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1.
Journal of the ASEAN Federation of Endocrine Societies ; : 125-130, 2023.
Artigo em Inglês | WPRIM | ID: wpr-984402

RESUMO

@#Autoimmunity associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been well-described as the mechanism of development of thyroid dysfunction following Coronavirus Disease 19 (COVID-19) infection and SARS-CoV-2 vaccination. However, the occurrence of thyroid eye disease (TED) after SARS-CoV-2 vaccination is scarcely described. The postulated mechanisms include immune reactivation, molecular mimicry and the autoimmune/inflammatory syndrome induced by adjuvants (ASIA). We report a case of new-onset TED after receiving the SARSCoV- 2 vaccine.


Assuntos
Oftalmopatia de Graves , Vacinas contra COVID-19 , Mimetismo Molecular
2.
Rev. Ciênc. Méd. Biol. (Impr.) ; 21(1): 94-97, maio 05,2022. fig
Artigo em Inglês | LILACS | ID: biblio-1370739

RESUMO

Introduction: there are reports of autoimmune disease related to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) such neurological syndromes and hematological syndromes, and more recently autoimmune thyroid dysfunctions have been described. These reports suggest that SARS-CoV-2 acts as a probable trigger for triggering the autoimmunity process. Aim: to evaluate structural similarity between thyroid peroxidase [Homo sapiens] (TPO) and SARS-CoV-2 spike glycoprotein (COVID-19), and to propose this similarity as a likely trigger for autoimmune thyroiditis. Methodology: using bioinformatics tools, we compare the amino acids (AA) sequences between protein structure of TPO and chain A COVID-19, chain B COVID-19, and chain C COVID-19, accessible in the National Center for Biotechnology Information database, by Basic Local Alignment Search Tool in order to locate the homologous regions between the sequences of AA. Results: the homology sequence between the TPO and COVID-19 ranged from 27.0 % (10 identical residues out of 37 AA in the sequence) to 56.0% (5 identical residues out of 9 AA in the sequence). The similar alignments demonstrated relatively high E values in function of short alignment. Conclusion: data suggest a possible pathological link between TPO and COVID-19. The structural similarity of AA sequences between TPO and COVID-19 may present a molecular mimicry suggesting the possibility of antigen crossover between TPO and COVID-19 that might represent an immunological basis for autoimmune thyroiditis associated with COVID-19.


Introdução: há relatos de doenças autoimunes relacionadas à síndrome respiratória aguda grave por coronavírus 2 (SARS-CoV-2), tais como síndromes neurológicas e hematológicas, e mais recentemente disfunções autoimunes da tireoide foram descritas. Esses relatos sugerem que o SARS-CoV-2 atue como um provável gatilho para desencadear o processo de autoimunidade. Objetivo: avaliar a similaridade estrutural entre a peroxidase tireoidiana [Homo sapiens] (TPO) e a glicoproteína de superfície SARS-CoV-2 (COVID-19) e propor essa similaridade como provável gatilho para o desencadeamento da tireoidite autoimune. Metodologia: utilizando ferramentas de bioinformática, comparamos as sequências de aminoácidos (AA) entre a estrutura da TPO e a estrutura da cadeia A do COVID-19, a cadeia B do COVID-19 e a cadeia C do COVID-19, acessível no banco de dados do National Center for Biotechnology Information, através da Ferramenta Básica de Pesquisa de Alinhamento Local para localizar as regiões homólogas entre as sequências de AA. Resultados: a sequência de homologia entre o TPO e COVID-19 variou de 27,0% (10 resíduos idênticos em 37 AA nas sequências) a 56,0% (5 resíduos idênticos em 9 AA nas sequências). Os alinhamentos semelhantes demonstraram valores E relativamente altos em função do alinhamento curto. Conclusão: os dados sugerem uma possível ligação patológica entre TPO e COVID-19. A similaridade estrutural das sequências de AA entre TPO e COVID-19 pode apresentar um mimetismo molecular sugerindo a possibilidade de cruzamento de antígeno entre TPO e COVID-19 que podem representar uma base imunológica para tireoidite autoimune associada a COVID-19.


Assuntos
Humanos , Masculino , Feminino , Tireoidite Autoimune , Peroxidase , Mimetismo Molecular , Síndrome Respiratória Aguda Grave , SARS-CoV-2
3.
Journal of the Korean Neurological Association ; : 8-19, 2019.
Artigo em Coreano | WPRIM | ID: wpr-766753

RESUMO

Guillain-Barré syndrome (GBS) is a representative form of post-infectious autoimmune neuropathy with heterogenous manifestations. It was originally considered as an ascending demyelinating polyneuropathy in Western countries. However, the discovery of anti-ganglioside antibodies on the basis of molecular mimicry theory could help us better understand various kinds of focal and regional variants as well as axonal type of GBS those were frequently found from Asian countries. Recent development of new techniques about anti-ganglioside complex antibodies is making more detailed descriptions for specific or unusual clinical manifestations. It has been regarded that GBS has good prognosis if treated properly as early as possible, but it still shows high mortality and morbidity rate with frequent long term neurologic and medical complications. Unfortunately, there are only two options for medical treatment, intravenous immunoglobulin and plasmapheresis, for the last 100 years. Several clinical studies on new immunotherapy targeting complement activating system with background of molecular mimicry using animal model are underway. We hope that these new treatments will be helpful for the future patients.


Assuntos
Humanos , Anticorpos , Povo Asiático , Axônios , Proteínas do Sistema Complemento , Gangliosídeos , Síndrome de Guillain-Barré , Esperança , Imunoglobulinas , Imunoterapia , Síndrome de Miller Fisher , Modelos Animais , Mimetismo Molecular , Mortalidade , Plasmaferese , Polineuropatias , Prognóstico
4.
National Journal of Andrology ; (12): 533-539, 2018.
Artigo em Chinês | WPRIM | ID: wpr-689695

RESUMO

<p><b>Objective</b>To investigate the effect of Qilan Capsules (QLC) on the expressions of the related proteins HIF-1α, VEGF-α, EphA2 and MMP-1 in the formation of vasculogenic mimicry (VM) in prostate cancer.</p><p><b>METHODS</b>Prostate cancer PC-3 cells were cultured, transfected with siRNA, and divided into eight groups, blank control, HIF-1α siRNA, VEGF-α siRNA, EphA2 siRNA, QLC intervention, QLC + HIF-1α siRNA, QLC + VEGF-α siRNA, and QLC + EphA2 siRNA. The expressions of the HIF-1α, VEGF-α and EphA2 proteins in the pathway of VEGF were determined by Western blot.</p><p><b>RESULTS</b>Compared with the blank control group, the expression of HIF-1α was evidently decreased in the HIF-lα siRNA and QLC + HIF-lα siRNA groups (0.624 7 ± 0.042 8 vs 0.032 8 ± 0.002 5 and 0.036 8 ± 0.018 1, P < 0.05), so were that of VEGF-α in the VEGF-α siRNA and QLC + VEGF-α siRNA groups (0.068 9 ± 0.005 1 vs 0.016 9 ± 0.000 7 and 0.010 9 ± 0.000 8, P < 0.05), that of EphA2 in the EphA2 siRNA and QLC + EphA2 siRNA groups though with no statistically significant difference (0.1684 ± 0.0126 vs 0.134 5 ± 0.028 6 and 0.165 4 ± 0.039 8, P > 0.05), and that of MMP-1 in the HIF-lα siRNA, VEGF-α siRNA and EphA2 siRNA groups (1.696 1 ± 0.152 7 vs 0.435 9 ± 0.036 9, 0.198 7 ± 0.009 0 and 0.0218 ± 0.000 7, P < 0.05).</p><p><b>CONCLUSIONS</b>Qilan Capsules can suppress VM formation in prostate cancer by inhibiting the expressions of HIF-1α, VEGF-α and MMP-1, which plays a role in the clinical treatment of prostate cancer by checking the growth and development of the blood supply system in the tumor tissue.</p>


Assuntos
Humanos , Masculino , Cápsulas , Medicamentos de Ervas Chinesas , Farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Metabolismo , Metaloproteinase 1 da Matriz , Metabolismo , Mimetismo Molecular , Neoplasias da Próstata , Metabolismo , RNA Interferente Pequeno , Metabolismo , Receptor EphA2 , Metabolismo , Transfecção , Fator A de Crescimento do Endotélio Vascular , Metabolismo
5.
The Korean Journal of Internal Medicine ; : 429-438, 2017.
Artigo em Inglês | WPRIM | ID: wpr-217840

RESUMO

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with diverse manifestations, and its pathogenesis is unclear and complicated. Infection and SLE are similar in that they both cause inf lammatory reactions in the immune system; however, one functions to protect the body, whereas the other is activated to damage the body. Infection is known as one of the common trigger factors for SLE; there are a number of reports on infectious agents that provoke autoimmune response. Several viruses, bacteria, and protozoa were revealed to cause immune dysfunction by molecular mimicry, epitope spreading, and bystander activation. In contrast, certain pathogens were revealed to protect from immune dysregulation. Infection can be threatening to patients with SLE who have a compromised immune system, and it is regarded as one of the common causes of mortality in SLE. A clinical distinction between infection and lupus f lare up is required when patients with SLE present fevers. With a close-up assessment of symptoms and physical examination, C-reactive protein and disease activity markers play a major role in differentiating the different disease conditions. Vaccination is necessary because protection against infection is important in patients with SLE.


Assuntos
Humanos , Doenças Autoimunes , Autoimunidade , Bactérias , Proteína C-Reativa , Febre , Sistema Imunitário , Lúpus Eritematoso Sistêmico , Mimetismo Molecular , Mortalidade , Exame Físico , Vacinação
6.
Arq. gastroenterol ; 53(3): 185-191, tab, graf
Artigo em Inglês | LILACS | ID: lil-787358

RESUMO

ABSTRACT Background - Exposure to viral antigens that share amino acid sequence similar with self- antigens might trigger autoimmune diseases in genetically predisposed individuals, and the molecular mimicry theory suggests that epitope mimicry between the virus and human proteins can activate autoimmune disease. Objective - The purpose of this study is to explore the possible sequence similarity between the amino acid sequences of thyroid self-protein and hepatitis C virus proteins, using databanks of proteins and immunogenic peptides, to explain autoimmune thyroid disease. Methods - Were performed the comparisons between the amino acid sequence of the hepatitis C virus polyprotein and thyroid self-protein human, available in the database of National Center for Biotechnology Information on Basic Local Alignment Search Tool. Results - The sequence similarity was related each hepatitis C virus genotype to each thyroid antigen. The similarities between the thyroid and the viral peptides ranged from 21.0 % (31 identical residues out of 147 amino acid in the sequence) to 71.0% (5 identical residues out of 7 amino acid in the sequence). Conclusion - Bioinformatics data, suggest a possible pathogenic link between hepatitis C virus and autoimmune thyroid disease. Through of molecular mimicry is observed that sequences similarities between viral polyproteins and self-proteins thyroid could be a mechanism of induction of crossover immune response to self-antigens, with a breakdown of self-tolerance, resulting in autoimmune thyroid disease.


RESUMO Contexto - A exposição a antígenos virais que compartilham sequência de aminoácidos semelhantes a auto-antígenos pode provocar doenças auto-imunes em indivíduos predispostos geneticamente, e a teoria do mimetismo molecular sugere que o mimetismo entre epítopos de vírus e proteínas humanas pode ativar doenças auto-imunes. Objetivo - O objetivo deste estudo foi explorar a possível semelhança entre as sequências de aminoácidos de auto-proteinas da tireóide e proteínas do vírus da hepatite C, utilizando bancos de dados de proteínas e peptídeos imunogênicos, para explicar a doença auto-imune da tireóide. Métodos - Foram realizadas comparações entre as sequências de aminoácidos de poliproteínas do vírus da hepatite C e auto-proteinas da tireóide humana, disponível na base de dados do National Center for Biotechnology Information no Basic Local Alignment Search Tool. Resultados - A semelhança de sequências foi relacionada para cada genótipo de vírus da hepatite C e proteínas da tireóide. As semelhanças entre proteínas da tireóide e os peptídeos virais variaram de 21,0% (31 resíduos idênticos da sequência de 147 aminoácidos) a 71,0% (cinco resíduos idênticos da sequência de 7 aminoácidos). Conclusão - Dados de bioinformática sugerem uma possível ligação entre vírus da hepatite C e doença auto-imune da tireóide. Através de mimetismo molecular observa-se que as semelhanças entre as sequências de poliproteínas virais e auto-proteínas da tireóide pode ser um mecanismo de indução de resposta imune resultando em doença auto-imune da tireóide.


Assuntos
Humanos , Autoantígenos/genética , Proteínas Virais/genética , Tireoidite Autoimune/imunologia , Homologia de Sequência de Aminoácidos , Hepacivirus/genética , Poliproteínas/genética , Tireoidite Autoimune/virologia , Hepacivirus/imunologia , Mimetismo Molecular/genética , Técnicas de Genotipagem , Epitopos/genética
7.
Arch. endocrinol. metab. (Online) ; 59(3): 210-214, 06/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-751317

RESUMO

Objective The aim of this study was to evaluate the genetic expression of adipokines in the adipocytes of monosodium glutamate (MSG)-treated obese rats submitted to physical activity.Materials and methods Obesity was induced by neonatal MSG administration. Exercised rats (MSG and control) were subjected to swim training for 30 min for 10 weeks, whereas their respective controls remained sedentary. Total RNA was obtained from sections of the mesenteric adipose tissue of the rats. mRNA levels of adiponectin (Adipoq), tumor necrosis factor alpha (Tnf), peroxisome proliferator-activated receptor alpha (Ppara), and peroxisome proliferator-activated receptor gamma (Pparg) adipokines were quantified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR).Results In the exercise-trained control group, the expression of Adipoq increased compared to the sedentary control, which was not observed in the MSG-obese rats. Increased levels of Tnf in MSG-obese rats were not reversed by the swim training. The expression of Ppara was higher in sedentary MSG-obese rats compared to the sedentary control. Swimming increased this adipokine expression in the exercise-trained control rats compared to the sedentary ones. mRNA levels of Pparg were higher in the sedentary MSG-rats compared to the sedentary control; however, the exercise did not influenced its expression in the groups analyzed.Conclusions In conclusion, regular physical activity was not capable to correct the expression of proinflammatory adipokines in MSG-obese rat adipocytes.


Assuntos
Animais , Humanos , Adjuvantes Imunológicos , Mimetismo Molecular/imunologia , Fatores de Necrose Tumoral , Vacinas Sintéticas/imunologia , Vacinas/química , Vacinas/imunologia , Adjuvantes Imunológicos/química , /imunologia , /química , /metabolismo , Vacinas Anticâncer/química , Vacinas Anticâncer/imunologia , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Imunoterapia , Ligantes , Lentivirus/genética , Lentivirus/imunologia , Macaca mulatta , Neoplasias/imunologia , Neoplasias/terapia , Multimerização Proteica , Ligante Indutor de Apoptose Relacionado a TNF/química , Receptores Toll-Like/agonistas , Fatores de Necrose Tumoral/química , Vacinas Sintéticas/química , Proteínas da Matriz Viral/imunologia
8.
Journal of Experimental Hematology ; (6): 39-44, 2015.
Artigo em Chinês | WPRIM | ID: wpr-259644

RESUMO

<p><b>OBJECTIVE</b>This study was to investigate the molecular biomarkers of apoptosis induced by BH3 mimetic S1 in human primary AML cells.</p><p><b>METHODS</b>Mononuclear cells were isolated from 27 newly diagnosed AML samples. Apoptosis was analyzed by flow cytometry. IC(50) value of S1 on these samples was determined by XTT assay. The expression level of BCL-2 family members and phosphorylated BCL-2 were assessed by Western blot with subsequent semi-quantitatively densitometric analysis. XTT assay was performed to determine the cell viability of the combined use of S1 and MEK/ERK inhibitor PD98059. The interactions between BCL-2 and pro-apoptosis proteins were tested by co-immunoprecipitation.</p><p><b>RESULTS</b>The flow-cytometry detection showed that S1 induced the apoptosis of primary AML cells. Based on the responses, 27 primary samples could be classified into three groups: (1) a sensitive group (12 of 27 cases) with IC(50)<14 µmol/L, (2) an intermediate group (8 of 27 cases) with IC(50) of 14-30 µmol/L and (3) a resistant group (7 of 27 cases) with IC(50)>30 µmol/L. The ratio of pBCL-2/(BCL-2+MCL-1) showed a good linear correlation with the IC(50) values. (R(2) = 0.71, P < 0.0001). PD98059 suppressed BCL-2 phosphorylation. When PD98059 suppressed BCL-2 phosphorylation, the apoptotic rate of drug-resistant cells induced by S1 increased from 9.8% to 64.5% (combination index, CI = 0.4), accompanied by more dissociation of BCL-2 heterodimers.</p><p><b>CONCLUSION</b>The combination of S1 with PD98059 decrease pBCL-2 level of AML patients and inhibits of the anti-apoptotic function of BCL-2 through enhancing the dissociation of BCL-2 heterodimers.</p>


Assuntos
Humanos , Antimetabólitos Antineoplásicos , Apoptose , Linhagem Celular Tumoral , Combinação de Medicamentos , Leucemia Mieloide Aguda , Mimetismo Molecular , Ácido Oxônico , Fosforilação , Proteínas Proto-Oncogênicas c-bcl-2 , Tegafur
9.
Immune Network ; : 7-13, 2014.
Artigo em Inglês | WPRIM | ID: wpr-192390

RESUMO

Molecular mimicry is an attractive mechanism for triggering autoimmunity. In this review, we explore the potential role of evolutionary conserved bacterial proteins in the production of autoantibodies with focus on granulomatosis with polyangiitis (GPA) and rheumatoid arthritis (RA). Seven autoantigens characterized in GPA and RA were BLASTed against a bacterial protein database. Of the seven autoantigens, proteinase 3, type II collagen, binding immunoglobulin protein, glucose-6-phosphate isomerase, alpha-enolase, and heterogeneous nuclear ribonuclear protein have well-conserved bacterial orthologs. Importantly, those bacterial orthologs are also found in human-associated bacteria. The wide distribution of the highly conserved stress proteins or enzymes among the members of the normal flora and common infectious microorganisms raises a new question on how cross-reactive autoantibodies are not produced during the immune response to these bacteria in most healthy people. Understanding the mechanisms that deselect auto-reactive B cell clones during the germinal center reaction to homologous foreign antigens may provide a novel strategy to treat autoimmune diseases.


Assuntos
Artrite Reumatoide , Autoanticorpos , Autoantígenos , Doenças Autoimunes , Autoimunidade , Bactérias , Infecções Bacterianas , Proteínas de Bactérias , Células Clonais , Colágeno Tipo II , Centro Germinativo , Glucose-6-Fosfato Isomerase , Proteínas de Choque Térmico , Imunoglobulinas , Mimetismo Molecular , Mieloblastina , Fosfopiruvato Hidratase
10.
Rev. peru. med. exp. salud publica ; 30(3): 441-445, jul.-sep. 2013. ilus, graf, tab
Artigo em Espanhol | LILACS, LIPECS | ID: lil-688044

RESUMO

El objetivo del estudio fue determinar los epítopes T de cuatro de las proteínas antigénicas más frecuentes de la membrana externa de Neisseria meningitidis B e identificar los sitios más relevantes donde existe mimetismo molecular para estos epítopes en seres humanos. Para ello se realizó un estudio in silico (estudios que usan herramientas bioinformáticas) usando las bases de datos SWISS-PROT/TrEMBL SYFPEITHI y FASTA, las cuales se emplearon para la determinación de las secuencias proteicas, la predicción de los epítopes T CD4 y CD8, y la determinación del mimetismo molecular en humanos, respectivamente. Se encontró similitud molecular en varias proteínas humanas presentes en diferentes órganos y tejidos, entre ellos: hígado, piel y epitelios, cerebro, sistema linfático y testículos, destacando las encontradas en estos últimos, ya que ellas mostraron la frecuencia más alta de secuencias miméticas. Este hallazgo ayuda a comprender el éxito de N. meningitidis B para colonizar tejidos humanos, el fracaso de ciertas vacunas contra esta bacteria e incluso ayuda a explicar posibles reacciones autoimmunes asociadas a la infección o vacunación.


The objective of the study was to determine the T-cell epitopes of four of the most frequent antigenic proteins of the outer membrane of Neisseria meningitidis B, and to identify the most relevant sites for molecular mimicry with T-cell epitopes in humans. In order to do so, an in silico study -a type of study that uses bioinformatic tools- was carried out using SWISS-PROT/TrEMBL, SYFPEITHI and FASTA databases, which helped to determine the protein sequences, CD4 and CD8 T-cell epitope prediction, as well as the molecular mimicry with humans, respectively. Molecular similarity was found in several human proteins present in different organs and tissues such as: liver, skin and epithelial tissues, brain, lymphatic system and testicles. Of these, those found in testicles were more similar, showing the highest frequency of mimetic sequences. This finding shed light on the success of N. meningitidis B to colonize human tissues and the failure of certain vaccines against this bacterium, and it even helps to explain possible autoimmune reactions associated with the infection or vaccination.


Assuntos
Humanos , Antígenos de Bactérias/imunologia , Simulação por Computador , Epitopos de Linfócito T/imunologia , Mimetismo Molecular , Neisseria meningitidis Sorogrupo B/imunologia , Proteoma
11.
Protein & Cell ; (12): 266-272, 2011.
Artigo em Inglês | WPRIM | ID: wpr-757095

RESUMO

Vasculogenic mimicry (VM), a newly-defined pattern of tumor blood supply, provides a special passage without endothelial cells and is conspicuously different from angiogenesis and vasculogenesis. The biological features of the tumor cells that form VM remain unknown. Cancer stem cells (CSCs) are believed to be tumor-initiating cells, capable of self-renewal and multipotent differentiation, which resemble normal stem cells in phenotype and function. Recently CSCs have been shown to contribute to VM formation as well as angiogenesis. These findings challenge the previous understanding of the cellular basis of VM formation. In this review, we present evidence for participation of CSCs in VM formation. We also discuss the potential mechanisms and possible interaction of CSCs with various elements in tumor microenvironment niche. Based on the importance of VM in tumor progression, it constitutes a novel therapeutic target for cancer.


Assuntos
Animais , Humanos , Camundongos , Diferenciação Celular , Células Endoteliais , Patologia , Transição Epitelial-Mesenquimal , Matriz Extracelular , Metabolismo , Patologia , Mimetismo Molecular , Neoplasias , Patologia , Processos Neoplásicos , Células-Tronco Neoplásicas , Patologia , Neovascularização Patológica , Genética , Metabolismo , Microambiente Tumoral
12.
An. bras. dermatol ; 84(6): 682-688, nov.-dez. 2009. ilus
Artigo em Inglês | LILACS | ID: lil-538461

RESUMO

Literature data analysis, providing an exact explanation of the lichen planus pathogenesis, as well as its transition into other rare forms such as Keratosis lichenoides chronica or Graham Lassueur Piccardi Little Syndrome are scant, or totally missing. The chronological course of the disease, known in the literature as lichen planus, varies. Some patients develop Lichen planus or lichen nitidus and there is no logical explanation why. It is also not clear why single patients initially develop ulcerative lesions in the area of the mucosa and only in a few of them these lesions affect the skin. Antigen Mimicry and Epitope Spreading could be the possible pathogenic inductor in cases of lichenoid dermatoses, as well as the cause for their transition into ulcerative, exanthematous or other rare forms. The Epitope Spreading is probably not the leading pathogenetic factor in lichen planus but a phenomenon which occurs later. This manuscript analyzes some basic pathogenic aspects and presents some possible medical hypotheses regarding the heterogenic clinical picture and pathogenesis of lichen planus and lichenoid like pathologies of the skin which, in the near future should be analyzed in details in order to clarify several dilemmas the clinical dermatologist has to face.


Análises das informações disponíveis na literatura que forneçam uma explicação precisa sobre a patogênese do Líquen Plano, assim como sobre sua transição para outras formas raras da doença, como Ceratose Liquenóide Crônica ou Síndrome de Graham-Little-Piccardi- Lassueur , são raras ou inexistentes. O curso cronológico da doença, conhecida na literatura como Líquen Plano, varia. Alguns pacientes desenvolvem Líquen Plano ou Líquen Nítido e não ha uma explicação lógica do por quê. Também não está claro por que alguns pacientes inicialmente desenvolvem lesões ulcerativas na área da mucosa e em apenas alguns deles essas lesões afetam a pele. Mimetismo Antigênico ou Espalhamento de Epítopos poderiam ser fatores patogênicos indutores em casos de Dermatoses Liquenóides, e também fatores responsáveis pela transição para a forma ulcerativa, exantematosa ou outras formas raras da doença. Espalhamento de Epítopos provavelmente não é o principal fator patogênico envolvido no Líquen Plano, mas um fenômeno de ocorrência posterior.Esse manuscrito analisa alguns aspectos patogênicos básicos e apresenta algumas hipóteses médicas sobre o quadro clínico heterogênico e a patogênese do Líquen Plano e de patologias da pele do tipo liquenóide. Essas patologias devem, em um futuro próximo, ser analisadas minuciosamente a fim de esclarecer vários dilemas que o dermatologista clínico tem de enfrentar.


Assuntos
Humanos , Epitopos , Ceratose/imunologia , Líquen Plano/imunologia , Erupções Liquenoides/imunologia , Mimetismo Molecular , Doença Crônica , Líquen Plano/complicações , Síndrome
13.
Journal of the Korean Neurological Association ; : 307-312, 2009.
Artigo em Coreano | WPRIM | ID: wpr-111688

RESUMO

The Miller Fisher syndrome (MFS), characterized by ataxia, areflexia, and ophthalmoplegia, is a localized variant of Guillain-Barre syndrome (GBS). Bickerstaff's brainstem encephalitis (BBE) is a related syndrome in which central nervous system abnormalities accompany the classic triad. The discovery of the anti-GQ1b antibody and localization of GQ1b ganglioside in human nervous system enabled us to understand various kinds of symptoms in MFS and related diseases. Molecular mimicry of antigenic epitope from infective organisms such as Campylobacter jejuni with this ganglioside is likely the predominant pathogenic mechanism. This could explain the unusual conditions such as atypical MFS, GBS with ophthalmoplegia and BBE are various manifestations of post-infectious autoimmune neuropathies. Now, we can speculate them as the anti-GQ1b antibody syndrome in according to their immunological profiles. In addition to this, recent new concept of anti-ganglioside complex antibody will lead us to further understanding of these disorders.


Assuntos
Humanos , Ataxia , Tronco Encefálico , Campylobacter jejuni , Sistema Nervoso Central , Encefalite , Gangliosídeos , Síndrome de Guillain-Barré , Síndrome de Miller Fisher , Mimetismo Molecular , Sistema Nervoso , Oftalmoplegia
14.
Pakistan Journal of Medical Sciences. 2009; 25 (2): 329-331
em Inglês | IMEMR | ID: emr-92429

RESUMO

Guillain Barre Syndrome [GBS] is a prototypical post-infectious autoimmune disease. We report a case of Guillain- Barre syndrome in a 9-year old boy who was admitted with weakness of both lower limbs for 10 days and a history of previously treated brucellosis


Assuntos
Humanos , Masculino , Brucelose , Autoimunidade , Doenças Autoimunes do Sistema Nervoso , Polineuropatias , Mimetismo Molecular
15.
Biomédica (Bogotá) ; 28(4): 510-522, dic. 2008. ilus
Artigo em Espanhol | LILACS | ID: lil-526126

RESUMO

Introduccion. Trabajos previos han aportado evidencias de que en la paraparesia espastica tropical/mielopatia asociada con el virus linfotropico humano tipo I, existe un componente autoinmune asociado a su patogenesis. Objetivo. Evaluar el estado autoinmune y la existencia de mimetismo molecular en pacientes con paraparesia espastica tropical del pacifico colombiano. Materiales y metodos. A partir de muestras de plasma de 37 pacientes con paraparesia espastica tropical/mielopatia asociada al HTLV-I, 10 con leucemia de celulas T del adulto, 22 individuos portadores asintomáticos y 20 seronegativos para el HTLV-I, se determinaron niveles plasmaticos de anticuerpos antinucleares y anticardiolipina-2 y de interferon e interleucina- 4. Se evaluo, por Western blot, la reactividad cruzada de plasmas contra proteinas obtenidas de varias fuentes celulares normales del sistema nervioso. Ademas, se estudio la reactividad cruzada de plasmas de seropositivos y del anticuerpo monoclonal LT4 anti-taxp40 en secciones de medula espinal de ratas Wistar no infectadas. Resultados. El 70,2 por ciento y el 83,8 por ciento de los pacientes con paraparesia espastica tropical fueron reactivos para anticuerpos ANA y ACL-2, respectivamente, en contraste con los de leucemia de celulas T del adulto y los seropositivos asintom¨¢ticos (P<0,001). Ademas, el 70,3 por ciento y el 43,2 por ciento de los pacientes con paraparesia espastica tropical tuvieron niveles detectables de IFN-¦Ã e IL-4, respectivamente. El anticuerpo LT4 anti tax-p40 y los plasmas de paraparesia espastica tropical/mielopatia asociada al HTLV-I mostraron una reaccion cruzada con una proteina de PMr 33-35 kDa, obtenida del nucleo de neuronas de la medula espinal de ratas Wistar no infectadas. Conclusion. Se obtuvieron evidencias que apoyan la existencia de un sindrome autoinmune mediado por mimetismo molecular como parte de la etiopatogenesis de la degeneracion axonal observada en la paraparesia espastica tropical en pacientes colombianos de la costa pacifica.


Assuntos
Paraparesia , Vírus Linfotrópico T Tipo 1 de Símios , Medula Espinal , Autoanticorpos , Autoimunidade , Mimetismo Molecular
16.
Indian J Biochem Biophys ; 2007 Oct; 44(5): 331-43
Artigo em Inglês | IMSEAR | ID: sea-26620

RESUMO

The complement system is a principal bastion of innate immunity designed to combat a myriad of existing as well as newly emerging pathogens. Since viruses are obligatory intracellular parasites, they are continuously exposed to host complement assault and, therefore, have imbibed various strategies to subvert it. One of them is molecular mimicry of the host complement regulators. Large DNA viruses such as pox and herpesviruses encode proteins that are structurally and functionally similar to human regulators of complement activation (RCA), a family of proteins that regulate complement. In this review, we have presented the structural and functional aspects of virally encoded RCA homologs (vRCA), in particular two highly studied vRCAs, vaccinia virus complement control protein (VCP) and Kaposi's sarcoma-associated herpesvirus complement regulator (kaposica). Importance of these evasion molecules in viral pathogenesis and their role beyond complement regulation are also discussed.


Assuntos
Proteínas do Sistema Complemento/imunologia , Imunidade Inata/imunologia , Modelos Moleculares , Mimetismo Molecular/imunologia , Proteínas Virais/imunologia , Vírus/imunologia
17.
Acta Academiae Medicinae Sinicae ; (6): 191-195, 2007.
Artigo em Chinês | WPRIM | ID: wpr-230006

RESUMO

<p><b>OBJECTIVE</b>To establish systemic lupus erythematosus (SLE) -like murine model by immunizing BALB/C mice with Sm mimotope.</p><p><b>METHODS</b>Sm mimotope was identified by screening a 12-mer random peptide library with monoclonal anti-Smith antibody. Sm mimotope was initially defined with sandwich ELISA, DNA sequencing, and deduced amino acid sequence; and BALB/C mice were subcutaneously injected with mixture phages clones. Sera Sm antibody, anti-double stranded DNA (dsDNA) antibody, and antinuclear antibody (ANA) of mice were detected using direct immunofluorescence; kidney histological changes were examined by HE staining.</p><p><b>RESULTS</b>Five randomly selected peptides were sequenced and the amino acid sequences IR, SQ, and PP were detected in a higher frequency. High-titer IgG autoantibodies of dsDNA, Sm, and ANA in the sera of experiment group were detected by ELISA 28 days after having been immunized by Sm mimotope. Proteinuria was detected 33 days later; immune complex and nephritis were observed in kidney specimens.</p><p><b>CONCLUSION</b>SLE-like murine model can be successfully induced by Sm phage mimotope.</p>


Assuntos
Animais , Camundongos , Anticorpos Antinucleares , Sangue , Autoanticorpos , Sangue , Modelos Animais de Doenças , Epitopos , Alergia e Imunologia , Imunoglobulina G , Sangue , Lúpus Eritematoso Sistêmico , Alergia e Imunologia , Camundongos Endogâmicos BALB C , Mimetismo Molecular , Oligopeptídeos , Alergia e Imunologia , Biblioteca de Peptídeos
18.
Chinese Journal of Biotechnology ; (12): 119-124, 2006.
Artigo em Chinês | WPRIM | ID: wpr-237014

RESUMO

To obtain peptides mimicking epitope of a protective McAb SSjl4 specific to Schistosoma japonicum and investigate their immuno-protection effects. A phage random 12 peptide library was screened using purified McAb SSj14, 33 clones were picked up for specificity identification by ELISA. The epitope of each positive clones were detected by the sequencing analysis technique. The antigenicity of three positive clones (P1, P2 and P11) and their mixture cock-tail were further confirmed by Western-blotting, and their protective efficiency were evaluated by mice vaccination experiment. IL-12 level between the vaccinated mice and control mice were compared. 30 positive phage clones were obtained, which represented 11 different epitopes respectively, there were a similar sequence "H-N/Q-X-S-P/F-X-X-L-A-T" among all of the epitopes. Western-blotting showed that all of the three tested clones were recognized by McAb SSj14. Significant adult worm reduction (13.84% to approximately 52.83%), liver tissue egg reduction (34.17% to approximately 65.47%) as well as fecal egg reduction (28.89% to approximately 73.78%) were observed in mice vaccinated with phages of P1, P2, P11 and mixture of three clones when compared with those of the blank control group, among them, the mice vaccinated with the mixture of phage clones got higher protection than any of the mice injected with only one kind of clone phages. At the same time, the IL-12 level in serum of vaccinated mice was found higher than those of the blank control one, this suggest that IL-12 may correlate with the protective efficiency induced by the clone phages. The study provides a new way for developing an effective vaccine against S. japonicum.


Assuntos
Animais , Masculino , Camundongos , Anticorpos Anti-Helmínticos , Alergia e Imunologia , Anticorpos Monoclonais , Alergia e Imunologia , Antígenos de Helmintos , Alergia e Imunologia , Epitopos , Alergia e Imunologia , Interleucina-12 , Sangue , Camundongos Endogâmicos BALB C , Mimetismo Molecular , Biblioteca de Peptídeos , Schistosoma japonicum , Alergia e Imunologia , Esquistossomose Japônica , Alergia e Imunologia , Vacinação
19.
Journal of the Korean Neurological Association ; : 270-273, 2006.
Artigo em Coreano | WPRIM | ID: wpr-9068

RESUMO

Guillain-Barre Syndrome (GBS) has been known to be preceded by various infections such as Campylobacter jejuni, cytomegalovirus, and so on. We have experienced a case of GBS after a preceding herpes zoster, which was complicated by GBS, which is rare. Some circumstantial and experimental clues suggest a possible causal relationship between those two. Here we report the case along with a literature review.


Assuntos
Campylobacter jejuni , Citomegalovirus , Síndrome de Guillain-Barré , Herpes Zoster , Mimetismo Molecular
20.
São Paulo; s.n; 2006. [104] p. ilus, tab, graf.
Tese em Português | LILACS | ID: lil-443947

RESUMO

Avaliamos o papel da proteína M na indução de lesões similares às observadas na febre reumática (FR), utilizando o rato Lewis como modelo experimental. Identificamos a cepa M1 do S. pyogenes como a mais freqüentemente isolada em amostras locais. Produzimos a proteína M1 recombinante e, mostramos que a imunização usando esta proteína produziu lesões similares às lesões patognomônicas da FR em 50 por cento dos animais. Demonstramos resposta humoral e celular específica contra a proteína M1 e contra as regiões M1AB e M1C. Não observamos, entretanto, reações cruzadas com a miosina cardíaca. Células mononucleares infiltrantes do miocárdio de animais imunizados foram cultivadas, em presença de IL-2, mostrando que estas células foram sensibilizadas. Em conclusão, o modelo proposto ajudará a esclarecer a imunopatologia da FR...


We have evaluated M protein role in eliciting rheumatic fever-like lesions, using the Lewis rat as an animal model. We have identified S. pyogenes M1 strain as the most frequently isolated from local samples. We have produced M1 recombinant protein and shown that immunization using this protein led to rheumatic fever characteristic lesions in 50 per cent of the animals. We demonstrated a humoral and cellular specific response targeting M1 protein and M1AB and M1C regions. We did not observe, however, cross reactions with cardiac myosin. Mononuclear cells infiltrating myocardium of immunized animals were grown in presence of IL-2, showing that these cells were sensitized. In conclusion, the proposed model will help clarifying on the...


Assuntos
Animais , Ratos , Febre Reumática/imunologia , Nódulo Reumático , Streptococcus pyogenes , Mimetismo Molecular
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