Establishment and characterization of embryonic cell lines of Rhipicephalus (Boophilus) microplus (RBME-6) and Amblyomma sculptum (ASE-14) (Acari:Ixodida) from Brazil

• Ano de defesa: 2021
• Autor(a) principal: Duarte, Leidiane Lima
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Brasil; Brazil; Carrapato-do-gado; Carrapato-estrela; Cattle tick; Cell line; Chromosome; Cromossomos; Linhagem celular; Star tick
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/10/10134/tde-15032022-101838/

Ticks are arthropods of great medical and veterinary importance, being responsible for the transmission of viruses, bacteria, helminths and protozoa to their hosts. Some of the tick-borne pathogens are difficult to grow in vitro, and do not grow on artificial media or other substrates. Tick cell lines represent a useful tool for studying many aspects of tick and tick-borne pathogen research. Here, we established and characterized two cell lines RBME-6 and ASE-14 derived from embryos of Rhipicephalus microplus and Amblyomma sculptum, respectively, both from Brazil. Primary tick cell cultures were prepared in L-15B at 30ºC.When they reached an adequate density, the cells were subcultured and cryopreserved in several passages. Cytological analysis were performed using phase contrast microscopy and cytocentrifuge smears stained with Giemsa, while periodic acid-Schiff and bromophenol blue staining techniques were used to detect total polysaccharides and the total protein, respectively. Anaplasma spp., Anaplasma marginale, Babesia/Theileria spp., Coxiella spp., Ehrichia canis, Mycoplasma spp. and Rickettsia sp. were not detected in the cells through PCR assays. In addition, we performed chromosomal characterization of the tick cell line and confirmed the origin of the cell line through conventional PCR and sequencing of the 16S rRNA gene mitochondrial fragment. In conclusion, two new cell lines derived from embryos of ticks were generated and characterized in this study. These cell lines can be used in future studies on different aspects, such as the relationship between ticks and pathogens transmitted by them, expression of proteins in infected and non-infected cells and obtaining antigens. In addition, it is important to have a larger panel of tick cell lines, as they can serve as efficient tools for advancing research in various areas of virology, bacteriology, biology and control of these ticks.