Your father has just been diagnosed with rheumatoid arthritis. He has pain and the sensation of "pins and needles" in some if his finger joints and also in his wrists. He knows you covered autoimmune diseases in your microbiology class, so asks you to help him understand his condition.
-You explain to your father that usually, the immune system routinely eliminates or silences any lymphocytes that recognize autoantigens, which are the "self" antigens found in cells and on body tissues. This process is called self-tolerance. In autoimmune disease, self-tolerance is faulty. There are at least two mechanisms that lead to self-tolerance. Which are they?
1) Negative selection of developing lymphocytes that recognize autoantigens, resulting in apoptosis of those cells.
2) Introduction of antigen by the oral route, so that the immune system "learns" to tolerate it, just as it does the many antigens ingested in food.
3) Failure of naive lymphocytes that recognize antigen but do not receive the necessary second signals (MHC) to become responsive.

Question

Your father has just been diagnosed with rheumatoid arthritis. He has pain and the sensation of "pins and needles" in some if his finger joints and also in his wrists. He knows you covered autoimmune diseases in your microbiology class, so asks you to help him understand his condition.
-You explain to your father that usually, the immune system routinely eliminates or silences any lymphocytes that recognize autoantigens, which are the "self" antigens found in cells and on body tissues. This process is called self-tolerance. In autoimmune disease, self-tolerance is faulty. There are at least two mechanisms that lead to self-tolerance. Which are they?
1) Negative selection of developing lymphocytes that recognize autoantigens, resulting in apoptosis of those cells.
2) Introduction of antigen by the oral route, so that the immune system "learns" to tolerate it, just as it does the many antigens ingested in food.
3) Failure of naive lymphocytes that recognize antigen but do not receive the necessary second signals (MHC) to become responsive.

Quizplus · Accepted Answer

The two mechanisms that lead to self-tolerance are negative selection of developing lymphocytes that recognize autoantigens, resulting in apoptosis of those cells and failure of naive lymphocytes that recognize antigen but do not receive the necessary second signals (MHC) to become responsive. Introduction of antigen by the oral route is a mechanism of inducing tolerance, but not specifically self-tolerance. Therefore, the best choice is B, which includes the two correct mechanisms of self-tolerance.

Your Father Has Just Been Diagnosed with Rheumatoid Arthritis