Immunomodulation

Immunomodulation is the manipulation of the immune system; it may augment or decrease the magnitude of immune responsiveness. The augmentation of immune response is known as immunostimulation or immunopotentiation, while suppression of immune responsiveness is termed as immunosuppression. The necessity of suppression of the function of the immune system is well recognized in the areas of transplantation and immunopathological disorder like autoimmunity. Conversely, augmentation of immune response has been a matter of considerable interest among the scientists of veterinary as well as medical sciences in order to increase the host’s resistance to diseases. Specific immunomodulation is limited to a single antigen such as vaccine i.e., immunopotentiation used, for development of resistance in body against a particular disease. Non-specific immunomodulation implies for a more generalized change in the immune responsiveness leading to altered host reactivity to many different antigens. Immunomodulation is one of the most important alternatives in order to control diseases with additional advantages of amplifying specific responses to vaccines. The immunomodulatory compounds also offer prospects of reversing immunosuppression caused by stress, viruses, or environmental pollution. A complete understanding of the activation and suppression of the immune response may pave the way towards the development of certain compounds with known and predictable activity for either augmenting the humoral or cell mediated immune response or lowering the undesirable and deleterious immune reactions in particular organ or tissue. The immunomodulatory properties of various agents with their mechanism of action are described in this chapter. Further, in this chapter, the emphasis has been given on the effect of neuroendocrine system on immune mechanisms and its manipulation through medication or by other means for positive modulation of immunity to control diseases.