antigen presenting cells, and cell mediated response. Flashcards
Explain why T-cells dont bind to antigens on a pathogen.
Because their receptors are only complementary to processed antigens that are showed on the surface of antigen presenting cells.
What are the 3 types of antigen presenting cells, and explain each one of them.
- B-cell ( you know the whole process).
- some Phagocytes: when phagocytes carry out phagocytosis, some of them process the antigens and present them on their surface , so that helper T-cells can identify them.
- our own body cells: When viruses enter our body cells , the virus begins to replicate inside the cell.
-during this replication, antigens form, which the cell then processes and present on its surface.
what are the two types of T-cells.
Helper T-cells, and cytotoxic T-cells.
Explain what stimulates a T-cell to clone itself.
A naive helper T-cell bins to a complementary antigen ( usually on a phagocyte).
The binding then stimlates the helper T-cell to clone.
What are the 3 main roles of cloned helper T-cells?
- Can help stimulate B-cell ( seen process).
- Can release chemicals which attract a phagocyte towards the pathogen.
- can stimulate a cytotoxic T-cell (Helper T-cell).
Explain the process of a cytotoxic T-cell.
Cytotoxic T-cells have receptors complementary to the modified antigen present on the surface of an infected body cell.
They cytotoxic T-cell, then binds and secretes a protein called PERFORIN.
Perforin causes wholes to form in an infected cells cell membrane membrane.
-This makes it easeir for ions to pass out of the cell, in an uncontrolled way, which will eventually lead to the infected cells death.