Modeling chikungunya virus neuroinvasion and neuropathogenesis in mice - PROJECT SUMMARY
The alphavirus chikungunya virus (CHIKV) represents a re-emerging public health concern as mosquito vectors
spread to new territories. While CHIKV typically induces an arthritogenic disease, up to 16% of cases result in
neurological disease such as encephalitis and meningitis. Surviving patients are often left with long-term
neurological deficits, including impaired motor control, emotional and behavioral disinhibition, and cognitive
disorders. Despite numerous published clinical case and public health impact reports, very little is known about
the neuropathogenesis of CHIKV infection. The limited accessibility and minimally regenerative nature of the
central nervous system (CNS) create an insurmountable barrier to studying the course of neurological CHIKV
infection in humans and require the use of animal models. Mice have been used extensively to study arthritogenic
disease induced by CHIKV and neurological disease induced by other alphaviruses, including long-term
neurological sequalae. However, almost all mouse studies examining neurological CHIKV infection have utilized
neonatal or immunocompromised mice, which do not accurately reflect the neurodevelopmental or
immunological status of susceptible human populations. Furthermore, both arthritogenic and neurological
disease induced by alphaviruses have been shown to primarily be mediated by the immune response rather than
by the virus itself, further necessitating the use of immunocompetent mice. Preliminary work by our group has
found that while young adult C57BL/6J mice are susceptible to infection and replicate the CNS pathology
reported in humans following intracranial infection, CNS infection cannot be consistently achieved following
peripheral inoculation. In contrast, CC041 mice, a Collaborative Cross strain, consistently demonstrate infection
of the brain and signs of neurological disease following subcutaneous inoculation, presenting a potential mouse
model by which to evaluate neurological disease induced by CHIKV following peripheral infection. This proposal
aims to characterize neurological CHIKV infection in CC041 mice following peripheral inoculation and determine
whether CC041 mice develop the neurological disease and CNS pathology seen in humans. In Aim 1, we will
determine the mechanism and dynamics by which CHIKV infects the brain in CC041 mice. In Aim 2, we will
determine whether CC041 mice develop CNS pathology and long-term neurological sequelae similar to human
patients following neurological CHIKV infection. Our studies will establish a new neurodevelopmentally-
appropriate, immunocompetent mouse model of peripheral CHIKV infection, allowing for future in depth
evaluation of the mechanisms driving neurological disease development and by which to test new potential
vaccines, antivirals, and host-directed treatments for neurological infection with CHIKV and other alphaviruses.