Related Experiment Video
Updated: Jun 23, 2026

Use of In vivo Imaging to Monitor the Progression of Experimental Mouse Cytomegalovirus Infection in Neonates
Published on: July 6, 2013
A proviral role for CpG in cytomegalovirus infection
Ann-Charlotte Iversen1, Bjørg Steinkjer, Nadra Nilsen
1Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. Ann-Charlotte.Iversen@ntnu.no
Abstract:
TLR9-dependent signaling in plasmacytoid dendritic cells is a key contributor to innate immune defense to mouse CMV infection. We aimed to study the expression and potential contribution of TLR9 signaling in human CMV (HCMV) infection of primary fibroblasts. HCMV infection strongly induced TLR9 expression in two of three fibroblast types tested. Furthermore, the TLR9 ligand CpG-B induced a strong proviral effect when added shortly after HCMV infection, enhancing virus production and cell viability. However, not all CpG classes displayed proviral activity, and this correlated with their IFN-beta-inducing ability. The proviral effect of CpG-B correlated completely with concurrent viral up-regulation of TLR9 in fibroblasts. Importantly, the timing of CpG addition was a critical parameter; in striking contrast to the proviral effect, CpG addition at the time of infection blocked viral uptake and nearly abolished HCMV production. The contrasting and time-dependent effects of CpG on HCMV infectivity reveal a complex interplay between CpG, TLR9, and HCMV infection. Additionally, the data suggest a potentially harmful role for CpG in the promotion of HCMV infection.
Related Concept Videos
Cytomegalovirus Disease
Mechanisms of Retrovirus-induced Cancers
Mechanisms of Retrovirus-induced Cancers
Retrovirus Life Cycles
Retroviruses
Rous Sarcoma Virus (RSV) and Cancer
RSV is a retrovirus that contains two copies of a plus-strand RNA genome. Its genome consists of four main open...

