Protective effects of CX3CR1 on autoimmune inflammation in a chronic EAE model for MS through modulation of antigen-presenting cell-related molecular MHC-II and its regulators

BACKGROUND

Recent evidences have implicated neuroprotective effects of CX3CR1 in multiple sclerosis (MS). But whether CX3CR1 is involved in modulation of antigen-presenting cell (APC)-related molecular MHC-II and what the possible mechanism is remain unidentified.

OBJECTIVE

In this study, we intended to investigate the effects of CX3CR1 on MHC-II expressions on brain myeloid cells in experimental autoimmune encephalomyelitis (EAE) mice and explore the possible regulators for it.

METHODS

CX3CR1-deficient EAE mice were created. Disease severity, pathological damage, and the expressions of MHC-II and its mediators on myeloid cells were detected.

RESULTS

We found that compare with wile-typed EAE mice, CX3CR1-deficient EAE mice exhibited more severe disease severity. An accumulation of CD45⁺CD115⁺Ly6C^-CD11c⁺ cells was reserved in the affected EAE brain of CX3CR1-deficient mice, consistent with disease severity and pathological damage in the brain. The expressions of MHC-II on the brain CD45⁺CD115⁺Ly6C^-CD11c⁺ cells of CX3CR1-deficient EAE mice were elevated, in accord with the increased protein and mRNA expressions of class II transactivator (CIITA) and interferon regulatory factor-1 (IRF-1).

CONCLUSIONS

The findings indicated that CX3CR1 might be an important regulator for MHC-II expressions on APCs, playing a beneficial role in EAE. The mechanism was probably through regulation on the MHC-II regulators CIITA and IRF-1.