Type V collagen-induced nasal tolerance prevents lung damage in an experimental model: new evidence of autoimmunity to collagen V in COPD.

Background: Chronic obstructive pulmonary disease (COPD) has been linked to immune responses to lung-associated self-antigens. Exposure to cigarette smoke (CS), the main cause of COPD, causes chronic lung inflammation, resulting in pulmonary matrix (ECM) damage. This tissue breakdown exposes collagen V (Col V), an antigen typically hidden from the immune system, which could trigger an autoimmune response. Col V autoimmunity has been linked to several lung diseases, and the induction of immune tolerance can mitigate some of these diseases. Evidence suggests that autoimmunity to Col V might also occur in COPD; thus, immunotolerance to Col V could be a novel therapeutic approach. Objective: The role of autoimmunity against collagen V in COPD development was investigated by analyzing the effects of Col V-induced tolerance on the inflammatory response and lung remodeling in a murine model of CS-induced COPD. Methods: Male C57BL/6 mice were divided into three groups: one exposed to CS for four weeks, one previously tolerated for Col V and exposed to CS for four weeks, and one kept in clean air for the same period. Then, we proceeded with lung functional and structural evaluation, assessing inflammatory cells in bronchoalveolar lavage fluid (BALF) and inflammatory markers in the lung parenchyma, inflammatory cytokines in lung and spleen homogenates, and T-cell phenotyping in the spleen. Results: CS exposure altered the structure of elastic and collagen fibers and increased the pro-inflammatory immune response, indicating the presence of COPD. Col V tolerance inhibited the onset of emphysema and prevented structural changes in lung ECM fibers by promoting an immunosuppressive microenvironment in the lung and inducing Treg cell differentiation. Conclusion: Induction of nasal tolerance to Col V can prevent inflammatory responses and lung remodeling in experimental COPD, suggesting that autoimmunity to Col V plays a role in COPD development.

Frequency of Mutations in the TPO Gene in Patients with Congenital Hypothyroidism Due to Dyshormonogenesis in Chile.

Background and Objectives: Congenital thyroid dyshormonogenesis is caused by alterations in the synthesis of thyroid hormones in a newborn. Additionally, 10 to 20% of these cases are hereditary, caused by defects in proteins involved in hormonal synthesis. One of the most common causes is mutations in the thyroid peroxidase (TPO) enzyme gene, an autosomal recessive disease. We aimed to detect mutations of the TPO gene in 12 Chilean patients with congenital hypothyroidism due to dyshormonogenesis (CHD) and to characterize these patients clinically and molecularly. Materials and Methods: Twelve patients under 20 years of age with CHD, controlled at San Juan de Dios Hospital in Santiago, Chile, were selected according to the inclusion criteria: elevated neonatal TSH, persistent hypothyroidism, and thyroid normotopic by imaging study. Those with deafness, Down syndrome, and central or transient congenital hypothyroidism were excluded. Blood samples were taken for DNA extraction, and the 17 exons and exon-intron junctions of the TPO gene were amplified by PCR. The PCR products were sequenced by Sanger. Results: Two possibly pathogenic mutations of the TPO gene were detected: c.2242G>A (p.Val748Met) and c.1103C>T (p.Pro368Leu). These mutations were detected in 2 of 12 patients (16.6%): 1 was compound heterozygous c.1103C>T/c.2242G>A, and the other was heterozygous for c.2242G>A. In the diagnostic confirmation test, both patients presented diffuse hyper-uptake goiter on thyroid scintigraphy and high TSH in venous blood (>190 uIU/mL). Conclusions: The frequency of patients with possibly pathogenic mutations in TPO with CHD was 16.6%. Its study would allow for genetic counseling to be offered to the families of affected patients.

[Molecular mimicry between Plasmodium sp and Guillain-Barre syndrome antigens]. / Mimetismo molecular entre el Plasmodium sp y los antígenos del síndrome de Guillain-Barre.

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.

[Molecular mimic between cardiovascular diseases and microorganism antigens]. / Mimetismo molecular entre enfermedades cardiovasculares y antígenos de microorganismos.

INTRODUCTION: Cardiovascular diseases are the result of genetic and environmental interaction that conditions the integrity of the heart and blood vessels. Risk factors include infections. The inflammatory response against the infectious agent is a trigger of autoimmune cardiovascular diseases due to the similarity between the pathogen proteins and human antigens, since the immune response can present cross-reactivity caused by molecular mimicry. METHODS: We performed a search for pathogens involved in autoimmune heart diseases and autoantigens 9 associated with these diseases in the Pubmed and Google Scholar search engines. Identity between proteins was performed through global alignments using PSI-BLAST. The 3D structures of the proteins were obtained by Uniprot or NCBI and, if not found, the structure was modeled by homology using the Swiss Model server. Epitope prediction was performed through Ellipro and the Immunological Epitope Database (IEDB). In addition, the PYMOL program was used to visualize proteins in 3D and position the epitopes in the structure. RESULTS: A total of ten cardiovascular proteins showed identity (30-88,24%) in their amino acid sequences with antigens from 10 pathogens. Actin proteins and heat shock protein (HSP) families had higher levels of identity with Trypanosoma Cruzi, Cryptococcus neoformans, and Chlamydia trachomatis, 71,47%, 88,24%, and 80,61%, respectively. Other pathogens, such as Streptococcus pyogenes, Bacillus sp, Magnetospirillum gryphiswaldense, Helicobacter pylori and Chlamydia pneumoniae, presented a moderate identity with a maximum value of 65,79%. CONCLUSION: Human actin and HSPs share a high degree of conservation with epitopes from various microorganisms, such as bacteria, fungi and protozoa, suggesting molecular mimicry and cross-reactivity as a mechanism for the development of atherosclerosis, heart disease rheumatic disease, myocarditis and Chagas heart disease. In vitro and in vivo work is needed to demonstrate the results obtained in the In Silico analysis.

INTRODUCCIÓN: Las enfermedades cardiovasculares son el resultado de la interacción genética y ambiental que condiciona la integridad del corazón y los vasos sanguíneos. Los factores de riesgo incluyen infecciones. La respuesta inflamatoria contra el agente infeccioso es un desencadenante de las enfermedades cardiovasculares autoinmunes, debido a la similitud entre las proteínas del patógeno y los antígenos humanos, pues la respuesta inmunitaria puede presentar reactividad cruzada causada por mimetismo molecular. MÉTODOS: Realizamos una búsqueda de patógenos involucrados en enfermedades cardíacas autoinmunes y de autoantígenos asociados a estas enfermedades en los buscadores Pubmed y Google Scholar. La identidad entre proteínas se realizó a través de alineamientos globales utilizando PSI-BLAST. Las estructuras 3D de las proteínas fue obtenida por Uniprot o NCBI y, si no se encontraban, las estructuras se modelaban por homología, utilizando el servidor Swiss Model. La predicción de los epítopes se realizó a través de Ellipro, y la Base de Datos de Epítopos Inmunológicos (IEDB). Además, se utilizó el programa PYMOL para la visualización de proteínas en 3D, y el posicionamiento de los epítopes en la estructura. RESULTADOS: Diez proteínas cardiovasculares mostraron una identidad (30-88,24%) en sus secuencias de aminoácidos con antígenos de diez patógenos. Las proteínas de actina y las familias de proteínas de choque térmico (HSP, por sus siglas en inglés), presentaron niveles de identidad más altos con Trypanosoma Cruzi, Cryptococcus neoformans y Chlamydia trachomatis, 71,47%, 88,24% y 80,61%, respectivamente. Otros patógenos, como Streptococcus pyogenes, Bacillus sp, Magnetospirillum gryphiswaldense, Helicobacter pylori y Chlamydia pneumoniae, presentaron identidad moderada con un valor máximo del 65,79%. CONCLUSIÓN: La actina humana y las HSP comparten un alto grado de conservación con epítopos de varios microorganismos, como bacterias, hongos y protozoos; lo que sugiere la imitación molecular y la reactividad cruzada como mecanismos para el desarrollo de la aterosclerosis, la enfermedad cardíaca reumática, la miocarditis y la enfermedad cardíaca de Chagas. Se necesitan trabajos in vitro e in vivo, que demuestren los resultados obtenidos en el análisis In Silico.

[Molecular mimicry between human thyroid peroxidase, thyroglobulin, cosinophil peroxidase, IL-24 and microorganisms antigens]. / Mimetismo molecular entre peroxidasa tiroidea humana, tiroglobulina, peroxidasa de eosinófilos, IL-24 y antígenos de microorganismos.

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.

Etiopathogenesis of Psoriasis: Integration of Proposed Theories.

Psoriasis is a chronic inflammatory disease characterized by squamous and erythematous plaques on the skin and the involvement of the immune system. Global prevalence for psoriasis has been reported around 1-3% with a higher incidence in adults and similar proportions between men and women. The risk factors associated with psoriasis are both extrinsic and intrinsic, out of which a polygenic predisposition is a highlight out of the latter. Psoriasis etiology is not yet fully described, but several hypothesis have been proposed: 1) the autoimmunity hypothesis is based on the over-expression of antimicrobial peptides such as LL-37, the proteins ADAMTSL5, K17, and hsp27, or lipids synthesized by the PLA2G4D enzyme, all of which may serve as autoantigens to promote the differentiation of autoreactive lymphocytes T and unleash a chronic inflammatory response; 2) dysbiosis of skin microbiota hypothesis in psoriasis has gained relevance due to the observations of a loss of diversity and the participation of pathogenic bacteria such as Streptococcus spp. or Staphylococcus spp. the fungi Malassezia spp. or Candida spp. and the virus HPV, HCV, or HIV in psoriatic plaques; 3) the oxidative stress hypothesis, the most recent one, describes that the cell injury and the release of proinflammatory mediators and antimicrobial peptides that leads to activate of the Th1/Th17 axis observed in psoriasis is caused by a higher release of reactive oxygen species and the imbalance between oxidant and antioxidant mechanisms. This review aims to describe the mechanisms involved in the three hypotheses on the etiopathogeneses of psoriasis.

Mechanism underlying polyvalent IgG-induced regulatory T cell activation and its clinical application: Anti-idiotypic regulatory T cell theory for immune tolerance.

The regulatory T (Treg) cells constitute a functionally defined subpopulation of T cells that modulate the immune system and maintain immune tolerance through suppression of the development of autoimmune responses to self-antigens and allergic reactions to external antigens. Reduction in the number or function of Treg cells has been suggested as a key immune abnormality underlying the development of autoimmune and allergic diseases. In vitro studies have demonstrated that purified polyvalent immunoglobulin G (IgG) from multiple healthy blood donors can exert immunomodulatory effects on Treg cells. Incubation of polyvalent human IgG with purified CD4+CD25high T cells increased the intracellular expression of interleukin (IL)-10. Intravenous administration of polyvalent human IgG induced significant expansions of CD4+ Foxp3+ Treg cells and clinical improvements in patients with autoimmune diseases. In human clinical trials, intramuscular administration of autologous total IgG significantly increased the percentage of IL-10-producing CD4+ Treg cells in the peripheral blood of healthy subjects and provided significant clinical improvements in patients with atopic dermatitis. These results suggest a clinical usefulness of polyvalent IgG-induced activation of Treg cells in human subjects. This review proposes a new hypothesis for immune tolerance mechanism by integrating the pre-existing "idiotypic network theory" and "Treg cell theory" into an "anti-idiotypic Treg cell theory." Based on this hypothesis, an "active anti-idiotypic therapy" for allergic and autoimmune diseases using autologous polyvalent IgG (as immunizing antigens) is suggested as follows: (1) Intramuscular or subcutaneous administration of autologous polyvalent IgG produces numerous immunogenic peptides derived from idiotypes of autologous IgG through processing of dendritic cells, and these peptides activate anti-idiotypic Treg cells in the same subject. (2) Activated anti-idiotypic Treg cells secrete IL-10 and suppress Th2 cell response to allergens and autoimmune T cell response to self-antigens. (3) These events can induce a long-term clinical improvements in patients with allergic and autoimmune diseases. Further studies are needed to evaluate the detailed molecular mechanism underlying polyvalent IgG-induced Treg cell activation and the clinical usefulness of this immunomodulatory therapy for autoimmune and allergic diseases.

Molecular mimicry between Zika virus and central nervous system inflammatory demyelinating disorders: the role of NS5 Zika virus epitope and PLP autoantigens.

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 (IIDD) 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 IIDD 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.

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 arbovírus 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.

Anti-BP180 IgG antibody ELISA values correlate with adverse pregnancy outcomes in pemphigoid gestationis.

BACKGROUND: Adverse pregnancy outcomes (APO) occur in 35% of patients with pemphigoid gestationis (PG). No biological predictor of APO has been established yet. OBJECTIVES: To assess a potential relationship between the occurrence of APO and the serum value of anti-BP180 antibodies at the time of PG diagnosis. METHODS: Multicentre retrospective study conducted from January 2009 to December 2019 in 35 secondary and tertiary care centres. INCLUSION CRITERIA: (i) diagnosis of PG according to clinical, histological and immunological criteria, (ii) ELISA measurement of anti-BP180 IgG antibodies determined at the time of PG diagnosis with the same commercial kit and (iii) obstetrical data available. RESULTS: Of the 95 patients with PG included, 42 had one or more APO, which mainly corresponded to preterm birth (n = 26), intrauterine growth restriction (IUGR) (n = 18) and small weight for gestational age at birth (n = 16). From a ROC curve, we identified a threshold of 150 IU ELISA value as the most discriminating to differentiate between patients with or without IUGR, with 78% sensitivity, 55% specificity, 30% positive and 91% negative predictive value. The threshold >150 IU was confirmed using a cross-validation based on bootstrap resampling, which showed that the median threshold was 159 IU. Upon adjusting for oral corticosteroid intake and main clinical predictors of APO, an ELISA value of >150 IU was associated with the occurrence of IUGR (OR = 5.11; 95% CI: 1.48-22.30; p = 0.016) but not with any other APO. The combination of blisters and ELISA values higher than 150 IU led to a 2.4-fold higher risk of all-cause APO (OR: 10.90; 95% CI: 2.33-82.3) relative to patients with blisters but lower values of anti-BP180 antibodies (OR of 4.54; 95% CI 0.92-34.2). CONCLUSION: These findings suggest that anti-BP180 antibody ELISA value in combination with clinical markers is helpful in managing the risk of APO, in particular IUGR, in patients with PG.

Analysis of the autoimmune response to BP180 in Chinese stroke patients.

BACKGROUND: Significant association between bullous pemphigoid (BP) and stroke has been reported. This study aimed to evaluate the level of anti-BP180 antibody in stroke patients to explore the relationship between BP and stroke in their pathogenesis. METHODS: We collected serum samples from stroke patients and matched controls between February 2019 and June 2020. The anti-BP180 antibody levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: A total of 1183 stroke patients including 970 with cerebral infarction (CI), 192 with intracerebral hemorrhage (ICH), 21 with CI and ICH, and 855 controls were enrolled in this study. Anti-BP180 autoantibody values were significantly higher in stroke patients than in controls (p<0.001). Anti-BP180 autoantibody-positive rates were 12.51% (148) in stroke patients and 4.68% (40) in controls (p<0.001, OR=2.65). In anti-BP180 autoantibody-positive subjects, the values were significantly higher in stroke patients than in controls (p<0.001). However, only 10 (6.76%) stroke patients and 3 (7.5%) controls had high values (> 100 RU/mL) (p=0.87). Stratified analysis showed that anti-BP180 antibody positive rates were independent of age, sex, and stroke subtypes in the stroke group. Positive rates in patients with both CI and ICH were nearly two times higher than those in patients with either CI or ICH alone (p=0.11, OR=1.94). STUDY LIMITATIONS: This study had a limited sample size and lacked quantitative criteria for stroke severity. CONCLUSIONS: Anti-BP180 antibody values and positive rates were higher in stroke patients than in controls, suggesting that stroke patients may have higher of developing BP.

Prediction of molecular mimicry between proteins from Trypanosoma sp. and human antigens associated with systemic lupus erythematosus.

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.

Major depression favors the expansion of Th17-like cells and decrease the proportion of CD39+Treg cell subsets in response to myelin antigen in multiple sclerosis patients.

BACKGROUND: Mood disorders have been associated with risk of clinical relapses in multiple sclerosis (MS), a demyelinating disease mediated by myelin-specific T cells. OBJECTIVES: We aimed to investigate the impact of major depressive disorder (MDD) and cytokine profile of T-cells in relapsing remitting MS patients. METHODS: For our study, plasma and PBMC were obtained from 60 MS patients (30 with lifetime MDD) in remission phase. The PBMC cultures were stimulated with anti-CD3/anti-CD28 beads or myelin basic protein (MBP), and effector and regulatory T cell phenotypes were determined by flow cytometry. The cytokine levels, both in the plasma or in the supernatants collected from PBMC cultures, were quantified by Luminex. In some experiments, the effect of serotonin (5-HT) was investigated. RESULTS: Here, higher Th17-related cytokine levels in response to anti-CD3/anti-CD28 and MBP were quantified in the plasma and PBMC cultures of the MS/MDD group in comparison with MS patients. Further, elevated frequency of CD4+ and CD8+ T cells capable of producing IL-17, IL-22 and GM-CSF was observed in depressed patients. Interestingly, the percentage of myelin-specific IFN-γ+IL-17+ and IFN-γ+GM-CSF+ CD4+ T cells directly correlated with neurological disabilities. In contrast, the occurrence of MDD reduced the proportion of MBP-specific CD39+Tregs subsets. Notably, the severity of both neurological disorder and depressive symptoms inversely correlated with these Tregs. Finally, the addition of 5-HT downregulated the release of Th17-related cytokines in response to anti-CD3/anti-CD28 and myelin antigen. CONCLUSIONS: In summary, our findings suggested that recurrent major depression, by favoring imbalances of effector Th17 and Treg cell subsets, contributes to MS severity.

Mutational screening of the TPO and DUOX2 genes in Argentinian children with congenital hypothyroidism due to thyroid dyshormonogenesis.

PURPOSE: Primary congenital hypothyroidism (CH) is the most common endocrine disease in children and one of the preventable causes of both cognitive and motor deficits. We present a genetic and bioinformatics investigation of rational clinical design in 17 Argentine patients suspected of CH due to thyroid dyshormonogenesis (TDH). METHODS: Next-Generation Sequencing approach was used to identify variants in Thyroid Peroxidase (TPO) and Dual Oxidase 2 (DUOX2) genes. A custom panel targeting 7 genes associated with TDH [(TPO), Iodothyrosine Deiodinase I (IYD), Solute Carrier Family 26 Member 4 (SLC26A4), Thyroglobulin (TG), DUOX2, Dual Oxidase Maturation Factor 2 (DUOXA2), Solute Carrier Family 5 Member 5 (SLC5A5)] and 4 associated with thyroid dysembryogenesis [PAX8, FOXE1, NKX2-1, Thyroid Stimulating Hormone Receptor (TSHR)] has been designed. Additionally, bioinformatic analysis and structural modeling were carried out to predict the disease-causing potential variants. RESULTS: Four novel variants have been identified, two in TPO: c.2749-2 A > C and c.2752_2753delAG, [p.Ser918Cysfs*62] and two variants in DUOX2 gene: c.425 C > G [p.Pro142Arg] and c.2695delC [p.Gln899Serfs*21]. Eighteen identified TPO, DUOX2 and IYD variants were previously described. We identified potentially pahogenic biallelic variants in TPO and DUOX2 in 7 and 2 patients, respectively. We also detected a potentially pathogenic monoallelic variant in TPO and DUOX2 in 7 and 1 patients respectively. CONCLUSIONS: 22 variants have been identified associated with TDH. All described novel mutations occur in domains important for protein structure and function, predicting the TDH phenotype.

Bullous pemphigoid and milia: prevalence and clinical laboratory findings in a Brazilian sample.

BACKGROUND: Bullous pemphigoid (BP) associated with milia lesions has been increasingly reported, but its prevalence has not been reported in a Brazilian BP population yet. OBJECTIVES: To describe the occurrence and clinical-laboratorial findings of BP-milia association in a southeastern Brazilian sample. METHODS: A descriptive study based on the medical charts of 102 BP patients was accomplished. Clinical and laboratory data of BP-milia patients were compiled. Total serum IgE measurements, immunoblot assays based on basement membrane zone antigens, and HLA-DQ alleles typing were performed. RESULTS: Milia was evident in 8 (7.8%) BP patients, five males, aged between 46 and 88 years. Increased total IgE levels were determined in 7 (87.5%) of the eight patients. In five of eight patients, immunoblotting showed IgG reactivity against the BP180-NC16a domain but not against collagen VII or laminin-332; it also revealed reactivity against the BP180 C-terminal domain or LAD-1, or both in four of them. The HLA-DQB1*03:01 and HLA-DQA1*05:05 alleles were identified in three of five BP-milia patients. Moreover, three of five cases presented the HLA-DQB1*06 allelic group. STUDY LIMITATIONS: HLA determination was performed in five patients. CONCLUSIONS: Milia formation in BP patients seems to be less uncommon than previously admitted. Laboratory data revealed increased IgE; autoantibodies against the BP180 C-terminal domain or LAD-1, or both; and the HLA-DQB1*06 allelic group, described for the BP-milia association. Careful determination of antibodies against basement membrane zone molecules and HLA characterization in different populations may provide further insights into this association.

Autoantigen characterization in the lower esophageal sphincter muscle of patients with achalasia.

BACKGROUND: Serum anti-myenteric autoantibodies define autoimmune achalasia and tissue MMP-9 activity may locally process autoantigenic proteins in the muscle of the lower esophageal sphincter (LES) of achalasia patients. METHODS: Biopsies of the LES muscle from 36 achalasia patients, 6 esophagogastric junction outflow obstruction (EGJOO) patients, and 16 transplant donors (TD) were compared in a blind cross-sectional study. Histological characteristics such as inflammation, fibrosis, presence of ganglion cells, cells of Cajal, GAD65, PNMA2, S-100, P substance, and MMP-9 proteoforms in tissue were assessed by H&E and Picrosirius Red staining and immunohistochemistry analysis. Anti-neuronal antibodies, onconeural antigens, recoverin, SOX-1, titin, zic4, GAD65, and Tr were evaluated by immunoblot/line assay. KEY RESULTS: Tissue of achalasia patients had heterogeneous inflammatory infiltrates with fibrosis and contrasting higher levels of activated MMP-9, as compared with EGJOO and TD. Moreover, lower ganglion cell percentages and cell of Cajal percentages were determined in esophageal tissues of achalasia patients versus TD. The tissues of achalasia versus EGJOO patients had higher GAD65 and PNMA2 protein expression. Unexpectedly, these proteins were absent in TD tissue. S-100 and P substance had similar expression levels in tissues of achalasia patients versus TD and EGJOO. Most of the achalasia sera had anti-GAD65 (83%) and anti-PNMA2 (90%) autoantibodies versus EGJOO (17% and 33%, respectively) and healthy volunteers (10% and 0%, respectively). CONCLUSIONS AND INFERENCES: Tissue-specific ectopic expression of GAD65 and PNMA/Ta2 and active MMP-9, associated with the presence of specific autoantibodies directed against these proteins, might participate in the pathophysiology of achalasia triggering and/or perpetuating autoimmune disease.

P3H4 and PLOD1 expression associates with poor prognosis in bladder cancer.

PURPOSE: The prolyl 3-hydroxylase family member 4 gene (P3H4) is involved in the development of human cancers. The association of P3H4 with bladder cancer (BC) prognosis is unclear. This study aimed to analyze the association of P3H4 with BC prognosis. METHODS: RNA-Seq data were downloaded from The Cancer Genome Atlas project and BC microarray datasets (GSE13507, GSE31684, and GSE32548) were downloaded from the Gene Expression Omnibus database. We analyzed the differences in P3H4 expression levels between BC tumors and non-tumor tissues and between samples with different clinical information. The association of P3H4 and P3H4-related genes with BC prognosis and the possibility of using P3H4 expression as a prognostic biomarker in BC patients were also analyzed. RevMan was used to perform the meta-analysis. RESULTS: P3H4 was upregulated in BC tissues compared with the adjacent non-tumor tissues (p = 4.06e-08). Univariate Cox regression analysis and meta-analysis showed that high P3H4 expression level contributed to a poor BC prognosis (Hazard ratio, HR = 1.348, 95% CI 1.140-1.594, p = 4.89e-04; meta-analysis: HR = 1.45, 95% CI 1.10-1.91; p = 9.00e-03). Among the genes related to P3H4, the PLOD1 gene was closely associated with P3H4 expression (r = 0.620, p = 2.49e-44). Also, a meta-analysis showed that PLOD1 expression was associated with a poor prognosis in BC patients (HR = 1.77, 95% CI 1.31-2.38; p = 2.00e-04). CONCLUSIONS: The P3H4 and PLOD1 genes might be used as reliable prognostic biomarkers for BC.

Tolerogenic Delivery of a Hybrid Insulin Peptide Markedly Prolongs Islet Graft Survival in the NOD Mouse.

The induction of antigen (Ag)-specific tolerance and replacement of islet ß-cells are major ongoing goals for the treatment of type 1 diabetes (T1D). Our group previously showed that a hybrid insulin peptide (2.5HIP) is a critical autoantigen for diabetogenic CD4+ T cells in the NOD mouse model. In this study, we investigated whether induction of Ag-specific tolerance using 2.5HIP-coupled tolerogenic nanoparticles (NPs) could protect diabetic NOD mice from disease recurrence upon syngeneic islet transplantation. Islet graft survival was significantly prolonged in mice treated with 2.5HIP NPs, but not NPs containing the insulin B chain peptide 9-23. Protection in 2.5HIP NP-treated mice was attributed both to the simultaneous induction of anergy in 2.5HIP-specific effector T cells and the expansion of Foxp3+ regulatory T cells specific for the same Ag. Notably, our results indicate that effector function of graft-infiltrating CD4+ and CD8+ T cells specific for other ß-cell epitopes was significantly impaired, suggesting a novel mechanism of therapeutically induced linked suppression. This work establishes that tolerance induction with an HIP can delay recurrent autoimmunity in NOD mice, which could inform the development of an Ag-specific therapy for T1D.

Immunoexpression of REGγ and apoptosis-related proteins in oral tongue squamous cell carcinoma.

The aim of this study was to investigate the immunohistochemical expression of REGγ, p53, MDM-2, Bcl-2, and Bax in oral tongue squamous cell carcinoma (OTSCC), and to correlate the findings with clinicopathological parameters. Fifty-eight OTSCC cases were selected for the study. The percentages of nuclear (REGγ, p53, and MDM-2) and cytoplasmic (Bcl-2 and Bax) staining in epithelial cells were determined and correlated with clinicopathological parameters (regional lymph node metastasis, clinical stage, clinical outcome, and histopathological grade of malignancy). Expression of REGγ was observed in all cases studied. Significantly lower percentages were observed in tumours with lymph node metastasis (P = 0.036) and in high-grade tumours (P = 0.013). No significant differences in p53, MDM-2, or Bax expression were observed according to the clinicopathological parameters. Lower percentages of Bcl-2 staining were found in high-grade OTSCC (P = 0.040) and in cases of disease-related death (P = 0.032). The expression of REGγ showed a weak positive correlation with the expression of MDM-2 (P = 0.001) and Bcl-2 (P = 0.014). The results of this study suggest that lower expression of REGγ may contribute to the progression of OTSCC. The role of REGγ in the development of OTSCC does not appear to be primarily related to the modulation of apoptosis in neoplastic cells.

Immunomodulation induced by central nervous system-related peptides as a therapeutic strategy for neurodegenerative disorders.

Neurodegenerative diseases (NDD) are disorders characterized by the progressive loss of neurons affecting motor, sensory, and/or cognitive functions. The incidence of these diseases is increasing and has a great impact due to their high morbidity and mortality. Unfortunately, current therapeutic strategies only temporarily improve the patients' quality of life but are insufficient for completely alleviating the symptoms. An interaction between the immune system and the central nervous system (CNS) is widely associated with neuronal damage in NDD. Usually, immune cell infiltration has been identified with inflammation and is considered harmful to the injured CNS. However, the immune system has a crucial role in the protection and regeneration of the injured CNS. Nowadays, there is a consensus that deregulation of immune homeostasis may represent one of the key initial steps in NDD. Dr. Michal Schwartz originally conceived the concept of "protective autoimmunity" (PA) as a well-controlled peripheral inflammatory reaction after injury, essential for neuroprotection and regeneration. Several studies suggested that immunizing with a weaker version of the neural self-antigen would generate PA without degenerative autoimmunity. The development of CNS-related peptides with immunomodulatory neuroprotective effect led to important research to evaluate their use in chronic and acute NDD. In this review, we refer to the role of PA and the potential applications of active immunization as a therapeutic option for NDD treatment. In particular, we focus on the experimental and clinical promissory findings for CNS-related peptides with beneficial immunomodulatory effects.

Strong Association of the Myriad Discrete Speckled Nuclear Pattern With Anti-SS-A/Ro60 Antibodies: Consensus Experience of Four International Expert Centers.

Introduction: The morphological patterns in indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) reflect the autoantibodies in the sample. The International Consensus on ANA Patterns (ICAP) classifies 30 relevant patterns (AC-0 to AC-29). AC-4 (fine speckled nuclear pattern) is associated to anti-SS-A/Ro, anti-SS-B/La, and several autoantibodies. Anti-SS-A/Ro samples may contain antibodies to Ro60 and Ro52. A variation of AC-4 (herein designated AC-4a), characterized by myriad discrete nuclear speckles, was reported to be associated with anti-SS-A/Ro. The plain fine speckled pattern (herein designated AC-4b) seldom was associated with anti-SS-A/Ro. This study reports the experience of four expert laboratories on AC-4a and AC-4b. Methods: Anti-Ro60 monoclonal antibody A7 was used to investigate the HEp-2 IFA pattern. Records containing concomitant HEp-2 IFA and SS-A/Ro tests from Durand Laboratory, Argentina (n = 383) and Fleury Laboratory, Brazil (n = 144,471) were analyzed for associations between HEp-2 IFA patterns and disease-associated autoantibodies (DAA): double-stranded DNA, Scl-70, nucleosome, SS-B/La, Sm, and U1-RNP. A total of 381 samples from Dresden Technical University (TU-Dresden), Germany, were assayed for HEp-2 IFA and DAA. Results: Monoclonal A7 recognized Ro60 in Western blot and immunoprecipitation, and yielded the AC-4a pattern on HEp-2 IFA. Analyses from Durand Laboratory and Fleury Laboratory yielded compatible results: AC-4a was less frequent (8.9% and 2.7%, respectively) than AC-4b (26.1% and 24.2%) in HEp-2 IFA-positive samples. Reactivity to SS-A/Ro occurred in 67.6% and 96.3% of AC-4a-pattern samples against 23% and 6.8% of AC-4b pattern samples. Reciprocally, AC-4a occurred in 24% and 47.1% of anti-SS-A/Ro-positive samples, and in 3.8% and 0.1% of anti-SS-A/Ro-negative samples. Data from TU-Dresden show that the AC-4a pattern occurred in 69% of 169 anti-SS-A/Ro-monospecific samples (62% of all anti-SS-A/Ro-positive samples) and in 4% of anti-SS-A/Ro-negative samples, whereas anti-SS-A/Ro occurred in 98.3% of AC-4a samples and in 47.9% of AC-4b samples. In all laboratories, coexistence of anti-SS-B/La, but not other DAA, in anti-SS-A/Ro-positive samples did not disturb the AC-4a pattern. AC-4a was predominantly associated with anti-Ro60 antibodies. Conclusions: This study confirms the association of AC-4a pattern and anti-SS-A/Ro in opposition to the AC-4b pattern. The results of four international expert laboratories support the worldwide applicability of these AC-4 pattern variants and their incorporation into ICAP classification under codes AC-4a and AC-4b, respectively. The AC-4 pattern should be maintained as an umbrella pattern for cases in which one cannot discriminate AC-4a and AC-4b patterns. The acknowledgment of the AC-4a pattern should add value to HEp-2 IFA interpretation.