RESUMO
Background: Atopic dermatitis (AD) is a chronic inflammatory skin condition that has a significant impact on quality of life. The immune response and allergy symptoms in AD are triggered by the recognition of specific allergens by IgE antibodies. Cross-reactivity can lead to auto-IgE responses, potentially worsening AD symptoms. Our research aimed to enhance our understanding of allergenic sources, including A. fumigatus, and their role in AD. We focused on molecular mimicry between human AQP3 and A. fumigatus aquaporin. Methods: In our in-silico analysis, we compared the amino acid sequences of human aquaporin 3 (AQP3) and A. fumigatus aquaporin with 25 aquaporins from various allergenic sources, sourced from the UniProt and NCBI databases. Phylogenetic relationship analysis and homology-based modeling were conducted. We identified conserved antigenic regions located within the 3D structures. Results: The global identity levels among the studied aquaporins averaged 32.6%. One antigenic site exhibited a remarkable local region, with a conserved identity of 71.4%. We categorized the aquaporins into five monophyletic clades (A-E), with group B showing the highest identity (95%), including six mammalian aquaporins, including AQP3. When comparing A. fumigatus aquaporins, the highest identity was observed with Malassezia sympodialis at 35%. Both human and A. fumigatus aquaporins have three linear and three discontinuous epitopes. Conclusions: We identified potential linear and conformational epitopes of AQP3, indicating a possible molecular mimicry between humans and A. fumigatus aquaporins. This suggests autoreactivity and potential cross-reactivity, although further validation using in vitro and in vivo experiments is required.
Assuntos
Aquaporina 3 , Aquaporinas , Aspergillus fumigatus , Simulação por Computador , Mimetismo Molecular , Filogenia , Humanos , Aspergillus fumigatus/imunologia , Aspergillus fumigatus/metabolismo , Aquaporina 3/metabolismo , Aquaporinas/metabolismo , Aquaporinas/química , Aquaporinas/genética , Sequência de Aminoácidos , Alérgenos/imunologia , Alérgenos/metabolismo , Hipersensibilidade/imunologia , Hipersensibilidade/microbiologia , Modelos Moleculares , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/imunologiaRESUMO
Epidemiological studies and meta-analyses have shown a strong association between high seroprevalence of Toxoplasma gondii (T. gondii) and schizophrenia. Schizophrenic patients showed higher levels of anti-Toxoplasma immunoglobulins M and G (IgM and IgG) when compared to healthy controls. Previously, in a rat model, we demonstrated that the progeny of mothers immunized with T. gondii lysates before gestation had behavioral and social impairments during adulthood. Therefore, we suggested that T. gondii infection can trigger autoreactivity by molecularly mimicking host brain proteins. Here, we aimed to identify the occurrence of antigenic mimicry between T. gondii epitopes and host brain proteins. Using a bioinformatic approach, we predicted T. gondii RH-88 B cell epitopes and compared them to human cell-surface proteins involved in brain development and differentiation (BrainS). Five different algorithms for B-cell-epitope prediction were used and compared, resulting in 8584 T. gondii epitopes. We then compared T. gondii predicted epitopes to BrainS proteins by local sequence alignments using BLASTP. T. gondii immunogenic epitopes significantly overlapped with 42 BrainS proteins. Among these overlapping proteins essential for brain development and differentiation, we identified HSP90 and NOTCH receptors as the proteins most likely to be targeted by the maternally generated pathogenic antibodies due to their topological overlap at the extracellular region of their sequence. This analysis highlights the relevance of pregestational clinical surveillance and screening for potential pathogenic anti-T. gondii antibodies. It also identifies potential targets for the design of vaccines that could prevent behavioral and cognitive impairments associated with pre-gestational T. gondii exposure.
Assuntos
Encéfalo , Epitopos de Linfócito B , Mimetismo Molecular , Toxoplasma , Toxoplasma/imunologia , Mimetismo Molecular/imunologia , Humanos , Epitopos de Linfócito B/imunologia , Encéfalo/parasitologia , Encéfalo/imunologia , Encéfalo/metabolismo , Biologia Computacional/métodos , Toxoplasmose/imunologia , Animais , Anticorpos Antiprotozoários/imunologia , RatosRESUMO
PURPOSE: To present an atypical case of severe bilateral ocular toxoplasmosis with systemic involvement that initially mimicked an autoimmune etiology, posing challenges to its diagnosis and treatment. CASE REPORT: A 39-year-old immunocompetent male was admitted to the hospital due to a presumed pulmonary thromboembolism concomitant with an abrupt onset of vision loss. Initial differential diagnoses included antiphospholipid syndrome and systemic lupus erythematosus, prompting the administration of corticosteroid pulses and rituximab. Despite observing a partial systemic response, there was no improvement in visual acuity. Subsequent aqueous humor polymerase chain reaction confirmed Toxoplasma gondii infection, leading to the introduction of oral antibiotic therapy. The patient's condition showed a partially favorable response; however, the treatment could not reverse the permanent retinal damage. CONCLUSION AND IMPORTANCE: This case underscores the importance of ruling out an infectious etiology in all cases of uveitis. Additionally, it alerts clinicians to the possibility that elevated positive autoantibodies may result from a severe inflammatory reaction caused by pathogens rather than an autoimmune or autoinflammatory disease, particularly in instances of poor treatment response or atypical clinical presentation.
Assuntos
Doenças Autoimunes , Toxoplasma , Toxoplasmose Ocular , Humanos , Masculino , Adulto , Toxoplasmose Ocular/diagnóstico , Toxoplasmose Ocular/tratamento farmacológico , Diagnóstico Diferencial , Toxoplasma/imunologia , Toxoplasma/isolamento & purificação , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/imunologia , Humor Aquoso/parasitologia , Acuidade Visual/fisiologia , DNA de Protozoário/análise , Glucocorticoides/uso terapêutico , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Infecções Oculares Parasitárias/diagnóstico , Infecções Oculares Parasitárias/tratamento farmacológico , Infecções Oculares Parasitárias/parasitologia , Síndrome Antifosfolipídica/diagnóstico , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/complicações , Reação em Cadeia da PolimeraseRESUMO
OBJECTIVE: To identify through In Silico analysis the possible molecular mimicry between Der p 23 and antigens from allergenic sources. METHODS: Identity was sought between Der p 23 and proteins from the mite families Pyroglyphidae, Acaridae, Chortoglyphidae and Echimyopodidae, through PSI-BLAST and They used PRALINE and EMBOSS for the alignments. Antigens with resolved experimental structure were obtained from Protein Data Bank and those not reported were generated using Swiss Model server and ALPHAFOLD 2. Epitope prediction was carried out with the Ellipro server and Pymol 2.3 was used to visualize the 3D models. RESULTS: The analysis between Pyroglyphidae allergens and Der p 23 showed identity with the endochitinase-like protein of D. pteronyssinus, and the type 2 chitin binding domain of D. farinae, with identities between 85 and 100%, with coverage of 100%, and 75% respectively. The allergens Der f 23 and Der p 23 of D. farinae and D. pteronyssinus had 100% coverage with identities of 85.42% and 79.59%, respectively. Among the allergens of Tyrophagus putrescentiae, binding to chitin, oviduct-specific glycoprotein and Cda4p were included, which had identity values corresponding to 40%, 42.22% and 34.78%, with coverage values that did not exceed the 55%. No results were found for Chortoglyphidae and Echimyopodidae. CONCLUSION: There is molecular mimicry and structural homology between Der P 23 and allergens from allergic sources of the Pyroglyphidae and Acaridae families. Potential epitopes were identified in Der p 23, which could present cross-reactivity with the proteins of the allergenic sources studied, which must be demonstrated in In vitro and In vivo studies. In vitro and in vivo work is needed to demonstrate the results obtained in the In Silico analysis.
OBJETIVO: Identificar, a través de análisis In Silico, el posible mimetismo molecular entre Der p 23 y antígenos de fuentes alergénicas. MÉTODOS: Se buscó identidad entre Der p 23 y proteínas de las familias de ácaros Pyroglyphidae, Acaridae, Chortoglyphidae y Echimyopodidae, a través de PSI-BLAST, y se utilizaron PRALINE y EMBOSS para los alineamientos. Los antígenos con estructura experimental resuelta se obtuvieron de Protein Data Bank, y aquellos no informados, se generaron mediante Swiss Model Server y ALPHAFOLD 2. La predicción de epítopes se realizó con el servidor Ellipro y para la visualización de los modelos en 3D, se utilizó Pymol 2.3. RESULTADOS: El análisis entre alérgenos de Pyroglyphidae y Der p 23, mostró identidad con la proteína parecida a endoquitinasa de D. pteronyssinus, y el dominio de unión a quitina tipo 2 de D. farinae, con identidades entre 85 y 100%, con coberturas de 100% y 75%, respectivamente. Los alérgenos Der f 23 y Der p 23 de D. farinae y D. pteronyssinu,s tuvieron una cobertura del 100% con identidades del 85,42% y 79,59%, respectivamente. Entre los alérgenos de Tyrophagus putrescentiae, se incluyeron la unión a quitina, glicoproteína específica del oviducto y Cda4p, las cuales tuvieron valores de identidad correspondientes al 40%, 42,22% y 34,78%, con valores de cobertura que no superan el 55%. No se encontraron resultados para Chortoglyphidae y Echimyopodidae. CONCLUSIÓN: Existe mimetismo molecular y homología estructural entre Der P 23 y alérgenos de fuentes alérgicas de las familias Pyroglyphidae y Acaridae. Se identificaron potenciales epítopes en Der p 23, los cuales podrían presentar reactividad cruzada con las proteínas de las fuentes alergénicas estudiadas, lo cual debe ser demostrado en estudios In Vitro e In Vivo. Se necesitan trabajos In Vitro e In Vivo que demuestren los resultados obtenidos en el análisis In Silico.
Assuntos
Alérgenos , Antígenos de Dermatophagoides , Mimetismo Molecular , Animais , Alérgenos/imunologia , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes/imunologia , Simulação por Computador , Mimetismo Molecular/imunologiaRESUMO
OBJECTIVE: Conduct an in-silico assessment of potential molecular mimicry between human aquaporins, A. fumigatus, and diverse allergenic sources. METHODS: Amino acid sequences of human AQP3 and A. fumigatus aquaporin were compared through multiple alignments with 25 aquaporins from diverse allergenic sources. Phylogenetic analysis and homology-based modeling were executed, and the ElliPro server predicted conserved antigenic regions on 3D structures. RESULTS: Global identity among studied aquaporins was 32.6%, with a specific conserved local region at 71.4%. Five monophyletic clades (A-E) were formed, and Group B displayed the highest identity (95%), including 6 mammalian aquaporins, notably AQP3. A. fumigatus aquaporin exhibited the highest identity with Malassezia sympodialis (35%). Three linear and three discontinuous epitopes were identified in both human and A. fumigatus aquaporins. The Root Mean Square Deviation (RMSD) from overlapping aquaporin structures was 1.006. CONCLUSION: Identification of potential linear and conformational epitopes on human AQP3 suggests likely molecular mimicry with A. fumigatus aquaporins. High identity in a specific antigenic region indicates potential autoreactivity and a probable antigenic site involved in cross-reactivity. Validation through in vitro and in vivo studies is essential for further understanding and confirmation.
OBJETIVO: Realizar una evaluación in silico del posible mimetismo molecular entre las acuaporinas humanas, A. fumigatus y diversas fuentes alergénicas. MÉTODOS: Se compararon secuencias de aminoácidos de AQP3 humana y acuaporina de A. fumigatus mediante alineamientos múltiples con 25 acuaporinas de diversas fuentes alergénicas. Se ejecutaron análisis filogenéticos y modelos basados en homología, y el servidor ElliPro predijo regiones antigénicas preservadas en estructuras 3D. RESULTADOS: La identidad global entre las acuaporinas estudiadas fue del 32.6%, con una región local específica preservada en el 71.4%. Se formaron cinco clados monofiléticos (A-E), y el grupo B mostró la identidad más alta (95%), incluidas 6 acuaporinas de mamíferos, en particular AQP3. A. fumigatus aquaporin exhibió la mayor identidad con Malassezia sympodialis (35%). Se identificaron tres epítopos lineales y tres discontinuos en acuaporinas tanto humanas como de A. fumigatus. La desviación cuadrática media (RMSD) de las estructuras de acuaporinas superpuestas fue de 1,006. CONCLUSIÓN: La identificación de posibles epítopos lineales y conformacionales en AQP3 humano sugiere un probable mimetismo molecular con acuaporinas de A. fumigatus. La identidad alta en una región antigénica específica indica autorreactividad potencial y un sitio antigénico probable implicado en la reactividad cruzada. La validación mediante estudios in vitro e in vivo es desicivo para una mayor comprensión y confirmación.
Assuntos
Alérgenos , Aquaporina 3 , Aquaporinas , Aspergillus fumigatus , Simulação por Computador , Mimetismo Molecular , Aspergillus fumigatus/imunologia , Humanos , Aquaporinas/química , Aquaporinas/genética , Aquaporinas/metabolismo , Aquaporinas/imunologia , Aquaporina 3/metabolismo , Aquaporina 3/genética , Alérgenos/imunologia , Hipersensibilidade/imunologia , Proteínas Fúngicas/química , Proteínas Fúngicas/imunologia , Proteínas Fúngicas/genética , Sequência de Aminoácidos , Filogenia , Epitopos/imunologiaRESUMO
OBJECTIVE: Analyze the molecular mimicry between Plasmodium spp. and autoantigens associated with GBS, identifying possible antigenic epitopes. METHODS: PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro and PyMol 2.3 were used to search for homologies, perform alignments, obtain protein structures, and predict epitopes. RESULTS: 17 autoantigens and seven immunological targets of the peripheral nervous system were included, identifying 72 possible epitopes associated with GBS. From the proteome of Plasmodium spp. (298 proteins), only two showed similarities close to 30% with TRIM21 and BACE1, generating seven possible epitopes. CONCLUSION: No significant homologies were observed between the proteome of GBS and Plasmodium spp. The exploration of other mechanisms such as immune-mediated capillary damage, Epitope Spreading or Bystander Activation is suggested to explain the mentioned association. These findings underscore the need to clarify the etiology of autoimmune diseases and the role of pathogens. The need for experimental studies to validate these results is emphasized.
OBJETIVO: Analizar el mimetismo molecular entre Plasmodium spp. y autoantígenos asociados al SGB, identificando posibles epítopos antigénicos. MÉTODOS: Se emplearon PSI-Blast, Praline, Emboss, Protein Data Bank, Swiss Model Server, AlphaFold 2, Ellipro y PyMol 2.3 para buscar homologías, realizar alineamientos, obtener estructuras proteicas y predecir epítopos. RESULTADOS: Se incluyeron 17 autoantígenos y siete objetivos inmunológicos del sistema nervioso periférico, identificándose 72 posibles epítopos asociados al SGB. Del proteoma de Plasmodium spp. (298 proteínas), solo dos mostraron similitud cercana al 30% con TRIM21 y BACE1, generando siete posibles epítopos. CONCLUSIÓN: No se observaron homologías significativas entre el proteoma de SGB y Plasmodium spp. Se sugiere la exploración de otros mecanismos como el daño capilar inmunomediado, Epitope Spreading o Bystander Activation para explicar la asociación mencionada. Estos hallazgos subrayan la necesidad de aclarar la etiología de las enfermedades autoinmunes y el papel de los patógenos. Se enfatiza la necesidad de estudios experimentales para validar estos resultados.
Assuntos
Síndrome de Guillain-Barré , Mimetismo Molecular , Mimetismo Molecular/imunologia , Síndrome de Guillain-Barré/imunologia , Humanos , Plasmodium/imunologia , Autoantígenos/imunologia , Epitopos/imunologiaRESUMO
OBJECTIVE: Identify molecular mimicry between TPO, eosinophil peroxidase (EPX), thyroglobulin and IL24 and microorganism antigens. METHODS: Through in silico analysis, we performed local alignments between human and microorganism antigens with PSI-BLAST. Proteins that did not present a 3D structure were modeled by homology through the Swiss Modeller server and epitope prediction was performed through Ellipro. Epitopes were located in the 3D models using PYMOL software. RESULTS: A total of 38 microorganism antigens (parasites, bacteria) had identities between 30% and 45%, being the highest with Anisakis simplex. The alignment between 2 candidate proteins from A. simplex and EPX presented significant values, with identities of 43 and 44%. In bacteria, Campylobacter jejuni presented the highest identity with thyroglobulin (35%). 220 linear and conformational epitopes of microorganism antigens were predicted. Peroxidasin-like proteins from Toxocara canis and Trichinella pseudospiralis presented 10 epitopes similar to TPO and EPX, as possible molecules triggering cross-reactivity. No virus presented identity with the human proteins studied. CONCLUSION: TPO and EPX antigens shared potential cross-reactive epitopes with bacterial and nematode proteins, suggesting that molecular mimicry could be a mechanism that explains the relationship between infections and urticaria/hypothyroidism. In vitro work is needed to demonstrate the results obtained in the in silico analysis.
OBJETIVO: Identificar mimetismo molecular entre TPO, eosinofil peroxidasa (EPX), tiroglobulina e IL24 y antígenos de microorganismos. MÉTODOS: A través de análisis in silico, realizamos los alineamientos locales entre los antígenos humanos y de microorganismos con PSI-BLAST. Las proteínas que no presentaban estructura 3D, fueron modeladas por homología a través del servidor Swiss Modeller y se realizó una predicción de epítopes a través de Ellipro. Los epítopes se localizaron en los modelos 3D utilizando el software PYMOL. RESULTADOS: Un total de 38 antígenos de microorganismos (parásitos y bacterias), tuvieron identidades entre 30 y 45%, siendo los más altos con Anisakis simplex. El alineamiento entre dos proteínas candidatas de A. simplex y EPX presentaron valores importantes, con identidades de 43 y 44%. En las bacterias, Campylobacter jejuni presentó la mayor identidad con tiroglobulina (35%). Se predijeron 220 epítopes lineales y conformacionales de antígenos de microorganismos. Las proteínas similares a la peroxidasina de Toxocara canis y Trichinella pseudospiralis presentaron diez epítopes similares a TPO y EPX, como posibles moléculas desencadenantes de una reactividad cruzada. Ningún virus presentó identidad con las proteínas humanas estudiadas. CONCLUSIÓN: Los antígenos TPO y EPX compartieron potenciales epítopes de reacción cruzada con proteínas bacterianas y nematodos, lo que sugiere que el mimetismo molecular podría ser un mecanismo que explique la relación entre infecciones y la urticaria/hipotiroidismo. Se necesitan trabajos in vitro que demuestren los resultados obtenidos en el análisis in silico.
Assuntos
Autoantígenos , Iodeto Peroxidase , Mimetismo Molecular , Tireoglobulina , Mimetismo Molecular/imunologia , Humanos , Tireoglobulina/imunologia , Iodeto Peroxidase/imunologia , Peroxidase de Eosinófilo/imunologia , Animais , Antígenos de Bactérias/imunologia , Reações Cruzadas , Proteínas de Ligação ao Ferro/imunologia , Epitopos/imunologiaRESUMO
SARS-CoV-2 can trigger autoimmune central nervous system (CNS) diseases in genetically susceptible individuals, a mechanism poorly understood. Molecular mimicry (MM) has been identified in other viral diseases as potential triggers of autoimmune CNS events. This study investigated if MM is the process through which SARS-CoV-2 induces the breakdown of immune tolerance. The frequency of autoimmune CNS disorders was evaluated in a prospective cohort with patients admitted to the COVID-19 Intense Care Unity (ICU) in Rio de Janeiro. Then, an in silico analysis was performed to identify the conserved regions that share a high identity between SARS-CoV-2 antigens and human proteins. The sequences with significant identity and antigenic properties were then assessed for their binding capacity to HLA subtypes. Of the 112 patients included, 3 were classified as having an autoimmune disorder. A total of eleven combinations had significant linear and three-dimensional overlap. NMDAR1, MOG, and MPO were the self-antigens with more significant combinations, followed by GAD65. All sequences presented at least one epitope with strong or intermediate binding capacity to the HLA subtypes selected. This study underscores the possibility that CNS autoimmune attacks observed in COVID-19 patients, including those in our population, could be driven by MM in genetically predisposed individuals.
RESUMO
An increase in the incidence of inflammatory arthritis after COVID-19 has been reported. Since many diseases exhibit population-specific causal effect sizes, we aimed to evaluate the incidence trends of inflammatory arthritis, including rheumatoid arthritis (RA), after COVID-19 in a large admixed Colombian population. Data analysis for this retrospective, population-based cohort study was carried out using the COOSALUD EPS registry. The following codes were selected for analyses: M059, seropositive RA, M069, unspecified RA, M060 seronegative RA, and other RA-related diagnoses: M064, M139, M068, M058, M130 and M053. The study period was limited to January 01, 2018, through December 31, 2022. Incidence rates (IRs) and incidence rate ratios (IRRs) were assessed. A Cox survival model was built to evaluate the influence of age, gender, and COVID-19 vaccination status on the development of inflammatory arthritis. A bioinformatic analysis was performed to evaluate the homology between SARS-CoV-2 and autoantigen peptides related to RA. The entire population study comprised 3,335,084 individuals. During the pandemic period (2020-2022) the total IIR for seropositive and unspecified RA were 1.60 (95% CI, 1.16-2.22) and 2.93 (95% CI, 2.04-4.19), respectively, and the IIR for overall RA-related diagnosis was 2.01 (95% CI 1.59-2.53). The age groups hazard ratios (HRs) were increased until the age group of 51-60 years (HR: 9.16; 95% CI, 7.24-11.59) and then decreased slightly in the age group 61 years or older (HR: 5.364; 95% CI, 4.24-6.78) compared to those within 18-30 years. Men were less at risk than women to develop inflammatory arthritis (HR: 0.21; 95% CI, 0.18-0.24). The greater time since COVID-19 diagnosis was associated with a lower likelihood of developing inflammatory arthritis (HR: 0.99; 95% CI:0.998-0.999). Vaccination (all types of COVID-19 vaccines included) did not prevent the development of inflammatory arthritis after COVID-19. Low identity was found between the SARS-CoV-2 ORF1ab antigen and the human antigens Poly ADP-ribose polymerase 14 and Protein mono-ADP-ribosyltransferase PARP9 isoform D (39% and 29%, respectively). In conclusion, our study confirms increased incidence of inflammatory arthritis, including RA, after COVID-19, with the greatest increase occurring before the first year post-covid. Women in their fifties were more susceptible. Further research is required to examine the effectiveness of vaccination in preventing post-COVID inflammatory arthritis and the mechanisms implicated in the development of RA after COVID-19.
Assuntos
Artrite Reumatoide , COVID-19 , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Vacinas contra COVID-19 , Estudos de Coortes , Incidência , Estudos Retrospectivos , Teste para COVID-19 , Estudos Prospectivos , COVID-19/complicações , COVID-19/epidemiologia , SARS-CoV-2 , Artrite Reumatoide/complicações , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/diagnósticoRESUMO
Abstract Background Evidence indicates a strong link between Zika virus (ZikV) and neurological complications. Acute myelitis, optic neuritis, polyneuropathy, and encephalomyelitis that mimic inflammatory idiopathic demyelination disorders (HDD) after ZikV infection have been reported in Brazil. Objective The present study aims to investigate the possible occurrence of molecular mimicry between ZikV antigens and Multiple Sclerosis (MS) autoantigens, the most frequent HDD of the central nervous system (CNS). Methods A retrospective cohort study with 305 patients admitted due to suspected arbovirus infection in Rio de Janeiro was performed, all subjects were submitted to neurological examination, and a biological sample was collected for serologic and molecular diagnostic. Bioinformatics tools were used to analyze the peptides shared between ZikV antigens and MS autoantigens. Results Of 305 patients, twenty-six were positive for ZikV and 4 presented IDD patterns found in MS cases. Sequence homology comparisons by bioinformatics approach between NS5 ZikV and PLP MS protein revealed a homology of 5/6 consecutive amino acids (CSSVPV/CSAVPV) with 83% identity, deducing a molecular mimicry. Analysis of the 3D structures revealed a similar conformation with alpha helix presentation. Conclusions Molecular mimicry between NS5 Zika virus antigen and PLP MS autoantigens emerge as a possible mechanism for IDD spectrum in genetically susceptible individuals.
Resumo Antecedentes Evidências indicam uma forte ligação entre o vírus Zika (ZikV) e complicações neurológicas. Mielite aguda, neurite óptica, polineuropatia e encefalomielite que mimetizam distúrbios inflamatórios de desmielinização idiopáticos (DDII) após infecção por ZikV têm sido relatadas no Brasil. Obejtivo O presente estudo tem como objetivo investigar a possível ocorrência de mimetismo molecular entre antígenos do ZikV e autoantígenos da Esclerose Múltipla (EM), a DDII mais frequente do sistema nervoso central (SNC). Métodos Foi realizado um estudo de coorte retrospectivo com 305 pacientes internados por suspeita de infecção por arbovirus no Rio de Janeiro, todos os indivíduos foram submetidos a exame neurológico e coleta de amostra biológica para diagnóstico sorológico e molecular. Ferramentas de bioinformática foram usadas para analisar os peptídeos compartilhados entre antígenos do ZikV e autoantígenos da EM. Resultados Dos 305 pacientes, vinte e seis foram positivos para ZikV e 4 apresentaram padrão IDD encontrado em casos de EM. As comparações de homologia de sequência por abordagem de bioinformática entre a proteína NS5 ZikV e PLP EM revelaram uma homologia de 5/6 aminoácidos consecutivos (CSSVPV/CSAVPV) com 83% de identidade, deduzindo um mimetismo molecular. A análise das estruturas 3D revelou uma conformação semelhante com apresentação em alfa-hélice. Conclusões O mimetismo molecular entre o antígeno NS5 do vírus Zika e o autoantígeno PLP da EM surge como um possível mecanismo para o espectro IDD em indivíduos geneticamente suscetíveis.
RESUMO
SARS-CoV-2, a virus belonging to the large family of coronavirus, aroused great interest following the outbreak of this new strain reported in 2019, in Wuhan China. Its clinical spectrum is highly variable, ranging from a self-limited disease to an acute respiratory distress syndrome with systemic clinical manifestations (COVID-19), in which the immune system plays a key role in the pathophysiology of this disease and in its severity; several studies show the prevalence of some autoimmune markers suggesting that they may lead to autoimmune states. The most important strategy worldwide to protect the population was the development of vaccines to induce immunity to severe COVID-19; however, vaccines have also been shown to have the ability to produce autoimmune states in a small percentage of the world's population; nevertheless, the best strategy remains vaccination. The aim of this review is to show the current overview of the mechanisms of SARS-CoV-2-induced autoimmunity and post-vaccination for a better understanding and identification of these in the population. Publications from 2019 to 2022 were reviewed in PubMed as the primary search source.
El SARS-CoV-2, un virus perteneciente a la gran familia de los coronavirus despertó gran interés después del brote de la nueva cepa reportada en 2019, en Wuhan, China. Las manifestaciones clínicas son variables: desde enfermedad con curación espontánea hasta síndrome de dificultad respiratoria aguda, con alteraciones clínicas sistémicas (COVID-19), donde el sistema inmunitario tiene participación importante en la fi-siopatología de la enfermedad y su gravedad. Diversos estudios demuestran la prevalencia de algunos marcadores autoinmunes, lo que sugiere que pueden conducir a estados de autoinmunidad. La estrategia más importante a nivel mundial para proteger a la población fue el desarrollo de vacunas para inducir inmunidad frente al COVID-19 grave; sin embargo, se ha demostrado que tienen la capacidad de producir estados autoinmunitarios en un pequeño porcentaje de la población; no obstante, siguen siendo la mejor estrategia de tratamiento. El objetivo de esta revisión es mostrar el panorama actual de los mecanismos de autoinmunidad inducidos por SARS-CoV-2 y la post-vacunación, para una mejor comprensión e identificación en la población. Se revisaron las publicaciones de 2019 a 2022 en PubMed como fuente principal de búsqueda.
Assuntos
Doenças Autoimunes , COVID-19 , Humanos , SARS-CoV-2 , COVID-19/prevenção & controle , Autoimunidade , Doenças Autoimunes/etiologia , VacinaçãoRESUMO
The activation of the maternal immune system by a prenatal infection is considered a risk factor for developing psychiatric disorders in the offspring. Toxoplasma gondii is one of the pathogenic infections associated with schizophrenia. Recent studies have shown an association between high levels of IgG anti-T. gondii from mothers and their neonates, with a higher risk of developing schizophrenia. The absence of the parasite and the levels of IgGs found in the early stages of life suggest a transplacental transfer of the anti-T. gondii IgG antibodies, which could bind fetal brain structures by molecular mimicry and induce alterations in neurodevelopment. This study aimed to determine the maternal pathogenic antibodies formation that led to behavioral impairment on the progeny of rats immunized with T. gondii. Female rats were immunized prior to gestation with T. gondii lysate (3 times/once per week). The anti-T. gondii IgG levels were determined in the serum of pregestational exposed females' previous mating. After this, locomotor activity, cognitive and social tests were performed. Cortical neurotransmitter levels for dopamine and glutamate were evaluated at 60 PND in the progeny of rats immunized before gestation (Pregestational group). The maternal pathogenic antibodies were evidenced by their binding to fetal brain mimotopes in the Pregestational group and the reactivity of the serum containing anti-T. gondii IgG was tested in control fetal brains (non-immunized). These results showed that the Pregestational group presented impairment in short and long-term memory, hypoactivity and alteration in social behavior, which was also associated with a decrease in cortical glutamate and dopamine levels. We also found the IgG antibodies bound to brain mimotopes in fetuses from females immunized with T. gondii, as well as observing a strong reactivity of the serum females immunized for fetal brain structures of fetuses from unimmunized mothers. Our results suggest that the exposure to T. gondii before gestation produced maternal pathogenic antibodies that can recognize fetal brain mimotopes and lead to neurochemical and behavioral alterations in the offspring.
Assuntos
Dopamina , Toxoplasma , Gravidez , Animais , Feminino , Ratos , Ácido Glutâmico , Imunoglobulina G , EncéfaloRESUMO
Introducción: La patogénesis de la anemia hemolítica autoinmune es un proceso complejo en el que muchos elementos tienen una función esencial que repercuten en la gran heterogeneidad clínica de la enfermedad, pero los mecanismos involucrados en su inducción se desconocen en gran medida. Objetivo: Explicar los principales mecanismos propuestos en el inicio y aparición de la anemia hemolítica autoinmune y su contribución a la fisiopatología de la enfermedad. Métodos: Se realizó una revisión de la literatura en los idiomas inglés y español, de artículos publicados en los últimos 10 años sobre mecanismos propuestos en el inicio de la anemia hemolítica autoinmune. Análisis y síntesis de la información: Los mecanismos propuestos en la inducción de la autoinmunidad contra los eritrocitos incluyen el mimetismo molecular entre antígenos endógenos y antígenos exógenos, el procesamiento desregulado de autoantígenos influenciado por factores adquiridos y la disfunción de los linfocitos B y T. Conclusiones: Los mecanismos propuestos en la aparición de la anemia hemolítica autoinmune brindan información valiosa para mejorar la comprensión de los mecanismos moleculares involucrados y subrayan la complejidad de los fenómenos involucrados en la perdida de la tolerancia hacia los eritrocitos autólogos y el delicado equilibrio entre factores genéticos y ambientales(AU)
Introduction: The pathogenesis of autoimmune hemolytic anemia is a complex process in which many elements play an essential role and have an impact on the great clinical heterogeneity of the disease, but the mechanisms involved in its induction are largely unknown. Objective: To explain the main mechanisms proposed in the initiation and occurrence of autoimmune hemolytic anemia and its contribution to the pathophysiology of the disease. Methods: A review of the literature, in English and Spanish languages, of articles published in the last 10 years on proposed mechanisms in the initiation of autoimmune hemolytic anemia was carried out. Analysis and synthesis of information: Proposed mechanisms for the induction of autoimmunity against erythrocytes include molecular mimicry between endogenous and exogenous antigens, deregulated processing of autoantigens influenced by acquired factors, and B and T cells dysfunction. Conclusions: The proposed mechanisms in the occurrence of autoimmune hemolytic anemia provide valuable information to improve the understanding of the mechanisms involved and underline the complexity of the phenomena involved in the loss of tolerance towards autologous erythrocytes and the delicate balance between genetic and environmental factors(AU)
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The immune response against pathogens induces protection from future infection, however, molecular mimicry between the pathogen and the human host can promote autoreactive responses. Using in silico approaches, we identified molecular mimicry between Trypanosoma sp. and human autoantigens involved in the development of systemic lupus erythematosus (SLE). We retrieved all reported autoantigen amino acid sequences for SLE from the AAgAtlas database to perform PSI-BLAST against the Trypanosoma sp proteome to determine amino acid sequence identity with each other. The antigens given in the Protein Data Bank without a 3D structure were modeled by homology with the "Swiss Modeller Server". Epitopes shared between Trypanosoma sp. and human antigens were identified using the Ellipro server and the Immune Epitope Database (IEDB), and cross-reactive epitopes were assigned to the 3D models. 36 autoantigens involved in SLE showed molecular mimicry with Trypanosoma sp. Antigens Epitope prediction revealed that some autoantigens shared several antigenic.
Assuntos
Lúpus Eritematoso Sistêmico , Trypanosoma , Humanos , Mimetismo Molecular , Proteoma , Autoantígenos , EpitoposRESUMO
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-2RESUMO
coronavirus disease 2019 (COVID-19), caused by the new coronavirus SARS-CoV-2, has been associated with the development of neurological diseases such as Guillain-Barré syndrome (GBS) and its variants. In the present work, two cases of demyelinating syndromes associated with COVID-19 are reported. Clinical cases: 53-year-old male with GBS and and 29-year-old female with Miller-Fisher syndrome (MFS) variant, respectively. Both patients presented the classic neurological signs and symptoms of demyelinating polyneuropathy that characterizes the syndromes. From the paraclinical biochemical tests, the increase of proteins in cerebrospinal fluid was distinctive. The positivity of the RT-qPCR for SARS-CoV-2 suggested the association of GBS and MFS with COVID-19. Both patients were treated with intravenous immunoglobulin showing improvement. Electromyography performed weeks ahead still showed chronic demyelinating involvement. Conclusion: The cases of GBS and MFS, along with other similar cases reported around the world, provide further evidence for SARS-CoV-2 as a new possible etiology of these rare neurological diseases.
Introducción: la enfermedad por coronavirus del 2019 (COVID-19), causada por el nuevo coronavirus SARS-CoV-2, se ha asociado con el desarrollo de enfermedades neurológicas como el síndrome de Guillain-Barré (SGB) y sus variantes. En el presente trabajo se reportan dos casos de síndromes desmielizantes asociados con la COVID-19. Casos clínicos: hombre de 53 años con SGB y mujer de 29 años con la variante del síndrome de Miller-Fisher (SMF), respectivamente. Ambos presentaron los signos y síntomas neurológicos clásicos de polineuropatía desmielinizante que caracterizan a estos síndromes. De las pruebas bioquímicas paraclínicas, el aumento de proteínas en líquido cefalorraquídeo fue distintiva. La positividad de la RT-qPCR para el SARS-CoV-2 indicó la asociación de los SGB y SMF con la COVID-19. Ambos pacientes se trataron con inmunoglobulina intravenosa y mostraron mejoría. La electromiografía realizada en semanas posteriores aún mostraba afectación desmielinizante crónica. Conclusión: los casos de los SGB y SMF, junto con otros casos similares reportados en todo el mundo, proporcionan más evidencia para el SARS-CoV-2 como nueva posible etiología de estas raras enfermedades neurológicas.
Assuntos
COVID-19 , Síndrome de Guillain-Barré , Síndrome de Miller Fisher , COVID-19/complicações , Feminino , Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/etiologia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Síndrome de Miller Fisher/diagnóstico , Síndrome de Miller Fisher/etiologia , Síndrome de Miller Fisher/terapia , SARS-CoV-2RESUMO
Wegener's granulomatosis is an autoimmune disease where autoantibodies target human autoantigen PR3, a serine protease locates on the neutrophil membrane. This disease affects blood small vessels and could be deadly. The origin of these autoantibodies is unknown, but infections have been implicated with autoimmune disease. In this study, we explored potential molecular mimicry between human PR3 and homologous pathogens through in silico analysis. Thirteen serine proteases from human pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Salmonella sp., Streptococcus suis, Vibrio parahaemolyticus, Bacteroides fragilis, Enterobacter ludwigii, Vibrio alginolyticus, Staphylococcus haemolyticus, Enterobacter cloacae, Escherichia coli and Pseudomonas aeruginosa) shared structural homology and amino acid sequence identity with human PR3. Epitope prediction found an only conserved epitope IVGG, located between residues 59-74. However, multiple alignments showed conserved regions that could be involved in cross-reactivity between human and pathogens serine proteases (90-98, 101-108, 162-169, 267 and 262 residues positions). In conclusion, this is the first report providing in silico evidence about the existence of molecular mimicry between human and pathogens serine proteases, that could explain the origins of autoantibodies found in patients suffering from Wegener's granulomatosis.
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Introducción: la enfermedad por coronavirus del 2019 (COVID-19), causada por el nuevo coronavirus SARSCoV-2, se ha asociado con el desarrollo de enfermedades neurológicas como el síndrome de Guillain-Barré (SGB) y sus variantes. En el presente trabajo se reportan dos casos de síndromes desmielizantes asociados con la COVID-19. Casos clínicos: hombre de 53 años con SGB y mujer de 29 años con la variante del síndrome de Miller-Fisher (SMF), respectivamente. Ambos presentaron los signos y síntomas neurológicos clásicos de polineuropatía desmielinizante que caracterizan a estos síndromes. De las pruebas bioquímicas paraclínicas, el aumento de proteínas en líquido cefalorraquídeo fue distintiva. La positividad de la RT-qPCR para el SARS-CoV-2 indicó la asociación de los SGB y SMF con la COVID-19. Ambos pacientes se trataron con inmunoglobulina intravenosa y mostraron mejoría. La electromiografía realizada en semanas posteriores aún mostrabaafectación desmielinizante crónica. Conclusión: los casos de los SGB y SMF, junto con otros casos similares reportados en todo el mundo, proporcionan más evidencia para el SARS-CoV-2 como nueva posible etiología de estas raras enfermedades neurológicas.
Background: coronavirus disease 2019 (COVID-19), caused by the new coronavirus SARS CoV-2, has been associated with the development of neurological diseases such as Guillain-Barré syndrome (GBS) and its variants. In the present work, two cases of demyelinating syndromes associated with COVID-19 are reported. Clinical cases: 53-year-old male with GBS and and 29-yearold female with Miller-Fisher syndrome (MFS) variant, respectively. Both patients presented the classic neurological signs and symptoms of demyelinating polyneuropathy that characterizes the syndromes. From the paraclinical biochemical tests, the increase of proteins in cerebrospinal fluid was distinctive. The positivity of the RT-qPCR for SARSCoV-2 suggested the association of GBS and MFS with COVID-19. Both patients were treated with intravenous immunoglobulin showing improvement. Electromyography performed weeks ahead still showed chronic demyelinating involvement. Conclusion: The cases of GBS and MFS, along with other similar cases reported around the world, provide further evidence for SARS-CoV-2 as a new possible etiology of these rare neurological diseases.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Síndrome de Guillain-Barré/virologia , COVID-19/complicações , Síndrome de Miller Fisher/virologia , Distúrbios Somatossensoriais/virologiaRESUMO
Red blood cells infected with Plasmodium falciparum secrete extracellular vesicles in order to facilitate the survival and infection of human cells. Various researchers have studied the composition of these extracellular vesicles and identified the proteins contained inside. In this work, we used that information to detect potential P. falciparum molecules that could be imitating host proteins. We carried out several searches to detect sequences and structural similarities between the parasite and host. Additionally, the possibility of functional mimicry was explored in line with the potential role that each candidate can perform for the parasite inside the host. Lastly, we determined a set of eight sequences (mainly moonlighting proteins) with a remarkable resemblance to human proteins. Due to the resemblance observed, this study proposes the possibility that certain P. falciparum molecules carried by extracellular vesicles could be imitating human proteins to manipulate the host cell's physiology.