| Up to now, it is difficult to block the transmission of schistosomasis by killing oncomelania and chemotherapy, especially in the marshland areas and mountain areas along Yangtze River. Yherefore, many researchers have shown great concern with the development of vaccines to against schistosomiasis. At early stage, the research of vaccines of schitosomiasis was centered on dead vaccine and athenuated cercaria of schistosomes while molecular vaccine and athenuated cercaria of schistosomes while molecular vaccine is currently the focus of research with anti-infection protective immunity as its main concern.Guan Xiaohong and Zhao Weixian (1986) certified that the allergen of egg granulonma of Schistosoma japonicum might firstly come from gut associated antigen (GAA) of schistosomula and adult worm and that DAA had cross reaction with soluble egg antigen (SEA) and membrane associated antigen (MAA) ; and the GAA of Schistosoma japonicum might play a sensitizing role in egg granuloma formation. Guan Xiaohong (1991) established a cell line of the monoclonal anti-idiotypic antibody (anti-id) NP30 of Schistosoma-6-japonicum, whose isotype was identified to be IgM and which was testified to be internal image of GAA. They found that NP30 had partial cross-reaction with SEA and MAA and could be used as "antigen reagent " in the immunodiagnostic assays based on antibody detection of schistosomasis Japonica. It is difficult to obtian GAA by genetic engineering methods, because GAA is glycoprotein.In addition to their effectiveness in immunity, antibodies have proven to be extremely useful tools for biological research. Antibodies also show promise as therapeutic agents. However, this promise has not yet been realized. One reason is that, for ethical reasons, antibodies cannot be elicited in humans for the purpose of preparing reagents. Therefore, these reagents must be elic-ited in experimental animals. However, continued injection of humans with antibodies made in another species eventually leads to the production of antibodies against the foreign antibodies.This problem may now be circumvented by immunizing mice that have been transfected with large segments of the human immunoglobulin loci so the mice actually produce human antibodies. Another problem is the relatively large size of antibodies which hinders their ability to penetrate deep into tissues. This is important in attempting to use antibodies as anti-tumor reagents, for example. Thus, immunologists have sought smaller molecules with the antigen-recognition capability of antibodies.The variable domains of the heavy (H) and light (L) chains are sufficient for antigen recognition but the non-covalent complex of the two variable domains (Fv) is unstable. It is possible to genetically engineer a single-chain Fv (scFv) with the H chain V region connected to the L chain V region via a 15 amino acid linker composed of serine and glycine amino acid residues. Glycine makes the linker flexible and serine makes it hydrophilic without the steric hin-drance of bulky side-7-chains. Each of the domains of the scFv folds independently just like they do in an intact antibody. It may be possible to obtain a single-chain antigen binding fragment smaller than the scFv. The Fv of an antibody consists only of the variable region domains of the H and L chains. Note the location of H and L chain complementarity-determining regions 3 (H3 and L3) at the center of the antibody combining site. H chain CDR3 region is thought to be the antigenic epitope of antibody of monoclonal antibody NP30. Therefore, anti-id antibody vaccine and antigenic epitope vaccine are important strategy in developing Schistosomajaponicum vaccine.?, AMPLIFICATION, CLONING AND SEQUENCE ANALYSIS OF THE LIGHT CHAIN AND THE HEAVY VARIABLE REGION GENES OF MONOCLONAL ANTI-IDIOTYPIC ANTIBODY NP30 OF SCHISTOSOMA JAPONICUMTo amplify and sequence the gene of the heavy chain and the heavy chain of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum. By comparing the conserved r...
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