This is not going to be a compete answer but there’s several processes involved. First for the WBCs to get to the right area of tissue in the body, the blood vessel wall cells start expressing “selectins” which start to slow the WBCs down, then the WBCs bind and cross through the vessel wall using integrins and Cell adhesion molecules. Also there are macrophages and dendritic cells which when they encounter a pathogen release “chemokines” which create a concentration gradient for the WBCs to follow. Once close enough to the bacteria, neutrophils particularly are able to follow bacteria in the same way, following the concentration gradient of products the bacteria is releasing. (I can’t remember which chemical they follow but I think it may be ammonia?)
tinybabymoose t1_iuhswx8 wrote
Reply to How do white blood cells know in which direction there is a bacteria? by Enocli
This is not going to be a compete answer but there’s several processes involved. First for the WBCs to get to the right area of tissue in the body, the blood vessel wall cells start expressing “selectins” which start to slow the WBCs down, then the WBCs bind and cross through the vessel wall using integrins and Cell adhesion molecules. Also there are macrophages and dendritic cells which when they encounter a pathogen release “chemokines” which create a concentration gradient for the WBCs to follow. Once close enough to the bacteria, neutrophils particularly are able to follow bacteria in the same way, following the concentration gradient of products the bacteria is releasing. (I can’t remember which chemical they follow but I think it may be ammonia?)