1. Programmed death ligand-1 expression and memory T-cell generation in Coxiella burnetii infection.
- Author
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Ka, Mignane B., Bechah, Yassina, Olive, Daniel, and Mege, Jean-Louis
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GENE expression , *APOPTOSIS , *LIGANDS (Biochemistry) , *T cells , *CELLULAR signal transduction , *COXIELLA burnetii , *GENETIC regulation - Abstract
Programmed death ligand-1 (PD-L1) is a co-signaling molecule that regulates T-cell responses in vivo . Its role in bacterial infections, including Q fever, a zoonosis due to Coxiella burnetii infection, is not well understood. We showed by flow cytometry that PD-L1 membrane expression was specifically increased in T-cells from patients with acute Q fever, not from patients with Q fever endocarditis, suggesting that PD-L1 plays a role in the early phases of C. burnetii infection. To assess this hypothesis, we studied the role of PD-L1 in C. burnetii -infected mice. C. burnetii infection resulted in PD-L1 up-regulation in splenocytes. Anti-PD-L1 antibodies injected into the mice did not affect the total number of splenic T-cells but increased the relative number of CD4 + T-cells compared with CD8 + T-cells. Additionally, anti-PD-L1 antibodies significantly increased the number of splenic CD4 + and CD8 + T cells that expressed low membrane CD62L levels. Our results indicate that the increased expression of PD-L1 by T-cells is associated with a decreased number of memory T-cells during C. burnetii infection, opening new perspectives in the understanding of Q fever pathophysiology. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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