FIGURE 2.

The immune response against SARS-CoV-2.The first line of host defense against SARS-CoV2, innate immunity, is the response against the virus by recognizing Pattern associated molecular patterns (PAMPs) through transmembrane or intracellular pattern recognition receptors (PRRs). Recognition of viral components leads to the activation of immune cells and transcription factors that lead to the production of different cytokines, chemokines, and anti-viral proteins. These processes can lead to activation of adaptive immune response that consists of three major cell types (B cells, CD4⁺ T cells, and CD8⁺ T cells). After pathogen elimination, adaptive immunity regulates innate immunity to avoid unnecessary host cell damage. Unbalanced response and immune system overactivation can cause collateral damage to host tissues and exacerbate disease severity.