The first thing that happens when the influenza virus infects the host cell, is initiating innate immunity. Innate immunity involves phagocytes binding to the pathogen using its pattern recognition receptors, such as toll-like receptors (TLRs), which binds to the pathogen-associated molecular patterns (PAMPs) that are present on pathogen. After binding to its cell surface, it starts ingesting the pathogen using either phagocytosis or macropinocytosis, and destructs the pathogen either by forming a phagolysosomes or secretion of soluble factors. Then, phagocytes recruit and activate other immune cells, such as T cells and B cells by secreting cytokines and chemokines. This is when the adaptive immune response takes place. CD8 T cells differentiates
