Avaliação da especificidade dos anticorpos monoclonais (mAbs) anti-GD3 R24 e anti-anti-idiotípico (Id) 5.G8
Data
2021-04
Autores
Yamada, Renata Yoshiko [UNIFESP]
Orientadores
Moraes, Jane Zveiter de [UNIFESP]
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O melanoma é um tipo de câncer agressivo que possui alta capacidade de metastatização, o que tem grande impacto nas taxas de mortalidade por esse tipo de tumor. Não existem terapias eficazes no tratamento da doença, por isso vêm sendo estudadas terapias alternativas como a utilização de anticorpos monoclonais (mAbs). O mAb R24, disponível comercialmente, apresenta resultados positivos na remissão de tumores, mas efeitos tóxicos limitam sua utilização. Assim, a aplicação da teoria da rede idiotípica para a terapêutica, por meio do desenvolvimento de anticorpos anti-idiotípicos e anti-anti-idiotípicos pode ser explorada como uma opção e mostrou resultados promissores em estudos anteriores realizados em nosso laboratório. O mAb anti-anti-Id 5.G8 foi produzido, caracterizado e mostrou atividade inibidora de crescimento de células tumorais in vitro e in vivo. Em experimentos in vitro, reconhece linhagens celulares que expressam GD3 e não se liga àquelas que não expressam esse antígeno. Estudos posteriores mostraram que esse anticorpo, além de reconhecer GD3, também se liga à molécula de natureza proteica, presente em células de linhagem de melanoma humano SK-Mel-28. Diante disso, a proposta deste trabalho foi avaliar a especificidade dos anticorpos monoclonais anti-GD3 R24 e anti-anti-idiotípico 5.G8. Após confirmação da integridade dos mAbs bem como da linhagem de células SK-Mel-28, foi possível constatar que os dois mAbs ligantes de GD3 reconhecem uma proteína. Apesar de não ter sido possível um desfecho na identificação dessa proteína, a imunoprecipitação de extrato celular com os mAbs revelou uma banda de 12 kDa. Os resultados abrem a possibilidade de se identificar um mimotopo de GD3, possivelmente relevante para fins terapêuticos.
Melanoma is a type of aggressive cancer that has a high metastatic capacity, which has a major impact on its mortality rates. There are no effective therapies for treating the disease, so alternative therapies such as the use of monoclonal antibodies (mAbs) have been studied. mAb R24 is commercially available and shows positive results in the remission of tumors, but toxic effects limit its use. Thus, the idiotypic network theory approach, through the development of anti-idiotypic and anti-anti-idiotypic antibodies can be explored as an option and has shown promising results in previous studies carried out in our laboratory. The anti-anti-Id 5.G8 mAb was produced, characterized and showed in vitro and in vivo tumor cell growth inhibitory activity. In in vitro experiments, it recognizes cell lines that express GD3 and does not bind to those that do not express this antigen. Subsequent studies have shown that this antibody, in addition to recognizing GD3, also appears to bind to a protein molecule, present in human melanoma SK-Mel-28 cells. In view of this, the purpose of this work was to evaluate the specificity of anti-GD3 R24 and anti-anti-idiotypic 5.G8 monoclonal antibodies. After confirming the integrity of the mAbs as well as the SK-Mel-28 cell line, it was found that both GD3 binding mAbs recognize a protein. Although an outcome in the identification of this protein was not possible, the immunoprecipitation of cell extract with the mAbs revealed a 12 kDa band. The results open the possibility of identifying a GD3 mimotope, possibly relevant for therapeutic purposes.
Melanoma is a type of aggressive cancer that has a high metastatic capacity, which has a major impact on its mortality rates. There are no effective therapies for treating the disease, so alternative therapies such as the use of monoclonal antibodies (mAbs) have been studied. mAb R24 is commercially available and shows positive results in the remission of tumors, but toxic effects limit its use. Thus, the idiotypic network theory approach, through the development of anti-idiotypic and anti-anti-idiotypic antibodies can be explored as an option and has shown promising results in previous studies carried out in our laboratory. The anti-anti-Id 5.G8 mAb was produced, characterized and showed in vitro and in vivo tumor cell growth inhibitory activity. In in vitro experiments, it recognizes cell lines that express GD3 and does not bind to those that do not express this antigen. Subsequent studies have shown that this antibody, in addition to recognizing GD3, also appears to bind to a protein molecule, present in human melanoma SK-Mel-28 cells. In view of this, the purpose of this work was to evaluate the specificity of anti-GD3 R24 and anti-anti-idiotypic 5.G8 monoclonal antibodies. After confirming the integrity of the mAbs as well as the SK-Mel-28 cell line, it was found that both GD3 binding mAbs recognize a protein. Although an outcome in the identification of this protein was not possible, the immunoprecipitation of cell extract with the mAbs revealed a 12 kDa band. The results open the possibility of identifying a GD3 mimotope, possibly relevant for therapeutic purposes.
Descrição
Citação
YAMADA, Renata Yoshiko. Avaliação da especificidade dos anticorpos monoclonais (mAbs) anti-GD3 R24 e anti-anti-idiotípico (Id) 5.G8. São Paulo, 2021. 63 p. Dissertação (Mestrado em Ciências Biológicas (Biologia Molecular) - Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP), São Paulo, 2021.