Immunologically privileged site

Immunologically privileged site is a term used in immunology to describe certain parts of the body that can tolerate the introduction of antigen without eliciting an inflammatory immune response. These sites include the brain, eyes, fetus, and testes.

Overview

Immunologically privileged sites are areas of the body where graft tissue can be accepted without being rejected. This is due to the unique immune response in these areas, which is different from the rest of the body. The concept of immunological privilege was first introduced by Peter Medawar in the 1940s when he discovered that skin grafts placed on the eyes of rabbits were not rejected.

Mechanism

The mechanism of immunological privilege is complex and involves several factors. These include the presence of blood-brain barrier and blood-testis barrier, which prevent the entry of immune cells and antibodies. Additionally, these sites have a low expression of Major Histocompatibility Complex (MHC) molecules, which are essential for the recognition of foreign antigens by the immune system.

Clinical significance

Understanding the concept of immunologically privileged sites has important implications in transplantation and autoimmune diseases. For instance, it can help in the development of strategies to induce immunological tolerance in organ transplantation. Moreover, the breakdown of immunological privilege can lead to autoimmune diseases such as multiple sclerosis and type 1 diabetes.

See also

• Immunology
• Antigen
• Inflammatory immune response
• Blood-brain barrier
• Blood-testis barrier
• Major Histocompatibility Complex
• Transplantation
• Autoimmune diseases

References

Immunologically privileged site Resources
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