Functional genomic studies of tick cells in response to infection with the cattle pathogen, Anaplasma marginale

Abstract

The coevolution of ticks and the pathogens that they transmit has ensured their mutual survival. In these studies, we used a functional genomics approach to characterize tick genes regulated in response to Anaplasma marginale infection. Differentially regulated genes/proteins were identified by suppression-subtractive hybridization and differential in-gel electrophoresis analyses of cultured IDE8 tick cells infected with A. marginale. Nine of 17 of these genes were confirmed by real-time RT-PCR to be differentially regulated in ticks and/or IDE8 tick cells in response to A. marginale infection. RNA interference was used for functional studies. Six genes, which encode putative selenoprotein W2a, hematopoietic stem/progenitor cells protein-like, proteasome 26S subunit, ferritin, GST, and subolesin control, were found to affect A. marginale infection in IDE8 tick cells. Four genes, which encode putative GST, salivary selenoprotein M, vATPase, and ubiquitin, affected A. marginale infection in different sites of development in ticks. The results of these studies demonstrated that a molecular mechanism occurs by which tick cell gene expression mediates the A. marginale developmental cycle and trafficking through ticks.

RNA Interference – A Powerful Functional Analysis Tool for Studying Tick Biology and its Control

“…Several proteins have been studied through RNAi to determine their importance in the development cycle of different pathogens. The knockdown of subolesin [142,156], GST, vATPase, and selenoprotein M [142] in D. variabilis, and putative von Willebrand factor, flagelliform silk protein and subolesin in R. (B.)…”

In vitro cultivation of Anaplasma marginale and A. phagocytophilum in tick cell lines: a review

“…In addition, in vitro cultivation of A. marginale in tick cells has been used in comparative studies with infected bovine erythrocytes for differential bacterial gene transcriptional analyses and expression profile of outer membrane proteins to search for potential A. marginale vaccine candidates GARCIA-GARCIA et al, 2004;NOH et al, 2006), and in RNA interference approaches for functional studies to discover genes/proteins that are differentially expressed in tick cells in response to infection with A. marginale (DE LA FUENTE et al, 2007;KOCAN et al, 2009). These studies indicate that A. marginale affects the expression of tick genes important for tick survival and pathogen multiplication; thus, a molecular mechanism occurs by which tick cell gene expression mediates the development of the pathogen through ticks.…”

Efeitos da infecção por Rickettsia rickettsii sobre o perfil de expressão gênica do carrapato vetor Amblyomma cajennense.

“…Os autores discutem que esse fenômeno pode estar relacionado com a produção de espécies reativas de oxigênio (ERO), originada após alimentação sanguínea (Rudenko et al, 2005). A COX também foi induzida em resposta à infecção de A. marginale em R. microplus [(de la Fuente et al, 2007a;Mercado-Curiel et al, 2011;Zivkovic et al, 2010) (Malossi, 2013). No entanto, em virtude dos baixos níveis em que esse gene é transcrito não infectados, utilizamos o método de quantificação absoluta para as duas espécies de carrapatos.…”

“…Dentre os métodos disponíveis, o RNA de interferência (RNAi) é um dos mais utilizados, inclusive em carrapatos (Aljamali et al, 2002;de la Fuente et al, 2005de la Fuente et al, , 2007aKocan et al, 2008Kocan et al, , 2009Kocan et al, , 2011Nijhof et al, 2007). A utilização da técnica de RNAi in vivo permite elucidar mecanismos fisiológicos de genes específicos e propiciam a descoberta rápida de alvos para vacinas contra carrapatos.…”

“…Similarmente, o silenciamento da ferritina em uma linhagem de células de carrapatos I. scapularis (IDE8) mantida em cultura também diminuiu a infecção, indicando que estas proteínas sejam importantes para a invasão e estabelecimento de A. marginale em carrapatos (de la Fuente et al, 2007a).…”