Either the flu or the coronavirus can take several days to improve the body’s effective response to a viral infection. New research describes how different cells in the immune system work together, communicate and – in the case of neutrophils – cause death to help fight infections. The findings could have a significant impact on the development of vaccines and antiviral therapies.

The immune system is made up of different cell types but they all act in a coordinated manner. Neutrophils play an important altruistic role that benefits other immune cells by providing essential resources for their survival and, in the process, enhancing the body’s immune response to a virus.

However, neutrophils are not fully equipped to eliminate a viral threat on their own. Instead, when the airway is infected with a flu virus or COVID-19, large numbers of neutrophils rush to the site of infection and release chemical signals. Using a multi-photon microscope, an interaction of neutrophils and phagocytes living in influenza-infected mouse airways was revealed.

New study shows that in addition to initiating an adaptive immune response, neutrophils have another important mission that requires sacrifice. Neutrophils initiate a process called apoptosis or controlled death, which releases large amounts of epidermal growth factor EGF that promotes the differentiation of monocytes {located in tissues} into antigen-presenting cells which then activate T + cells ενε which act on T cells for immunoprotection. The production of specialized T cells {part of the adaptive immune system} once mobilized in sufficient quantities {process that takes several days ουν targets and destroys infected cells.

This shows that the adaptive immune system does not create a successful response without instructions and help from the innate immune system.

The findings reveal, for the first time, how different immune cells work together and even sacrifice to achieve the same goal of protecting the host from viral infection.

SOURCE: University of Rochester (URMC) {October 2020}