Immune evasion of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2); molecular approaches.

In December 2019, a new betacoronavirus , known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), caused an outbreak at the Wuhan seafood market in China. The disease was further named coronavirus disease 2019 (COVID-19). In March 2020, the World Health Organization (WHO) announced the disease to be a pandemic, as more cases were reported globally. SARS-CoV-2, like many other viruses, employs diverse strategies to elude the host immune response and/or counter immune responses. The infection outcome mainly depends on interactions between the virus and the host immune system. Inhibiting IFN production, blocking IFN signaling, enhancing IFN resistance, and hijacking the host's translation machinery to expedite the production of viral proteins are among the main immune evasion mechanisms of SARS-CoV-2. SARS-CoV-2 also downregulates the expression of MHC-I on infected cells, which is an additional immune-evasion mechanism of this virus. Moreover, antigenic modifications to the spike (S) protein, such as deletions, insertions, and also substitutions are essential for resistance to SARS-CoV-2 neutralizing antibodies. This review assesses the interaction between SARS-CoV-2 and host immune response and cellular and molecular approaches used by SARS-CoV-2 for immune evasion. Understanding the mechanisms of SARS-CoV-2 immune evasion is essential since it can improve the development of novel antiviral treatment options as well as vaccination methods. ● The ongoing global pandemic of COVID-19,is the most important health issue around the world since 2019. ● SARS-CoV-2 immune evasion is an important issue contributing to the progression of the pandemic since it can cause pandemic outbreaks, vaccine-induced immunity escaping, and therapy resistance. ● The immune evasion of SARS-CoV-2 is mediated by several mechanisms, including the suppression of IFN production, inhibition of IFN-signaling, host protein synthesis shutoff through downregulation of mRNA, downregulation of major histocompatibility complex I (MHC-I) on infected cells, and spike protein mutations that lead to antigenic alterations. ● Understanding the immune escape machanisms of SARS-CoV-2 is necessary for developing novel treatment approaches, such as targeted therapies, and improving the vaccination efficacy against COVID-19. [ABSTRACT FROM AUTHOR]