Immunopathological Disorders of Cattle and Buffalo

The immune system deals with the collection of cells and proteins in the body, that functions to protect the skin, respiratory passages, intestinal tract, and other areas from foreign antigens such as bacteria, viruses, fungi, parasites, cancer cells, and toxins. Innate immunity is entitled as the first line of defense towards any intruding pathogen and it is the rapid immune response. The innate immune response is an antigen-independent (non-specific) defense mechanism and has no immunologic memory. Certain immunopathological diseases take place when there is defect in either system. Immunopathology is the study of diseases caused by immune reaction; therefore, the word immunopathology connotes that protective immune response may cause the tissue damage and diseases. Immunopathological diseases are characterized into immunodeficiency, hypersensitivity, and autoimmunity. Immunodeficiency disorders have been described as diseases caused by one or more defects of the immune system, leading to increased susceptibility to infections. Hypersensitivity reactions are immune responses that are exaggerated or inappropriate against an antigen or allergen and classified into type I (anaphylaxis), type II (cytotoxic), type III (immune-mediated), and type IV (T-cell mediated). Type I, Type II, and Type III are also known as antibody-mediated hypersensitivity; whereas, Type IV is also known as cell-mediated hypersensitivity. Autoimmune diseases occur when the immune system attack the self–antigens as a result of breakdown of immunologic tolerance to autoreactive immune cells.