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Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is an important public health problem, occurring mainly in Latin America. The disease has a major social and economical effect, negatively impacting the life of the infected individuals, and bringing great costs to public health. An early and accurate diagnosis is essential for administration of early treatment. In addition, prognostic tests may aid disease management, decreasing hospitalization costs. However, the serological diagnostic scenario for CD still faces several challenges, making the development of new diagnostic kits a pressing matter. Facing this scenario, several researchers have expanded efforts in developing and testing new antigens, such as recombinant proteins and recombinant multiepitope proteins, with promising results. These recombinant antigens offer several advantages, such as improved sensitivity and specificity, in addition to facilitated scaling. Also, it has been possible to observe a rising number of studies using ELISA and point-of-care platforms, employing these antigens in the past few years. Among them, recombinant proteins were the most applied antigens, demonstrating great capacity to discriminate between positive and negative samples. Although fewer in number, recombinant multiepitope proteins also demonstrated an improved diagnostic performance. Indeed, a great number of studies employing these antigens showed sensitivity and specificity values above 90%, greatly impacting diagnostic accuracy. Nevertheless, despite the good results found, it is still possible to observe some bottlenecks in the development of new antigens, such as the scarcity of tests with sera from the acute phase and the variability of results in different geographic areas. In this sense, aiming to contribute to control and health programs, the continuous search for a more accurate serological diagnosis is essential, both for the acute and chronic phases of the disease.
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INTRODUCTION: Producing commercial bacterins/toxoids against Clostridium spp. is laborious and hazardous. Conversely, developing prototype vaccines using purified recombinant toxoids, though safe and effective, is both laborious and costly for application in production animals. OBJECTIVE: Considering that inactivated recombinant Escherichiacoli (bacterin) is a simple, cost-effective, and to be safe solution, we evaluated, for the first time, a pentavalent formulation of recombinant bacterins containing the alpha, beta, and epsilon toxins of Clostridiumperfringens and C and D neurotoxins of Clostridiumbotulinum in sheep. METHODS: Subcutaneously, 18 Texel sheep received two doses (200 µg of each antigen) of recombinant bacterin (n = 7) or purified recombinant antigens (n = 6) on days 0 and 28, while the control group (n = 5) did not receive an immunization. Sera samples from days 0 (before the 1st dose), 28 (before the 2nd dose), and 56, 84, and 112 were used for measuring IgG (indirect ELISA) and neutralizing antibodies (mouse serum neutralization). RESULTS: Both formulations induced significant levels of IgG against all five toxins (p < 0.05) up to day 112, with peaks at days 28 and 56 post-immunization. The expected booster effect occurred only for the botulinum toxins. The neutralizing antibody titers were satisfactory against ETX (≥2 IU/ml for both formulations) and BoNT-D [5 IU/ml (bacterin) and 10 IU/ml (purified)]. CONCLUSION: While adjustments are required, the recombinant bacterin platform holds great potential for polyvalent vaccines due to its straightforward, safe, and cost-effective production, establishing it as a user-friendly technology for the veterinary immunobiological industry.
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Anticorpos Antibacterianos , Anticorpos Neutralizantes , Vacinas Bacterianas , Botulismo , Enterotoxemia , Animais , Botulismo/prevenção & controle , Botulismo/veterinária , Botulismo/imunologia , Ovinos , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Anticorpos Antibacterianos/sangue , Enterotoxemia/prevenção & controle , Enterotoxemia/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Doenças dos Ovinos/prevenção & controle , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/microbiologia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Imunoglobulina G/sangue , Escherichia coli/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , FemininoRESUMO
Introduction: This study in Argentina evaluated the impact of the growzen™ buddy smartphone app on adherence to recombinant human growth hormone (r-hGH) treatment. Methods: The adherence data, invitation dates with a link to the app, app activation dates, and height measurements entered were extracted from the growzen™ digital health ecosystem. Patients with 12 months of adherence data, aged ≥2 years at treatment start, and aged <19 years were selected both before and after app implementation. Mean adherence was classified as optimal (≥85%) versus suboptimal (<85%). Adherence before and after implementation and the pre-post effect on adherence were assessed. Results: Data for 830 patients were available. Prior to app implementation, the proportion of patients with optimal adherence was 68% (n = 348/515). Following the app implementation, out of 315 patients, 302 (96%) received an invitation with a link to the app, 225 (71%) activated their account, and 127 (40%) entered height data in the first year. There was a significant early increase in the proportion of patients with optimal adherence following implementation: 82% (n = 258/315), p < 0.001. After implementation, the proportion of patients with optimal adherence included 80% (n = 78/98) of those with an active account who did not enter height measurements and 89% (n = 113/127) of those who did. There was a significant and positive pre-post app effect on adherence (p < 0.01) in patients with an active account. Discussion: Our results show that using the growzen™ buddy app has a rapid and positive impact on adherence to r-hGH treatment, and patients who were more engaged with the app demonstrated better adherence.
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Hormônio do Crescimento Humano , Adesão à Medicação , Aplicativos Móveis , Proteínas Recombinantes , Smartphone , Humanos , Argentina , Masculino , Feminino , Estudos Retrospectivos , Hormônio do Crescimento Humano/uso terapêutico , Hormônio do Crescimento Humano/administração & dosagem , Adesão à Medicação/estatística & dados numéricos , Adolescente , Criança , Proteínas Recombinantes/uso terapêutico , Pré-Escolar , Adulto Jovem , AdultoRESUMO
The diagnosis of tegumentary leishmaniasis (TL) is hampered by variable sensitivity and/or specificity of the tests. Serological assays are suitable to diagnose visceral leishmaniasis (VL); however, they present low performance for the detection of TL cases. Additionally, blood collection to obtain patient serum represents a challenge, as it is an invasive and uncomfortable procedure, requiring laboratorial infrastructure and trained professionals. In this context, the present study proposed to evaluate patient urine to detect TL, given that this analyte has proven to be effective in ELISA experiments for the detection of VL cases. For this, a Leishmania protein called LiHyV, two specific B-cell epitopes derived from protein amino acid sequence, and a Leishmania antigenic extract (SLA) were used as antigens. A total of 215 paired urine and serum samples were evaluated, and results showed that, when serum was employed as an analyte, rLiHyV, Peptide1, Peptide2, and SLA presented a sensitivity of 85 %, 29 %, 58 %, and 31 %, respectively, and a specificity of 97.5 %, 98 %, 100 %, and 97.5 %, respectively, in the diagnosis of TL. When urine was used, rLiHyV, Peptide1, Peptide2, and SLA presented a sensitivity of 95 %, 74 %, 67 %, and 52 %, respectively, and a specificity of 100 %, 99 %, 98 %, and 86 %, respectively. In conclusion, preliminary data suggest that urine could be considered as an alternative biological sample for the detection of TL cases.
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Anticorpos Antiprotozoários , Antígenos de Protozoários , Ensaio de Imunoadsorção Enzimática , Leishmania , Leishmaniose Cutânea , Proteínas de Protozoários , Proteínas Recombinantes , Sensibilidade e Especificidade , Humanos , Ensaio de Imunoadsorção Enzimática/métodos , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/urina , Proteínas de Protozoários/urina , Proteínas de Protozoários/imunologia , Antígenos de Protozoários/urina , Antígenos de Protozoários/imunologia , Leishmania/imunologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/urina , Adulto , Feminino , Anticorpos Antiprotozoários/sangue , Anticorpos Antiprotozoários/urina , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Idoso , Urina/química , Urina/parasitologia , Criança , Pré-Escolar , Epitopos de Linfócito B/imunologiaRESUMO
l-asparaginases play a crucial role in the treatment of acute lymphoblastic leukemia (ALL), a type of cancer that mostly affects children and teenagers. However, it is common for these molecules to cause adverse reactions during treatment. These downsides ignite the search for novel asparaginases to mitigate these problems. Thus, this work aimed to produce and characterize a recombinant asparaginase from Phaseolus vulgaris (Asp-P). In this study, Asp-P was expressed in Escherichia coli with high yields and optimum activity at 40 °C, pH 9.0. The enzyme Km and Vmax values were 7.05 mM and 1027 U/mg, respectively. Asp-P is specific for l-asparagine, showing no activity against l-glutamine and other amino acids. The enzyme showed a higher cytotoxic effect against Raji than K562 cell lines, but only at high concentrations. In silico analysis indicated that Asp-P has lower immunogenicity than a commercial enzyme. Asp-P induced biofilm formation by Candida sp. due to sublethal dose, showing an underexplored potential of asparaginases. The absence of glutaminase activity, lower immunogenicity and optimal activity similar to physiological temperature conditions are characteristics that indicate Asp-P as a potential new commercial enzyme in the treatment of ALL and its underexplored application in the treatment of other diseases.
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Asparaginase , Phaseolus , Proteínas Recombinantes , Asparaginase/química , Asparaginase/farmacologia , Asparaginase/genética , Asparaginase/imunologia , Phaseolus/química , Humanos , Cinética , Proteínas Recombinantes/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Leucemia/tratamento farmacológico , Células K562 , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Biofilmes/efeitos dos fármacos , Concentração de Íons de Hidrogênio , TemperaturaRESUMO
The COVID-19 pandemic has been marked by novel viral variants, posing challenges to global public health. Recombination, a viral evolution mechanism, is implicated in SARS-CoV-2's ongoing evolution. The XBB recombinant lineage, known for evading antibody-mediated immunity, exhibits higher transmissibility without increased disease severity. We investigated the prevalence and genomic features of XBB in SARS-CoV-2-positive cases in Rio Grande do Sul (RS), Brazil. We sequenced 357 samples from epidemiological weeks (EW) 47/2022 to 17/2023, and included 389 publicly available sequences. Clinical and epidemiological data were obtained from DATASUS, e-SUS, and SIVEP GRIPE (data recording systems of the Brazilian Ministry of Health). Of these, 143 were classified as XBB and 586 were other Omicron lineages. In March 2023 (EW 10), XBB became dominant, accounting for 83.3% of cases. 97.7% of XBB-infected patients successfully recovered from the infection, with a low mortality rate (2.3%). Even after receiving three vaccine doses and having been previously infected, 59.5% of the patients experienced reinfection with XBB. However, for 54% of the individuals, the interval between their XBB infection and the last vaccine dose exceeded one year, potentially leading to a decline in antibody levels. In addition, we identified 90 mutations in RS circulating XBB, spread throughout the genome, notably in the Spike protein region associated with immune resistance. This study provides insights into the dynamics and impact of a recombinant variant becoming predominant for the first time in the state. Continued surveillance of SARS-CoV-2 genomic evolution is crucial for effective public health management.
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Vacinas contra COVID-19 , COVID-19 , Genoma Viral , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Brasil/epidemiologia , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/virologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/imunologia , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Idoso , Filogenia , Adulto Jovem , Adolescente , Genômica/métodosRESUMO
OBJECTIVES: Exophytic Sinonasal Papilloma (ESP) is a benign tumor of the sinonasal tract. Complete surgical excision by endoscopic surgery is the treatment of choice. However, a high recurrence rate (36% at 5-year follow-up) is associated with this method, which may indicate the presence of microorganisms such as Human Papillomavirus (HPV). It is important to note that the standard treatment for ESP does not include antiviral drugs. In our study, we are testing the effectiveness of an interferon-containing drug in reducing recurrence and postoperative reactions in patients with ESP. METHODS: We included 78 patients aged 23-83 years with a confirmed diagnosis of ESP by rhinoscopy and nasal endoscopy and a positive PCR test for HPV in nasal scrapings. To compare the results, we divided the patients into main and control groups. The main group received recombinant human interferon after surgery, while the control group did not receive the drug. We performed a statistical analysis to compare the proportion of patients without reactive manifestations at different stages of the postoperative period, as well as to compare the proportion of patients with recurrent ESP at certain stages of observation. RESULTS: The introduction of recombinant human interferon accelerated the resolution of postoperative reactions and promoted the healing of the nasal mucosa after surgical removal of the ESP. We also found a statistically significant association between treatment with recombinant interferon and a reduction in the recurrence rate of ESP. CONCLUSION: According to the results of the study, it was found that in the main group of patients who received rhIFN-α2b (recombinant human Interferon alpha 2b) in the postoperative period, the frequency of relapses of ESP and the time of postoperative recovery were significantly lower than in patients in the control group who did not take the drug. LEVEL OF EVIDENCE: Cohort Study.
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Interferon alfa-2 , Interferon-alfa , Papiloma , Infecções por Papillomavirus , Humanos , Pessoa de Meia-Idade , Adulto , Idoso , Masculino , Feminino , Interferon alfa-2/uso terapêutico , Infecções por Papillomavirus/tratamento farmacológico , Idoso de 80 Anos ou mais , Adulto Jovem , Interferon-alfa/uso terapêutico , Resultado do Tratamento , Papiloma/tratamento farmacológico , Papiloma/cirurgia , Papiloma/virologia , Neoplasias Nasais/cirurgia , Neoplasias Nasais/tratamento farmacológico , Neoplasias Nasais/virologia , Proteínas Recombinantes/uso terapêutico , Recidiva Local de Neoplasia , Antivirais/uso terapêuticoRESUMO
Leptospirosis, a neglected zoonotic disease, is caused by pathogenic spirochetes belonging to the genus Leptospira and has one of the highest morbidity and mortality rates worldwide. Vaccination stands out as one of the most effective preventive measures for susceptible populations. Within the outer membrane of Leptospira spp., we find the LIC12287, LIC11711, and LIC13259 lipoproteins. These are of interest due to their surface location and potential immunogenicity. Thorough examination revealed the conservation of these proteins among pathogenic Leptospira spp.; we mapped the distribution of T- and B-cell epitopes along their sequences and assessed the 3D structures of each protein. This information aided in selecting immunodominant regions for the development of a chimeric protein. Through gene synthesis, we successfully constructed a chimeric protein, which was subsequently expressed, purified, and characterized. Hamsters were immunized with the chimeric lipoprotein, formulated with adjuvants aluminum hydroxide, EMULSIGEN®-D, Sigma Adjuvant System®, and Montanide™ ISA206VG. Another group was vaccinated with an inactivated Escherichia coli bacterin expressing the chimeric protein. Following vaccination, hamsters were challenged with a virulent L. interrogans strain. Our evaluation of the humoral immune response revealed the production of IgG antibodies, detectable 28 days after the second dose, in contrast to pre-immune samples and control groups. This demonstrates the potential of the chimeric protein to elicit a robust humoral immune response; however, no protection against challenge was achieved. While this study provides valuable insights into the subject, further research is warranted to identify protective antigens that could be utilized in the development of a leptospirosis vaccine. KEY POINTS: ⢠Several T- and B-cell epitopes were identified in all the three proteins. ⢠Four different adjuvants were used in vaccine formulations. ⢠Immunization stimulated significant levels of IgG2/3 in vaccinated animals.
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Anticorpos Antibacterianos , Vacinas Bacterianas , Leptospirose , Lipoproteínas , Animais , Leptospirose/prevenção & controle , Leptospirose/imunologia , Lipoproteínas/imunologia , Lipoproteínas/genética , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/genética , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Cricetinae , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito B/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/genética , Adjuvantes Imunológicos/administração & dosagem , Imunoglobulina G/sangue , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/genética , Leptospira interrogans/imunologia , Leptospira interrogans/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/genética , Vacinação , Imunidade Humoral , Leptospira/imunologia , Leptospira/genética , Imunogenicidade da VacinaRESUMO
The success of using the insect cell-baculovirus expression technology (BEST) relies on the efficient construction of recombinant baculovirus with genetic stability and high productivity, ideally within a short time period. Generation of recombinant baculoviruses requires the transfection of insect cells, harvesting of recombinant baculovirus pools, isolation of plaques, and the expansion of baculovirus stocks for their use for recombinant protein production. Moreover, many options exist for selecting the genetic elements to be present in the recombinant baculovirus. This chapter describes the most commonly used homologous recombination systems for the production of recombinant baculoviruses, as well as strategies to maximize generation efficiency and recombinant protein or baculovirus production. The key steps for generating baculovirus stocks and troubleshooting strategies are described.
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Baculoviridae , Proteínas Recombinantes , Baculoviridae/genética , Animais , Proteínas Recombinantes/genética , Vetores Genéticos/genética , Transfecção/métodos , Recombinação Homóloga , Células Sf9 , Linhagem Celular , Spodoptera/virologia , Insetos/genética , Insetos/virologiaRESUMO
BACKGROUND: Chagas disease (CD), a neglected parasitic disease caused by Trypanosoma cruzi, poses a significant health threat in Latin America and has emerged globally because of human migration. Trypanosoma cruzi infects humans and over 100 other mammalian species, including dogs, which are important sentinels for assessing the risk of human infection. Nonetheless, the serodiagnosis of T. cruzi in dogs is still impaired by the absence of commercial tests. In this study, we investigated the diagnostic accuracy of four chimeric recombinant T. cruzi IBMP antigens (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) for detecting anti-T. cruzi antibodies in dogs, using latent class analysis (LCA). METHODS: We examined 663 canine serum samples, employing indirect ELISA with the chimeric antigens. LCA was utilized to establish a latent variable as a gold standard for T. cruzi infection, revealing distinct response patterns for each antigen. RESULTS: The IBMP (Portuguese acronym for the Molecular Biology Institute of Paraná) antigens achieved area under the ROC curve (AUC) values ranging from 90.9% to 97.3%. The highest sensitivity was attributed to IBMP-8.2 (89.8%), while IBMP-8.1, IBMP-8.3, and IBMP-8.4 achieved 73.5%, 79.6%, and 85.7%, respectively. The highest specificity was observed for IBMP-8.4 (98.6%), followed by IBMP-8.2, IBMP-8.3, and IBMP-8.1 with specificities of 98.3%, 94.4%, and 92.7%, respectively. Predictive values varied according to prevalence, indicating higher effectiveness in endemic settings. CONCLUSIONS: Our findings underscore the remarkable diagnostic performance of IBMP-8.2 and IBMP-8.4 for the serodiagnosis of Trypanosoma cruzi in dogs, representing a promising tool for the diagnosis of CD in dogs. These chimeric recombinant antigens may not only enhance CD surveillance strategies but also hold broader implications for public health, contributing to the global fight against this neglected tropical disease.
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Anticorpos Antiprotozoários , Antígenos de Protozoários , Doença de Chagas , Doenças do Cão , Ensaio de Imunoadsorção Enzimática , Sensibilidade e Especificidade , Testes Sorológicos , Trypanosoma cruzi , Animais , Cães , Doença de Chagas/diagnóstico , Doença de Chagas/veterinária , Doença de Chagas/parasitologia , Trypanosoma cruzi/imunologia , Trypanosoma cruzi/genética , Doenças do Cão/diagnóstico , Doenças do Cão/parasitologia , Antígenos de Protozoários/imunologia , Antígenos de Protozoários/genética , Testes Sorológicos/métodos , Testes Sorológicos/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Anticorpos Antiprotozoários/sangue , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genéticaRESUMO
Assisted reproduction is a key aspect of modern animal breeding, providing valuable assistance in improving breeding programs. In this field, the administration of exogenous hormones, such as follicle-stimulating hormone (FSH), plays a crucial role in the induction of multiple ovulations. However, commercial FSH used in veterinary practice has been derived primarily from pituitary glands, obtained mostly from pigs for nearly four decades. Although these hormones have contributed significantly to the advancement of assisted reproductive techniques, they have certain limitations that warrant further improvements. These limitations include contamination with luteinizing hormone (LH), the potential risk of pathogen contamination, the potential to trigger an immune response in non-pig species, and the short half-life in circulation, requiring the implementation of complex 8-dose superovulation schedules. Our research team has developed and characterized a new variant of bovine follicle-stimulating hormone (bscrFSH) to address these limitations. The new hormone is produced recombinantly in CHO cell cultures, with a specific productivity of about 30 pg/cell/day. The bscrFSH can be purified to a high purity of 97 % using a single step of immobilized metal affinity chromatography (IMAC). N-glycan analysis of bscrFSH showed that approximately 74 % of the glycans corresponded to charged structures, including mono-, di-, tri-, and tetra-sialylated glycans. Superovulation trials conducted in cattle revealed that bscrFSH, administered at a total dose of about 0.5 µg per kg of body weight, using a decrescent schedule of 4 doses with 24-h intervals, resulted in an average yield of 8-12 transferable embryos per animal. Further research is required; however, the preliminary findings indicate that bscrFSH, currently packaged under the provisional brand name of Cebitropin B, holds potential as a commercial product for assisted reproduction in ruminants.
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Hormônio Foliculoestimulante , Animais , Bovinos , Hormônio Foliculoestimulante/farmacologia , Hormônio Foliculoestimulante/administração & dosagem , Feminino , Células CHO , Cricetulus , Proteínas Recombinantes , Superovulação/efeitos dos fármacosRESUMO
Introduction: Vascular ulcers constitute a serious global public health problem, responsible for causing a significant social and economic impact due to their recurrent, disabling nature and the need for prolonged therapies to cure them. Objective: To evaluate the use and efficacy of the rhEGF in the epithelialization of patients with a diagnosis of CEAP stage 6 venous insufficiency, in the two regimes of the health system in Colombia, the contributive (equivalent to a health system where citizens with payment capacity contribute a percentage of their salary) and the subsidized (equivalent to a health system where the state covers the vulnerable population and low socioeconomic level) versus the other treatments used. Methodology: Observational, descriptive, retrospective, multicenter study, in which 105 medical records with 139 ulcers were reviewed, in 2 centers, one belonging to the subsidized system and the other to the contributive system in Colombia. Results: The association with the epithelialization variable of the different treatment groups for ulcers according to the application of the mixed effect model test, for both regimes was for the Biologicals (EC 34.401/p = 0.000), Bioactive Agents (Hydrogels) (EC 24.735/p = 0.005) groups; for the rest of the treatment groups, the results were neither associated nor statistically significant. Conclusion: Intra- and perilesional therapy with rhEGF expands the therapeutic spectrum in patients with venous ulcers, regardless of the type of health system in which it will be applied, shortening the healing time and reaching a possible therapeutic goal, which according to this study there is an association with epithelialization regardless of the regime applied.
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Úlcera Varicosa , Humanos , Colômbia , Úlcera Varicosa/tratamento farmacológico , Úlcera Varicosa/economia , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Fator de Crescimento Epidérmico , Proteínas Recombinantes/economia , Proteínas Recombinantes/uso terapêutico , Proteínas Recombinantes/administração & dosagem , IdosoRESUMO
We conducted a development and standardization of an IgG ELISA assay for serological detection of human orthohantavirus infections using the recombinant antigen rLECH13 produced in bacterial and derived from the LECHV. The evaluation and standardization were carried out by analyzing serum samples from a total of 50 patients with confirmed Hantavirus Pulmonary Syndrome (HPS) diagnosis through the reference technique, 50 negative sera, and 53 patients with other medical conditions. The data from the assay analysis showed a diagnostic sensitivity value of 95% and a diagnostic specificity of 80%. The high sensitivity of this novel assay leads us to conclude that rLECH13 is a feasible option for use in the immunodiagnostic of orthohantavirus infection. Additionally, it is crucial to have an antigen that can be produced under conditions that do not require highly complex laboratories. Furthermore, the new assay is cost-effective, reproducible, and demonstrates excellent performance.
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Anticorpos Antivirais , Ensaio de Imunoadsorção Enzimática , Infecções por Hantavirus , Orthohantavírus , Sensibilidade e Especificidade , Humanos , Ensaio de Imunoadsorção Enzimática/métodos , Orthohantavírus/imunologia , Orthohantavírus/genética , Orthohantavírus/isolamento & purificação , Argentina , Infecções por Hantavirus/diagnóstico , Anticorpos Antivirais/sangue , Proteínas do Nucleocapsídeo/imunologia , Proteínas do Nucleocapsídeo/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Imunoglobulina G/sangue , Antígenos ViraisRESUMO
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.
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Alérgenos , Asma , Imunoglobulina E , Humanos , Asma/imunologia , Asma/diagnóstico , Asma/epidemiologia , Imunoglobulina E/imunologia , Imunoglobulina E/sangue , Adulto , Masculino , Feminino , Estudos de Casos e Controles , Criança , Adolescente , Colômbia/epidemiologia , Alérgenos/imunologia , Adulto Jovem , Pessoa de Meia-Idade , Antígenos de Plantas/imunologia , Reações Cruzadas , Clima Tropical , Prevalência , Pré-EscolarRESUMO
Recombinant multiepitope proteins (RMPs) are a promising alternative for application in diagnostic tests and, given their wide application in the most diverse diseases, this review article aims to survey the use of these antigens for diagnosis, as well as discuss the main points surrounding these antigens. RMPs usually consisting of linear, immunodominant, and phylogenetically conserved epitopes, has been applied in the experimental diagnosis of various human and animal diseases, such as leishmaniasis, brucellosis, cysticercosis, Chagas disease, hepatitis, leptospirosis, leprosy, filariasis, schistosomiasis, dengue, and COVID-19. The synthetic genes for these epitopes are joined to code a single RMP, either with spacers or fused, with different biochemical properties. The epitopes' high density within the RMPs contributes to a high degree of sensitivity and specificity. The RMPs can also sidestep the need for multiple peptide synthesis or multiple recombinant proteins, reducing costs and enhancing the standardization conditions for immunoassays. Methods such as bioinformatics and circular dichroism have been widely applied in the development of new RMPs, helping to guide their construction and better understand their structure. Several RMPs have been expressed, mainly using the Escherichia coli expression system, highlighting the importance of these cells in the biotechnological field. In fact, technological advances in this area, offering a wide range of different strains to be used, make these cells the most widely used expression platform. RMPs have been experimentally used to diagnose a broad range of illnesses in the laboratory, suggesting they could also be useful for accurate diagnoses commercially. On this point, the RMP method offers a tempting substitute for the production of promising antigens used to assemble commercial diagnostic kits.
Assuntos
Epitopos , Escherichia coli , Proteínas Recombinantes , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Humanos , Epitopos/imunologia , Epitopos/genética , Testes Imunológicos/métodos , Animais , COVID-19/diagnósticoRESUMO
Only a few halophilic archaea producing carboxylesterases have been reported. The limited research on biocatalytic characteristics of archaeal esterases is primarily due to their very low production in native organisms. A gene encoding carboxylesterase from Halobacterium salinarum NRC-1 was cloned and successfully expressed in Haloferax volcanii. The recombinant carboxylesterase (rHsEst) was purified by affinity chromatography with a yield of 81%, and its molecular weight was estimated by SDS-PAGE (33 kDa). The best kinetic parameters of rHsEst were achieved using p-nitrophenyl valerate as substrate (KM = 78 µM, kcat = 0.67 s-1). rHsEst exhibited great stability to most metal ions tested and some solvents (diethyl ether, n-hexane, n-heptane). Purified rHsEst was effectively immobilized using Celite 545. Esterase activities of rHsEst were confirmed by substrate specificity studies. The presence of a serine residue in rHsEst active site was revealed through inhibition with PMSF. The pH for optimal activity of free rHsEst was 8, while for immobilized rHsEst, maximal activity was at a pH range between 8 to 10. Immobilization of rHsEst increased its thermostability, halophilicity and protection against inhibitors such as EDTA, BME and PMSF. Remarkably, immobilized rHsEst was stable and active in NaCl concentrations as high as 5M. These biochemical characteristics of immobilized rHsEst reveal its potential as a biocatalyst for industrial applications.
Assuntos
Carboxilesterase , Clonagem Molecular , Halobacterium salinarum , Proteínas Recombinantes , Carboxilesterase/genética , Carboxilesterase/metabolismo , Carboxilesterase/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Halobacterium salinarum/enzimologia , Halobacterium salinarum/genética , Enzimas Imobilizadas/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/genética , Concentração de Íons de Hidrogênio , Cinética , Estabilidade Enzimática , Proteínas Arqueais/genética , Proteínas Arqueais/química , Proteínas Arqueais/metabolismo , TemperaturaRESUMO
The production of fermentable sugars from lignocellulosic biomass is achieved by the synergistic action of a group of enzymes called cellulases. Cellulose is a long chain of chemically linked glucoses by ß-1,4 bonds. The enzyme ß-1,4-endoglucanase is the first cellulase involved in the degradation, breaking the bond of the amorphous regions. A ß-1,4-endoglucanase enzyme with high activity was obtained from a Bacillus subtilis strain isolated from wastewater of a pulp and paper mill. Sequencing and bioinformatic analysis showed that the gene amplified by PCR consisting of 1407 nucleotides and coding for a ß-1,4-endoglucanase enzyme of approximately 55 kDa. The open reading frame (ORF) encoding the mature endoglucanase (eglS) was successfully inserted in a modified cloning plasmid (pITD03) and into the pYD1 plasmid used for its expression in yeast. Carboxymethylcellulose (CMC) plate assay, SDS-PAGE, and zymogram confirmed the production and secretion by the transformed E. coli BL21-SI strain of a 39 kDa ß-1,4-endoglucanase consistent with the catalytic domain without the cellulose-binding module (CBM). The results showed that the truncated ß-1,4-endoglucanase had higher activity and stability.
Assuntos
Bacillus subtilis , Celulase , Papel , Proteínas Recombinantes , Águas Residuárias , Bacillus subtilis/genética , Bacillus subtilis/enzimologia , Bacillus subtilis/isolamento & purificação , Águas Residuárias/microbiologia , Águas Residuárias/química , Celulase/genética , Celulase/química , Celulase/biossíntese , Celulase/isolamento & purificação , Celulase/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Clonagem Molecular , Expressão GênicaRESUMO
Streptococcus pneumoniae can cause diseases with high mortality and morbidity. The licensed vaccines are based on capsular polysaccharides and induce antibodies with low cross reactivity, leading to restricted coverage of serotypes. For surpassing this limitation, new pneumococcal vaccines are needed for induction of broader protection. One important candidate is the pneumococcal surface protein A (PspA), which can be classified in 6 clades and 3 families. We have reported an efficient process for production and purification of untagged recombinant PspA from clade 4 (PspA4Pro). We now aim to obtain a highly pure recombinant PspA from clade 1 (PspA1) to be included, together with PspA4Pro, in a vaccine formulation to broaden response against pneumococci. The vector pET28a-pspA1 was constructed and used to transform Escherichia coli BL21(DE3) strain. One clone with high production of PspA1 was selected and adapted to high-density fermentation (HDF) medium. After biomass production in 6 L HDF using a bioreactor, the purification was defined after testing 3 protocols. During the batch bioreactor cultivation, plasmid stability remained above 90% and acetate formation was not detected. The final protein purification process included treatment with a cationic detergent after lysis, anion exchange chromatography, cryoprecipitation, cation exchange chromatography, and multimodal chromatography. The final purification process showed PspA1 purity of 93% with low endotoxin content and an overall recovery above 20%. The novel established process can be easily scaled-up and proved to be efficient to obtain a highly pure untagged PspA1 for inclusion in vaccine formulations. KEY POINTS: ⢠Purification strategy for recombinant PspA1 from Streptococcus pneumoniae ⢠Downstream processing for untagged protein antigens, the case of PspA1 ⢠Purification strategy for PspA variants relies on buried amino acids in their sequences.
Assuntos
Proteínas de Bactérias , Streptococcus pneumoniae , Humanos , Animais , Camundongos , Proteínas de Bactérias/química , Streptococcus pneumoniae/genética , Vacinas Pneumocócicas/metabolismo , Anticorpos Antibacterianos , Camundongos Endogâmicos BALB CRESUMO
Acinetobacter baumannii is an opportunistic bacterium that causes infection in several sites. Carbapenem-resistant A. baumannii strains (CRAb) lead the World Health Organization's list of 12 pathogens considered a priority for developing new antimicrobials. The pathogenicity of A. baumannii is related to the different virulence factors employed in the colonization of biotic and abiotic surfaces, biofilm formation and multidrug resistance. We analyze the outer membrane protein FilF from A. baumannii in silico and produce it in recombinant form (rFilF). rFilF protein was successfully expressed in Escherichia coli BL21 Star in an insoluble form. Immunization with rFilF induced significant anti-rFilF IgG antibody production in mice, detected by indirect enzyme-linked immunosorbent assay, since the first evaluation until 49th. On the last experimentation day, the predominant immunoglobulin found was IgG1 followed by IgG2a, IgG2b, IgM, IgG3, and IgA. We observe that interleukins 4 and 10 show significant production after the 28th day of experimentation in mice immunized with rFilF. Anti-rFilF pAbs were able to inhibit biofilm formation in nine CRAb strains evaluated, and in the standard strain ATCC® 19606. These results demonstrate the anti-biofilm activity of anti-rFilF antibodies, promising in the development of a non-antibiotic approach based on the control of CRAb strains.
Assuntos
Acinetobacter baumannii , Anticorpos Antibacterianos , Biofilmes , Carbapenêmicos , Biofilmes/efeitos dos fármacos , Acinetobacter baumannii/imunologia , Acinetobacter baumannii/efeitos dos fármacos , Animais , Anticorpos Antibacterianos/imunologia , Carbapenêmicos/farmacologia , Camundongos , Imunoglobulina G/imunologia , Antibacterianos/farmacologia , Infecções por Acinetobacter/imunologia , Infecções por Acinetobacter/microbiologia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/genética , Camundongos Endogâmicos BALB C , Feminino , Escherichia coli/genética , Escherichia coli/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/genéticaRESUMO
L-Lactate is an important bioanalyte in the food industry, biotechnology, and human healthcare. In this work, we report the development of a new L-lactate electrochemical biosensor based on the use of multiwalled carbon nanotubes non-covalently functionalized with avidin (MWCNT-Av) deposited at glassy carbon electrodes (GCEs) as anchoring sites for the bioaffinity-based immobilization of a new recombinant biotinylated lactate oxidase (bLOx) produced in Escherichia coli through in vivo biotinylation. The specific binding of MWCNT-Av to bLOx was characterized by amperometry, surface plasmon resonance (SPR), and electrochemical impedance spectroscopy (EIS). The amperometric detection of L-lactate was performed at -0.100 V, with a linear range between 100 and 700 µM, a detection limit of 33 µM, and a quantification limit of 100 µM. The proposed biosensor (GCE/MWCNT-Av/bLOx) showed a reproducibility of 6.0% and it was successfully used for determining L-lactate in food and enriched serum samples.