Ross River Virus Immune Evasion Strategies and the Relevance to Post-viral Fatigue, and Myalgic Encephalomyelitis Onset.

Frontiers in medicine. 2021;8:662513
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Plain language summary

Ross river virus (RRV) is a mosquito borne virus that is thought to be the trigger of myalgic encephalomyelitis (ME) in many Australians. Viruses like RRV are thought to be so successful due to their ability to avoid and often manipulate the hosts immune response. This review of 75 studies aimed to discuss immune evasion strategies employed by RRV and understand the relevance to post viral fatigue and the development of ME. The authors began by explaining how RRV manipulates the hosts immune system to gain entry to cells and replicate. Once the virus has entered the cells, it is thought that it disrupts inflammatory pathways and decreases anti-viral genes. Disruption of inflammation has also been reported to affect energy production in individuals with ME. It was concluded that viruses such as RRV can manipulate the hosts immune system resulting in disruption of energy production. Understanding these pathways and interactions may explain why some individuals go on to develop ME post infection and others do not. Findings may also help to understand ME like symptoms reported by some patients who have recovered from Covid-19. This paper could be used by healthcare professionals to understand the development of ME and fatigue symptoms in individuals who have recovered from viruses such as RRV and Covid-19.

Abstract

Ross River virus (RRV) is an endemic Australian arbovirus, and member of the Alphavirus family that also includes Chikungunya virus (CHIK). RRV is responsible for the highest prevalence of human disease cases associated with mosquito-borne transmission in Australia, and has long been a leading suspect in cases of post-viral fatigue syndromes, with extrapolation of this link to Myalgic Encephalomyelitis (ME). Research into RRV pathogenesis has revealed a number of immune evasion strategies, impressive for a virus with a genome size of 12 kb (plus strand RNA), which resonate with insights into viral pathogenesis broadly. Drawing from observations on RRV immune evasion, mechanisms of relevance to long term idiopathic fatigue are featured as a perspective on infection and eventual ME symptoms, which include considerations of; (1) selective pro-inflammatory gene suppression post antibody-dependent enhancement (ADE) of RRV infection, (2) Evidence from other virus families of immune disruption and evasion post-ADE, and (3) how virally-driven immune evasion may impact on mitochondrial function via target of rapamycin (TOR) complexes. In light of these RRV measures to counter the host immune - inflammatory responses, links to recent discoveries explaining cellular, immune and metabolomic markers of ME will be explored and discussed, with the implications for long-COVID post SARS-CoV-2 also considered. Compelling issues on the connections between virally-induced alterations in cytokine expression, for example, will be of particular interest in light of energy pathways, and how these perturbations manifest clinically.

Lifestyle medicine

Fundamental Clinical Imbalances : Immune and inflammation
Patient Centred Factors : Triggers/Ross River Fever
Environmental Inputs : Microorganisms
Personal Lifestyle Factors : Environment
Functional Laboratory Testing : Not applicable

Methodological quality

Jadad score : Not applicable
Allocation concealment : Not applicable
Publication Type : Journal Article

Metadata

Nutrition Evidence keywords : Ross River virus ; RRV ; Covid-19 ; Long-Covid