects , Complement System Proteins/drug effects , Hep G2 Cells , Hepatocytes/drug effects , Hepatocytes/metabolism , Histones/metabolism , Humans , Promoter Regions, Genetic/genetics , Reproducibility of ResultsABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Epimedium brevicornu Maxim, Dioscorea nipponica Makino, and Salvia miltiorrhiza Bunge formula (EDS) are three traditional Chinese medicines commonly combined and used to treat osteoarthritis (OA). However, the mechanism of its therapeutic effect on OA is still unclear. AIM OF THE STUDY: The aim of this study was to investigate the potential anti osteoarthritis mechanism of EDS in the treatment of OA rats' model by quantitative proteomics. MATERIALS AND METHODS: A papain-induced rat OA model was established, and then EDS was intragastrically administered for 28 days. A label-free quantification proteomics was performed to evaluate the holistic efficacy of EDS against OA and identify the possible protein profiles mechanisms. The expression levels of critical changed proteins were validated by RT-qPCR and Western blotting. The effects of EDS were then assessed by evaluating pathologic changes in the affected knee joint and measuring pressure pain threshold, acoustic reflex threshold, angle of joint curvature. RESULTS: Proteomics analysis showed that 62 proteins were significantly upregulated and 208 proteins were downregulated in OA group compared to control group. The changed proteins were involved in activation of humoral immunity response, complement cascade activation, leukocyte mediated immunity, acute inflammatory response, endocytosis regulation, and proteolysis regulation. The EDS treatment partially restored the protein profile changes. The protective effects of EDS on pathologic changes in OA rats' knee joint and pain threshold assessment were consisted with the proteomics results. CONCLUSIONS: The results suggest that EDS exerted synergistic therapeutic efficacies to against OA through suppressing inflammation, modulating the immune system, relieving joint pain, and attenuating cartilage degradation.
Subject(s)
Drugs, Chinese Herbal/pharmacology , Immunity/drug effects , Inflammation/prevention & control , Osteoarthritis/prevention & control , Animals , Cartilage, Articular/drug effects , Cartilage, Articular/pathology , Complement System Proteins/drug effects , Complement System Proteins/genetics , Complement System Proteins/metabolism , Cytokines/blood , Disease Models, Animal , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/therapeutic use , Immunity/genetics , Inflammation/immunology , Knee Joint/pathology , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/genetics , Osteoarthritis/chemically induced , Osteoarthritis/immunology , Osteoarthritis/pathology , Pain Threshold/drug effects , Papain/toxicity , Proteome/drug effects , Proteome/genetics , Proteome/immunology , Proteomics/methods , Rats, Wistar , Ribosomal Proteins/drug effects , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolismABSTRACT
Carfilzomib has been associated with the development of thrombotic microangiopathy (TMA) in relapsed/refractory multiple myeloma patients, a severe disease with no currently available aetiological treatment. We evaluated the potential role of terminal complement pathway in four patients with carfilzomib-induced TMA. Membrane attack complex (C5b-9) deposition on endothelial cells in culture exposed to plasma from patients during the acute phase of the disease suggests complement overactivation as a mechanism of potential endothelial damage in three out of four patients. If confirmed in larger cohorts, C5b-9 evaluation will allow early identification of patients who could benefit from complement blockade and treatment monitoring.
Subject(s)
Complement System Proteins/drug effects , Multiple Myeloma/drug therapy , Oligopeptides/adverse effects , Thrombotic Microangiopathies/chemically induced , Ubiquitin/antagonists & inhibitors , Adult , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/pharmacology , Antibodies, Monoclonal, Humanized/therapeutic use , Complement Membrane Attack Complex/adverse effects , Complement Membrane Attack Complex/metabolism , Complement System Proteins/metabolism , Endothelial Cells/immunology , Endothelial Cells/metabolism , Female , Humans , Male , Middle Aged , Multiple Myeloma/complications , Oligopeptides/therapeutic use , Prospective Studies , Proteasome Inhibitors/adverse effects , Proteasome Inhibitors/therapeutic use , Thrombotic Microangiopathies/drug therapy , Thrombotic Microangiopathies/etiology , Thrombotic Microangiopathies/metabolism , Ubiquitin/metabolismABSTRACT
Coronavirus disease of 2019 (COVID-19) is a highly contagious respiratory infection that is caused by the severe acute respiratory syndrome coronavirus 2. Although most people are immunocompetent to the virus, a small group fail to mount an effective antiviral response and develop chronic infections that trigger hyperinflammation. This results in major complications, including acute respiratory distress syndrome, disseminated intravascular coagulation, and multiorgan failure, which all carry poor prognoses. Emerging evidence suggests that the complement system plays a key role in this inflammatory reaction. Indeed, patients with severe COVID-19 show prominent complement activation in their lung, skin, and sera, and those individuals who were treated with complement inhibitors all recovered with no adverse reactions. These and other studies hint at complement's therapeutic potential in these sequalae, and thus, to support drug development, in this review, we provide a summary of COVID-19 and review complement's role in COVID-19 acute respiratory distress syndrome and coagulopathy.
Subject(s)
Blood Coagulation Disorders/virology , Complement Activation/physiology , Coronavirus Infections/complications , Pneumonia, Viral/complications , Respiratory Distress Syndrome/virology , Animals , Betacoronavirus/immunology , Blood Coagulation/drug effects , Blood Coagulation Disorders/immunology , COVID-19 , Complement Activation/drug effects , Complement Inactivating Agents/therapeutic use , Complement System Proteins/drug effects , Coronavirus Infections/blood , Coronavirus Infections/immunology , Humans , Inflammation/immunology , Inflammation/virology , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , SARS-CoV-2ABSTRACT
BACKGROUND: Intravenous immunoglobulin (Ig) therapy is used based on empirical findings for treatment of antibody-mediated rejection (AMR) in cases of renal transplantation, although its therapeutic efficacy has not been proven and the functional mechanism of an administered Ig remains elusive. In this study, the therapeutic effects of an Ig were examined in a preclinical rat renal transplant model of AMR to investigate this mechanism. METHODS: To establish an AMR renal graft model, skin graft specimens were obtained from Brown-Norway (BN) rats and transplanted to Lewis rats to produce donor-specific antibodies (DSAs), after which kidney transplantation from the Brown-Norway to Lewis rats was performed. AMR model rats were administered the Ig at a dose of 2 g/kg or saline as a control. Survival period, renal graft histopathology, complement factors, and DSA levels were assessed. RESULTS: The survival period of the group administered the Ig was significantly prolonged. Histopathological examinations of renal grafts also showed significant suppression of glomerulitis and peritubular capillaritis in the Ig group, and real-time polymerase chain reaction analysis results demonstrated significantly lower levels of expression of the complement factors C1q and C3. When the Ig was given to rats that underwent skin grafting but not renal transplantation, DSA was decreased after 6 hours and remained lower than the baseline level for at least 7 days. CONCLUSION: Ig administration suppressed DSA production. The present results showed that suppression of the complement system contributed to effective Ig treatment for AMR.
Subject(s)
Graft Rejection/immunology , Graft Survival/drug effects , Immunoglobulins, Intravenous/pharmacology , Isoantibodies/drug effects , Kidney Transplantation/adverse effects , Adult , Animals , Complement System Proteins/drug effects , Disease Models, Animal , Female , Humans , Isoantibodies/immunology , Male , Rats , Rats, Inbred BN , Rats, Inbred Lew , Treatment OutcomeABSTRACT
In a recent study, we identified a fucosylated damage-associated ligand exposed by ischemia on renal tubule epithelial cells, which after recognition by collectin-11 (CL-11 or collectin kidney 1 (CL-K1)), initiates complement activation and acute kidney injury. We exploited the ability to increase the local tissue concentration of free l-fucose following systemic administration, in order to block ligand binding by local CL-11 and prevent complement activation. We achieved a thirty-five-fold increase in the intrarenal concentration of l-fucose following an IP bolus given before the ischemia induction procedure - a concentration found to significantly block in vitro binding of CL-11 on hypoxia-stressed renal tubule cells. At this l-fucose dose, complement activation and acute post-ischemic kidney injury are prevented, with additional protection achieved by a second bolus after the induction procedure. CL-11-/- mice gained no additional protection from l-fucose administration, indicating that the mechanism of l-fucose therapy was largely CL-11-dependent. The hypothesis is that a high dose of l-fucose delivered to the kidney obstructs the carbohydrate recognition site on CL-11 thereby reducing complement-mediated damage following ischemic insult. Further work will examine the utility in preventing post-ischemic injury during renal transplantation, where acute kidney injury is known to correlate with poor graft survival.
Subject(s)
Complement Activation/drug effects , Fucose/pharmacokinetics , Ischemia/drug therapy , Reperfusion Injury/drug therapy , Acute Kidney Injury/drug therapy , Acute Kidney Injury/metabolism , Animals , Complement System Proteins/drug effects , Complement System Proteins/metabolism , Fucose/metabolism , Graft Survival/drug effects , Ischemia/metabolism , Kidney/drug effects , Kidney/metabolism , Kidney Transplantation/methods , Mice, Knockout , Reperfusion Injury/metabolismABSTRACT
Although the use of EDTA-containing collection tubes is known to stabilize the complement analytes and to make the results more reliable, no external quality assessment (EQA) scheme based on EDTA plasma samples is available to date in France. Consequently, a number of clinical laboratories currently participate to EQA program on samples whose matrix is different from their routine practice. The aim of this work was to offer a new external quality assessment scheme, as an inter-laboratory exchange (ILE). The ILE samples come from pooled EDTA plasmas of healthy subjects and are diluted to obtain distinct control levels. The protocol has been validated on CH50, C3, C4 and C1-inhibitor measurements, through: (i) a stability study of post-centrifugation storage of EDTA plasma samples at room temperature, 4ÌC and -20ÌC; (ii) the demonstration of the linearity of the dilution steps; and (iii) a stability study of the diluted samples. Our results demonstrate a four-weeks stability of the ILE samples prepared and stored according to our protocol. Those results are compatible with the ILE implementation constraints, and the program has been implemented in January 2018. The one-year ILE implementation experience is also presented. The newly implemented ILE will be useful for the accreditation of the complement activity of French laboratories using EDTA plasma samples.
Subject(s)
Blood Chemical Analysis/methods , Blood Specimen Collection , Complement System Proteins/analysis , Edetic Acid/chemistry , Plasma/chemistry , Blood Chemical Analysis/standards , Blood Preservation/methods , Blood Preservation/standards , Blood Specimen Collection/methods , Blood Specimen Collection/standards , Complement System Proteins/drug effects , Complement System Proteins/metabolism , Edetic Acid/pharmacology , Excipients/chemistry , Excipients/pharmacology , Humans , Laboratory Proficiency Testing , Plasma/drug effects , Plasma/metabolism , Protein Stability/drug effects , Quality Assurance, Health Care/methods , Quality Control , Time Factors , Transportation/standardsABSTRACT
Bacterial meningitis is most commonly caused by Streptococcus pneumoniae and Neisseria meningitidis and continues to pose a major public health threat. Morbidity and mortality of meningitis are driven by an uncontrolled host inflammatory response. This comprehensive update evaluates the role of the complement system in upregulating and maintaining the inflammatory response in bacterial meningitis. Genetic variation studies, complement level measurements in blood and CSF, and experimental work have together led to the identification of anaphylatoxin C5a as a promising treatment target in bacterial meningitis. In animals and patients with pneumococcal meningitis, the accumulation of neutrophils in the CSF was mainly driven by C5-derived chemotactic activity and correlated positively with disease severity and outcome. In murine pneumococcal meningitis, adjunctive treatment with C5 antibodies prevented brain damage and death. Several recently developed therapeutics target C5 conversion, C5a, or its receptor C5aR. Caution is warranted because treatment with C5 antibodies such as eculizumab also inhibits the formation of the membrane attack complex, which may result in decreased meningococcal killing and increased meningococcal disease susceptibility. The use of C5a or C5aR antagonists to specifically target the harmful anaphylatoxins-induced effects, therefore, are most promising and present opportunities for a phase 2 clinical trial.
Subject(s)
Complement System Proteins/physiology , Meningitis, Bacterial/therapy , Animals , Complement C5a/genetics , Complement C5a/immunology , Complement System Proteins/cerebrospinal fluid , Complement System Proteins/drug effects , Humans , Immunotherapy , Inflammation/etiology , Inflammation/pathology , Meningitis, Bacterial/immunology , Meningitis, Bacterial/pathology , MiceABSTRACT
The triatomine insect Panstrongylus megistus , one of the most important Chagas disease vectors in Brazil, presents salivary molecules pharmacologically active to counteract homeostatic responses from the host, including inhibitors of the human complement system, a major effector of immune responses. The aim of the present study was to investigate the effect of P. megistus salivary gland extract (SGE) on the complement system from different host species and characterize the inhibitory effect of SGE and intestinal contents on human complement. Glands and midguts from fourth instar nymphs were used. Hemolytic assays were performed with sheep erythrocytes as complement activators by using human, rats and chickens sera in the presence or absence of SGE. An ELISA assay was carried out detect deposition of the C3b component on IgG- or agarose-sensitized microplates, in the presence or absence of SGE or midgut contents. P. megistus SGE was able to significantly inhibit the complement of the three studied species (human, rat and chiken). Both, SGE and midgut contents inhibited C3b deposition in either the classical or the alternative pathways. As conclusions, SGE and midgut from P. megistus possess anti-complement activity. The inhibitors are effective against different host species and act on the initial steps of the complement system cascade. These inhibitors may have a role in blood feeding and Trypanosoma cruzi transmission by the vector.
Subject(s)
Complement System Proteins/drug effects , Digestive System/chemistry , Insect Vectors , Panstrongylus , Salivary Glands/chemistry , Animals , Chagas Disease/transmission , Chickens , Humans , Rats , SheepABSTRACT
Subunit vaccines are safer but often poorly immunogenic in comparison to traditional vaccines, and thus, adjuvants and delivery vehicles are needed to enhance the immune response. The complement system is a part of the innate immune system, which plays an important role in innate and adaptive immunity. Therefore, the activation of the complement system could be utilized as a potential strategy for vaccine applications. Herein, cysteamine hydrochloride was grafted onto a methoxy poly(ethylene glycol)-block-poly (allyl glycidyl ether)-block-poly(ε-caprolactone) copolymer to synthesize a triblock polymer mPEG5k-PAGE15(NH2)-PCL5k(TPCAH) with amino groups on the side chain. The positive charge of the amino groups could bind with the negatively charged protein (like ovalbumin (OVA)) to form a stable complex by electrostatic interaction. The triblock copolymer TPCAH we designed can easily self-assemble into polymer nanomicelles, and the size of the nanoparticles is similar to that of the pathogens, which was beneficial to the uptake by lymphocytes. Furthermore, the amino groups modified on the side chain can not only integrate with proteins but also activate the complement system, thereby enhancing the immune response of subunit vaccines. The results showed that the complex TPCAH@OVA could efficiently promote powerful anti-OVA-specific antibody production, enhance CD4+ T- and CD8+ T-cell activation, improve the lymphocyte proliferation efficiency, and increase the secretion of different cytokines. In addition, the abundant amino groups on the surface of TPCAH@OVA could effectively activate the complement system to further enhance adaptive immunity. Overall, these results indicated that the triblock copolymer TPCAH as an adjuvant and carrier can effectively improve the ability of innate and adaptive immune responses to resist pathogens, making it a potential candidate for vaccine applications.
Subject(s)
Adaptive Immunity/drug effects , Complement System Proteins/immunology , Nanoparticles/chemistry , Vaccines, Subunit/pharmacology , Adaptive Immunity/immunology , Adjuvants, Immunologic/chemistry , Adjuvants, Immunologic/pharmacology , Animals , CD4-Positive T-Lymphocytes/drug effects , CD8-Positive T-Lymphocytes/drug effects , Cell Proliferation/drug effects , Complement System Proteins/drug effects , Cysteamine/chemistry , Drug Carriers/chemistry , Drug Carriers/pharmacology , Humans , Lymphocyte Activation/drug effects , Mice , Mice, Inbred C57BL , Micelles , Ovalbumin/chemistry , Ovalbumin/pharmacology , Polyesters/chemical synthesis , Polyesters/chemistry , Polyesters/pharmacology , Polyethylene Glycols/chemical synthesis , Polyethylene Glycols/chemistry , Polyethylene Glycols/pharmacology , Vaccines, Subunit/chemistry , Vaccines, Subunit/immunologyABSTRACT
The complement system plays a key role in pathogen immunosurveillance and tissue homeostasis. However, subversion of its tight regulatory control can fuel a vicious cycle of inflammatory damage that exacerbates pathology. The clinical merit of targeting the complement system has been established for rare clinical disorders such as paroxysmal nocturnal haemoglobinuria and atypical haemolytic uraemic syndrome. Evidence from preclinical studies and human genome-wide analyses, supported by new molecular and structural insights, has revealed new pathomechanisms and unmet clinical needs that have thrust a new generation of complement inhibitors into clinical development for a variety of indications. This review critically discusses recent clinical milestones in complement drug discovery, providing an updated translational perspective that may guide optimal target selection and disease-tailored complement intervention.
Subject(s)
Complement Activation/drug effects , Complement Inactivating Agents/pharmacology , Complement Inactivating Agents/therapeutic use , Complement System Proteins/drug effects , Complement System Proteins/immunology , Chronic Disease/drug therapy , Complement Inactivating Agents/adverse effects , Drug Discovery/methods , Humans , Inflammation/drug therapy , Models, BiologicalABSTRACT
The most frequent form of hemolytic-uremic syndrome (HUS) is associated with infections caused by Shiga-like toxin-producing Enterohaemorrhagic Escherichia coli (STEC). In rarer cases HUS can be triggered by Streptococcus pneumoniae. While production of Shiga-like toxins explains STEC-HUS, the mechanisms of pneumococcal HUS are less well-known. S. pneumoniae produces neuraminidases with activity against cell surface sialic acids that are critical for factor H-mediated complement regulation on cells and platelets. The aim of this study was to find out whether S. pneumoniae neuraminidase NanA could trigger complement activation and hemolysis in whole blood. We studied clinical S. pneumoniae isolates and two laboratory strains, a wild-type strain expressing NanA, and a NanA deletion mutant for their ability to remove sialic acids from various human cells and platelets. Red blood cell lysis and activation of complement was measured ex vivo by incubating whole blood with bacterial culture supernatants. We show here that NanA expressing S. pneumoniae strains and isolates are able to remove sialic acids from cells, and platelets. Removal of sialic acids by NanA increased complement activity in whole blood, while absence of NanA blocked complement triggering and hemolytic activity indicating that removal of sialic acids by NanA could potentially trigger pHUS.
Subject(s)
Neuraminidase/blood , Neuraminidase/metabolism , Streptococcus pneumoniae/enzymology , Streptococcus pneumoniae/metabolism , Bacterial Proteins/genetics , Blood Platelets/metabolism , Complement System Proteins/drug effects , Erythrocytes , HEK293 Cells , Hemolysis , Hemolytic-Uremic Syndrome/microbiology , Humans , Inflammation , Neuraminidase/genetics , Neuraminidase/pharmacology , Pneumococcal Infections/microbiology , Sequence Deletion , Sialic AcidsABSTRACT
CpG-DNA activates the host immune system to resist bacterial infections. In this study, we examined the protective effect of CpG-DNA in mice against Escherichia coli (E. coli) K1 infection. Administration of CpG-DNA increased the survival of mice after E. coli K1 infection, which reduces the numbers of bacteria in the organs. Pre-injection of mice with CpG-DNA before E. coli K1 infection increased the levels of the complement C3 but not C3a and C3b. The survival of the mice after E. coli K1 infection was significantly decreased when the mice were pre-injected with the cobra venom factor (CVF) removing the complement compared to the non-CVF-treated mice group. It suggests that the complement has protective roles against E. coli K1 infection. In addition, the survival of complement-depleted mice was increased by CpG-DNA pre-administration before E. coli K1 infection. Therefore, we suggest that CpG-DNA enhances the anti-bacterial activity of the immune system by augmenting the levels of complement systems after E. coli K1 infection and triggering other factors as well. Further studies are required to investigate the functional roles of the CpG-DNA-induced complement regulation and other factors against urgent bacterial infection.
Subject(s)
Anti-Bacterial Agents/pharmacology , Complement System Proteins/drug effects , Complement System Proteins/immunology , Immunologic Factors/pharmacology , Oligodeoxyribonucleotides/pharmacology , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemistry , Complement Activation/drug effects , Complement Activation/immunology , Escherichia coli/drug effects , Escherichia coli/immunology , Escherichia coli Infections/drug therapy , Escherichia coli Infections/immunology , Escherichia coli Infections/microbiology , Immunologic Factors/administration & dosage , Immunologic Factors/chemistry , Infusions, Parenteral , Mice , Oligodeoxyribonucleotides/administration & dosage , Oligodeoxyribonucleotides/chemistry , Phagocytosis/drug effects , Phagocytosis/immunologyABSTRACT
In previous studies, crude Houttuynia cordata polysaccharides showed beneficial effects on acute lung injury in vivo, a syndrome in which anti-complementary activities played an important role. Anti-complementary activity-guided fractionation of H. cordata polysaccharides led to the isolation of two highly branched homogeneous polysaccharides, HC-PS1 and HC-PS3, with a molecular weight of 274â530 and 216â384 Da, respectively. The polysaccharides were purified by chromatography on DEAE-cellulose and Superdex columns. Their structural characterization was performed by IR, GC-MS, methylation, NMR, and SEM analysis. Both HC-PS1 and HC-PS3 are composed of eight types of monosaccharides, including rhamnose, arabinose, mannose, glucose, glucuronic acid, galactose, galacturonic acid, and xylose. The main linkages of the sugar residues in HC-PS1 include terminal Rhap, terminal and 1,5-linked Araf; 1,3,6-linked and 1,4,6-linked Manp; terminal, 1,4-linked, 1,3-linked, 1,3,6-linked and 1,4,6-linked and 1,3,4,6-linked Glcp; and terminal, 1,4-linked and 1,6-linked Galp. The main monosaccharide linkages in HC-PS3 are similar to that of HC-PS1, except the additional 1,3,4-linked Manp and the absence of 1,3,6-linked Glcp. HC-PS1 and HC-PS3 were found to inhibit complement activation through both the classical and alternative pathways with 50% inhibition concentrations of 0.272â-â0.318 mg/mL without interfering with the coagulation system. Preliminary mechanism studies indicated that both HC-PS1 and HC-PS3 inhibited the activation of the complement system by interacting with C2, C4, and C5. The results suggest that HC-PS1 and HC-PS3 could be valuable for the treatment of diseases associated with the excessive activation of the complement system.
Subject(s)
Complement System Proteins/drug effects , Houttuynia/chemistry , Chromatography, DEAE-Cellulose , Complement Activation/drug effects , Humans , Magnetic Resonance Spectroscopy , Polysaccharides/chemistry , Polysaccharides/pharmacology , Spectroscopy, Fourier Transform InfraredABSTRACT
RATIONALE: Gain of function (GOF) mutations in PIK3CD gene encoding PI3K p110δ were recently associated with a novel combined immune deficiency characterized by recurrent sinopulmonary infections, CD4 lymphopenia, reduced class-switched memory B cells, lymphadenopathy, cytomegalovirus and/or epstein-Barr virus (EBV) viremia, and EBV-related lymphoma. A subset of affected patients also had elevated serum IgM. PATIENT CONCERNS: We report a patient who was diagnosed with systemic lupus erythematosus (SLE) at a young age and was recently found to carry heterozygous mutations in PIK3CD. The patient not only presented with recurrent sinopulmonary infections, CD4 lymphopenia, lymphadenopathy, EBV viremia, and elevated serum IgM, but also met classification criteria of SLE based on persistent proteinuria and hematuria, leukopenia and anemia, low level of serum complement, and positive autoantibody for antinuclear antibodies. DIAGNOSES: Activated PI3Kδ syndrome. INTERVENTIONS: Oral prednisolone and hydroxychloroquine combined with mycophenolate mofetil was given to the patient. He was currently receiving intravenous immunoglobulin per month in association with hydroxychloroquine, low-dose prednisolone, and mycophenolate mofetil. OUTCOMES: At present, the level of complement restored to normal, hematuria and proteinuria disappeared, and liver function returned to normal. LESSONS: SLE may be a novel phenotype of GOF mutation in PI3CKD gene (GOF PIK3CD).
Subject(s)
Class I Phosphatidylinositol 3-Kinases/genetics , Gain of Function Mutation/genetics , Immunologic Deficiency Syndromes/diagnosis , Immunologic Deficiency Syndromes/genetics , Lupus Erythematosus, Systemic/genetics , Adolescent , Antibodies, Antinuclear/blood , Asian People/genetics , Class I Phosphatidylinositol 3-Kinases/drug effects , Complement System Proteins/analysis , Complement System Proteins/drug effects , Enzyme Inhibitors/therapeutic use , Epstein-Barr Virus Infections/diagnosis , Epstein-Barr Virus Infections/etiology , Epstein-Barr Virus Infections/immunology , Glucocorticoids/therapeutic use , Herpesvirus 4, Human/immunology , Humans , Hydroxychloroquine/administration & dosage , Hydroxychloroquine/therapeutic use , Immunoglobulins, Intravenous/therapeutic use , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/etiology , Lupus Erythematosus, Systemic/immunology , Male , Mycophenolic Acid/administration & dosage , Mycophenolic Acid/therapeutic use , Phenotype , Prednisolone/administration & dosage , Prednisolone/therapeutic use , Primary Immunodeficiency DiseasesABSTRACT
Oligochitosan (OCHI) is known to have some specific biological activities. However, its interactions with blood components and related correlation with molecular structures remains to be clarified due to its growing use in biomedical areas. Herein, a series of OCHI were prepared by hydrogen peroxide induced degradation combined fractionation in ethanol solutions and their molecular structures were characterized by GPC, FTIR, 1H and 13C NMR, and then the interactions of the prepared OCHI with blood components, including red blood cells (hemolysis, deformability, and aggregation), coagulation system, complement (C3a, and C5a activation), and platelet (activation, and aggregation), were investigated. For red blood cells, OCHI has a quite low risk of hemolysis in a dose- and MW-dependent manner and the deformability and aggregation were observed in its high MW fraction. The coagulation tests revealed that OCHI is capable of a mild anticoagulation through blocking the intrinsic pathway and the anticoagulation corresponding MW was identified. In terms of complement, OCHI could inhibit C3a in a dose-dependent manner and activate C5a with its high MW fraction. In addition, there is no significant effect of OCHI on platelet activation and aggregation. Based on above results, the interactions related mechanism was discussed and proposed.
Subject(s)
Blood Coagulation/drug effects , Blood Platelets/drug effects , Chitin/analogs & derivatives , Platelet Aggregation/drug effects , Chitin/chemistry , Chitin/pharmacology , Chitosan , Complement Activation/drug effects , Complement System Proteins/drug effects , Erythrocytes/drug effects , Hemolysis/drug effects , Humans , Hydrogen Peroxide/chemistry , Oligosaccharides , Platelet Activation/drug effectsABSTRACT
Complement activation contributes to the pathogenesis of numerous inflammatory and autoimmune diseases. Therapeutic complement inhibitors have proven effective in several of these diseases and have now entered clinical use. Complement activation has multiple different biologic effects, however, and the currently available drugs can have undesirable side-effects, such as an increased risk of infection. Several different complement inhibitors have been developed that bind to target molecules, thereby concentrating the drug at a specific anatomic site. This approach appears to be both more effective than untargeted drugs and to have fewer side effects. In this article we review different targeting strategies that have been developed and the evidence supporting the use and benefits of targeted drugs.
Subject(s)
Complement Inactivating Agents/pharmacology , Complement System Proteins/drug effects , Molecular Targeted Therapy , Complement Activation/drug effects , HumansABSTRACT
The complement system resembles a double-edged sword since its activation can either benefit or harm the host. Thus, regulation of this system is of utmost importance and performed by several circulating and membrane-bound complement inhibitors. The pool of well-established regulators has recently been enriched with proteins that either share structural homology to known complement inhibitors such as Sushi domain-containing (SUSD) protein family and Human CUB and Sushi multiple domains (CSMD) families or extracellular matrix (ECM) macromolecules that interact with and modulate complement activity. In this review, we summarize the current knowledge about newly discovered complement inhibitors and discuss their implications in complement regulation, as well as in processes beyond complement regulation such cancer development. Understanding the behavior of these proteins will introduce new mechanisms of complement regulation and may provide new avenues in the development of novel therapies.