Hybridoma-derived antibodies

In order to compare the specific activity of plant-derived C5-1 to that of the hybridoma-derived antibody, the antigen-binding capacity of antibodies produced in each system was assayed by enzyme-linked immunosorbent assay (ELISA). As shown in Table 1.2, antibodies from both sources demonstrated similar binding characteristics against human IgGs [8]. Furthermore, the stability of alfalfa-derived C5-1 in the blood stream of Balb/c mice was comparable to that of the hybridoma-derived IgG [8]. 

The isolation of an antibody is an extremely useful first step toward understanding the function of the protein to which it binds. scFvs derived from phage antibody libraries have been used in immunofluorescence, immunoprecipitation, fluorescence-activated cell sorting, Western blotting, and inhibition of function studies, both in vivo, in tissue culture cells, and in vitro. In this sense, they can essentially be used in the same way as conventional hybridoma-derived antibodies. They have the advantage, however, that the genes for the variable regions are cloned simultaneously with selection. This allows the fusion of functional elements, such as dimerization domains, effector or detector functions to selected scFvs [38], the re-creation of complete... 

Fig. 15.4 Structure of glycans N-linked to IgG molecules expressed in hybridomas and transgenic plants. Glycans N-linked to plant-derived antibodies are structurally different from their mammalian counterparts. In contrast with antibodies produced in alfalfa, antibodies produced in tobacco plants present a very high glycan heterogeneity.

As an alternative, antibody can be produced in vivo. Many cultured hybridomas have been successfully transplanted to genetically compatible recipients, and hybridomas derived fi om cells of nonmurine origin have been successfully transplanted to athymic nude mice. In vivo antibody production is achieved by inoculating the cloned, hybrid cells... 

Monoclonal antibodies are produced in a series of steps beginning with the immunization of a mouse and removal of its spleen after an appropriate period of time. Antibody-producing cells are isolated from the spleen and fused with "immortal" myeloma cells from tissue culture through the use of polyethylene glycol. Cells resulting from the fusion of a B-cell and a myeloma cell are called hybridomas. Hybridomas derive the ability to produce a single type of antibody from the B-cell partner and the ability to survive and proliferate outside the body of the animal for an extended period of time from the myeloma cell partner. Through a series of manipulations in tissue culture, individual hybridomas are isolated and allowed to divide and produce antibody. Antibody in the cell culture medium is then tested for... 

Antibodies prepared from hybridomas derived after immunization vith 1,3-diketone hapten 1-carrier protein conjugate vere screened for their capacity to form the stable enaminone (absorption maximum = 316 nm)... 

Monoclonal antibodies are derived from a single, monospecific B cell clone. Monoclonal antibodies can be obtained from hybridoma cells that result from the fusion of antibody-producing B cells with immortal cells of a myeloma cell line. 

Figure 13.5 Outline of the production strategy of CEA-SCAN. The antibody-producing hybridoma cell line was originally obtained by standard methods of hybridoma generation. Spleen-derived murine B-lymphocytes were fused with murine myeloma calls. The resulting stable hybridomas were screened for the production of anti-CEA monoclonals. The clone chosen produces an IgG anti-CEA antibody. Note that the finished product outlined above is not radiolabelled. The freeze-dried antibody preparation (which has a shelf life of 2 years at 2-8 °C) is reconstituted immediately prior to its medical use. The reconstituting solution contains 99mTc, and is formulated to facilitate direct conjugation of the radiolabel to the antibody fragment...

Monoclonal antibody, mAb Describes an antibody derived from a single clone of cells or a clonally obtained cell line. Its common use denotes an antibody secreted by a hybridoma cell line. Monoclonal antibodies are used very widely in the study of antigens, and as diagnostics. 

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