In positive selection, thymocytes undergo apoptosis when:
I-They do not interact with MHC molecules
II-They bind to MHC molecules with high affinity
III-They bind to MHC molecules with low affinity
A) I only
B) III only
C) I and II
D) II and III
E) I, II, and III

Question

Quizplus · Accepted Answer

In positive selection, thymocytes that do not interact with MHC undergo apoptosis because they are nonreactive. Thymocytes that bind to MHC with high affinity also undergo apoptosis because they are considered autoreactive. Thymocytes that bind to MHC with low affinity are considered non-threatening and migrate deeper into the thymic cortex for further maturation.

In Positive Selection, Thymocytes Undergo Apoptosis When