Ehrlichia chaffeensis tandem repeat effector targets differentially influence infection

Tian Luo, Paige S. Dunphy, Jere McBride

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Ehrlichia chaffeensis infects mononuclear phagocytes and survives intracellularly by exploiting host cell processes to evade host defenses. The mechanisms involved are not fully defined, but appear to rely largely on a subset of tandem repeat proteins (TRP) effectors. E. chaffeensis TRPs are type 1 secreted effectors that interact with a functionally diverse group of host cell targets associated with various biological processes. In this study, we investigated the influence of TRP host target proteins on ehrlichial infection by RNA interference. In total, 138 TRP-interacting host proteins identified by yeast two-hybrid were targeted by siRNA and the infection level determined by real-time qPCR. Knockdown of 124 (89%) TRP target proteins had significant influence on infection either by inhibiting (85%) or promoting (15%) ehrlichial infection. Notably, knockdown of 18 host proteins which interacted with TRP120 promoted the infection, suggesting that these targets may be degraded to promote infection. Host proteins that interact with TRPs are involved in cellular processes, including cell signaling, vesicle trafficking and intracellular transport, transcriptional regulation, metabolism, protein posttranslational modification, and apoptosis. Selected host targets were examined by immunofluorescent microscopy during infection and were found to localize with the morulae, or in the host cell cytoplasm adjacent to morulae. This study confirms that the majority of host proteins known to interact with TRP effectors influence infection and further extends the current knowledge that E. chaffeensis TRPs participate in a complex array of host protein interactions in order to reprogram the host cell and promote intracellular survival.

Original languageEnglish (US)
Article number178
JournalFrontiers in cellular and infection microbiology
Volume7
Issue numberMAY
DOIs
StatePublished - May 12 2017

Fingerprint

Ehrlichia chaffeensis
Tandem Repeat Sequences
Infection
Proteins
Morula
Biological Phenomena
Protein Array Analysis
Fungal Proteins
Post Translational Protein Processing
Phagocytes
RNA Interference
Small Interfering RNA

Keywords

  • Cell signaling
  • Effector-host interaction
  • Ehrlichia chaffeensis
  • Infection
  • Posttranslational modification
  • Tandem repeat protein
  • Transcriptional regulation
  • Vesicle trafficking

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Medicine(all)
  • Microbiology (medical)
  • Infectious Diseases

Cite this

Ehrlichia chaffeensis tandem repeat effector targets differentially influence infection. / Luo, Tian; Dunphy, Paige S.; McBride, Jere.

In: Frontiers in cellular and infection microbiology, Vol. 7, No. MAY, 178, 12.05.2017.

Research output: Contribution to journalArticle

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