Brain tissue-derived autoimmune encephalitis cytokine TSLP primes
neuroinflammation by activating JAK2-NLRP3 axis
Abstract
Hyperactivation of NLRP3 inflammasome contributes to the
neuroinflammation in autoimmune disorders, but the underlying regulating
mechanism remains to be elucidated. We here demonstrate that mice
lacking thymic stromal lymphopoietin receptor gene (Tslpr-/-) exhibit
significant decreases in experimental autoimmune encephalitis (EAE)
score, reduced CD4+ T cells infiltration, and restored expression of
myelin basic protein (MBP) in the brain after induction of EAE by
injection of myelin oligodendrocyte glycoprotein35-55 (MOG35-55) . TSLPR
signals through Janus Kinase 2 (JAK2) to activate NLRP3. Tslpr-/- mice
of EAE show decreased phosphorylation of JAK2 and expression of NLRP3 in
the brain. In wild type (WT) mice after induction of EAE, inhibition of
JAK2 by ruxolitinib inflammatory and CD4+ cell infiltration, decreased
expression of NLRP3, and restored BMP expression in the brain.
Ruxolitinib also decreased levels of IL-1β and TSLP in brain of EAE
mouse when compared to that without ruxolitinib treatment. Further
results with NLRP3 inhibitor MCC950 in EAE mouse of WT verified the
proinflammatory role of NLRP3 by showing decreased inflammatory cells
and CD4+ T cells, restored MBP expression, and declined levels of IL-1β
and TSLP in the brain. In patients with anti-N-methyl-D-aspartate
receptor (NMDAR) encephalitis we found increased level of NLRP3 and
IL-1β in CSF when compared to that in control subjects. These findings
highlight TSLP as a prospective target for treating JAK2-NLRP3
axis-associated autoimmune inflammatory disorders.