RESUMO
BACKGROUND: Monitoring and analysing the infection rates of the vector of Trypanosoma cruzi, that causes Chagas disease, helps assess the risk of transmission. OBJECTIVES: A study was carried out on triatomine in the State of Paraná, Brazil, between 2012 and 2021 and a comparison was made with a previous study. This was done to assess the risk of disease transmission. METHODS: Ecological niche models based on climate and landscape variables were developed to predict habitat suitability for the vectors as a proxy for risk of occurrence. FINDINGS: A total of 1,750 specimens of triatomines were recorded, of which six species were identified. The overall infection rate was 22.7%. The areas with the highest risk transmission of T. cruzi are consistent with previous predictions in municipalities. New data shows that climate models are more accurate than landscape models. This is likely because climate suitability was higher in the previous period. MAIN CONCLUSION: Regardless of uneven sampling and potential biases, risk remains high due to the wide presence of infected vectors and high environmental suitability for vector species throughout the state and, therefore, improvements in public policies aimed at wide dissemination of knowledge about the disease are recommended to ensure the State remains free of Chagas disease.
Assuntos
Doença de Chagas , Insetos Vetores , Triatominae , Trypanosoma cruzi , Doença de Chagas/transmissão , Animais , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Brasil/epidemiologia , Triatominae/classificação , Triatominae/parasitologia , Humanos , Fatores de Risco , Medição de Risco , EcossistemaRESUMO
BACKGROUND Monitoring and analysing the infection rates of the vector of Trypanosoma cruzi, that causes Chagas disease, helps assess the risk of transmission. OBJECTIVES A study was carried out on triatomine in the State of Paraná, Brazil, between 2012 and 2021 and a comparison was made with a previous study. This was done to assess the risk of disease transmission. METHODS Ecological niche models based on climate and landscape variables were developed to predict habitat suitability for the vectors as a proxy for risk of occurrence. FINDINGS A total of 1,750 specimens of triatomines were recorded, of which six species were identified. The overall infection rate was 22.7%. The areas with the highest risk transmission of T. cruzi are consistent with previous predictions in municipalities. New data shows that climate models are more accurate than landscape models. This is likely because climate suitability was higher in the previous period. MAIN CONCLUSION Regardless of uneven sampling and potential biases, risk remains high due to the wide presence of infected vectors and high environmental suitability for vector species throughout the state and, therefore, improvements in public policies aimed at wide dissemination of knowledge about the disease are recommended to ensure the State remains free of Chagas disease.
RESUMO
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.
Assuntos
Venenos de Aranha , Aranhas , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Antígenos/química , Antivenenos/química , Reações Cruzadas , Miniproteínas Nó de Cistina/química , Fosfolipase D/química , Venenos de Aranha/química , Aranhas/química , Epitopos/químicaRESUMO
We reconstructed a transcriptional regulatory network for adrenocortical carcinoma (ACC) using transcriptomic and clinical data from The Cancer Genome Atlas (TCGA)-ACC cohort. We investigated the association of transcriptional regulatory units (regulons) with overall survival, molecular phenotypes, and immune signatures. We annotated the ACC regulons with cancer hallmarks and assessed single sample regulon activities in the European Network for the Study of Adrenal Tumors (ENSAT) cohort. We found 369 regulons associated with overall survival and subdivided them into four clusters: RC1 and RC2, associated with good prognosis, and RC3 and RC4, associated with worse outcomes. The RC1 and RC3 regulons were highly correlated with the 'Steroid Phenotype,' while the RC2 and RC4 regulons were highly correlated with a molecular proliferation signature. We selected two regulons, NR5A1 (steroidogenic factor 1, SF-1) and CENPA (Centromeric Protein A), that were consistently associated with overall survival for further downstream analyses. The CENPA regulon was the primary regulator of MKI-67 (a marker of proliferation KI-67), while the NR5A1 regulon is a well-described transcription factor (TF) in ACC tumorigenesis. We also found that the ZBTB4 (Zinc finger and BTB domain-containing protein 4) regulon, which is negatively associated with CENPA in our transcriptional regulatory network, is also a druggable anti-tumorigenic TF. We anticipate that the ACC regulons may be used as a reference for further investigations concerning the complex molecular interactions in ACC tumors.
RESUMO
Loxoscelism pose a health issue in the South America. The treatment for these accidents is based on the administration of antivenom produced in animals immunized with Loxosceles venom. In this work, a previously produced non-toxic multiepitopic chimeric protein (rMEPlox), composed of epitopes derived from the main toxins families (sphyngomielinase-D, metalloproteases, and hyaluronidases) of Loxosceles spider venoms, was used as antigen to produce monoclonal antibodies (mAbs). A selected anti-rMEPlox mAb (Lox-mAb3) reacted with metalloprotease from L. intermedia venom and showed cross-reactivity with metalloproteses from Brazilian and Peruvian Loxosceles laeta and Loxosceles gaucho venoms in immunoassays. The sequence recognized by Lox-mAb3 (184ENNTRTIGPFDYDSIMLYGAY205) corresponds to the C-terminal region of Astacin-like metalloprotease 1 and the amino acid sequence IGPFDYDSI, conserved among the homologs metalloproteases sequences, is important for antibody recognition. Lox-mAb3 neutralizes the fibrinogenolytic activity caused by metalloprotease from L. intermedia spider venom in vitro, which may lead to a decrease in hemorrhagic disturbances caused by Loxosceles envenomation. Our results show, for the first time, the use of a non-toxic multiepitopic protein for the production of a neutralizing monoclonal antibody against a metalloprotease of medically important Loxosceles venoms. These results contribute for the production improvement of therapeutic antivenom against loxoscelism.
Assuntos
Anticorpos Monoclonais Murinos/imunologia , Anticorpos Neutralizantes/imunologia , Proteínas de Artrópodes , Epitopos , Metaloendopeptidases , Diester Fosfórico Hidrolases , Venenos de Aranha , Aranhas , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Feminino , Metaloendopeptidases/química , Metaloendopeptidases/genética , Metaloendopeptidases/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Diester Fosfórico Hidrolases/química , Diester Fosfórico Hidrolases/genética , Diester Fosfórico Hidrolases/imunologia , Engenharia de Proteínas , Venenos de Aranha/química , Venenos de Aranha/genética , Venenos de Aranha/imunologiaRESUMO
Envenoming due to Loxosceles spider bites still remains a neglected disease of particular medical concern in the Americas. To date, there is no consensus for the treatment of envenomed patients, yet horse polyclonal antivenoms are usually infused to patients with identified severe medical conditions. It is widely known that venom proteins in the 30-35 kDa range with sphingomyelinase D (SMasesD) activity, reproduce most of the toxic effects observed in loxoscelism. Hence, we believe that monoclonal antibody fragments targeting such toxins might pose an alternative safe and effective treatment. In the present study, starting from the monoclonal antibody LimAb7, previously shown to target SMasesD from the venom of L. intermedia and neutralize its dermonecrotic activity, we designed humanized antibody V-domains, then produced and purified as recombinant single-chain antibody fragments (scFvs). These molecules were characterized in terms of humanness, structural stability, antigen-binding activity, and venom-neutralizing potential. Throughout this process, we identified some blocking points that can impact the Abs antigen-binding activity and neutralizing capacity. In silico analysis of the antigen/antibody amino acid interactions also contributed to a better understanding of the antibody's neutralization mechanism and led to reformatting the humanized antibody fragment which, ultimately, recovered the functional characteristics for efficient in vitro venom neutralization.
Assuntos
Anticorpos Monoclonais , Antivenenos , Anticorpos de Cadeia Única , Venenos de Aranha/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Antígenos/imunologia , Antivenenos/administração & dosagem , Antivenenos/imunologia , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Modelos Moleculares , Testes de Neutralização , Anticorpos de Cadeia Única/administração & dosagem , Anticorpos de Cadeia Única/imunologia , Picada de Aranha/terapia , Venenos de Aranha/efeitos adversos , Aranhas/imunologiaRESUMO
AIM: To develop a monoclonal antibody against dehydroepiandrosterone (DHEA) and miniaturize it, generating a single-chain antibody variable fragment (scFv) against DHEA as an adrenocortical carcinoma (ACC) marker. MATERIAL & METHODS: DHEA conjugated to keyhole limpet hemocyanin was used as an immunogen to obtain anti-DHEA hybridomas. Variable fragments were cloned from hybridoma 5B7 total RNA, and used to detect DHEA in normal adrenal tissue and ACC cells. RESULTS: IgM monoclonal antibody was highly specific, and the recombinant scFv preserved parental antibody characteristics, allowing tissue localization of DHEA. CONCLUSION: Undefined small lesions are challenges for clinicians and impact clinical adrenocortical tumor management. Generating an anti-DHEA scFv facilitates development of imaging tests for early diagnosis of pediatric ACC.
Assuntos
Neoplasias do Córtex Suprarrenal/diagnóstico , Carcinoma Adrenocortical/diagnóstico , Biomarcadores Tumorais/análise , Desidroepiandrosterona/análise , Anticorpos de Cadeia Única/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Desidroepiandrosterona/metabolismo , Expressão Gênica , Humanos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Conformação Proteica , Engenharia de Proteínas/métodos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Anticorpos de Cadeia Única/genética , Zona Reticular/metabolismoRESUMO
The biotechnological evolution towards the development of antigens to detect leprosy has been progressing. However, the identification of leprosy in paucibacillary patients, based solely on the antigen-antibody interaction still remains a challenge. The complexity of clinical manifestations requires innovative approaches to improve the sensitivity of assays to detect leprosy before the onset of symptoms, thus avoiding disabilities and contributing, indirectly, to reduce transmission. In this study, the strategies employed for early leprosy diagnosis were: i. using a phage-displayed mimotope (APDDPAWQNIFNLRR) which mimics an immunodominant sequence (PPNDPAWQRNDPILQ) of an antigen of Mycobacterium leprae known as Ag85B; ii. engineering the mimotope by adding a C-terminal flexible spacer (SGSG-C); iii. conjugating the mimotope to a carrier protein to provide better exposure to antibodies; iv. amplifying the signal using biotin-streptavidin detection system in an ELISA; and v. coating the optimized mimotope on a quartz crystal microbalance (QCM) sensor for label-free biosensing. The ELISA sensitivity increased up to 91.7% irrespective of the immunological profile of the 132 patients assayed. By using comparative modeling, the M. tuberculosis Ag85B was employed as a template to ascertain which features make the mimotope a good antigen in terms of its specificity. For the first time, a sensitive QCM-based immunosensor to detect anti M. leprae antibodies in human serum was used. M. leprae antibodies could also be detected in the sera of paucibacillary patients; thus, the use of a mimotope-derived synthetic peptide as bait for antibodies in a novel analytical label-free immunoassay for leprosy diagnosis exhibits great potential.
Assuntos
Técnicas Biossensoriais , Imunoensaio , Hanseníase/diagnóstico , Mycobacterium leprae/isolamento & purificação , Técnicas de Microbalança de Cristal de Quartzo , Adulto , Animais , Biomarcadores/análise , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Breast cancer is a heterogeneous disease with differences in its clinical, molecular and biological features. Traditionally, immunohistochemical markers together with clinicopathologic parameters are used to classify breast cancer and to predict disease outcome. Triple-negative breast cancer (TNBC) is a particular type of breast cancer that is defined by a lack of expression of hormonal receptors and the HER2 gene. Most cases of TNBC also have a basal-like phenotype (BLBC) with expression of cytokeratin 5/6 and/or EGFR. A basal marker alone is insufficient for a better understanding of the tumor biology of TNBC. In that regard, the ADAM33 gene is silenced by DNA hypermethylation in breast cancer, which suggests that ADAM33 might be useful as a molecular marker. In the present study, we have produced monoclonal antibodies against the ADAM33 protein and have investigated the role of ADAM33 protein in breast cancer. We used 212 breast tumor samples and lower levels of ADAM33 were correlated with TNBC and basal-like markers. A lower level of ADAM33 was also correlated with shorter overall survival and metastasis-free survival and was considered an independent prognostic factor suggesting that ADAM33 is a novel molecular biomarker of TNBC and BLBC that might be useful as a prognostic factor.
Assuntos
Proteínas ADAM/genética , Biomarcadores Tumorais/genética , Prognóstico , Neoplasias de Mama Triplo Negativas/genética , Adulto , Idoso , Metilação de DNA/genética , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Células MCF-7 , Pessoa de Meia-Idade , Receptor ErbB-2/genética , Receptores de Estrogênio/genética , Neoplasias de Mama Triplo Negativas/epidemiologia , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Loxosceles spider bites often lead to serious envenomings and no definite therapy has yet been established. In such a context, it is of interest to consider an antibody-based targeted therapy. We have previously prepared a murine monoclonal IgG (LiMab7) that binds to 32-35kDa components of Loxosceles intermedia venom and neutralizes the dermonecrotic activity of the venom. Here, we re-engineered LiMab7 into a recombinant diabody. The protein was produced in bacteria and then it was functionally characterized. It proved to be efficient at neutralizing sphingomyelinase and hemolytic activities of the crude venom despite the slightly altered binding kinetic constants and the limited stability of the dimeric configuration. This is the first report of a specific recombinant antibody for a next-generation of Loxosceles antivenoms.