Immunology Notes6 10 February 2011

Immunoglobulins Immunoglobulins Immunglobulins are antibodies Are the specific receptors of the immune response produced by B lymphocytes Have two functions: 1. Specifically bind m olecules of the pathogen 2. Recruit other molecules and cells to destroy the pathogen once the antibody has bound to it Immunoglobulins Most antigens are complex and have multiple antigenic sites / antigenic determinants / epitopes The immune system typically produces a polyclonal response to most antigens by producing antibodies to multiple epitopes on it Immunoglobulins One B cell produces one type of antibody recognizing one antigenic determinant or epitope i.e. immunoglobulin of a single antigen binding specificity Figure 1-14 part 2 of 2 Immunoglobulins If a B cell undergoes mitotic cell division, all of the resulting daughter cells have the same genetic composition, and all will produce the same antibody The resulting cells are a single clone, and the antibody they produce is a monoclonal antibody Immunoglobulins Several different B cells, each producing a different antibody, together produce a polyclonal antiserum Your immune system naturally produces a polyclonal response to an antigen Immunoglobulins In order to get a monoclonal antiserum or antibody one can: 1. Have a tumor of antibody producing cells, a myeloma, the cells of which may be derived from the same parental cell, and therefore all produce the same antibody 2. Individually isolate an antibody producing cell, and cause that cell, through mitotic cell division, to produce a single clone of cells, all of which would then produce the same antibody molecule 3. Molecularly clone the genes for immunoglobulin polypeptides into an expression vector Immunoglobulins Basic Antibody Structure Each antibody molecule consists of 4 polypeptide chains of two types:

Immunology Notes6 10 February 2011

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