How much dreadful the cytokine storm appears after the entry of SARS-CoV-2 into the host?
The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is on its aggressive mode round the world so far accounting for approximately 600000 out of nearly 15000000 infected cases with extremely rapid transmission dynamics. The viral entry mediated by its unique spike (S) protein using the receptor-binding domain (RBD) for the attachment to the host angiotensin-converting enzyme receptor 2 (ACE2) acts as a cellular doorway for the virus to trigger the pathogenic events. Current write up shortly discussed about the host immunological response towards the SARS-CoV-2 entry. The viral entry is very much likely to initiate an immune response involving the innate immune cells to attack the virus. As the immune system recognizes the virus particles particularly the viral antigenic epitopes, the antigen-presenting cells (APCs) should process these antigens and present them both to the natural killer (NK) cells and the CD8+ cytotoxic T cells (Tc) in the context of major tissue histocompatibility (MHC) antigens which is in harmony to augment the signaling cells like the toll-like receptors (TLR-3, 7, 8) facilitating the recognition of the pathogen associated molecular patterns (PAMPs) under the innate immune system principally involving macrophages, dendritic cells, epithelial cells, neutrophils, and the natural killer (NK) cells.