Question

You want to assess the graft rejection capacity of different MHC molecules in female mice. You plan to use 5 mouse strains (S1-S5), which are genetically identical except various differences in their four MHC loci:

Allelic differences in the mouse strains’ MHC loci

Strain   K IA IE D

S1 k/k k/k  d/d s/s

S2 b/b b/b  b/b b/b

S3 b/k b/k  d/s d/s

S4 b/k b/k   b/k b/k

S5 b/k b/k  d/d s/s

When transplanting tissue grafts, you expect that [complete the sentence and assess the resulting statements (21-45) as either factually correct (true) or incorrect (false)]:
21. S1 mice will reject S1 grafts.
22. S1 mice will reject S2 grafts.

23. S1 mice will reject S3 grafts.

24. S1 mice will reject S4 grafts.

25. S1 mice will reject S5 grafts.

26. S2 mice will reject S1 grafts.

27. S2 mice will reject S2 grafts.

28. S2 mice will reject S3 grafts.

29. S2 mice will reject S4 grafts.

30. S2 mice will reject S5 grafts.

31. S3 mice will reject S1 grafts.

32. S3 mice will reject S2 grafts.

33. S3 mice will reject S3 grafts.

34. S3 mice will reject S4 grafts.

35. S3 mice will reject S5 grafts.

36. S4 mice will reject S1 grafts.

37. S4 mice will reject S2 grafts.

38. S4 mice will reject S3 grafts.

39. S4 mice will reject S4 grafts.

40. S4 mice will reject S5 grafts.

41. S5 mice will reject S1 grafts.

42. S5 mice will reject S2 grafts.

43. S5 mice will reject S3 grafts.

44. S5 mice will reject S4 grafts.

45. S5 mice will reject S5 grafts.

Answer 1

Transplanted tissues belonging to the individuals of same species or to different species are recognized as non-self. Hence, there will be rejection of the grafts. This process of recognition of pathogens, transplantation antigens, and tumors by the immune system includes the same antigen recognition molecules. The rejection response of the grafted tissue is created by the cell surface molecules that actually trigger the antigenic stimulus.

21, 25 False

22, 23, 24. True

26, 28, 29, 30. True

27. False

31, 32. True

33, 34, 35. False

36, 37. True

39, 38, 40. False

42. True

45, 43, 44, 41. False