Epigenetic regulation of the COVID-19 pathogenesis: its impact on the host immune response and disease progression

Coronavirus disease 2019 (COVID-19) is highly infectious and may induce epigenetic alteration of the host immune system. Understanding the role of epigenetic mechanisms in COVID-19 infection is a clinical need to minimize critical illness and widespread transmission. The susceptibility to infection and progression of COVID-19 varies from person to person; pathophysiology substantially depends on epigenetic changes in the immune system and preexisting health conditions. Recent experimental and epidemiological studies have revealed the method of transmission and clinical presentation related to COVID-19 pathogenesis, however, the underlying pathology of variation in the severity of infection remains questionable. Epigenetic changes may also be responsible factors for multisystem association and deadly systemic complications of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infected patients. Commonly, epigenetic changes are evoked by alteration of the host's immune response, stress, preexisting condition, oxidative stress response, external behavioral or environmental factors, and age. In addition, the viral infection itself might manipulate the host immune responses associated with inflammation by reprogramming epigenetic processes which are the susceptible factor for disease severity and death. As a result, epigenetic events such as histone modification and DNA methylation are implicated in regulating pro-inflammatory cytokines production by remodeling macrophage and T-cell activity towards inflammation, consequently, may also affect tissue repair and injury resolution process. This review aims to discuss the comprehensive understanding of the epigenetic landscape of COVID-19 disease progression that varies from person to person with supporting interdisciplinary prognosis protocol to overcome systemic impairment.