, Volume 39, Issue 2, pp 718–726 | Cite as

Enolase of Streptococcus Suis Serotype 2 Enhances Blood–Brain Barrier Permeability by Inducing IL-8 Release

  • Yingying Sun
  • Na Li
  • Jing Zhang
  • Hongtao Liu
  • Jianfang Liu
  • Xiaojing Xia
  • Changjiang Sun
  • Xin Feng
  • Jingmin Gu
  • Chongtao Du
  • Wenyu Han
  • Liancheng LeiEmail author


Streptococcus suis serotype 2 (SS2) is an emerging zoonosis, and meningitis is the most frequent clinical manifestation, but mechanism of its virulent factor, enolase (Eno), is unknown in meningitis. In this study, Eno was inducibly expressed and added to an in vitro Transwell co-culture model of the blood–brain barrier (BBB) consisted of porcine brain microvascular endothelial cells (PBMECs) and astrocytes (ACs), the results showed that Eno induces a significant increase in BBB permeability and promotes the release of IL-8 et al. cytokines. Furthermore, IL-8 could significantly destroy the integrity of the BBB model in vitro. In mice models administered Eno for 24 h, Eno could significantly promote Evans blue (EB) moving from the blood to the brain and significantly increased the serum and brain levels of IL-8, as detected by ELISA. While G31P (IL-8 receptor antagonist) significantly decreased the concentration of EB in the brains of mice injected with Eno. The present study demonstrated that SS2 Eno may play an important role in disrupting BBB integrity by prompting IL-8 release.


streptococcus suis serotype 2 meningitis blood–brain barrier enolase 



This study was supported by “Public welfare industry-specific special research (Agriculture): Streptococcus suis disease prevention and control technology research and demonstration” (201303041).

Compliance with Ethical Standards

The experimental protocol was conducted with the approval of the Institutional Animal Care and Use Committee of the Jilin University under the approved protocol number JLUA-1309. Moreover, all efforts were made to minimize suffering.

Conflict of Interest

The authors declare that they have no competing interests


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Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Yingying Sun
    • 1
  • Na Li
    • 1
  • Jing Zhang
    • 2
  • Hongtao Liu
    • 1
  • Jianfang Liu
    • 1
  • Xiaojing Xia
    • 1
  • Changjiang Sun
    • 1
  • Xin Feng
    • 1
  • Jingmin Gu
    • 1
  • Chongtao Du
    • 1
  • Wenyu Han
    • 1
  • Liancheng Lei
    • 1
    Email author
  1. 1.College of Veterinary MedicineJilin UniversityChangchunChina
  2. 2.Changchun University of Chinese MedicineChangchunPeople’s Republic of China

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