Antigens Flashcards
Where are antigens found?
On the surface of all cells.
Why are there antigens on body cells?
So the body can recognise self cells.
How are antigens on bacteria and viruses recognised?
As foreign.
What is a problem found with many live viruses, bacteria and protozoa?
They can evolve mechanisms that evade the immune system.
What is antigenic variation?
A process by which a pathogen is able to change its surface proteins so that it can evade the host immune response.
Why is antigenic variation important for pathogens?
It allows them to target hosts which are long-lived or susceptible to the pathogen, transmit the disease easily and infect a single host on more than one occasion.
What does this drift result in?
Small antigenic changes in the pathogen population which reduce the efficacy of T and B memory cells.
