Video Transcript
Complete the sentence. Blank cells are involved in shutting down the immune response after infection. Option (A) T helper; option (B) cytotoxic T; option (C) plasma; option (D) natural killer, NK; or option (E) T suppressor, regulatory.
Let’s go through the journey of the process of an infection and the fight against said infection in our body. When a pathogen manages to enter our body, it often gets into our bloodstream and is transported in the blood plasma to the target cell it will infect. When the body realizes that it has been infected by a pathogen, the innate immune system will start working. The site of infection will be inflamed, and natural killer cells might attack and kill infected cells.
Sometimes the innate immune system is not good enough or not fast enough to fight the pathogen. Then, the specific immune response will start to work. Helper T cells, sometimes called T helper cells, might recognize the infection by binding to an antigen-presenting cell. This causes the helper T cell to become activated. Activated helper T cells release cytokines, for example, interleukin, which helps to activate B cells and cytotoxic T cells. Cytotoxic T cells can recognize an infected host cell as well. Once a cytotoxic T cell recognizes an infected host cell and interleukin released from helper T cells reach them, the cytotoxic T cell becomes activated.
An activated cytotoxic T cell releases proteins, including a protein called perforin, which perforates the cell membrane of the infected cell, which means that the cell membrane gets holes in it. A cell with a damaged cell membrane is not viable and will die soon after the perforin has done its deed. Finally, once the infection has been successfully fought, suppressor T cells deactivate or kill activated helper T cells, cytotoxic T cells, B cells, and other cells. This means that they are responsible for shutting down an immune response after an infection.
The answer to our question is therefore option (E) T suppressor, regulatory, cells are involved in shutting down the immune response after infection.
