[Note: The 2-5A synthetase/RNase L pathway is an antiviral defense pathway. The antiviral activity of RNase L is ‘turned on’ by the 2-5A molecule
Background: Evidence in support of intracellular immune dysfunctions in people with myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS) is accumulating, but few studies have addressed intracellular immunity as a potential therapeutic target.
Objective: To provide an overview of our present understanding of intracellular immunity in ME/CFS, to relate the intracellular immune dysfunctions to other aspects of the illness like decreased natural killer cell function, the presence of infections and poor exercise performance, and to point to potential therapeutic targets.
Methods: An in-depth review of the scientific literature of intracellular immunity in people with ME/CFS was performed.
From the scientific literature it is concluded that proteolytic cleavage of the native RNase L enzyme is characteristic of the dysregulation of intracellular immunity in people with ME/CFS, but the origin of the dysregulation is speculative.
There is increasing evidence for immune cell apoptosis [programmed cell death] and upregulation of various aspects of the 2'-5' oligoadenylate (2-5A) synthetase/RNase L pathway in ME/CFS.
This review provides the theoretical rationale for conducting studies examining the effectiveness of direct or indirect drug targeting of the 2-5A synthetase/RNase L pathway in ME/CFS patients.
Source: Expert Opinion on Therapeutic Targets. 2008 Mar;12(3):281-9. PMID: 18269338 Nijs J, Frémont M. Vrije Universiteit Brussel, Faculty of Physical Education & Physiotherapy, Department of Human Physiology, Brussels, Belgium. [E-mail: Jo.Nijs@vub.ac.be]