Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2023 Jun 24;13(7):787. doi: 10.3390/metabo13070787

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2023 by the authors.

Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

PMC Copyright notice

Immunological outcomes of purine nucleoside phosphorylase (PNP) inhibition. The lack of PNP causes accumulation of both ribo and deoxyribo guanosine [(d)Guo]. Panel (A), upper: Deoxyguanosine (dGuo) is phosphorylated by deoxycytidine kinase (dCK) to deoxyGMP (dGMP), then converted to deoxyGTP (dGTP), which accumulates in sterile alpha motif and HD domain containing protein 1 (SAMHD1)-deficient cells (namely, T-cell progenitors). Panel (A), lower: In SAMDH1-proficient cells (namely, B lymphoblastic cells), dGTP does not accumulate because it is efficiently converted to dGuo and triphosphate. Panel (B): Elevated endolysosomal guanosine nucleoside levels trigger Toll-like receptor 7 (TLR 7) activation, through a dual binding of single-stranded ribonucleic acid (ssRNA) and guanosine, which causes transcription of the gene encoding for interleukin-6 (IL-6). Parts of the figure were drawn by using pictures from Servier Medical Art. Servier Medical Art by Servier is licensed under a Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/ accessed on 23 May 2023).