Antigen Rules in Human Immune System

[Craps]

Can you tell me what general rules does antigen have in human immune system ? I assume it is statically floating around in our blood till it is eaten by Tcells.
I also just learned it has a specific identity such that Tcells can recognize it, but what is that specific identity ?
Second, Tcells kill other Tcells when the latters malfunction, but how the formers know their relatives are mafunctioning ?
Thank-you

 

[iansmith]

It will depend on the location of entry of the antigen. If an antigen is ingested than immune system cells inside the intestinal track will react to it. The antigen move inside the blood usually when invading pathogen penetrated the mucosal layer of the skin.

As far as specificity goes, the body has to encounter the antigen at least one time in order to produce specific antibodies. However, some cells have receptor (Toll-like receptor) that recognized conserved protein or other compound patterns found on/in pathogens. These receptor are not specific but it will iniate an immune response.

T-cell can recognize "malfunctionning" cell based on the proteins expressed on the surface. In a nutshell, if the proteins do not match the "self" pattern than the cell is destroyed.

 

[Craps]

Something like that is always loved., thanks