why does white blood cells attacks the germs first , when macrophage and killer T cells pack more punch?

Question

I just want to understand what exactly is the advantage of using one of those cells over the other.

*edit: my bad for the poor title, it’s supposed to be why does neutrophils attack first when T cells and macrophages are considerably stronger?

In: Biology

Answer 1

I would say you think a bit too much in ‘textbook’ format. It’s not Neutrophils or Macrophages, it will be both of them and largely at the same time (Macrophages will persist though, while Neutrophil infiltration wanes quickly). Macrophages are usually dispersed quite well through barrier tissues like many mucous membranes and your skin but they do not move / migrate very quickly and you don’t have a large pool of them in the blood to be recruited quickly. In many cases, they are among the first cells to react to an infection becauae they are already there before the pathogen arrives. Neutrophils are not found in healthy tissues so need a bit longer because they need to immigrate. In exchange they are very powerful, essentially kill in a ‘suicide mission’ kind of way and are easily replaced. T cells are a bit different from Macrophages and Neutrophiles because they are part of the ‘adaptive’ immune system. They take the longest to respond because other cells (e.g. called dendritic cells) need to take up part of the virus/bacteria and take it to a Lymph node. They will ‘show’ it to T cells and ‘teach’ them to kill anything that looks like this. This process means that a good T cell response takes days to start whereas solid Neutrophil and Macrophages responses happen in minutes to hours. The advantage is a very strong response by T cells, very high specificity to certain pathogens and also a ‘training’ effect; some T cells which know this pathogen will survive in the blood and if you get the same infection again, will start to kill the invader extremely quickly and efficiently. This is partly how (some) vaccines work. So it’s the only one of these systems that possesses a ‘memory’ and will protect you better against a reinfection with the same virus/bacteria.