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Updated: Jun 21, 2026
12:23
Analysis of Yersinia enterocolitica Effector Translocation into Host Cells Using Beta-lactamase Effector Fusions
Published on: October 13, 2015
Cell type-specific effects of Yersinia pseudotuberculosis virulence effectors
Anna Fahlgren1, Linda Westermark, Karen Akopyan
1Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, S-90187 Umeå, Sweden.
Cellular Microbiology
|August 18, 2009
Summary
Yersinia pseudotuberculosis uses YopE to resist internalization by dendritic cells (DCs), while YopH does not affect this process. Different immune cells internalize bacteria using distinct mechanisms, impacting immune responses.
Area of Science:
- Microbiology
- Immunology
- Cell Biology
Background:
- Yersinia pseudotuberculosis employs antiphagocytic effectors YopH and YopE to evade host immune defenses.
- YopH dephosphorylates tyrosine, affecting integrin signaling, while YopE disrupts cytoskeletal dynamics by inhibiting Rho GTPases.
- Dendritic cells (DCs) internalize antigens to initiate adaptive immune responses.
Purpose of the Study:
- To investigate the impact of YopH and YopE on the internalization of Yersinia pseudotuberculosis by dendritic cells (DCs).
- To compare bacterial internalization mechanisms in DCs and macrophages.
- To understand how effector proteins influence immune cell function.
Main Methods:
- Live cell microscopy was used to observe the internalization process.
- Expression levels of YopH targets (Fyb and p130Cas) in DCs and macrophages were analyzed.
- The roles of YopE and YopH in bacterial uptake by DCs were assessed.
Main Results:
- Yersinia pseudotuberculosis resists internalization by DCs primarily through the effector YopE.
- YopH, crucial for blocking phagocytosis in macrophages and neutrophils, did not contribute to DC resistance.
- Macrophages use a receptor-mediated zipper mechanism, whereas DCs employ macropinocytosis for bacterial internalization.
Conclusions:
- YopE inhibits DC macropinocytosis by affecting cytoskeletal dynamics and ruffling.
- YopH influences phagocytic signaling via integrins, a pathway not utilized in DC macropinocytosis.
- Differential internalization mechanisms in DCs and macrophages are linked to their distinct immune functions: antigen sampling and pathogen elimination.
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