Expansion of activated regulatory T cells by myeloid-specific chemokines via an alternative pathway in CSF of bacterial meningitis patients.

Abstract

Previous studies have demonstrated that activation/expansion by certain cytokines as well as recruitment by specific chemokines is involved in enrichment of regulatory T (Treg) cells in local tissues or organs under pathological conditions. Recent evidence indicates that human Treg cells are a heterogeneous population that comprises three distinct subpopulations: CD25⁺CD45RA⁺ resting Treg (rTreg) cells, CD25(hi)CD45RA⁻ activated Treg (aTreg) cells, which are both suppressive, and CD25⁺CD45RA⁻ cytokine-secreting T cells with proinflammatory capacity. Moreover, rTreg cells can proliferate and convert to aTreg cells. Here, we found an increase in aTreg-cell frequency in the cerebrospinal fluid (CSF) of patients with postneurosurgery bacterial meningitis. We revealed that such an increased aTreg-cell frequency in the CSF was not due to enhanced chemotaxis. Instead of a classic conversion pathway from rTreg to aTreg cells, we identified an alternative route of Treg-cell conversion from cytokine-secreting cells to aTreg cells induced by myeloid-specific chemokine CXC chemokine receptor (CXCR) ligand 5 via CXCR1 and CXCR2 receptors, or by CSF myeloid cells in a cell-cell contact manner. Our results reveal a different view of how the immune system controls overwhelming local immune responses during infection, and provide evidence of how innate immunity negatively regulates adaptive immunity.

• Authors: Guangzhi Shi, Junyan Han, Gang Liu, Yu Hao, Yaluan Ma, Tong Li, Xueying Wu, Henghui Zhang, Yanan Liu, Beibei Wang, Yaxian Kong, Jianxin Zhou, Hui Zeng
• Journal: European journal of immunology (Eur J Immunol) Vol. 44 Issue 2 Pg. 420-30 (Feb 2014) ISSN: 1521-4141 [Electronic] Germany
• PMID: 24155161 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical References

• Receptors, Chemokine
• Transforming Growth Factor beta

Topics

• Adult
• Cerebrospinal Fluid (immunology)
• Chemotaxis (immunology)
• Female
• Granulocytes (immunology)
• Humans
• Male
• Meningitis, Bacterial (immunology)
• Myeloid Cells (immunology)
• Receptors, Chemokine (immunology)
• T-Lymphocytes, Regulatory (immunology)
• Transforming Growth Factor beta (immunology)