Properties Of Antigen Pdf

Age Age can also influence immunogenicity. Epitope is immunologically active regions of an immunogen or antigen that binds to antigen-specific membrane receptors on lymphocytes or to secreted antibodies.

Properties of Antigens


This is known as cross-reactivity. Degradability Antigens that are easily phagocytosed are generally more immunogenic.

Boyd, Widened reactivity of antibody produced by prolonged immunization, Proc. Antigens are mainly proteins and some are polysaccharides. Answer Now and help others.

These may be pure proteins or they may be glycoproteins or lipoproteins. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. Antigen Specificity Antigen Specificity depends on the specific actives sites on the antigenic molecules Antigenic determinants. Alloantigens are antigens found in different members of the same species the red blood cell antigens A and B are examples.

Nucleic Acids Nucleic acids are usually poorly immunogenic. Nucleoproteins, Nucleic acids, etc. Chemical Nature and Composition In general, the more complex the substance is chemically the more immunogenic it will be. Antigenic determinants or epitopes are the regions of antigen which specifically binds with the antibody molecule.

However, low molecular substance can demonstrate immunogenicity, if coupled to a suitable carrier molecule like protein. However, they may become immunogenic when single stranded or when complexed with proteins. The use of adjuvants, however, is often hampered by undesirable side effects such as fever and inflammation.

The substance or molecule must have certain physio-chemical properties, where molecular size is an important factor. Complete Antigen or Immunogen Posses antigenic properties denovo, anatomia y fisiologia del sistema musculo esqueletico.pdf i.


Antigen- Properties Types and Determinants of Antigenicity

Types of Antigen On the basis of order of their class (Origin)

There is a dose of antigen above or below which the immune response will not be optimal. In general, proteins are usually very good immunogens.

Denatured antigens are more immunogenic than the native form. Only limited parts of the large antigen molecule are involved in the binding to antibodies. Because it is not possible for a small molecule to have more than one antigenic determinant. For example, if serum albumin from a mouse is injected back into the same mouse or into another mouse, no antibody production will occur. The immunogenicity is very much dependent on the complexity of the antigens.

Anybody can ask a question Anybody can answer The best answers are voted up and rise to the top. The rigidity and complexity of the molecule are the important factors for immunogenicity.

Properties of Antibodies

In some cases antibodies can bind to an antigen other than one which initiated antibody production. Although all antigens are recognized by specific lymphocytes or by antibodies, only some antigens are capable of activating lymphocytes. Hence small molecules like amino acids or monosaccharides are usually not antigenic. Protein Structure and Function Sympos.

Current Problems of Contemporary Biochemistry, Vol. The route of antigen administration can also alter the nature of the response.

Properties of Antibodies

Determinants of Antigenicity The whole antigen does not evoke immune response and only a small part of it induces B and T cell response. Say for example, human serum albumin Mol. The immune response against a certain substance can be enhanced by administering an adjuvant together with the antigen. Top Menu BiologyDiscussion.

Similarly, some substances are immunogenic in one individual but not in others i. Lipids In general lipids are non-immunogenic, although they may be haptens. As a result the immune system must be able to distinguish between normal body components and foreign substances. The prerequisite for immunogenicity is that the substance should be foreign to the body of recipient. This is more than enough for my M.

Normally the body has no tendency to recognize its own components as antigens, therefore does not initiate an immune response against these. Incomplete Antigen or Hapten These are the foreign substance, usually non-protein substances Unable to induce an immune response by itself, they require carrier molecule to act as a complete antigen. These parts are called antigenic determinants. This process is experimental and the keywords may be updated as the learning algorithm improves.

It was Wyman who for the first time reported that allergy runs in families and some families suffer more than others. The carrier molecule is a non-antigenic component and helps in provoking the immune response. It is established that a molecule must have at least two antigenic determinants in order to stimulate antibody production. Definition, Functions and Importance.

Properties of Antibodies

Genetic Factors in the Individual. These antigens are called superantigens. All individuals within a species need not show the same allergic response against a particular antigen.

Polysaccharides Pure polysaccharides and lipopolysaccharides are good immunogens. The number of antigenic determinants on a small molecule varies with molecular size. Genetic factors are of prime importance for the immunogenicity. Adjuvants Substances that can enhance the immune response to an immunogen are called adjuvants. The small area of chemical grouping on the antigen molecule that determines specific immune response and reacts specifically with antibody is called an antigenic determinant.