Immunological interactions in helminths‐SARS CoV‐2 coinfection: Could old enemy be a friend today?

Abstract

AbstractHelminths are metazoan parasites affecting about one third of the worldwide population. Chronic helminth infections (CHIs) confer immunological tolerance to harmless and self‐antigens mediated by regulatory T cells (Treg) that are up‐regulated. In coronavirus disease 2019 (COVID‐19), abnormal adaptive immune response and unrestrained innate immune response could result in local and systemic immune‐mediated tissue damage. COVID‐19 and CHIs establish complicated immune interactions due to SARS‐CoV‐2‐induced immunological stimulation and CHIs‐induced immunological tolerance. However, COVID‐19 severity in patients with CHIs is mild, as immuno‐suppressive anti‐inflammatory cytokines counterbalance the risk of cytokine storm. Here, an overview of the interplay between helminths and COVID‐19 severity is given. CHIs through helminth‐derived molecules may suppress SARS‐CoV‐2 entry and associated hyperinflammation through attenuation of the TLR4/NF‐kB signalling pathway. In addition, CHIs may reduce the COVID‐19 severity by reducing the SARS‐CoV‐2 entry points at ACE2/DPP4/CD147 axis in the initial phase and immunomodulation in the late phase of the disease by suppressing TLR4/NF‐kB signalling pathway.