Expression and regulation of the PD‐L1 immunoinhibitory molecule on microvascular endothelial cells

MJ Eppihimer, J Gunn, GJ Freeman… - …, 2002 - Wiley Online Library
MJ Eppihimer, J Gunn, GJ Freeman, EA Greenfield, T Chernova, J Erickson, JP Leonard
Microcirculation, 2002Wiley Online Library
Objective: To evaluate the expression and regulation of a novel B7‐like protein, PD‐L1, the
ligand for the immunoinhibitory receptor PD‐1 expressed on activated T‐cells, on
microvascular endothelial cells (ECs) Methods: PD‐L1 expression on ECs in vitro and in
vivo was quantified by using a dual radiolabeled antibody technique after treatment with
interferons (IFN) and IL‐12, respectively. Changes in the level of PD‐L1 mRNA were
determined by using RT‐PCR. Results: PD‐L1 was observed to be present on ECs under …
Objective: To evaluate the expression and regulation of a novel B7‐like protein, PD‐L1, the ligand for the immunoinhibitory receptor PD‐1 expressed on activated T‐cells, on microvascular endothelial cells (ECs)
Methods: PD‐L1 expression on ECs in vitro and in vivo was quantified by using a dual radiolabeled antibody technique after treatment with interferons (IFN) and IL‐12, respectively. Changes in the level of PD‐L1 mRNA were determined by using RT‐PCR.
Results: PD‐L1 was observed to be present on ECs under basal conditions. Treatment of ECs with IFN‐α, ‐β and ‐γ, but not LPS, was observed to induce elevations in the mRNA and surface expression of PD‐L1 on ECs. By using a dual radiolabeled monoclonal antibody (mAb) technique, PD‐L1 expression in various tissues of control and IL‐12 challenged wild‐type and IFN‐γ‐deficient mice was measured. A significant increase in PD‐L1 expression was observed in tissues at 24 hours after IL‐12‐challenge, with peak levels of PD‐L1 occurring 72 hours after IL‐12 challenge. IL‐12 was not effective at inducing PD‐L1 expression in tissues of IFN‐γ‐deficient mice.
Conclusions: These data show the expression of a novel B7‐like molecule on murine ECs that is mediated by IFN‐α, ‐β, and ‐gamma;, and suggest a potential pathway by which ECs may modulate T‐cell function.
Wiley Online Library