| In 1975, Kohler and Milstein invented the hybridoma tcchnology and made murine monoclonal antibody (McAb) by fusion antibody-secreting spleen cell with myeloma cells. However hybridomas derived from the MOPC-21 myeloma ancestor contains two kinds of kappa chain transcripts, namely the correct (functional) and aberrant one, which causes the VJ rearrangement out of the normal reading frame, and results in a stop codon. It has been shown that cellular levels of this transcript may exceed those generated from the productive gene, and consequently a large proportion of the product of PCR amplification of hybridoma cDNA will not encode a functional lightchain . For these reasons several groups developed method to minimize and /or eliminate the possibility of capturing of the aberrant kappa chain transcript. However, to what extent this high-level endogenous aberrant kappa chain transcript affects those with normal functions is still not known. Are there any changes generated by the disproportional expression of these two transcripts in the functional aspects of antibodies, including secretion, affinity or activity? In an attempt to understand these mechanisms, we are interested in comparing the expression levels of the two transcripts in anti-CEA and anti-AFP hybridomas by Northern Blot analysis, using the correct and aberrant transcript sequence as specific probes once the cloning and sequencing was completed. These data were correlated with those of the function evaluation of hybridomas and thus provided insight into the role of these transcripts play in transcription. When two sets of primers were employed to amplify the kappa chain transcripts from the cDNA of AFP-12 and CEA-92 respectively, the expected size band approximately about 310 to 350 base pairs could be observed after running the PCR products on the 1.0% agarose gel stained with ethilidum bromide, in which the cDNA from Sp2/0 myeloma cells was used as the control when the...
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