The ability to fight against infections is confined to specially evolved immune cells such as B-lymphocytes that are destined to produce immunoglobulins also known as antibodies. These molecules have been classified into five types like IgG, IgM, IgD, IgA, IgE. Available reports have described the connection between central nervous, neuroendocrine and immune systems (Manfred Schedlowski, 1999).This relationship is crucial to understand the significance of Psychoneuroimmunology (PNI).The present description deals with the description of roles of antibodies and functions of IgA and IgE. During a first antigenic challenge by a foreign body, antibodies especially IgM mount an immune response primarily by activating the complement in a cascade manner (Manfred Schedlowski, 1999).Complements are serum proteins that assist a plethora of immunological functions. It provides an accessory function as a secretory immunoglobulin (Manfred Schedlowski, 1999).
Secondary immune response is provided by the antibody IgG when it recognizes a previously known antigen. These antibodies are unique for their potential to cross the placenta and confer (Manfred Schedlowski, 1999) antibody-mediated protection for newborns with negligible amounts of antibodies. These antibodies also bind to Fc receptors on phagocytic cells and thereby promotes opsonization (Manfred Schedlowski, 1999).IgD was considered to possess poor immune function. However, it combines with IgM and is reported to participate in the activation of B cells by antigen.
Next, the important immunoglubin IgA.This is widely believed to be present in external secretions like saliva, tears, breast milk, mucus of the bronchial, genitourinary and digestive tracts (Richard, Thomas & Barbara, 2000). As such, the antibodies of secretory IgA class may play a vital role in providing a great defense barrier. For example, when present in breast milk, these antibodies bind to microbial pathogens in the newborn’s gastrointestinal tract and avoids the contact of pathogens along the gut walls and their passage into body’s tissues (Richard, Thomas & Barbara, 2000).
The ultimate function of preventing the pathogen entry is to facilitate viral infection and bacterial colonization. This generally happens when the complex generated by the interaction of secretory IgA and antigen gets captured and removed by the epithelial cells resent in the respiratory tract and peristaltic movement of the gut.
Finally, IgE antibodies function in mediating hypersensitivity reactions that are important for asthma, hives, hay fever and anaphylactic shock (Richard, Thomas & Barbara, 2000). Its actual physiological mechanism was believed to be present in the defense of worms and metazoic parasites (Manfred Schedlowski, 1999).The ultimate function is that when the surface-bound IgE recognizes antigens on the external portions of parasites, it induces a process of degranulation that causes various enzymes and certain chemical substances like histamines to get poured over the invading the pathogens (Manfred Schedlowski, 1999).This destroys the parasite and tends to attract other fast responding cells. The cells that take part in the functional aspects of IgE are mast cells and basophils (Manfred Schedlowski, 1999).Here, IgE binds to Fc receptors present in these cells. On binding, IgE selects the antigen, rapidly changes its confirmation and then provides a signal to the cells to deregulate (Richard, Thomas & Barbara, 2000). Hence, these functional events are essential to understand the immune effector roles of IgE.
Thus, antibodies are crucial in offering protection against a wide range of pathogenic invasions. They are very specific in choosing the targeted antigen by taking the assistance of specially equipped molecular machinery that involves interplay of specialized cells.
The association between neuroendocrine and immune systems has been of much research interest for many investigators whose objective is to assess the vital relationships between the behavioral factors and the progression of immunologically mediated illnesses and to evaluate the role of immune products in central nervous system disturbances (Janice ,1995).
References
Maek, K., Petrovickýb, P., EvÃka, J., ZÃdeka, Z., and Frankova, D. (2000). Past, present and future of psychoneuroimmunology. Toxicology, 142,179-188.
Manfred Schedlowski, Uwe Tewes.(1999) Psnychoneuroimmunology : an interdisciplinary introduction. Web.
3. Richard A.Goldsby, Thomas J.Kindt, Barbara A Osborne. Kuby Immunology.4th ed.2000. Immunoglobulins: Structure and Function.83-113.
4. Janice M Zeller. (1995).Psychoneuroimmunology: an emerging framework for nursing research. Journal of Advanced Nursing, 23, 657 – 664.