Interferon-gamma increases monocyte PD-L1 but does not diminish T-cell activation

Galbraith, N. J. , Walker, S. P., Gardner, S. A., Bishop, C., Galandiuk, S. and Polk, H. C. (2020) Interferon-gamma increases monocyte PD-L1 but does not diminish T-cell activation. Cellular Immunology, 357, 104197. (doi: 10.1016/j.cellimm.2020.104197) (PMID:32891037)

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Abstract

Immune dysfunction can occur during sepsis or following major trauma. Decreased monocyte HLA-DR expression and cytokine responses are associated with mortality. Recent studies have shown that adaptive immune system defects can also occur in such patients, characterised by increased PD-L1 expression and associated T-cell anergy. The aim of this study was to determine the effects of an immune adjuvant, interferon-gamma, on monocyte PD-L1 expression and T-cell activation in an ex-vivo human whole blood model of infection. We found that with interferon-gamma treatment, monocytes had increased HLA-DR expression and augmented TNF-α production in response to LPS stimulation, with a decrease in IL-10 levels. Both LPS and interferon-gamma increased the level of monocyte PD-L1 expression, and that a combination of both agents synergistically stimulated a further increase in PD-L1 levels as measured by flow cytometry. However, despite elevated PD-L1 expression, both CD4 and CD8 T-cell activation was not diminished by the addition of interferon-gamma treatment. These findings suggest that PD-L1 may not be a reliable marker for T-cell anergy, and that interferon-gamma remains an adjuvant of interest that can improve the monocyte inflammatory response while preserving T-cell activation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Galbraith, Dr Norman
Creator Roles:
Galbraith, N.Conceptualization, Data curation, Formal analysis, Methodology, Writing – review and editing
Authors: Galbraith, N. J., Walker, S. P., Gardner, S. A., Bishop, C., Galandiuk, S., and Polk, H. C.
College/School:College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Journal Name:Cellular Immunology
Publisher:Elsevier
ISSN:0008-8749
Published Online:21 August 2020

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