Host cell-specific protein expression in vitro in Ehrlichia ruminantium

Abstract

Ehrlichia ruminantium, a tick-transmitted pathogen, is the causative agent of heartwater in ruminants. In this study, a proteomic approach was used to identify host cell-specific E. ruminantium proteins encoded by the map1 multigene family, expressed in vitro in bovine endothelial and tick cell cultures. Two-dimensional gel electrophoresis combined with mass spectrometry analysis was used to establish the identities of immunodominant proteins. Proteins extracted from E. ruminantiuminfected endothelial cells were shown to be products of the map1 gene, whereas tick cell-derived E. ruminantium proteins were products of a different gene, map1-1. The expressed proteins were found to be glycosylated. Differential expression of MAP1 family proteins in vitro in mammalian and tick cell cultures indicates that the map1 multigene family might be involved in the adaptation of E. ruminantium to the mammalian host and vector tick. #

Global gene expression profiling ofEhrlichia ruminantiumat different stages of development

“…At RB stage, we also showed an overexpression of map1-6, secF, sppA, and lolD genes that code for proteins involved in nutrient and protein exchanges and transports, indicating a possible important role in ER growth and division. Map1-6 is essential for ER host adaptation and intracellular survival (Postigo et al, 2008). The Sec system represents the major route in Rickettsia typhi for protein secretion including the secretion of virulence factors (Ammerman et al, 2008).…”

Understanding Anaplasmataceae pathogenesis using “Omics” approaches

“…Furthermore, the authors showed a higher proportion of up-regulated genes encoding other OMPs in A. phagocytophilum infecting human cell lines rather than in tick cell lines (Nelson et al, 2008). For E. ruminantium , MAP 1-1 was expressed only in tick cells and not in host cells (Postigo et al, 2008). A differential expression of OMP-family genes between host cells and vector cells was also observed for E. chaffeensis (Kuriakose et al, 2011).…”

Progress and obstacles in vaccine development for the ehrlichioses

“…A significant gap in our understanding exists regarding the influence of the host environment (invertebrate/vertebrate) on the molecular phenotype of Ehrlichia and how this relates to transmission, immunogenicity and ultimately vaccine composition. The influence of the host environment on pathogen phenotype is becoming more appreciated, as shown in recent studies that have identified some differences in gene and protein expression of major OMPs of E. chaffeensis and E. canis in mammalian and tick-derived cell lines [70,71], E. canis in dogs, ticks and cell culture [72], and host cell-specific protein expression of E. ruminantium in vitro [73,74] and in ticks [75]. These studies have focused on the major OMP family and suggest that these proteins are differentially regulated in invertebrate and vertebrate hosts.…”