Recombinant mouse cytomegalovirus expressing a ligand for the NKG2D receptor is attenuated and has improved vaccine properties
Irena Slavuljica, … , Astrid Krmpotić, Stipan Jonjić
Irena Slavuljica, … , Astrid Krmpotić, Stipan Jonjić
Published November 22, 2010
Citation Information: J Clin Invest. 2010;120(12):4532-4545. https://doi.org/10.1172/JCI43961.
View: Text | PDF
Research Article

Recombinant mouse cytomegalovirus expressing a ligand for the NKG2D receptor is attenuated and has improved vaccine properties

Abstract

Human CMV (HCMV) is a major cause of morbidity and mortality in both congenitally infected and immunocompromised individuals. Development of an effective HCMV vaccine would help protect these vulnerable groups. NK group 2, member D (NKG2D) is a potent activating receptor expressed by cells of the innate and adaptive immune systems. Its importance in HCMV immune surveillance is indicated by the elaborative evasion mechanisms evolved by the virus to avoid NKG2D. In order to study this signaling pathway, we engineered a recombinant mouse CMV expressing the high-affinity NKG2D ligand RAE-1γ (RAE-1γMCMV). Expression of RAE-1γ by MCMV resulted in profound virus attenuation in vivo and lower latent viral DNA loads. RAE-1γMCMV infection was efficiently controlled by immunodeficient hosts, including mice lacking type I interferon receptors or immunosuppressed by sublethal γ-irradiation. Features of MCMV infection in neonates were also diminished. Despite tight innate immune control, RAE-1γMCMV infection elicited strong and long-lasting protective immunity. Maternal RAE-1γMCMV immunization protected neonatal mice from MCMV disease via placental transfer of antiviral Abs. Despite strong selective pressure, the RAE-1γ transgene did not exhibit sequence variation following infection. Together, our results indicate that use of a recombinant virus encoding the ligand for an activating NK cell receptor could be a powerful approach to developing a safe and immunogenic HCMV vaccine.

Authors

Irena Slavuljica, Andreas Busche, Marina Babić, Maja Mitrović, Iva Gašparović, Đurđica Cekinović, Elitza Markova Car, Ester Pernjak Pugel, Ana Ciković, Vanda Juranić Lisnić, William J. Britt, Ulrich Koszinowski, Martin Messerle, Astrid Krmpotić, Stipan Jonjić

×

Figure 4

RAE-1γMCMV infection induces protective immunity.

Options: View larger image (or click on image) Download as PowerPoint
RAE-1γMCMV infection induces protective immunity. (A) Donors of mem...
(A) Donors of memory CD8+ T cells were μMT/μMT B cell–deficient mice either naive or latently infected with RAE-1γMCMV or WT MCMV (>6 months p.i.). Splenocytes from 3 donors per group were pooled, and the number of MCMV-specific CD8+ T cells was assessed by combined staining with IE1/m123, m164, M83, M84, and m04 MHC class I tetramers. 104 naive CD8+ T cells or graded numbers of MCMV-specific CD8+ T cells were i.v. transferred to recipient BALB/c mice immunocompromised by 6 Gy γ-irradiation. Recipients were f.p. injected with 105 PFU WT MCMV 6 hours after the cell transfer. Viral titers in spleen were determined 12 days p.i. by plaque assay. Titers of individual mice (circles) and median values (horizontal bars) are shown. Ø, no transfer. (B) Mice infected as described in Figure 3 were i.p. challenged with 105 PFU of salivary gland–derived MCMV (SGV) 6 months p.i. Lymphocytes were isolated from blood, spleen, and liver at different time points after the challenge and stained with IE1/m123 MHC class I tetramer and anti-CD8 Ab. The percentage of IE1/m123-specific CD8+ T cells for individual mice (circles) and median values (horizontal bars) are shown. (C) Naive mice and mice infected as described in Figure 3 were i.p. challenged with 2 × 105 or 5 × 105 PFU of SGV 6 months p.i. Survival rates were monitored daily. Results from 1 of 2 similar experiment are shown. *P < 0.05, **P < 0.01.