What are the factors that affect antigen-antibody reaction?

What are the factors that affect antigen-antibody reaction?

Factors that influence antigen–antibody reactions

• Distance between reactive sites on antibodies.
• Electric repulsion between red cells – zeta potential.
• Site of the antigenic determinants.
• Number of antigenic determinants.
• Goodness of fit.
• Effects of time.
• Effects of temperature.
• Effects of pH.

What is the basis of specificity of the AG AB reaction?

The specificity of the binding is due to specific chemical constitution of each antibody. The antigenic determinant or epitope is recognized by the paratope of the antibody, situated at the variable region of the polypeptide chain.

Which factors are responsible for antigenicity?

Property of antigens/ Factors Influencing Immunogenicity

• Foreignness. An antigen must be a foreign substances to the animal to elicit an immune response.
• Molecular Size.
• Chemical Nature and Composition.
• Physical Form.
• Antigen Specificity.
• Species Specificity.
• Organ Specificity.
• Auto-specificity.

What happens when an antigen and antibody react?

Red cell antigen-antibody reactions When red cells carrying the target antigen are mixed with serum, plasma or a reagent in which the corresponding antibody is present, an antigen-antibody reaction occurs. The antibodies make random contact with the red cells and can then bind to the corresponding red cell antigens.

What is the antibody antigen complex AB AG?

Antigen-antibody complex: The complex formed by the binding of an antibody to an antigen. Antigen-antibody complexes initiate immune responses. Also known as an immune complex.

Which part of the antibody interacts with the antigen?

paratope
The paratope is the part of an antibody which recognizes an antigen, the antigen-binding site of an antibody. It is a small region (15–22 amino acids) of the antibody’s Fv region and contains parts of the antibody’s heavy and light chains.

What are antibodies and antigens how do they interact to cause a transfusion reaction?

In transfusion reactions, antibodies attach to antigens on the surfaces of erythrocytes and cause agglutination and hemolysis. ABO blood group antigens are designated A and B. People with type A blood have A antigens on their erythrocytes, whereas those with type B blood have B antigens.

What makes an ag/a more potent immunogen?

The number of epitopes is directly proportional to the size of the antigen. Haptens are tiny molecules, so they need to combine with the carrier (larger molecule) to be antigenic. The larger molecules of antigens are more immunogenic because: These are easily phagocytosed.

What is the antibody antigen complex AB AG )?

What is the two crucial features of AB and AG interactions?

Antibodies (Abs) have two distinct functions: one is to bind specifically to their target antigens (Ags); the other is to elicit an immune response against the bound Ag by recruiting other cells and molecules.

What are antigenic changes in the influenza virus?

These are small changes (or mutations) in the genes of influenza viruses that can lead to changes in the surface proteins of the virus: HA (hemagglutinin) and NA (neuraminidase). The HA and NA surface proteins of influenza viruses are “antigens,” which means they are recognized by the immune system and are capable…

What is the difference between influenza type A and B viruses?

Type A viruses undergo both antigenic drift and shift and are the only influenza viruses known to cause pandemics, while influenza type B viruses change only by the more gradual process of antigenic drift.

What happens when the flu virus shifts?

When shift happens, most people have little or no immunity against the new virus. While influenza viruses change all the time due to antigenic drift, antigenic shift happens less frequently. Influenza pandemics occur very rarely; there have been four pandemics in the past 100 years. For more information, see pandemic flu.

What is the flu and what causes it?

What Causes the Flu? The flu is caused by influenza viruses that infect the nose, throat, and lungs. These viruses spread when people with flu cough, sneeze or talk, sending droplets with the virus into the air and potentially into the mouths or noses of people who are nearby.