Question

Neutrophils arc blood cells normally responsible for killing bacteria at sites of infection. Neutrophils are able to find their way toward sites of infection by the process of chemotaxis. In this process, neutrophils sense the presence of bacterial proteins and then follow the trail of these proteins toward the site of infection. Suppose you find that chemotaxis is inhibited by pertussis toxin. What kind of receptor is likely to be involved in responding to bacterial proteins? Draw a diagram that indicates where and why pertussis toxin inhibiting the process

Draw a diagram that indicates where and why pertussis toxin inhibiting the process.

Answer 1

When a bacteria enters a human body it is detected as a foreign material ny are immune system.This detection can also be possible by the proteins or substances that a bacteria excretes.This entry of bacteria initiates a SOS response leading to the production of chemokines.Chemokines are nothing but signaling proteins secreated by infected cells,which induce chemotaxis.Chemotaxis thus causes movement of macrophages or neutrophils from the blood vessel to the site of infection and they kill or engulf the bacteria completely.Dendritic cells also work along with macrophages and neutrophils.They basically take a small sample of the foreign bacteria and enter into the lymph nodes where this sample is detected by other immune cells and thus antibody formation is initiated.These antibodies then leave the blood vessels by the small openings caused due to the SOS reponse.In case of pertussis toxin (PT) they do not allow the signaling of cells either by SOS response or by chemotaxis by inhibiting chemokines.