Experts in human, murine and porcine roseolovirus combined forces to write a fascinating comparative review.
Little is known about murine roseolovirus/ MRV and porcine roseolovirus/ PRV (initially mis-named porcine cytomegalovirus/PCMV) but they each have some important commonalities with human roseoloviruses HHV-6 & HHV-7. While they are generally asymptomatic with transient self-limiting disease, they can reactivate and cause significant disease, in part due to their immunosuppressive properties.
In pigs, PCMV/PRV does not cause significant disease. But when pig organs are used for xenotransplantation, the roseolovirus in the transplanted organ reactivates and causes a significant reduction in survival time of the transplanted organ. This has been the biggest reason for the failure to develop safe xenotransplantation of pig hearts to humans. Fortunately, PCMV/PRV free herds have finally been developed, so type of pig to human organ transplantation may be possible in the future.
Another important commonality discussed in this review is the detection of roseoloviruses in the brains of their respective species. Human roseoloviruses have been implicated in several neurological conditions including multiple sclerosis (HHV-6A) mesial temporal lobe epilepsy (HHV-6B & HHV-7) and Alzheimer’s disease (HHV-6A & HHV-7). PCMV/ PRV has recently been found in multi-focal lesions in the cerebrum and cerebellum of pigs and MRV also was recently isolated in the brains of infant mice.
Based on recent findings at Washington University (Patel 2017, Patel 2018) and University of Michigan (Zhou 2019), MRV may be a promising murine model for HHV-6B. Additionally, further study of PCMV/ PRV will help advance the field of xenotransplantation. Now that roseolovirus-free herds have been established, it might also be possible to utilize PCMV/PRV as an animal model for HHV-6/7.
Led by Joachim Denner of Robert Koch Institute, contributors included Benedikt Kaufer and Cosima Zimmerman of Freie University, Xiaofeng Zhou of University of Michigan, Tarin Bigley of Washington University and Tuan Phan of Tulane University & HHV-6 Foundation.
Read the full review: Denner 2019