RESUMO
The current vaccine development strategies for the COVID-19 pandemic utilize whole inactive or attenuated viruses, virus-like particles, recombinant proteins, and antigen-coding DNA and mRNA with various delivery strategies. While highly effective, these vaccine development strategies are time-consuming and often do not provide reliable protection for immunocompromised individuals, young children, and pregnant women. Here, we propose a novel modular vaccine platform to address these shortcomings using chemically synthesized peptides identified based on the validated bioinformatic data about the target. The vaccine is based on the rational design of an immunogen containing two defined B-cell epitopes from the spike glycoprotein of SARS-CoV-2 and the universal T-helper epitope PADRE. The epitopes were conjugated to short DNA probes and combined with a complementary scaffold strand, resulting in sequence-specific self-assembly. The immunogens were then formulated by conjugation to gold nanoparticles by three methods or by co-crystallization with epsilon inulin. BALB/C mice were immunized with each formulation, and the IgG immune responses and virus neutralizing titers were compared. The results demonstrate that this assembly is immunogenic and generates neutralizing antibodies against wildtype SARS-CoV-2 and the Delta variant.
Assuntos
COVID-19 , Nanopartículas Metálicas , Complicações Infecciosas na Gravidez , Vacinas Virais , Gravidez , Camundongos , Animais , Feminino , Humanos , SARS-CoV-2 , Vacinas contra COVID-19 , Glicoproteína da Espícula de Coronavírus/química , Pandemias/prevenção & controle , COVID-19/prevenção & controle , Ouro , Camundongos Endogâmicos BALB C , Anticorpos Neutralizantes , Epitopos de Linfócito B/química , Anticorpos AntiviraisRESUMO
Hemostasis is a proteolytically regulated process that requires activation of platelets and the blood coagulation cascade upon vascular injury. Activated platelets create a thrombogenic environment and amplify the coagulation process. Plant latex proteases (PLPs) have been used as therapeutic components to treat various ailments by folk healers. One of the main applications of plant latices is to stop bleeding from minor injuries and to enhance wound healing activity. Although many studies have reported the pro-coagulant activities of PLPs, an in-depth investigation is required to understand the mechanism of action of PLPs on platelets. Here, the effect of PLPs on platelet aggregation was studied systematically to validate the observed pharmacological effect by folk healers. Among 29 latices from the Ficus genus tested, Ficus drupacea exhibited potent pro-coagulant and thrombin-like activity. Drupin, a thrombin-like cysteine protease responsible for platelet aggregation was purified from F. drupacea latex. Drupin exhibits pro-coagulant activity and reduces the bleeding time in mice tail. It induces platelet aggregation by activating mitogen-activated protein kinases and the nuclear factor-κB and PI3K/Akt signalling cascade, which, in turn, phosphorylats, cytosolic phospholipase A2 leading to the release of thromboxane A2 from the granules to activate the nearby platelets to aggregate. Furthermore, we investigated the involvement of protease-activated receptors in drupin-induced platelet aggregation using specific protease activated receptor 1 (PAR1) and PAR4 receptor antagonists. The results confirmed that the drupin-induced platelet aggregation was mediated by both PAR1 and PAR4, synergistically. Overall, drupin reduces the bleeding time by exerting pro-coagulant activity and induces platelet aggregation by activating the intracellular signalling cascade.
Assuntos
Plaquetas/metabolismo , Ficus/enzimologia , Peptídeo Hidrolases/farmacologia , Proteínas de Plantas/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Receptores de Trombina/metabolismo , Animais , Masculino , Camundongos , Transdução de Sinais/efeitos dos fármacosRESUMO
Coronavirus disease 2019 (COVID-19) is a global health emergency caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The rapid worldwide spread of SARS-CoV-2 infection has necessitated a global effort to identify effective therapeutic strategies in the absence of vaccine. Among the re-purposed drugs being tested currently, hydroxychloroquine (HCQ), without or with zinc ion (Zn++) and the antibiotic azithromycin (AZM), has been administered to prevent or treat patients with COVID-19. The outcome of multiple clinical studies on HCQ has been mixed. Zn++ interferes with viral replication by inhibiting replicative enzymes and its entry into cells may be facilitated by HCQ. Another immunomodulatory drug, methotrexate (MTX), is well known for its ability to mitigate overactive immune system by upregulating the anti-inflammatory protein, A20. However, its beneficial effect in treating COVID-19 has not drawn much attention. This review provides an overview of the virology of SARS-CoV-2 and an analysis of the mechanisms by which these anti-inflammatory agents may act in the treatment of COVID-19 patients. We propose a rationale for the combinatorial use of these re-purposed drugs that may help to combat this ongoing pandemic health emergency.
Assuntos
Anti-Inflamatórios/uso terapêutico , Antivirais/uso terapêutico , Infecções por Coronavirus/tratamento farmacológico , Reposicionamento de Medicamentos , Pneumonia Viral/tratamento farmacológico , COVID-19 , Infecções por Coronavirus/virologia , Quimioterapia Combinada , Humanos , Pandemias , Pneumonia Viral/virologia , Tratamento Farmacológico da COVID-19RESUMO
Trimeresurus malabaricus is a venomous pit viper species endemic to southwestern part of India. In earlier reports, we have shown that envenomation by T. malabaricus venom leading to strong local tissue damage but the mechanism of action is not clearly revealed. Local tissue damage affected by T. malabaricus venom is of great importance since the poison has serious systemic effects including death in the case of multiple attacks. The present study details the major manifestations of T. malabaricus venom and the induction of local tissue damage, which suggests that most toxins are present in the form of hydrolytic enzymes. Hydrolytic activity of the enzymes was measured and the data indicated that protease and phospholipase A2 activity was high which is responsible for local tissue damage. Furthermore, the role of hydrolytic enzymes in the induction of pathological events such as hemorrhage, edema, myotoxicity, and blood coagulation examination were assessed through animal models.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Venenos de Crotalídeos/toxicidade , Edema/patologia , Hemólise/efeitos dos fármacos , Hemorragia/patologia , Animais , Edema/induzido quimicamente , Hemorragia/induzido quimicamente , Humanos , Hidrólise , Peptídeo Hidrolases/metabolismo , Fosfolipases A2/metabolismo , TrimeresurusRESUMO
Dimerization of Toll-like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD2) heterodimers is critical for both MyD88- and TIR-domain-containing adapter-inducing IFN-ß (TRIF)-mediated signaling pathways. Recently, Zanoni et al. [(2011) Cell 147(4):868-880] reported that cluster of differentiation 14 (CD14) is required for LPS-/Escherichia coli- induced TLR4 internalization into endosomes and activation of TRIF-mediated signaling in macrophages. We confirmed their findings with LPS but report here that CD14 is not required for receptor endocytosis and downstream signaling mediated by TLR4/MD2 agonistic antibody (UT12) and synthetic small-molecule TLR4 ligands (1Z105) in murine macrophages. CD14 deficiency completely ablated the LPS-induced TBK1/IRF3 signaling axis that mediates production of IFN-ß in murine macrophages without affecting MyD88-mediated signaling, including NF-κB, MAPK activation, and TNF-α and IL-6 production. However, neither the MyD88- nor TRIF-signaling pathways and their associated cytokine profiles were altered in the absence of CD14 in UT12- or 1Z105-treated murine macrophages. Eritoran (E5564), a lipid A antagonist that binds the MD2 "pocket," completely blocked LPS- and 1Z105-driven, but not UT12-induced, TLR4 dimerization and endocytosis. Furthermore, TLR4 endocytosis is induced in macrophages tolerized by exposure to either LPS or UT12 and is independent of CD14. These data indicate that TLR4 receptor endocytosis and the TRIF-signaling pathway are dissociable and that TLR4 internalization in macrophages can be induced by UT12, 1Z105, and during endotoxin tolerance in the absence of CD14.
Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Receptor 4 Toll-Like/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/genética , Animais , Western Blotting , Células Cultivadas , Dissacarídeos/farmacologia , Relação Dose-Resposta a Droga , Endocitose/efeitos dos fármacos , Citometria de Fluxo , Células HEK293 , Humanos , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/metabolismo , Ligantes , Receptores de Lipopolissacarídeos/genética , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Confocal , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fosfatos Açúcares/farmacologia , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/antagonistas & inibidoresRESUMO
Innate immune inflammatory responses are subject to complex layers of negative regulation at intestinal mucosal surfaces. Although the type I IFN system is critical for amplifying antiviral immunity, it has been shown to play a homeostatic role in some models of autoimmune inflammation. Type I IFN is triggered in the gut by select bacterial pathogens, but whether and how the type I IFN might regulate innate immunity in the intestinal environment have not been investigated in the context of Salmonella enterica serovar Typhimurium (ST). ST infection of human or murine macrophages reveals that IFN-ß selectively restricts the transcriptional responses mediated by both the TLRs and the NOD-like receptors. Specifically, IFN-ß potently represses ST-dependent innate induction of IL-1 family cytokines and neutrophil chemokines. This IFN-ß-mediated transcriptional repression was independent of the effects of IFN-ß on ST-induced macrophage cell death, but significantly dependent on IL-10 regulation. We further evaluated ST pathogenesis in vivo following oral inoculation of mice lacking IFN-ß. We show that IFN-ß(-/-) mice exhibit greater resistance to oral ST infection and a slower spread of ST to distal sterile sites. This work provides mechanistic insight into the relationship between ST and type I IFN, and demonstrates an additional mechanism by which IFN-ß may promote spread of enteric pathogens.
Assuntos
Expressão Gênica/imunologia , Imunidade Inata/imunologia , Interferon beta/imunologia , Macrófagos/imunologia , Salmonella typhimurium/imunologia , Animais , Western Blotting , Linhagem Celular , Células Cultivadas , Quimiocinas/genética , Quimiocinas/imunologia , Quimiocinas/metabolismo , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Íleo/citologia , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/genética , Interferon beta/genética , Interferon beta/farmacologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salmonelose Animal/genética , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Salmonella typhimurium/fisiologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismoRESUMO
Endotoxin tolerance is a complex phenomenon characterized primarily by decreased production of proinflammatory cytokines, chemokines, and other inflammatory mediators, whereas the expression of other genes are induced or unchanged. Endotoxin tolerance is induced by prior exposure of murine macrophages/human monocytes, experimental animals, or people to TLR ligands. Although recent studies reported a possible relationship between endotoxin tolerance and differentiation of alternatively activated macrophages (AA-MΦs or M2), we show in this study that LPS pretreatment of IL-4Rα(-/-) and STAT6(-/-) macrophages, which fail to develop into AA-MΦs, resulted in tolerance of proinflammatory cytokines, as well as molecules and chemokines previously associated with AA-MΦs (e.g., arginase-1, mannose receptor, CCL2, CCL17, and CCL22). In contrast to LPS, wild-type (WT) MΦs pretreated with IL-4, the prototype inducer of AA-MΦs, did not induce endotoxin tolerance with respect to proinflammatory cytokines, AA-MΦ-associated chemokines, negative regulators, NF-κB binding and subunit composition, and MAPKs; conversely, IL-13(-/-) macrophages were tolerized equivalently to WT MΦs by LPS pretreatment. Further, IL-4Rα deficiency did not affect the reversal of endotoxin tolerance exerted by the histone deacetylase inhibitor trichostatin A. Like WT mice, 100% of LPS-tolerized IL-4Rα-deficient mice survived LPS + d-galactosamine-induced lethal toxicity and exhibited decreased serum levels of proinflammatory cytokines and AA-MΦ-associated chemokines induced by LPS challenge compared with nontolerized mice. These data indicate that the signaling pathways leading to endotoxin tolerance and differentiation of AA-MΦs are dissociable.
Assuntos
Diferenciação Celular/imunologia , Endotoxinas/imunologia , Tolerância Imunológica/imunologia , Macrófagos/imunologia , Animais , Diferenciação Celular/genética , Linhagem Celular , Endotoxinas/metabolismo , Tolerância Imunológica/genética , Interleucina-13/genética , Interleucina-13/imunologia , Interleucina-13/metabolismo , Lipopolissacarídeos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , NF-kappa B/genética , NF-kappa B/imunologia , NF-kappa B/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Receptores de Superfície Celular/metabolismo , Fator de Transcrição STAT6/genética , Fator de Transcrição STAT6/imunologia , Fator de Transcrição STAT6/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Transcriptoma/genética , Transcriptoma/imunologiaRESUMO
Autoimmune diseases, such as rheumatoid arthritis, frequently target one major tissue/organ despite the systemic nature of the immune response. This is particularly perplexing in the case of ubiquitously distributed antigens invoked in arthritis induction. We reasoned that selective targeting of the synovial joints in autoimmune arthritis might be due in part to the unique attributes of the joint vasculature. We examined this proposition using the adjuvant-induced arthritis model of human rheumatoid arthritis, and profiled the synovial vasculature using ex vivo and in vivo screening of a defined phage peptide-display library. We identified phage that preferentially homed to the inflamed joints. The corresponding synthetic peptides showed binding to the joint-derived endothelial cells, as well as specificity in inhibiting binding of the respective phage to the synovial vasculature. Intriguingly, the treatment of arthritic rats with one such peptide resulted in efficient inhibition of the progression of arthritis. The suppression of arthritis was attributable in part to the peptide-induced reduction of T-cell trafficking into the joints and the inhibition of angiogenesis. This peptide differed in sequence, in receptor binding specificity, and in angiogenesis/inflammation-related cell signaling from the previously characterized arginine-glycine-aspartic acid-containing peptide. Thus, our study reveals joint-homing peptides that can be further exploited for the selective delivery of antiarthritic agents into the inflamed joints to enhance their efficacy while reducing systemic toxicity, and also for examining intricacies of the pathogenesis of arthritis. This approach can be customized for application to other organ-specific autoimmune diseases as well.
Assuntos
Artrite Experimental/imunologia , Peptídeos/imunologia , Membrana Sinovial/imunologia , Vasculite/imunologia , Sequência de Aminoácidos , Animais , Artrite Experimental/patologia , Artrite Experimental/prevenção & controle , Western Blotting , Adesão Celular/efeitos dos fármacos , Adesão Celular/imunologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Células Cultivadas , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Humanos , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Biblioteca de Peptídeos , Peptídeos/genética , Peptídeos/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Endogâmicos Lew , Membrana Sinovial/irrigação sanguínea , Membrana Sinovial/patologia , Vasculite/prevenção & controleRESUMO
Snake bite envenomation causes tissue damage resulting in acute and chronic inflammatory responses. Inflammasome activation is one of the factors involved in tissue damage in a mouse model of snake envenomation. The present study examines the potency of Indian Big Four snake venoms in the activation of inflammasome and its role in local and systemic tissue toxicity. Among Indian Big Four snake venoms, Naja naja venom activated NLRP3 inflammasome in mouse macrophages. Activation of NLRP3 inflammasome was also observed in mouse foot paw and thigh muscle upon administration of N. naja venom. Intraperitoneal administration of N. naja venom cause systemic lung damage showed activation of NLRP3 inflammasome. Treatment with MCC950, a selective NLRP3 inflammasome inhibitor effectively inhibited N. naja venom-induced activation of caspase-1 and liberation of IL-1ß in macrophages. In mice, MCC950 partially inhibited the activation of NLRP3 inflammasome in N. naja venom administered foot paw and thigh muscle. In conclusion, the present data showed that inflammasome is one of the host responses involved in N. naja snake venom-induced toxicities. The inhibition of inflammasome activation will provide new insight into better management of snake bite-induced local tissue damage.
Assuntos
Inflamassomos , Mordeduras de Serpentes , Camundongos , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR , Naja naja , Venenos Elapídicos/toxicidade , Venenos de Serpentes , SulfonamidasRESUMO
Psoriasis is a chronic immune-mediated inflammatory skin disease that involves dysregulated proliferation of keratinocytes. Psoriatic skin lesions are characterized by redness, thickness, and scaling. The interleukin axis of IL-23/IL-17 is critically involved in the development of human psoriasis. Imiquimod (IMQ), an agonist of TLR7 is known to induce psoriatic-like skin inflammation in mice. The topical application of IMQ induces systemic inflammation with increased proinflammatory cytokines in serum and secondary lymphoid organs. Further, matrix metalloproteases (MMPs) have been implicated in the pathophysiology of psoriatic-like skin inflammation. The increased MMP9 activity and gene expression of proinflammatory cytokines in IMQ-induced psoriatic skin is mediated by the activation of the MAPK pathway. Moreover, the increased expression of neutrophil-specific chemokines confirmed the infiltration of neutrophils at the site of psoriatic skin inflammation. In contrast, expression of IL-10, an anti-inflammatory cytokine gene expression is reduced in IMQ-treated mice skin. Topical application of unconjugated bilirubin (UCB) and its derivative dimethyl ester of bilirubin (BD1) on IMQ-induced psoriatic mice skin significantly mitigated the symptoms of psoriasis by inhibiting the activity of MMP9. Further, UCB and BD1 reduced neutrophil infiltration as evidenced by decreased myeloperoxidase (MPO) activity and reduced gene expression of proinflammatory cytokines, and neutrophil-specific chemokines. Apart from these modulations UCB and BD1 reduced MAPK phosphorylation and upregulated anti-inflammatory cytokines. To conclude, UCB and BD1 immunomodulated the psoriatic skin inflammation induced by IMQ in mice by inhibiting neutrophil mediated MMP9, decreased proinflammatory cytokines gene expression and modulating the MAPK pathway.
Assuntos
Dermatite , Psoríase , Humanos , Animais , Camundongos , Imiquimode/uso terapêutico , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Psoríase/metabolismo , Pele/patologia , Queratinócitos/metabolismo , Dermatite/patologia , Citocinas/metabolismo , Inflamação/metabolismo , Anti-Inflamatórios/efeitos adversos , Quimiocinas/metabolismo , Modelos Animais de Doenças , Camundongos Endogâmicos BALB CRESUMO
Naja naja snake bite causes thousands of deaths worldwide in a year. N. naja envenomed victims exhibit both local and systemic reactions that potentially lead to death. In clinical practice, pulmonary complications in N. naja envenomation are commonly encountered. However, the molecular mechanisms underlying N. naja venom-induced lung toxicity remain unknown. Here, we reasoned that N. naja venom-induced lung toxicity is prompted by NLRP3 inflammasome and MAPKs activation in mice. Treatment with dimethyl ester of bilirubin (BD1), significantly inhibited the N. naja venom-induced activation of NLRP3 inflammasome and MAPKs both in vivo and in vitro (p < 0.05). Further, BD1 reduced N. naja venom-induced recruitment of inflammatory cells, and hemorrhage in the lung toxicity examined by histopathology. BD1 also diminished N. naja venom-induced local toxicities in paw edema and myotoxicity in mice. Furthermore, BD1 was able to enhance the survival time against N. naja venom-induced mortality in mice. In conclusion, the present data showed that BD1 alleviated N. naja venom-induced lung toxicity by inhibiting NLRP3 inflammasome and MAPKs activation. Small molecule inhibitors that intervene in venom-induced toxicities may have therapeutic applications complementing anti-snake venom.
Assuntos
Venenos Elapídicos , Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Naja naja , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Camundongos , Venenos Elapídicos/toxicidade , Bilirrubina , Mordeduras de Serpentes/tratamento farmacológico , Pulmão/efeitos dos fármacos , Pulmão/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , MasculinoRESUMO
Inflammation underlying immune pathology and tissue damage involves an intricate interplay between multiple immunological and biochemical mediators. Cytokines represent the key immune mediators that trigger a cascade of reactions that drive processes such as angiogenesis and proteolytic damage to tissues. IL-17 has now been shown to be a pivotal cytokine in many autoimmune diseases, supplanting the traditional Th1-Th2 paradigm. Also, the dual role of proinflammatory IFN-γ has unraveled new complexities in the cytokine biology of such disorders. A major hurdle in fully understanding the effector pathways in these disorders is the lack of information regarding the temporal kinetics of the cytokines during the course of the disease, as well as the interplay among the key cytokines. Using an experimental model of arthritic inflammation, we demonstrate that the temporal expression of cytokines during the incubation phase is a critical determinant of disease susceptibility. The susceptible rats raised a vigorous IL-17 response early, followed by IFN-γ and IL-27 response in that sequence, whereas the resistant rats displayed an early and concurrent response to these three cytokines. Accordingly, treatment with exogenous IFN-γ/IL-27 successfully controlled arthritic inflammation and inhibited the defined mediators of inflammation, angiogenesis, cell survival, apoptosis, and tissue damage. Furthermore, IFN-γ enhanced IL-27 secretion, revealing a cooperative interplay between the two cytokines. Our results offer a novel immunobiochemical perspective on the pathogenesis of autoimmune arthritis and its therapeutic control.
Assuntos
Artrite Experimental/metabolismo , Doenças Autoimunes/metabolismo , Interferon gama/metabolismo , Interleucinas/metabolismo , Indutores da Angiogênese/imunologia , Indutores da Angiogênese/metabolismo , Animais , Apoptose/imunologia , Artrite Experimental/induzido quimicamente , Artrite Experimental/tratamento farmacológico , Artrite Experimental/imunologia , Artrite Experimental/patologia , Doenças Autoimunes/induzido quimicamente , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Sobrevivência Celular/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Interferon gama/imunologia , Interferon gama/farmacologia , Interleucina-17/imunologia , Interleucina-17/metabolismo , Interleucinas/imunologia , Interleucinas/farmacologia , Ratos , Ratos Endogâmicos Lew , Ratos Endogâmicos WKY , Especificidade da EspécieRESUMO
Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation and articular damage. Proinflammatory cytokines, antibodies, and matrix-degrading enzymes orchestrate the pathogenic events in autoimmune arthritis. Accordingly, these mediators of inflammation are the targets of several anti-arthritic drugs. However, the prolonged use of such drugs is associated with severe adverse reactions. This limitation has necessitated the search for less toxic natural plant products that possess anti-arthritic activity. Furthermore, it is imperative that the mechanism of action of such products be explored before they can be recommended for further preclinical testing. Using the rat adjuvant-induced arthritis model of human RA, we demonstrate that celastrol derived from Celastrus has potent anti-arthritic activity. This suppression of arthritis is mediated via modulation of the key proinflammatory cytokines (IL-17, IL-6, and IFN-γ) in response to the disease-related antigens, of the IL-6/IL-17-related transcription factor STAT3, of antibodies directed against cyclic citrullinated peptides and Bhsp65, and of the activity of matrix metalloproteinase-9 and phospho-ERK. Most of the clinical and mechanistic attributes of celastrol are similar to those of Celastrus extract. Several studies have addressed the antitumor activity of celastrol. Our study highlights the anti-arthritic activity of Celastrus-derived celastrol and the underlying mechanisms. These results provide a strong rationale for further testing and validation of the use of celastrol and the natural plant extract from Celastrus as an adjunct (with conventional drugs) or alternative modality for the treatment of RA.
Assuntos
Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Celastrus , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Animais , Antígenos/imunologia , Doenças Autoimunes , Celastrus/química , Ratos , Resultado do TratamentoRESUMO
OBJECTIVE: Rheumatoid arthritis (RA) is a debilitating autoimmune disease, and smoking is an important environmental factor in a subset of RA patients. A role of the cholinergic antiinflammatory pathway in autoimmune inflammation is increasingly being realized. Nicotine is a major component of cigarette smoke, and it stimulates the α7 nicotinic acetylcholine receptors. Therefore, defining the mechanisms underlying the immunomodulatory effects of nicotine on arthritis is of high relevance. The purpose of this study was to address this issue using the rat adjuvant-induced arthritis (AIA) model of human RA. METHODS: Lewis rats were immunized subcutaneously with heat-killed Mycobacterium tuberculosis H37Ra for disease induction. Rats were treated with nicotine intraperitoneally either before (pretreatment) or after (posttreatment) the onset of AIA. Control rats received the vehicle (buffer) in place of nicotine. The severity of arthritis was assessed and graded. The draining lymph node cells were tested for T cell proliferative and cytokine responses against the disease-related antigen mycobacterial heat-shock protein 65. The sera were tested for anti-cyclic citrullinated peptide (anti-CCP) antibodies and anti-mycobacterial Hsp65 antibodies. RESULTS: Nicotine pretreatment aggravated the arthritis, whereas nicotine posttreatment suppressed the disease. This altered severity of AIA directly correlated with the levels of the anti-CCP antibodies, of the Th1/Th17 cytokines, and of the corresponding dendritic cell-derived cytokines. The majority of these effects on cellular responses could be replicated in vitro. CONCLUSION: Nicotine-induced modulation of AIA involves specific alterations in the disease-related cellular and humoral immune responses in AIA. These results are of significance in advancing our understanding of the pathogenesis of RA.
Assuntos
Anticorpos Anti-Idiotípicos/metabolismo , Artrite Experimental/metabolismo , Doenças Autoimunes/metabolismo , Proteínas de Bactérias/imunologia , Chaperonina 60/imunologia , Interleucina-17/metabolismo , Nicotina/farmacologia , Peptídeos Cíclicos/imunologia , Animais , Artrite Experimental/patologia , Doenças Autoimunes/patologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Ratos , Ratos Endogâmicos Lew , Índice de Gravidade de Doença , Linfócitos T/patologia , Fatores de TempoRESUMO
This study was aimed at examining the effect of an ointment containing essential oils (EO) on the severity of adjuvant arthritis (AA), an experimental model of human rheumatoid arthritis (RA), in Lewis rats and to define the underlying mechanisms. At the onset of AA, the rats received topical application twice daily of an ointment containing 20% EO or placebo ointment. The synovial fluid (SF) and synovium-infiltrating cells (SIC) of rats were tested for pro-inflammatory cytokines TNF-α and IL-1ß. The hind paws and skin were examined histologically. The activity/level of matrix metalloproteinases (MMPs) and anti-mycobacterial heat-shock protein 65 (Bhsp65) antibodies were tested. Arthritic rats treated with ointment containing EO developed less severe clinical arthritis compared with the controls, and this activity was attributable to EO and not to the carrier oil. The levels of TNF-α and IL-1ß, and the activity of MMPs in SF and SIC-lysate were significantly reduced in EO-treated arthritic rats compared with the controls. However, the levels of anti-Bhsp65 antibodies were unaffected by treatment. Thus, topical dermal delivery of EO-containing ointment down-modulates the severity of AA in Lewis rats by inhibiting defined mediators of inflammation. Such ointments should be tested in patients with RA and other arthritic conditions.
Assuntos
Anti-Inflamatórios/uso terapêutico , Artrite Experimental/tratamento farmacológico , Mediadores da Inflamação/metabolismo , Inflamação/prevenção & controle , Óleos Voláteis/uso terapêutico , Extratos Vegetais/uso terapêutico , Membrana Sinovial/efeitos dos fármacos , Administração Tópica , Animais , Anti-Inflamatórios/farmacologia , Artrite Experimental/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Masculino , Metaloproteinases da Matriz/metabolismo , Óleos Voláteis/farmacologia , Pomadas , Extratos Vegetais/farmacologia , Ratos , Ratos Endogâmicos Lew , Índice de Gravidade de Doença , Membrana Sinovial/citologia , Membrana Sinovial/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The current vaccine development strategies for the COVID-19 pandemic utilize whole inactive or attenuated viruses, virus-like particles, recombinant proteins, and antigen-coding DNA and mRNA with various delivery strategies. While highly effective, these vaccine development strategies are time-consuming and often do not provide reliable protection for immunocompromised individuals, young children, and pregnant women. Here, we propose a novel modular vaccine platform to address these shortcomings using chemically synthesized peptides and identified based on the validated bioinformatic data about the target. The vaccine is based on the rational design of an immunogen containing two defined B-cell epitopes from the spike protein of SARS-Co-V2 and a universal T-helper epitope PADRE assembled on the DNA scaffold. The results demonstrate that this assembly is immunogenic and generates neutralizing antibodies against SARS-CoV-2 wild type and its variants of concerns (VOC). This newly designed peptide nanoarray scaffold vaccine is useful in controlling virus transmission in immunocompromised individuals, as well as individuals who are prone to vaccine-induced adverse reactions. Given that the immunogen is modular, epitopes or immunomodulatory ligands can be easily introduced in order to tailor the vaccine to the recipient. This also allows the already developed vaccine to be modified rapidly according to the identified mutations of the virus.
RESUMO
Rheumatoid arthritis (RA) is a debilitating autoimmune disease of global prevalence. The disease is characterized by synovial inflammation leading to cartilage and bone damage. Most of the conventional drugs used for the treatment of RA have severe adverse reactions and are quite expensive. Over the years, increasing proportion of patients with RA and other immune disorders are resorting to complementary and alternative medicine (CAM) for their health needs. Natural plant products comprise one of the most popular CAM for inflammatory and immune disorders. These herbal CAM belong to diverse traditional systems of medicine, including traditional Chinese medicine, Kampo, and Ayurvedic medicine. In this paper, we have outlined the major immunological pathways involved in the induction and regulation of autoimmune arthritis and described various herbal CAM that can effectively modulate these immune pathways. Most of the information about the mechanisms of action of herbal products in the experimental models of RA is relevant to arthritis patients as well. The study of immunological pathways coupled with the emerging application of genomics and proteomics in CAM research is likely to provide novel insights into the mechanisms of action of different CAM modalities.
RESUMO
Rheumatoid arthritis (RA) is one of the major autoimmune diseases of global prevalence. The use of the anti-inflammatory drugs for the treatment of RA is associated with severe adverse reactions and toxicity. This limitation has necessitated the search for novel therapeutic products. We report here a traditional Chinese medicine-based herbal formula, Huo luo xiao ling dan (HLXL), which has potent antiarthritic activity as validated in the rat adjuvant-induced arthritis (AA) model. HLXL (2.3 g/Kg) was fed to Lewis (RT.1(1)) rats daily by gavage beginning at the onset of arthritis and then continued through the observation period. HLXL inhibited the severity of ongoing AA. This suppression of arthritis was associated with significant alterations in the T cell proliferative and cytokine responses as well as the antibody response against the disease-related antigen, mycobacterial heat-shock protein 65 (Bhsp65). There was a reduction in the level of the proinflammatory cytokines IL-17 and IL-1ß but enhancement of the anti-inflammatory cytokine IL-10 level. In addition, there was inhibition of both the anti-Bhsp65 antibody response and the serum level of nitric oxide. Thus, HLXL is a promising CAM modality for further testing in RA patients.
RESUMO
The COVID-19 pandemic has persisted for more than a year, and post-COVID-19 sequelae of neurological complications, including direct and indirect effects on the central nervous system (CNS), have been recognized. There is a plethora of evidence for neurological, cognitive, and emotional deficits in COVID-19 patients. Acute neurological symptoms like neuroinflammation, cognitive impairment, loss of smell, and brain stroke are common direct effects among SARS-CoV-2 infected individuals. Work-associated stress, lockdowns, social distancing, and quarantine in response to contain SARS-CoV-2 have also affected the mental health of large populations, regardless of age. Public health emergencies have affected individuals and communities, resulting in emotional reactions and unhealthy behaviors. Although vaccines have been widely distributed and administered among large populations, vaccine hesitancy still exists and may be due to apprehension about vaccine efficacy, preliminary trials, and associated side effects. This review highlights the impact of COVID-19 on the CNS by outlining direct and indirect effects and factors contributing to the decline in people's mental health throughout the COVID-19 pandemic both during and after vaccine administration. Furthermore, we also discuss reasons for vaccine hesitancy and why some groups of people are deprived of vaccines. Finally, we touched upon the social determinants of mental health and their impact on disadvantaged populations during times of crisis which may help policymakers set up some action plans to mitigate the COVID-19 mental health turmoil during this ongoing pandemic.
Assuntos
COVID-19/psicologia , Recusa de Vacinação/psicologia , Vacinação/psicologia , Vacinas contra COVID-19/administração & dosagem , Controle de Doenças Transmissíveis , Humanos , Estudos Longitudinais , Saúde Mental/tendências , Pandemias/prevenção & controle , Saúde Pública , SARS-CoV-2/patogenicidade , Vacinação/tendências , Recusa de Vacinação/tendências , VacinasRESUMO
Echis carinatus (EC) is known as saw-scaled viper and it is endemic to the Indian subcontinent. Envenoming by EC represents a major cause of snakebite mortality and morbidity in the Indian subcontinent. Zinc (Zn++) dependent snake venom metalloproteases (SVMPs) present in Echis carinatus venom (ECV) is well known to cause systemic hemorrhage and coagulopathy in experimental animals. An earlier report has shown that ECV activates neutrophils and releases neutrophil extracellular traps (NETs) that blocks blood vessels leading to severe tissue necrosis. However, the direct involvement of SVMPs in the release of NETs is not clear. Here, we investigated the direct involvement of EC SVMPs in observed pathological symptoms in a preclinical setup using specific Zn++ metal chelator, Tetraethyl thiuram disulfide (TTD)/disulfiram. TTD potently antagonizes the activity of SVMPs-mediated ECM protein degradation in vitro and skin hemorrhage in mice. In addition, TTD protected mice from ECV-induced footpad tissue necrosis by reduced expression of citrullinated H3 (citH3) and myeloperoxidase (MPO) in footpad tissue. TTD also neutralized ECV-induced systemic hemorrhage and conferred protection against lethality in mice. Moreover, TTD inhibited ECV-induced NETosis in human neutrophils and decreased the expression of peptidyl arginine deiminase (PAD) 4, citH3, MPO, and p-ERK. Further, we demonstrated that ECV-induced NETosis and tissue necrosis are mediated via PAR-1-ERK axis. Overall, our results provide an insight into SVMPs-induced toxicities and the promising protective efficacy of TTD can be extrapolated to treat severe tissue necrosis complementing anti-snake venom (ASV).