With the term neuroinflammation has defined the typical inflammatory response of the brain closely related to the onset of many neurological diseases. Neuroinflammation is well known, but its mechanisms and pathways are not entirely comprehended. Currently, some progress has been achieved through many efforts and research. Consequently, new cellular and molecular mecha-nisms, diverse from conventional ones, are emerging. In listing some of those that will be the sub-ject of our description and discussion, essential are the important role of peripheral and infiltrated monocytes and clonotypic cells, alterations in gut/brain axis, dysregulation of the apelinergic sys-tem, as well as changes in the endothelial glycocalyx of blood-brain barrier, variation in expres-sion of some genes and levels of the encoding molecules by microRNAs (miRNAs), or other epige-netic factors and distinctive transcriptional factors, as well as the role of autophagy, ferroptosis, sex differences and modifications in the circadian cycle. Such mentioned mechanisms can add significant pieces in understanding the complex etiological puzzle of neuroinflammation. In addi-tion, they could represent biomarkers and targets of neurodegenerative diseases, in increase in our old populations.

Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disease, characterized by progressive degeneration of upper and lower motor neurons in the cortex and spinal cord. Although the pathogenesis of ALS remains unclear, evidence on the role of the clonotypic immune system is growing. Adaptive immunity cells often appear changed in number or activation profile peripherally and centrally. However, their role in ALS appears conflicting. Data, from human and animal model studies, currently reported in literature show that each subset of lymphocytes and their mediators may mediate a protective or toxic mechanism in ALS, affecting both its progression and risk of death. In the present review article and attempt is made to shed light on the actual role of the cellular clonotypic immunity in ALS by integrating recent clinical studies and experimental observations.