0000000000050268
AUTHOR
Zsolt Ruzsics
Peptide Processing Is Critical for T-Cell Memory Inflation and May Be Optimized to Improve Immune Protection by CMV-Based Vaccine Vectors.
Cytomegalovirus (CMV) elicits long-term T-cell immunity of unparalleled strength, which has allowed the development of highly protective CMV-based vaccine vectors. Counterintuitively, experimental vaccines encoding a single MHC-I restricted epitope offered better immune protection than those expressing entire proteins, including the same epitope. To clarify this conundrum, we generated recombinant murine CMVs (MCMVs) encoding well-characterized MHC-I epitopes at different positions within viral genes and observed strong immune responses and protection against viruses and tumor growth when the epitopes were expressed at the protein C-terminus. We used the M45-encoded conventional epitope HGI…
Dominant-negative FADD rescues the in vivo fitness of a cytomegalovirus lacking an anti-apoptotic viral gene
ABSTRACT Genes that inhibit apoptosis have been described for many DNA viruses. Herpesviruses often contain even more than one gene to control cell death. Apoptosis inhibition by viral genes is postulated to contribute to viral fitness, although a formal proof is pending. To address this question, we studied the mouse cytomegalovirus (MCMV) protein M36, which binds to caspase-8 and blocks death receptor-induced apoptosis. The growth of MCMV recombinants lacking M36 (ΔM36) was attenuated in vitro and in vivo. In vitro, caspase inhibition by zVAD-fmk blocked apoptosis in ΔM36-infected macrophages and rescued the growth of the mutant. In vivo, ΔM36 infection foci in liver tissue contained sign…
Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.
Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre + heart and kidney transplants were readily transmitted to MCMV-naïve recipients by primary viremia. In contrast, when a Tie2-cre + transplant was infected by pri…
The Major Virus-Producing Cell Type during Murine Cytomegalovirus Infection, the Hepatocyte, Is Not the Source of Virus Dissemination in the Host
SummaryThe course of systemic viral infections is determined by the virus productivity of infected cell types and the efficiency of virus dissemination throughout the host. Here, we used a cell-type-specific virus labeling system to quantitatively track virus progeny during murine cytomegalovirus infection. We infected mice that expressed Cre recombinase selectively in vascular endothelial cells or hepatocytes with a murine cytomegalovirus for which Cre-mediated recombination would generate a fluorescently labeled virus. We showed that endothelial cells and hepatocytes produced virus after direct infection. However, in the liver, the main contributor to viral load in the mouse, most viruses…