Infection with an acute virus such as influenza initiates a race between the virus and immune system; virus’s ability to rapidly mutate lets it escape from the immune system memory and explaining why people be repeatedly reinfecting with flu unlike measles or polio.
But as the virus spreads, some cells detect infection and begin producing interferon (IFN). This IFN directs expression of anti-viral interferon stimulated genes (ISGs) in the infected cell and its neighbors via autocrine and paracrine signaling;as well as helping launch a broader immune response; the virus jump from one species to another and evade the defenses provided by the flu vaccine.
A flu infection begins when flu viruses enter a handful of cells. The viral proteins get to work replicating their genomes and tricking infected cells into making viral proteins; Influenza virus only rarely triggers IFN expression in infected cells; a fact that poses a challenge for the study IFN induction in single cells;viruses will soon infect cells throughout the body that’s when the aches and pains begin.
But some new viruses bearing a copy of the invader’s genome quickly package themselves up and find more cells to invade. study developing a method to identify and enrich rare IFN+ cells by creating A549 cells that carrying IFN reporters consisting of a type I or type III promoter driving expression of a cell surface protein following by a fluorescent protein.
By testing the infected human lung cells in a dish with lab generated influenza viruses with relatively uniform genetic sequences; letting to the viruses infect and replicate within the cells and assessed their responses. To determine whether a given cell had detecting its invader; they measured production of interferon, a molecule used to activate anti-viral defenses.For knowing how well an invading virus is replicating, by measuring levels of viral messenger RNA; the building instructions for viral proteins.
But some of its mutations inevitably foil its hiding mechanisms. If someone is infected by mutated viruses; the immune system might more easily gain the upper hand than in someone infected by unmutated viruses.Due to this initial variation might help determine how an infection proceeds and why the flu affects people so differently.