Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

National Institute of Environmental Health Sciences

Use this QR code to view the newest version of this document
Use this QR code to view the newest version of this document

Your Environment. Your Health.

Publication Detail

Title: Surface translocator protein 18 kDa (TSPO) localization on immune cells upon stimulation with LPS and in ART-treated HIV+ subjects.

Authors: Blevins, Lance K; Crawford, Robert B; Azzam, Diana J; Guilarte, Tomás R; Kaminski, Norbert E

Published In J Leukoc Biol, (2021 07)

Abstract: Translocator protein 18 kDa (TSPO) is a well-known outer mitochondrial membrane protein and it is widely used as a biomarker of neuroinflammation and brain injury. Although it is thought that TSPO plays key roles in a multitude of host cell functions, including steroid biosynthesis, apoptosis, generation of reactive oxygen species, and proliferation, some of these functions have recently been questioned. Here, we report the unexpected finding that circulating immune cells differentially express basal levels of TSPO on their cell surface, with a high percentage of monocytes and neutrophils expressing cell surface TSPO. In vitro stimulation of monocytes with LPS significantly increases the frequency of cells with surface TSPO expression in the absence of altered gene expression. Importantly, the LPS increase in TSPO cell surface expression in monocytes appears to be selective for LPS because two other distinct monocyte activators failed to increase the frequency of cells with surface TSPO. Finally, when we quantified immune cell TSPO surface expression in antiretroviral therapy-treated HIV+ donors, a chronic inflammatory disease, we found significant increases in the frequency of TSPO surface localization, which could be pharmacologically suppressed with ∆9 -tetrahydrocannabinol. These findings suggest that cell surface TSPO in circulating leukocytes could serve as a peripheral blood-based biomarker of inflammation.

PubMed ID: 33205494 Exiting the NIEHS site

MeSH Terms: Animals; Antiretroviral Therapy, Highly Active; Apoptosis; Biomarkers; Disease Susceptibility; HIV Infections/drug therapy; HIV Infections/immunology*; HIV Infections/metabolism*; HIV Infections/virology*; Humans; Inflammation/etiology; Inflammation/metabolism; Leukocytes/immunology; Leukocytes/metabolism; Lipopolysaccharides/adverse effects*; Mitochondria/genetics; Mitochondria/metabolism; Protein Transport; Reactive Oxygen Species/metabolism; Receptors, GABA/genetics; Receptors, GABA/metabolism*

Back
to Top