Live, Attenuated Venezuelan Equine Encephalitis Virus Vaccine (TC83) Causes Persistent Brain Infection in Mice with Non-functional αß T-Cells.

Intranasal infection with vaccine strain of Venezuelan equine encephalitis virus (TC83) caused persistent viral infection in the brains of mice without functional αß T-cells (αß-TCR -/-). Remarkably, viral kinetics, host response gene transcripts and symptomatic disease are similar between αß-TCR -/- and wild-type C57BL/6 (WT) mice during acute phase of infection [0-13 days post-infection (dpi)]. While WT mice clear infectious virus in the brain by 13 dpi, αß-TCR -/- maintain infectious virus in the brain to 92 dpi. Persistent brain infection in αß-TCR -/- correlated with inflammatory infiltrates and elevated cytokine protein levels in the brain at later time points. Persistent brain infection of αß-TCR -/- mice provides a novel model to study prolonged alphaviral infection as well as the effects and biomarkers of long-term viral inflammation in the brain.