RESUMEN
Approximately 10% of the population reports being allergic to penicillin, although usually less than 1% really are. In addition, people with proven allergies over the years may no longer be allergic. Unconfirmed penicillin allergy and use of alternative antimicrobials result in more treatment failures; more severe adverse effects. Higher cost; longer hospitalizations; increase in the emergence of multi-resistant germs associated with health care. The risk of cross-allergy between ß-lactam groups is usually <2%, depending on the similarity of the side chains, so prescribing antibiotics from another ß-lactam group is safe as long as we take into account the structural similarity. Incorporating the reassessment of allergies and improving the prescription of antibiotics in this group of patients reduces the generation and spread of multi-resistant germs, and the associated costs. There are simple methods and specific scores that simplify allergy reassessment. The objective of this review is to expose how, through these methods, the delabeling of patients erroneously labeled as allergic and the safe prescription of ß-lactam antibiotics can be achieved.
Aproximadamente el 10% de la población refiere ser alérgico a la penicilina, aunque habitualmente menos del 1% lo es; además las personas con alergia demostrada con el paso de los años pueden dejar de ser alérgicos. La alergia a la penicilina sin confirmación y el uso de antimicrobianos alternativos tienen como efecto más fallas en el tratamiento; más efectos adversos graves; mayor costo; internaciones más prolongadas; incremento en la emergencia de gérmenes multirresistentes asociados a los cuidados de la salud. El riesgo de alergia cruzada entre grupos de ß-lactámicos suele ser <2%, dependiendo de la similitud de las cadenas laterales, por lo que prescribir antibióticos de otro grupo de ß-lactámicos es seguro siempre que tengamos en cuenta la similitud estructural. Incorporar la reevaluación de alergias y mejorar la prescripción de antibióticos en este grupo de pacientes, disminuye la generación y propagación de gérmenes multirresistentes, y los costos asociados. Existen métodos sencillos y escalas específicas que permiten simplificar la reevaluación de la alergia. El objetivo de esta revisión es exponer cómo a través de estos métodos, puede lograrse el desrotulado de pacientes erróneamente etiquetados como alérgicos y la prescripción segura de antibióticos ß-lactámicos.
Asunto(s)
Antibacterianos , Hipersensibilidad a las Drogas , Penicilinas , beta-Lactamas , Humanos , Antibacterianos/efectos adversos , Penicilinas/efectos adversos , beta-Lactamas/efectos adversos , Farmacorresistencia Bacteriana Múltiple , Etiquetado de Medicamentos/normas , Reacciones Cruzadas , Antibióticos BetalactámicosRESUMEN
Despite successful vaccination efforts, the emergence of new SARS-CoV-2 variants poses ongoing challenges to control COVID-19. Understanding humoral responses regarding SARS-CoV-2 infections and their impact is crucial for developing future vaccines that are effective worldwide. Here, we identified 41 immunodominant linear B-cell epitopes in its spike glycoprotein with an SPOT synthesis peptide array probed with a pool of serum from hospitalized COVID-19 patients. The bioinformatics showed a restricted set of epitopes unique to SARS-CoV-2 compared to other coronavirus family members. Potential crosstalk was also detected with Dengue virus (DENV), which was confirmed by screening individuals infected with DENV before the COVID-19 pandemic in a commercial ELISA for anti-SARS-CoV-2 antibodies. A high-resolution evaluation of antibody reactivity against peptides representing epitopes in the spike protein identified ten sequences in the NTD, RBD, and S2 domains. Functionally, antibody-dependent enhancement (ADE) in SARS-CoV-2 infections of monocytes was observed in vitro with pre-pandemic Dengue-positive sera. A significant increase in viral load was measured compared to that of the controls, with no detectable neutralization or considerable cell death, suggesting its role in viral entry. Cross-reactivity against peptides from spike proteins was observed for the pre-pandemic sera. This study highlights the importance of identifying specific epitopes generated during the humoral response to a pathogenic infection to understand the potential interplay of previous and future infections on diseases and their impact on vaccinations and immunodiagnostics.
Asunto(s)
Anticuerpos Antivirales , COVID-19 , Reacciones Cruzadas , Virus del Dengue , Epítopos de Linfocito B , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Glicoproteína de la Espiga del Coronavirus/inmunología , Humanos , Reacciones Cruzadas/inmunología , SARS-CoV-2/inmunología , COVID-19/inmunología , COVID-19/virología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Epítopos de Linfocito B/inmunología , Virus del Dengue/inmunología , Dengue/inmunología , Dengue/virología , Acrecentamiento Dependiente de Anticuerpo/inmunología , Pandemias , Epítopos Inmunodominantes/inmunologíaRESUMEN
BACKGROUND: Paracoccidioidomycosis (PCM) and histoplasmosis are endemic fungal diseases in South America. Both can lead to lung involvement with fungal dissemination progressing to systemic and severe clinical manifestations, especially in immunosuppressed hosts. As the population of immunosuppressed individuals has been rising, a higher occurrence of fungal infections is predicted in this setting. This poses challenges regarding the differential diagnosis due to overlapping clinical and laboratorial findings, hampering the management of cases. OBJECTIVES: In this study, the authors discuss the occurrence of a false-positive Histoplasma urinary antigen detection in a kidney transplant recipient with acute PCM. Given the scarce information about this subject, a review on literature data is provided. METHODS: A comprehensive literature search was conducted to investigate previous studies that found cross-reactivity between Histoplasma urinary antigen assays in human patients with confirmed diagnosis of PCM. Additionally, an update of PCM in transplant recipients is provided. FINDINGS: The included studies reported 120 samples from patients with PCM tested for Histoplasma antigen, presenting an overall cross-reactivity of 51.67% and 17 cases of PCM in transplant recipients. CONCLUSIONS: The galactomannan urinary antigen developed to diagnose histoplasmosis can cross react with PCM, which may represent a concern in countries where both mycoses overlap.
Asunto(s)
Antígenos Fúngicos , Histoplasma , Histoplasmosis , Trasplante de Riñón , Paracoccidioidomicosis , Receptores de Trasplantes , Humanos , Antígenos Fúngicos/orina , Histoplasma/inmunología , Paracoccidioidomicosis/diagnóstico , Paracoccidioidomicosis/orina , Histoplasmosis/orina , Histoplasmosis/diagnóstico , Masculino , Reacciones Cruzadas , Huésped Inmunocomprometido , Mananos/orina , Reacciones Falso Positivas , Persona de Mediana Edad , Galactosa/análogos & derivadosRESUMEN
Dengue (DENV) and Chikungunya (CHIKV) viruses can be transmitted simultaneously by Aedes mosquitoes, and there may be co-infections in humans. However, how the adaptive immune response is modified in the host has yet to be known entirely. In this study, we analyzed the cross-reactivity and neutralizing activity of IgG antibodies against DENV and CHIKV in sera of patients from the Mexican Institute of Social Security in Veracruz, Mexico, collected in 2013 and 2015 and using IgG antibodies of BALB/c mice inoculated with DENV and/or CHIKV. Mice first inoculated with DENV and then with CHIKV produced IgG antibodies that neutralized both viruses. Mice were inoculated with CHIKV, and then with DENV; they had IgG antibodies with more significant anti-CHIKV IgG antibody neutralizing activity. However, the inoculation only with CHIKV resulted in better neutralization of DENV2. In sera obtained from patients in 2013, significant cross-reactivity and low anti-CHIKV IgG antibody neutralizing activity were observed. In CHIKV-positive 2015 sera, the anti-DENV IgG antibody neutralizing activity was high. These results suggest that CHIKV stimulates DENV2-induced memory responses and vice versa. Furthermore, cross-reactivity between the two viruses generated neutralizing antibodies, but exchanging CHIKV for DENV2 generated a better anti-CHIKV neutralizing response.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Fiebre Chikungunya , Virus Chikungunya , Reacciones Cruzadas , Virus del Dengue , Dengue , Inmunoglobulina G , Ratones Endogámicos BALB C , Animales , Virus Chikungunya/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Dengue/inmunología , Dengue/virología , Virus del Dengue/inmunología , Humanos , Fiebre Chikungunya/inmunología , Fiebre Chikungunya/virología , Reacciones Cruzadas/inmunología , Ratones , México , Femenino , Pruebas de Neutralización , Masculino , Coinfección/inmunología , Coinfección/virología , AdultoRESUMEN
In response to the 2015 Zika virus (ZIKV) epidemic that occurred in Brazil, numerous commercial serological assays have been developed for clinical and research applications. Diagnosis of recent infection in pregnant women remains challenging. Having standardized, comparative studies of ZIKV tests is important for implementing optimal diagnostic testing and disease surveillance. This is especially important for serology tests used to detect ZIKV infection given that antibodies against ZIKV can cross-react with other arboviruses in the same virus family, such as dengue virus (DENV), yellow fever virus (YFV) and West Nile virus (WNV). We looked at the sensitivity and specificity of tests detecting ZIKV antibodies (IgM, IgG) from multiple manufacturers using panels of samples previously collected with known exposure to ZIKV and other arboviruses. We found that performance of the IgM tests was highly variable, with only one test (Inbios 2.0 IgM capture ELISA) having both high sensitivity and specificity. All IgG tests showed good sensitivity; however, specificity was highly variable, with some assays giving false-positive results on samples infected by another flavivirus. Overall, the results confirmed that accurate ZIKV antibody testing is challenging, especially in specimens from regions endemic for multiple other flaviviruses, and highlight the importance of available and suitable reference samples to evaluate ZIKV diagnostics.
Asunto(s)
Anticuerpos Antivirales , Inmunoglobulina G , Inmunoglobulina M , Sensibilidad y Especificidad , Pruebas Serológicas , Infección por el Virus Zika , Virus Zika , Humanos , Virus Zika/inmunología , Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/inmunología , Infección por el Virus Zika/sangre , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Pruebas Serológicas/métodos , Pruebas Serológicas/normas , Inmunoglobulina M/sangre , Inmunoglobulina G/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/normas , Reacciones Cruzadas/inmunología , Femenino , Embarazo , BrasilRESUMEN
Camelid immunoglobulins represent a unique facet of antibody biology, challenging conventional understandings of antibody diversification. IgG2 and IgG3 in particular are composed solely of heavy chains and exhibit a reduced molecular weight (90 kDa); their elongated complementarity determining region (CDR) loops play a pivotal role in their functioning, delving deep into enzyme active sites with precision. Serum therapy stands as the primary venom-specific treatment for snakebite envenomation, harnessing purified antibodies available in diverse forms such as whole IgG, monovalent fragment antibody (Fab), or divalent fragment antibody F (ab')2. This investigation looks into the intricacies of IgGs derived from camelid serum previously immunized with crotamine and crotoxin, toxins predominantly in Crotalus durissus venom, exploring their recognition capacity, specificity, and cross-reactivity to snake venoms and its toxins. Initially, IgG purification employed affinity chromatography via protein A and G columns to segregate conventional antibodies (IgG1) from heavy chain antibodies (IgG2 and IgG3) of camelid isotypes sourced from Lama glama serum. Subsequent electrophoretic analysis (SDS-PAGE) revealed distinct bands corresponding to molecular weight profiles of IgG's fractions representing isotypes in Lama glama serum. ELISA cross-reactivity assays demonstrated all three IgG isotypes' ability to recognize the tested venoms. Notably, IgG1 exhibited the lowest interactivity in analyses involving bothropic and crotalic venoms. However, IgG2 and IgG3 displayed notable cross-reactivity, particularly with crotalic venoms and toxins, albeit with exceptions such as PLA2-CB, showing reduced reactivity, and C. atrox, where IgGs exhibited insignificant reactivity. In Western blot assays, IgG2 and IgG3 exhibited recognition of proteins within molecular weight (≈15 kDa) of C. d. collilineatus to C. d. terrificus, with some interaction observed even with bothropic proteins despite lower reactivity. These findings underscore the potential of camelid heavy-chain antibodies, suggesting Lama glama IgGs as prospective candidates for a novel class of serum therapies. However, further investigations are imperative to ascertain their suitability for serum therapy applications.
Asunto(s)
Antivenenos , Inmunoglobulina G , Animales , Antivenenos/inmunología , Inmunoglobulina G/inmunología , Crotalus/inmunología , Venenos de Crotálidos/inmunología , Reacciones Cruzadas , Camélidos del Nuevo Mundo/inmunología , Crotoxina/inmunología , Camelidae/inmunologíaRESUMEN
Background: The Coronaviridae family comprises seven viruses known to infect humans, classified into alphacoronaviruses (HCoV-229E and HCoV-NL63) and betacoronaviruses (HCoV-OC43 and HCoV-HKU1), which are considered endemic. Additionally, it includes SARS-CoV (severe acute respiratory syndrome), MERS-CoV (Middle East respiratory syndrome), and the novel coronavirus SARS-CoV-2, responsible for COVID-19. SARS-CoV-2 induces severe respiratory complications, particularly in the elderly, immunocompromised individuals and those with underlying diseases. An essential question since the onset of the COVID-19 pandemic has been to determine whether prior exposure to seasonal coronaviruses influences immunity or protection against SARS-CoV-2. Methods: In this study, we investigated a cohort of 47 couples (N=94), where one partner tested positive for SARS-CoV-2 infection via real-time PCR while the other remained negative. Plasma samples, collected at least 30 days post-PCR reaction, were assessed using indirect ELISA and competition assays to measure specific antibodies against the receptor-binding domain (RBD) portion of the Spike (S) protein from SARS-CoV-2, HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1. Results: IgG antibody levels against the four endemic coronavirus RBD proteins were similar between the PCR-positive and PCR-negative individuals, suggesting that IgG against endemic coronavirus RBD regions was not associated with protection from infection. Moreover, we found no significant IgG antibody cross-reactivity between endemic coronaviruses and SARS-CoV-2 RBDs. Conclusions: Taken together, results suggest that anti-RBD antibodies induced by a previous infection with endemic HCoVs do not protect against acquisition of COVID-19 among exposed uninfected individuals.
Asunto(s)
Anticuerpos Antivirales , COVID-19 , Inmunoglobulina G , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , COVID-19/inmunología , COVID-19/prevención & control , SARS-CoV-2/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Masculino , Femenino , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Adulto , Persona de Mediana Edad , Glicoproteína de la Espiga del Coronavirus/inmunología , Coronavirus/inmunología , Enfermedades Endémicas , Reacciones Cruzadas/inmunologíaRESUMEN
BACKGROUND AND OBJECTIVE: Sensitization to Blomia tropicalis is associated with asthma in various tropical and subtropical countries; however, information about the specific molecular components associated with this disease is scarce. Using molecular diagnosis, we sought to identify B tropicalis allergens associated with asthma in Colombia. METHODS: Specific IgE (sIgE) to 8 B tropicalis recombinant allergens (Blo t 2, 5, 7, 8, 10, 12, 13, and 21) was determined using an in-house ELISA system in asthma patients (n=272) and controls (n=298) recruited in a national prevalence study performed in several Colombian cities (Barranquilla, Bogotá, Medellín, Cali, and San Andrés). The study sample included children and adults (mean [SD] age, 28 [17] years). Cross-reactivity between Blo t 5 and Blo t 21 was evaluated using ELISA-inhibition. RESULTS: Specific IgE (sIgE) to 8 B tropicalis recombinant allergens (Blo t 2, 5, 7, 8, 10, 12, 13, and 21) was determined using an in-house ELISA system in asthma patients (n=272) and controls (n=298) recruited in a national prevalence study performed in several Colombian cities (Barranquilla, Bogotá, Medellín, Cali, and San Andrés). The study sample included children and adults (mean [SD] age, 28 [17] years). Cross-reactivity between Blo t 5 and Blo t 21 was evaluated using ELISA-inhibition. CONCLUSION: Although Blo t 5 and Blo t 21 are considered common sensitizers, this is the first report of their association with asthma. Both components should be included in molecular panels for diagnosis of allergy in the tropics.
Asunto(s)
Alérgenos , Asma , Inmunoglobulina E , Humanos , Asma/inmunología , Asma/diagnóstico , Asma/epidemiología , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Adulto , Masculino , Femenino , Estudios de Casos y Controles , Niño , Adolescente , Colombia/epidemiología , Alérgenos/inmunología , Adulto Joven , Persona de Mediana Edad , Antígenos de Plantas/inmunología , Reacciones Cruzadas , Clima Tropical , Prevalencia , PreescolarRESUMEN
Immunodiagnostic tests for detecting dengue virus infections encounter challenges related to cross-reactivity with other related flaviviruses. Our research focuses on the development of a synthetic multiepitope antigen tailored for dengue immunodiagnostics. Selected dengue epitopes involved structural linearity and dissimilarity from the proteomes of Zika and Yellow fever viruses which served for computationally modeling the three-dimensional protein structure, resulting in the design of two proteins: rDME-C and rDME-BR. Both proteins consist of seven epitopes, separated by the GPGPG linker, and a carboxy-terminal 6 × -histidine tag. The molecular weights of the final proteins rDME-C and rDME-BR are 16.83 kDa and 16.80 kDa, respectively, both with an isoelectric point of 6.35. The distinguishing factor between the two proteins lies in the origin of their epitope sequences, where rDME-C is based on the reference dengue proteome, while rDME-BR utilizes sequences from prevalent Dengue genotypes in Brazil from 2008 to 2019. PyMol analysis revealed exposure of epitopes in the secondary structure. Successful expression of the antigens was achieved in soluble form and fluorescence experiments indicated a disordered structure. In subsequent testing, rDME-BR and rDME-C antigens were assessed using an indirect Elisa protocol against Dengue infected serum, previously examined with a commercial diagnostic test. Optimal concentrations for antigens were determined at 10 µg/mL for rDME-BR and 30 µg/mL for rDME-C, with serum dilutions ranging from 1:50 to 1:100. Both antigens effectively detected IgM and IgG antibodies in Dengue fever patients, with rDME-BR exhibiting higher sensitivity. Our in-house test showed a sensitivity of 77.3 % and 82.6 % and a specificity of 89.4 % and 71.4 % for rDME-C and rDEM-BR antigens. No cross-reactivity was observed with serum from Zika-infected mice but with COVID-19 serum samples. Our findings underscore the utility of synthetic biology in crafting Dengue-specific multiepitope proteins and hold promise for precise clinical diagnosis and monitoring responses to emerging Dengue vaccines.
Asunto(s)
Antígenos Virales , Virus del Dengue , Dengue , Ensayo de Inmunoadsorción Enzimática , Epítopos , Dengue/diagnóstico , Dengue/inmunología , Dengue/sangre , Antígenos Virales/inmunología , Epítopos/inmunología , Humanos , Virus del Dengue/inmunología , Virus del Dengue/genética , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Reacciones Cruzadas/inmunología , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: This study aimed to identify by in silico methods tropomyosin consensus B and T epitopes of shrimp species, house dust mites, insects, and nematodes associated with allergic diseases in tropical countries. METHODS: In silico analysis included tropomyosin from mites (Der p 10, Der f 10, Blo t 10), insects (Aed a 10, Per a 7, Bla g 7), shrimp (Lit v 1, Pen m 1, Pen a 1), and nematode (Asc l 3) all sequences were taken from the UniProt database. Linear IgE epitopes were predicted with AlgPred 2.0 and validated with BepiPred 3.0. MHC-II binding T cell epitopes were predicted using the IEDB server, which implements nine predictive methods (consensus method, combinatorial library, NN-align-2.3, NN- align-2.2, SMM-align, Sturniolo, NetMHCIIpan 3.1, and NetMHCIIpan 3.2) these predictions focused on 10 HLA-DR and 2 HLA-DQ alleles associated with allergic diseases. Subsequently, consensus B and T epitopes present in all species were identified. RESULTS: We identified 12 sequences that behaved as IgE-epitopes and B-cell epitopes, three of them: 160RKYDEVARKLAMVEA174, 192ELEEELRVVGNNLKSLEVSEEKAN215, 251KEVDRLEDELV261 were consensus in all species. Eleven peptides (T-epitopes) showed strong binding (percentile rank ≤ 2.0) to HLA-DRB1*0301, *0402, *0411, *0701, *1101, *1401, HLA-DQA1*03:01/DQB1*03:02, and HLA- DQA1*05:01/DQB1*02:01. Only two T-epitopes were consensus in all species: 167RKLAMVEADLERAEERAEt GEsKIVELEEELRV199, and 218EEeY KQQIKT LTaKLKEAEARAEFAERSV246. Subsequently, we identified 2 B and T epitope sequences and reached a consensus between species 167RKLAMVEA174 and 192ELEEELRV199. CONCLUSIONS: These data describe three sequences that may explain the IgE cross-reactivity between the analyzed species. In addition, the consensus B and T epitopes can be used for further in vitro investigations and may help to design multiple-epitope protein-based immunotherapy for tropomyosin-related allergic diseases.
OBJETIVO: Este estudio tuvo como objetivo identificar mediante métodos in silico epítopes B y T consenso de tropomiosina de especies de camarón, ácaros del polvo doméstico, insectos y nematodos asociados a enfermedades alérgicas en países tropicales. MÉTODOS: El análisis in silico incluyó tropomiosina de ácaros (Der p 10, Der f 10, Blo t 10), insectos (Aed a 10, Per a 7, Bla g 7), camarones (Lit v 1, Pen m 1, Pen a 1), y nematodo (Asc l 3). Todas las secuencias se tomaron de la base de datos UniProt. Los epítopes IgE lineales se predijeron con AlgPred 2.0 y se validaron con BepiPred 3.0. Los epítopes de células T de unión a MHC-II se predijeron utilizando el servidor IEDB, que implementa nueve métodos predictivos (método de consenso, biblioteca combinatoria, NN-align-2.3, NN-align-2.2, SMM-align, Sturniolo, NetMHCIIpan 3.1 y NetMHCIIpan 3.2). Estas predicciones se centraron en diez alelos HLA-DR y 2 HLA-DQ asociados con enfermedades alérgicas. Posteriormente, se identificaron epítopes consenso B y T presentes en todas las especies. RESULTADOS: Se identificaron 12 secuencias que se comportaron como epítopes de IgE y, también, como epítopes de células B. Tres de ellas: 160RKYDEVARKLAMVEA174, 192ELEEELRVVGNNLKSLEVSEEKAN213 y 251KEVDRLEDELV261, fueron consenso en todas las especies. Once péptidos mostraron una fuerte unión (rango percentil ≤ 2,0) a HLA-DRB1*0301, *0402, *0411, *0701, *1101, *1401 y a HLA HLA-DQA1*03:01/DQB1*03:02, o HLA-DQA1*05:01/DQB1*02:01. Solo se encontraron dos secuencias: 167RKLAMVEADLERAEERAEtGEsKIVELEEELRV199 con fuerte afinidad por HLA-DQA1*03:01/DQB1*03:02, y HLA-DQA1*05:01/DQB1*02:01. Se identificaron dos secuencias que son epítopos B y T, y son consenso entre especies: 167RKLAMVEA174 y 192ELEEELRV199. CONCLUSIONES: Estos datos describen tres secuencias que pueden explicar la reactividad cruzada de IgE entre las especies analizadas. Además, los epítopos B y T consenso se pueden usar para investigaciones in vitro adicionales, y pueden ayudar a diseñar inmunoterapia basada en proteínas de múltiepítopes para enfermedades alérgicas relacionadas con la tropomiosina.
Asunto(s)
Simulación por Computador , Reacciones Cruzadas , Epítopos de Linfocito B , Epítopos de Linfocito T , Hipersensibilidad , Tropomiosina , Animales , Secuencia de Consenso , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito T/inmunología , Insectos/inmunología , Penaeidae/inmunología , Pyroglyphidae/inmunología , Tropomiosina/inmunología , Tropomiosina/genética , Hipersensibilidad/inmunología , Ácaros/inmunología , Crustáceos/inmunología , Nematodos/inmunologíaRESUMEN
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.
Asunto(s)
Autoantígenos , Yoduro Peroxidasa , Imitación Molecular , Tiroglobulina , Imitación Molecular/inmunología , Humanos , Tiroglobulina/inmunología , Yoduro Peroxidasa/inmunología , Peroxidasa del Eosinófilo/inmunología , Animales , Antígenos Bacterianos/inmunología , Reacciones Cruzadas , Proteínas de Unión a Hierro/inmunología , Epítopos/inmunologíaRESUMEN
BACKGROUND: Visceral leishmaniasis (VL) is a zoonotic disease, with dogs being the main reservoir of the Leishmania infantum parasite. OBJECTIVE: To develop a new flow cytometry test to diagnosis canine VL (CVL) diagnosis. METHODS: The current study addresses a new flow cytometry test using beads coupled to the multiepitope antigen rMELEISH. RESULTS: In the study set of samples a sensitivity (87.1%) and specificity (89.9%) was observed. Considering the dogs' clinical status, 20/20 (100.0%) of the symptomatic sera tested positive, while 19/22 (86.4%) of the oligosymptomatic and 16/20 (80.0%) of asymptomatic were positive. In the non-infected control, all samples (0/30) tested as negative. In the cross-reaction control, the test was more efficient in dogs infected with L. braziliensis (2/10) and Trypanosoma cruzi (0/10), than those with Babesia canis (4/10) and Ehrlichia canis (4/10). Dogs immunized with different vaccines (Leishmune, Leish-Tec®, or LBSap) did not present serological reactivity. CONCLUSION: The flow cytometry serology through coupling the antigen rMELEISH in functional beads showed high accuracy in diagnosing CVL.
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Antígenos de Protozoos , Enfermedades de los Perros , Citometría de Flujo , Leishmaniasis Visceral , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/veterinaria , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/sangre , Animales , Perros , Citometría de Flujo/métodos , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/inmunología , Enfermedades de los Perros/parasitología , Enfermedades de los Perros/sangre , Antígenos de Protozoos/inmunología , Sensibilidad y Especificidad , Epítopos/inmunología , Leishmania infantum/inmunología , Anticuerpos Antiprotozoarios/sangre , Anticuerpos Antiprotozoarios/inmunología , Reacciones Cruzadas/inmunología , Pruebas Serológicas/métodosRESUMEN
Cross-neutralizing activity of human antibody response against Dengue virus complex (DENV) changes importantly over time. Domain III (DIII) of the envelope protein of DENV elicits a potently neutralizing and mostly type-specific IgG response. We used sera from 24 individuals from early- or late convalescence of DENV1 infection to investigate the evolution of anti-DIII human IgG with the time lapse since the infection. We evaluated the correlation between the serotype-specific reactivity against recombinant DIII proteins and the neutralization capacity against the four serotypes, and examined its behavior with the time of convalescence. Also, we use a library of 71 alanine mutants of surface-exposed amino acid residues to investigate the dominant epitopes. In early convalescence anti-DIII titers and potency of virus neutralization were positively associated with correlation coefficients from 0.82 to 1.0 for the four serotypes. For late convalescence, a positive correlation (r = 0.69) was found only for DENV1. The dominant epitope of the type-specific response is centered in the FG-loop (G383, E384, and K385) and includes most of the lateral ridge. The dominant epitope of the anti-DIII cross-reactive IgG in secondary infections shifts from the A-strand during early convalescence to a site centered in residues E314-H317 of the AB-loop and I352-E368 of the DI/DIII interface, in late convalescence. An immunoassay based on the detection of IgG anti-DIII response can be implemented for detection of infecting serotype in diagnosis of DENV infection, either primary or secondary. Human dominant epitopes of the cross-reactive circulating antibodies change with time of convalescence.
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Virus del Dengue , Dengue , Humanos , Epítopos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Formación de Anticuerpos , Convalecencia , Proteínas del Envoltorio Viral , Proteínas Recombinantes/metabolismo , Inmunoglobulina G/metabolismo , Reacciones CruzadasRESUMEN
In 2015, the Zika virus (ZIKV) emerged in Brazil, leading to widespread outbreaks in Latin America. Following this, many countries in these regions reported a significant drop in the circulation of dengue virus (DENV), which resurged in 2018-2019. We examine age-specific incidence data to investigate changes in DENV epidemiology before and after the emergence of ZIKV. We observe that incidence of DENV was concentrated in younger individuals during resurgence compared to 2013-2015. This trend was more pronounced in Brazilian states that had experienced larger ZIKV outbreaks. Using a mathematical model, we show that ZIKV-induced cross-protection alone, often invoked to explain DENV decline across Latin America, cannot explain the observed age-shift without also assuming some form of disease enhancement. Our results suggest that a sudden accumulation of population-level immunity to ZIKV could suppress DENV and reduce the mean age of DENV incidence via both protective and disease-enhancing interactions.
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Virus del Dengue , Dengue , Infección por el Virus Zika , Virus Zika , Humanos , Brasil/epidemiología , Anticuerpos Antivirales , Reacciones CruzadasRESUMEN
BACKGROUND: The co-circulation of flaviviruses in tropical regions has led to the hypothesis that immunity generated by a previous dengue infection could promote severe disease outcomes in subsequent infections by heterologous serotypes. This study investigated the influence of antibodies generated by previous Zika infection on the clinical outcomes of dengue infection. METHODOLOGY/PRINCIPAL FINDINGS: We enrolled 1,043 laboratory confirmed dengue patients and investigated their prior infection to Zika or dengue. Severe forms of dengue disease were more frequent in patients with previous Zika infection, but not in those previously exposed to dengue. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that previous Zika infection may represent a risk factor for subsequent severe dengue disease, but we did not find evidence of antibody-dependent enhancement (higher viral titer or pro-inflammatory cytokine overexpression) contributing to exacerbation of the subsequent dengue infection.
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Virus del Dengue , Dengue , Infección por el Virus Zika , Virus Zika , Humanos , Anticuerpos Antivirales , Reacciones CruzadasRESUMEN
The emergence of Zika virus (ZIKV) and its associated neonatal and congenital complications pose a threat to global health, particularly in tropical and subtropical regions with co-circulation of related flaviviruses and intense vector proliferation. Diagnosis of ZIKV by RT-PCR is limited to the viraemic phase and is not always accessible in low-income tropical settings, while serological tests often show cross-reactivity with other flaviviruses. Given the similarity of ZIKV symptoms to those of other arboviruses, but the different prognosis and risks, it is important to develop specific and accessible diagnostic tools. Egg yolk antibodies (IgY) were obtained from Leghorn laying hens immunized with recombinant ZIKV NS2B protein produced in agroinfiltrated Nicotiana benthamiana. After three immunizations, total IgY was recovered from the eggs by the 20% ammonium sulfate precipitation method. After characterisation by SDS-PAGE, dot blotting and ELISA, the IgY was adsorbed to dengue virus (DENV) from cell culture supernatants and tested for its ability to specifically detect ZIKV-positive sera samples. High yield and purity were observed on SDS-PAGE for polyclonal IgY, which reacted with NS2B at high titres in ELISA and detected both NS2B and ZIKV in dot blotting. However, a cross-reaction with DENV was observed and the anti-NS2B IgY was unable to discriminate ZIKV from DENV positive sera samples, even after adsorption with DENV. This is probably due to the phylogenetic relationship of the viruses and the shared identity of their proteins.
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Infección por el Virus Zika , Virus Zika , Animales , Femenino , Infección por el Virus Zika/diagnóstico , Pollos , Nicotiana , Yema de Huevo , Filogenia , Anticuerpos Antivirales , Proteínas Recombinantes/genética , Reacciones CruzadasRESUMEN
The arrival of the Zika virus (ZIKV) in dengue virus (DENV)-endemic areas has posed challenges for both differential diagnosis and vaccine development. Peptides have shown promise in addressing these issues. The aim of this study was to identify the linear epitope profile recognized by serum samples from dengue and Zika patients in the E and NS1 proteins of DENV and ZIKV. This cross-sectional study included individuals of all ages with laboratory-confirmed DENV and ZIKV infections, who were selected through convenience sampling. The serum samples from dengue and Zika patients detected epitopes evenly distributed across the viral proteins in a peptide microarray platform. However, several epitopes were located within "epitope hotspots", characterized by clusters of peptides recognized in more than 30% of the sub-arrays analyzed using individual or pooled serum samples. The serum samples from dengue and Zika patients showed a high level of cross-reactivity with peptides in the DENV and ZIKV proteins. Analysis using an additional peptide microarray platform, which contained peptides selected based on the results of the initial screening, revealed that two DENV and one ZIKV peptide, highly specific to their related viruses, were located within the epitope hotspots; however, they presented low detection rates (32.5, 35.0, and 28.6%, respectively). In addition, two DENV peptides detected at similarly high rates by both dengue and Zika patients were also found within the epitope hotspots. These hotspots contain several immunodominant epitopes that are recognized by a larger number of individuals when compared to 15-amino acid (aa) sequence peptides. Thus, epitope hotspots may have greater potential to serve as antigens in diagnostic tests and vaccine development than peptides composed of only 15 amino acids.
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Virus del Dengue , Mapeo Epitopo , Proteínas del Envoltorio Viral , Proteínas no Estructurales Virales , Virus Zika , Humanos , Anticuerpos Antivirales , Reacciones Cruzadas , Estudios Transversales , Dengue/diagnóstico , Dengue/prevención & control , Epítopos , Péptidos , Vacunas , Infección por el Virus Zika/diagnóstico , Infección por el Virus Zika/prevención & controlRESUMEN
In the Americas and specially in Brazil, the Loxosceles intermedia, Loxosceles gaucho and Loxosceles laeta are the three most medically relevant brown spider species, and whose bites can lead to the condition known as loxoscelism. Here, we report the development of a tool capable of identifying a common epitope amongst Loxosceles sp. venom's toxins. A murine monoclonal antibody (LmAb12) and its recombinant fragments (scFv12P and diabody12P) have been produced and characterized. This antibody and its recombinant constructs were able to recognize proteins of Loxosceles spider venoms with specificity. The scFv12P variant was also able to detect low concentrations of Loxosceles venom in a competitive ELISA assay, displaying potential as a venom identification tool. The primary antigenic target of LmAb12 is a knottin, a venom neurotoxin, that has a shared identity of 100 % between the L. intermedia and L. gaucho species and high similarity to L. laeta. Furthermore, we observed LmAb12 was able to partially inhibit in vitro hemolysis, a cellular event typically induced by the Loxosceles sp. venoms. Such behavior might be due to LmAb12 cross-reactivity between the antigenic target of LmAb12 and the venom's dermonecrotic toxins, the PLDs, or even the existence of synergism between these two toxins.
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Venenos de Araña , Arañas , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Antígenos/química , Antivenenos/química , Reacciones Cruzadas , Miniproteínas Nodales de Cistina/química , Fosfolipasa D/química , Venenos de Araña/química , Arañas/química , Epítopos/químicaRESUMEN
Mites are among the major sources of domestic and occupational allergens worldwide, and continuous exposure to these allergens leads to chronic airway inflammation. One of the most allergenic species is the storage mite Tyrophagus putrescentiae (Schrank). Protein extracts are produced from this mite for tests that help the clinical diagnosis (via prick test), treatment, and monitoring of disease progression in patients who had positive results for allergic reactions. Therefore, the aim of the present study was to evaluate the cell viability of RAW 264.7 and L929 cells when exposed to in-house raw protein extracts of T. putrescentiae compared to a commercial product, as well as quantify TNF-α secretion by RAW 264.7. Additionally, this study quantified the effect of these extracts in IgE secretion in total blood of people affected by this mite. The study found similarity between the in-house extract and the commercial extract as they had equivalent TNF-α secretion. Additionally, viabilities of RAW 264.7 and L929 exposed to the in-house extract were compatible with viabilities of cells exposed to the commercial extract, with no cytotoxicity at the concentrations tested. Results corroborated the hypothesis that the extract produced in-house would be equivalent to the commercial extract in allergic patients when the IgE was quantified. This study is the first to show the cytotoxicity of T. putrescentiae extracts, and to provide a quantitative analysis of TNF-α and IgE.
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Acaridae , Hipersensibilidad , Ácaros , Humanos , Animales , Ratones , Factor de Necrosis Tumoral alfa , Inmunoglobulina E , Reacciones Cruzadas , Alérgenos , Ácaros/metabolismoRESUMEN
The C-terminal portion of the E protein, known as stem, is conserved among flaviviruses and is an important target to peptide-based antiviral strategies. Since the dengue (DENV) and Zika (ZIKV) viruses share sequences in the stem region, in this study we evaluated the cross-inhibition of ZIKV by the stem-based DV2 peptide (419-447), which was previously described to inhibit all DENV serotypes. Thus, the anti-ZIKV effects induced by treatments with the DV2 peptide were tested in both in vitro and in vivo conditions. Molecular modeling approaches have demonstrated that the DV2 peptide interacts with amino acid residues exposed on the surface of pre- and postfusion forms of the ZIKA envelope (E) protein. The peptide did not have any significant cytotoxic effects on eukaryotic cells but efficiently inhibited ZIKV infectivity in cultivated Vero cells. In addition, the DV2 peptide reduced morbidity and mortality in mice subjected to lethal challenges with a ZIKV strain isolated in Brazil. Taken together, the present results support the therapeutic potential of the DV2 peptide against ZIKV infections and open perspectives for the development and clinical testing of anti-flavivirus treatments based on synthetic stem-based peptides.