Immunological Tolerance

Immunological tolerance: what is it and how does it work?

Immunological tolerance is a condition in which the body's immune system does not respond to certain antigens that would normally trigger an immune response. This condition can be induced in the body by exposure to an antigen at an early age or under certain conditions.

An example of immunological tolerance is the transplantation of organs or tissues between identical twins or genetically homogeneous lines. However, if the graft comes from a donor with a different genotype, the recipient's body begins to produce an immune response to the graft, which can lead to its rejection.

One of the methods for inducing immunological tolerance is the implantation of donor tissue or cells into the recipient's body at the early stages of development. For example, if you introduce cells from the embryo of a mouse of line A into the embryo of a mouse of line B, then when the mouse of line B grows up and skin or other organs from mice of line A are transplanted into it, the transplant will take root.

This happens because donor cells introduced at an early age do not provoke an immune response in the recipient and, thus, the body acquires immunological tolerance. Also, immunological tolerance can be induced by total body irradiation in lethal doses, after which hematopoietic cells from another animal are introduced, which causes the proliferation of these cells in the recipient's body and promotes its survival.

Immunological tolerance is important in medicine, especially in the context of organ and tissue transplantation. It reduces the risk of transplant rejection and increases the effectiveness of treatment. In addition, understanding the mechanisms of immunological tolerance may lead to the development of new methods for the treatment and prevention of immune diseases.

In conclusion, immunological tolerance is a complex process that allows the body to fail to respond to certain antigens. Induction of immunological tolerance can be achieved by exposure to an antigen at an early age or under certain conditions. Understanding the mechanisms of this process is important for the development of new methods for treating and preventing immune diseases.