Data from: Early detection of cerebrovascular pathology and protective antiviral immunity by MRI

Central nervous system (CNS) infections are a major cause of human
morbidity and mortality worldwide. Even patients that survive CNS
infections can have lasting neurological dysfunction resulting from immune
and pathogen induced pathology. Developing approaches to noninvasively
track pathology and immunity in the infected CNS is crucial for patient
management and development of new therapeutics. Here, we develop novel
MRI-based approaches to monitor virus-specific CD8+ T cells and their
relationship to cerebrovascular pathology in the living brain. We studied
a relevant murine model in which a neurotropic virus (vesicular stomatitis
virus) was introduced intranasally and then entered the brain via
olfactory sensory neurons – a route exploited by many pathogens in humans.
Using T2*-weighted high-resolution MRI, we identified small cerebral
microbleeds as the earliest form of pathology associated with viral entry
into the brain. Mechanistically, these microbleeds occurred in the absence
of peripheral immune cells and were associated with infection of vascular
endothelial cells. We monitored the adaptive response to this infection by
developing methods to iron label and track individual virus specific CD8+
T cells by MRI. Transferred antiviral T cells were detected in the brain
within a day of infection and were able to reduce cerebral microbleeds.
These data demonstrate the utility of MRI in detecting the earliest
pathological events in the virally infected CNS as well as the therapeutic
potential of antiviral T cells in mitigating this pathology.