Page 1111 - Veterinary Immunology, 10th Edition

Pregnancy, 385
VetBooks.ir

LEARNING OBJECTIVES

After reading this chapter, you should be able to:

• Define allografts, isografts, and xenografts.
• Explain how allografts are rejected.
• Describe how the response to donor histocompatibility antigens causes acute

rejection.
• Understand why chronic rejection and rejection directed against donor blood

groups are mainly antibody mediated.
• Explain how bone marrow stem cell allografts given to immunosuppressed
recipients may cause graft-versus-host disease.

• Describe the basic processes occurring in graft-versus-host disease.
• Explain why some allografts, such as those from the cornea, are not readily
rejected.

• Describe the mechanisms that ensure that the fetal allograft is not rejected.
• Describe how xenografts trigger very strong rejection responses.
• List the major drugs employed to combat allograft rejection.

Although the immune responses first attracted the attention of

scientists because of their ability to fight infections, the observation
that animals reject foreign organ grafts led to a much broader view
of the immune system in that it indicated that the immune system
had a surveillance function. The rejection of a foreign organ graft

simply reflects the role of the immune system in identifying and
destroying “abnormal” cells.

1111