Inquiry Basket
Loading ......
Theiler Murine Encephalomyelitis Virus (TMEV) is a naturally occurring intestinal pathogen in mice. This virus has been used as a mouse model for two different human diseases: multiple sclerosis (MS) and epilepsy. These mouse models are powerful tools for studying how immune responses to viral infections lead to the mechanisms of MS and epilepsy, and this article will review the latest knowledge in this field. TMEV is a non-enveloped, single stranded RNA virus from the cardiovirus genus, picornavirus family. TMEV normally infects mouse gut without causing symptoms, however TMEV can, rarely, naturally infect the CNS. Based on neurovirulence in the CNS of susceptible mouse strains, TMEV can be divided into two different subgroups: 1) GDVII, comprised of the strains GDVII and FA, is extremely virulent to mice and mice die within 1–2 weeks of infection; and 2) TO, that includes the DA and BeAn strains, causes encephalitis during the acute stage of infection and demyelinating disease during the chronic stage of infection.
Figure 1. Schematic representation of two distinct mouse models using TMEV infection. (DePaula-Silva A B,et al, 2017)
The establishment of persistent infection and subsequent demyelination by TO subgroup strains is a complex process involving active viral evasion of host innate and adaptive immunity. The Native Theiler Murine Encephalomyelitis Virus Antigen, derived from purified viral particles, serves as an essential tool to dissect these interactions. It is used in immunological assays (e.g., ELISA, Western Blot) to detect and quantify virus-specific antibodies in infected mice, thereby mapping the host's humoral immune response over time. Key viral proteins target specific host pathways to facilitate persistence and drive immunopathology.
| Target/Pathway | Key Viral Factor(s) | Mechanism and Role in Pathogenesis |
| Type I Interferon (IFN-α/β) Response | Leader (L) Protein | A key immune evasion protein. Inhibits the transcription of IFN-α4 and IFN-β genes, blocking the host's early antiviral alarm system. Mutation of its zinc finger motif abolishes this function and severely impairs viral persistence. |
| Innate Immune Activation & Viral Replication | Viral RNA / dsRNA intermediates | Viral RNA is recognized by host Toll-like Receptor 7 (TLR7), while double-stranded RNA intermediates are recognized by TLR3. This activation leads to NF-κB activation and production of pro-inflammatory cytokines. |
| Inflammasome Activation | NLRP3 Inflammasome | Activated via TLR signaling following TMEV infection. Leads to the production of mature IL-1β, a potent pro-inflammatory cytokine. |
| Pathogenic Immune Polarization | Cytokines IL-6 & IL-1β | Excessive levels of these cytokines, produced via sustained TLR/NF-κB signaling, drive the development of pathogenic Th17 immune responses instead of protective Th1 responses. This cytokine milieu also inhibits apoptosis of infected cells and cytotoxic T lymphocyte function, promoting persistence. |
In most cases, natural infection with Theiler Murine Encephalomyelitis Virus is asymptomatic. Some viral strains can cause transient viremia followed by lethal encephalitis. Approximately one in ten thousand naturally infected mice exhibit central nervous system demyelination damage. The demyelination caused by artificial inoculation of MEV can serve as a model for demyelination damage caused by poliomyelitis, multiple sclerosis, and other viruses. Demyelinating animals may have flaccid unilateral or bilateral hind limb paralysis. Although this pathogen is common, hind limb paralysis in mice is often caused by other reasons, such as infiltration of spinal cord lymphoma. No clinical symptoms were observed in rats infected with RTV, only one case was reported from Brazil.
TMEV is an enveloped virus with an icosahedral capsid composed of four structural proteins: VP1, VP2, VP3, and VP4, surrounding its sense RNA genome. The virus is mainly transmitted through fecal oral route. After experimental intracerebral inoculation, the disease outcome heavily depends on the viral strain and the genetic background of the host mouse. TMEV strains are divided into two subgroups with different biological activities:
Once Theiler Murine Encephalomyelitis Virus is diagnosed, measures should be taken to prevent transmission to other animals through materials or contact. Cell lines, transplanted tumors, and other biological materials should be detected by PCR or MAP (mouse antibody production) before inoculation in animals. Wild rodents are storage hosts and entry into animal rooms should be strictly controlled. It is recommended to conduct routine serum testing on animals and isolate and quarantine newly introduced animals. The long-term stable existence of the virus is the primary consideration for controlling disease outbreaks. It is recommended to use chemical disinfectants, detergents, and oxidants in conjunction with materials that come into direct contact with animals for high-pressure sterilization or cold sterilization. For infected animals, appropriate measures should be taken based on their value and whether they can be replaced. Theiler Murine Encephalomyelitis Virus is not very contagious, and cage level detection and elimination procedures can clear infections from populations raised in isolation or IVC immune normal populations. Newborns of antibody positive mother mice can find clean mother mouse milk substitutes. Hysterectomy and embryo transfer can also successfully purify the uterus.
Theiler's Murine Encephalomyelitis Virus is a pathogen of dual significance. It is an important natural infectious agent in mouse colonies and a cornerstone experimental model in neurovirology and immunology. The molecular dissection of its pathogenesis, particularly the roles of the L protein in interferon antagonism and the unique L* protein in macrophage-specific persistence, has provided profound insights into how viruses evade immunity to establish chronic infection. The resulting immune-mediated demyelination offers a highly relevant model for human MS. Furthermore, the virus's ability to elicit robust T-cell responses is being harnessed to develop novel vaccine platforms. Continued study of TMEV will undoubtedly yield further discoveries in viral persistence, autoimmune mechanisms, and immunotherapeutic design.
Reference
DePaula-Silva A B, Hanak T J, Libbey J E, et al. Theiler's murine encephalomyelitis virus infection of SJL/J and C57BL/6J mice: Models for multiple sclerosis and epilepsy. Journal of neuroimmunology, 2017, 308: 30-42.
| Target | Cat. No. | Product Name | Host | |
| TMEV | DAG-WT3381 | Native Theiler Murine Encephalomyelitis Virus Antigen | N/A | Inquiry |
Loading ......
