Proteínas imunorreativas de Conidiobolus lamprauges isoladas de ovinos infectados naturalmente / Immunoreactive proteins of Conidiobolus lamprauges isolated from naturally infected sheep

O estudo de conidiobolomicose ovina tem sido realizado nos seus aspectos clínicos, epidemiológicos, patológicos e moleculares. Informações, entretanto, sobre a resposta imune do hospedeiro na infecção por Conidiobolus lamprauges são inexistentes. Este estudo teve por objetivo a identificação de proteínas imunorreativas que possam desempenhar papel importante na resposta imune de ovinos naturalmente infectados por C. lamprauges. Para a caracterização protéica e imunológica foi utilizada a cepa de C. lamprauges (FIOCRUZ-INCQS 40316) isolada de ovino com sinais clínicos de conidiobolomicose no Estado do MT e cinco amostras de soro de ovinos infectados naturalmente pelo fungo. A presença de anticorpos IgG foi observada em todos os animais doentes com títulos reagentes em diluições de até 1:1.600. Na técnica do immunoblot, o perfil antigênico frente aos soros ovinos com a doença apresentou doze bandas reativas, com massas moleculares variando de 35 a 198 kDa. Dentre estas, a proteína de 198 kDa foi reativa em 3 soros de ovinos e a de 53 kDa apresentou a maior intensidade comparativamente com outras bandas, sendo provavelmente imunodominante. Amostras de soro de animais sadios não apresentaram reatividade demostrando a especificidade da técnica. A presença de proteínas antigênicas de C. lamprauges e IgG específicos em soros de ovinos observados no presente trabalho poderá auxiliar no desenvolvimento de métodos de diagnóstico precoces e na utilização de proteínas candidatas a vacinas para o controle e prevenção da infecção em animais e humanos.(AU)

The study of sheep conidiobolomycosis has been carried out in its clinical, epidemiological, pathological and molecular aspects. Information, however, about the host immune response in infection Conidiobolus lamprauges is absent. This study aimed to identify immunoreactive proteins that may play an important role in the immune response of sheep naturally infected by C. lamprauges. For protein and immunological characterization, C. lamprauges (strain FIOCRUZ-INCQS 40316) isolated from a sheep with clinical signs of conidiobolomycosis in the MT state and five sera samples of naturally infected sheep were used. The presence of IgG antibody was observed in all patients with reagent titers in dilutions up to 1:1600. In immunoblot technique, the antigenic profile against infected sheep sera showed twelve reactive bands with molecular weights ranging from 35 to 198 kDa. Among them, the 198 kDa protein was reactive against sera from three sheep and the 53 kDa showed increased intensity compared to other bands probably being immunodominant. Healthy animal serum samples showed no reactivity demonstrating the specificity of the technique. The presence of antigenic proteins of C. lamprauges and specific IgG in sheep sera observed in this study may assist in the development of early diagnostic methods and the use of protein as candidate vaccines for the control and prevention of infection in animals and human.(AU)

Synthesis and identification of artificial antigen of loganin and preliminary study on its immunogenicity / 中草药

Objective: To synthesize and identify the artificial antigen of loganin for the first time, and provide a foundation for the preparation of specific monoclonal antibody and establishment of immunoassay method. Methods: Sodium periodate oxidation method was used to synthesize immunogenic antigen (loganin-BSA) and coating antigen (loganin-OVA) of loganin. Whether loganin was conjugated with BSA and OVA or not was confirmed by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF-MS). The titer and specificity of the antibody in serum of immunised mice were detected by enzyme-linked immunosorbent assay (ELISA). Results: The results of MALDI-TOF-MS indicated that loganin was conjugated to BSA. The antibody against loganin obtained from immunised-mice could bind to loganin and the titer was up to 1:40 000. Conclusion: The artificial antigen of loganin was synthesized, which can be used further in the preparation of monoclonal antibody, application in quality control of Chinese materia medica and the pharmacokinetic study of loganin in laboratory animals.

Identification of an immunogenic protein of Giardia lamblia using monoclonal antibodies generated from infected mice

The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.