Tissue immunity

Tissue immunity is the immunity of tissues to damage by certain microorganisms or their metabolic products, which is determined genetically. This type of immunity plays an important role in protecting the body from infections and other diseases.

Tissue immunity is provided by several mechanisms. The first is the presence of specialized cells called antigen-presenting cells, which recognize foreign antigens and present them to T lymphocytes. T lymphocytes are then activated and begin to produce cytokines that regulate the immune response. Secondly, there is also a tissue recognition system that allows the immune system to distinguish its own tissue from foreign tissue.

One example of tissue immunity is a delayed-type hypersensitivity reaction. In this case, the antigen is introduced into the body, but is not recognized by the immune system as foreign. Instead, it induces the production of cytokines that activate macrophages and T cells, leading to inflammation at the site of antigen injection. This inflammation can lead to tissue destruction if left unchecked.

Another example of tissue immunity is immunological tolerance. This is the ability of the immune system not to recognize its own tissues as foreign. This occurs because the cells that are involved in recognizing antigens do not express the molecules necessary for their recognition. Thus, the immune system does not react to its own tissues and does not cause autoimmune diseases.

Although tissue immunity plays an important role in protecting against infections, it can also lead to unwanted reactions. For example, when organs and tissues are transplanted from a donor who has tissue immunity to foreign tissues, rejection reactions may occur. In addition, some viruses, such as HIV, can use tissue immunity to reproduce.

Tissue immunity should not be confused with acquired immunity, since it is based on two fundamental points: genetic predisposition and damage to a specific organ or tissue by agents that damage it. This type of immunity is not related to antibodies, but is closely related to them.

The concept of “tissue” was originally used because nonspecific resistance mechanisms predominated before the advent of hereditary antibodies. Essentially, what is now called nonspecific immunity or innate (innate) immune defenses is the primary means by which innate immunity manifests itself. Among them is the innate insensitivity of the animal’s body to foreign substances.