| Heamorrhagic fever with renal syndrome virus(HFRSV),member of genus Hantanvirus(HV)of the Bunyavirus Family, is worldwide enzootic in rodents, and humans are occasionally infected, which may lead to two life-threatening illnesses: heamorrhagic fever with renal syndrome (HFRS) caused by Hantaan,Seoul and Dobrava viruses,and hantavirus pulmonary syndrome (HPS) by Sin Nombre (SNV) and related viruses. Hantavirus was determined as a potential agent for developing biological weapon by WHO. More than 30 000 cases of HFRS with a mortality rate of 2% to 10%, are reported annually, and among all cases approximately over 90% are in China. There are two main serotypes of HV (HTN and SEO) prevailing in China. Though the incidence and mortality of HFRS in China have decreased to some extent in recent years, the endemic area extended continually, even affected some big cities. HFRS continues to be a health threat in many regions of China. Due to the significant morbidity and mortality of HFRS and the high incidence in some areas, it urgently requires the safe and effective vaccines and therapeutic reagents for HFRS patients. 1. According to amino acid consensus sequences of mouse immunoglobulins (Igs) as described by Kabat et al, degenerated primers were designed and synthesized. The nucleotide sequences were derived by using the codons preferentially used in murine Ig variable region (V) genes as listed in the Kabat database. Based on RT-PCR technology, we succeeded in preparing mRNA,amplifying cDNA and in cloning Ig heavy (VH) and light (VK) chain variable domains from three murine hybridomas (H7,F3 and B11), which secret antibody specifically binding to HFRSV, and the variable genes were cloned into T7-sequencing vector respectively. The subsequent sequence analyses were performed with a DNA-STAR sequence analysis program, and the nucleotide and predicted amino acid sequences indicated that B11-VH gene consisted of 345 bp and 115 amino acids (JH4), 357 bp and 119 amino acids of H7-VK gene (JK4), 360 bp and 120 amino acids of H7-VH gene (JH4), 348 bp and 116amino acids of F3-VK gene (JK1), and 366 bp and 122 amino acids of F3-VH gene (JH3), respectively. All sequences were submitted to the GenBank databaseand they were given the following accession numbers: AY245600~AY245604. These results would be potentially useful in constructing engineering antibody (such as genetic evolvement and affinity maturation in vitro) as therapeutic reagents for HFRS patients. 2. Recently, phage display library (PDL) has been widely used as an in vitro selection technique by which a peptide or protein was genetically fused with coat protein of a bacteriophage. The linkage of genotype and phenotype via PDL provides a format for rapidly sorting peptide library and also provides a convenient way for selecting a peptide with specific function from a vast library of peptides. Phage display peptide libraries have been successfully used in numerous applications, including epitope mapping, vaccine development, identification of protein kinase substrates, determination of the natural ligands for a given protein, and identification of novel bioactive peptides against immobilized cell-surface receptors. By using PDL technique, the research of epitope biology has been deepened, and the latest research reveals that the phage-displayed peptide can not only induce the same strongly specific immunity just as natural linear epitope does, but also mimic the discontinuous or conformational epitopes in which the displayed peptide was called "mimotope". The purpose of selecting peptides or mimotopes from random libraries displayed on phage with neutralizing antibodies is to define epitopes of antigen with protective function and to find peptide mimics that would possess the same immunogenicity as the natural antigen. Here, we utilize a 12-mer PDL for epitope-determining of monoclonal antibody (McAb) of HFRSV. McAb F3, an neutralizing monoclonal antibody, which is HFRSV group-specific with strong animal protective activity, and McAb B11,a group-...
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