Homogenous antibodies

As they differentiate into populations with differing functions, B and T cells acquire molecules on their surfaces that reflect their specializations. It is possible to produce homogenous antibodies of a single specificity, termed monoclonal antibodies, which can recognize such surface markers. When laboratories from all over the world compared the monoclonal antibodies they had raised, it was found that clusters of monoclonal antibodies were recognizing the same molecule on the surface of the lymphocyte. Each surface molecule so defined was referred to as a CD molecule (Table 2), where CD refers to a cluster determinant. 

Sequence determinations showed that in some regions of immunoglobulin molecules there is extreme variation in the amino acid sequence between one homogeneous antibody and the next other regions have a constant sequence. The molecule can also be divided into domains. The variable regions, which occupy the N-terminal ends of the chains, are designated... 

Schilling, J., Clevinger, B., Davie, J.M., Hood, L. (1980). Amino acid sequence of homogeneous antibodies to dextran and DNA rearrangements in heavy chain V-region gene segments. Nature 283, 35-40. 

Monoclonal antibodies Homogeneous antibody populations directed at against a single antigenic determinant, produced by a single clone of cells... 

Because each B-cell clone produces antibody to a single epitope on an antigen, an opportunity exists for producing chemically and functionally homogeneous antibody in substantial quantity. However, the short B-cell lifetime that is determined by normal apoptosis initially made this impractical. However, the discovery by Kohler and Milstein that B cells could be fused with immortal myeloma cells to create hybridomas that can be maintained almost indef-... 

Further sequence analysis by Mole et al. (1971) of pooled IgG heavy chains of either allotype al or a3 delineated additional areas for potential allotypic correlations (Todd, 1972). These were compared with the sequence of a homogeneous antibody of allotype a2 (Fleischman, 1971). These studies showed, when corrected for hypervariable sequences and group a negative molecules, that amino acid interchanges occurring at positions 4, 7, 9, 11, 12, 15, and 16 could be correlated with group a allotypes. In addition substitutions at positions 80-85 from the amino-terminal end of the heavy chain could also be associated with allotypic differences. 

Capra et al. (1971) examined the light chains from some homogeneous antibodies derived from patients with hypergammaglobulinemic purpura. All these antibodies had IgG-ligating activity. The amino acid residue sequence was identical in some up to residue 40 between others... 

Monoclonal Antibodies (mAB). Exposure to antigens such as those found on bacteria or viruses triggers the production of a lai e number of different antibodies, each of which is specific for a particular molecular determinant on an organism. In the 1960 s, it was discovered that persons with multiple myeloma, a cancer of plasma cells, produced large quantities of homogeneous antibodies. 

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