The "Dialogue" Between Central and Peripheral Immunity After Ischemic Stroke: Focus on Spleen.

Hongchen Yu,Yichen Cai,Shixin Xu,Aiqin Zhong,Yunsha Zhang,Junping Zhang

doi:10.3389/fimmu.2021.792522

Abstract

The immune response generated by the body after the incidence of ischemic stroke, runs through the comprehensive process of aftermath. During this process of ischemic stroke, the central neuroinflammation and peripheral immune response seriously affect the prognosis of patients, which has been the focus of research in recent years. As this research scenario progressed, the “dialogue” between central nervous inflammation and peripheral immune response after ischemic stroke has become more closely related. It’s worth noting that the spleen, as an important peripheral immune organ, plays a pivotal role in this dialogue. Multiple mechanisms have previously been reported for brain-spleen crosstalk after ischemic stroke. Further, neuroinflammation in the brain can affect the peripheral immune state by activating/inhibiting spleen function. However, the activation of the peripheral immune inflammatory response can work reversibly in the spleen. It further affects intracerebral neuroinflammation through the injured blood-brain barrier. Therefore, paying close attention to the role of spleen as the pivot between central and peripheral immunity in ischemic stroke may help to provide a new target for immune intervention in the treatment of ischemic stroke. In the present review, we reviewed the important role of spleen in central neuroinflammation and peripheral immune response after ischemic stroke. We summarized the relevant studies and reports on spleen as the target of immune intervention which can provide new ideas for the clinical treatment of ischemic stroke.

Highlights

Ischemic stroke (IS) accounts for about 80% of all cerebrovascular diseases, and it is characterized by a rapid progression, high rates of disability, death and recurrence
We reviewed the important role of spleen in central neuroinflammation and peripheral immune response after ischemic stroke
We summarized the relevant studies and reports on spleen as the target of immune intervention which can provide new ideas for the clinical treatment of ischemic stroke

Summary

INTRODUCTION

Ischemic stroke (IS) accounts for about 80% of all cerebrovascular diseases, and it is characterized by a rapid progression, high rates of disability, death and recurrence. The cellular composition of the spleen changes dramatically after IS, significant alterations are observed in splenic function which increases the production of circulating proinflammatory cytokines, induces systemic T and B lymphocyte activation, helps peripheral immune cells and inflammatory mediators to invade the brain as Table 1, and exacerbate the local inflammatory response [35]. NaB was shown to be effective in reducing infarct size after MCAO in female rats by a mechanism that may be related to the ability to increase IGF-1 (a known neuroprotective agent) The distribution of this molecule in the spleen and its expression in serum and splenic peripheral tissues in the acute late phase of stroke [74]. One of the studies found that in IS SEC can upregulate splenic IL-10 expression, exerting anti-inflammatory effects and improving the peripheral inflammatory response [44]

Findings

DISCUSSION

SUMMARY