Novel Covid-19: Spike Protein, Immune Pathogenesis and Management

Abstract

Corona virus pandemic is caused by Severe Acute Respiratory Syndrome corona virus It is a single stranded (positive sense) RNA associated with a nucleoprotein within a capsid comprised of matrix protein. The spike protein is  a type 1 membrane glycoprotein constitutes the peplomers. Spike protein uses to bend to a receptor, then allowing the genome of the virus to enter human cells and begin infection. The corona virus spike contains three segments: a large ectoderm, single- pass transmembrane anchor, and a short intracellular tail. The ectodomain consists of a receptor- binding subunit S1 and a membrane- fusion subunit S2. ACE2 is a single- pass type 1 membrane protein, with its enzymatically active domain exposed on the surface of cells in lungs and other tissues. SARS- Cov-2 Covid-19 binds to ACE2 by its  pike and allows Covid-19 to enter and infect cells. The state of cell differentiation and ACE2 expression levels are both important determinants of the susceptibility of human airway epithelia to infection. Macrophages confer protection against viruses through either an intrinsic or an extrinsic process. The permissiveness of macrophages for virus replication may depend on the age and genetic constitution of the host.

In case if Covid-19 patients they suppress excess inflammation. Cytokine storms are also seen with severely infected patients. Chloroquine and Hydrochloroquine, Fevilavir have been approved by FDA to treat Coronavirus-19. Convalescent plasma is an experimental procedure for Covid-19 patients. Development of immunity is essential to fight against pathogens.