禽白血病病毒J亚群囊膜蛋白env基因的克隆和表达

禽白血病病毒J亚群（ALV－J）是90年代鉴定出的ALV的新亚群，其囊膜蛋白env基因序列别与ALV A－E亚群的有相当大的差别。为ALV－J env基因及春表达产物的特点，用PCR方法扩增出ADOL－4817毒株的env基因，并克隆进TA载体，经电泳鉴定大小为1.7kb。将克隆出的env基因与杆状病毒pBlue-Bac4表达质粒DNA连接，构建成转移性载体pBac4817env，通过与Bac-N-Blue杆状病毒DNA共转染，区得了重组病毒rBac4817env-2。该重组杆状病毒感染Sf9细胞，能高效表达env基因产物，免疫荧光分析结果证明，单克隆抗体G2或多价兔抗env gp37血清能识别Sf9细胞，能高效表达env基因表达的特异性抗原；Western blotting分析结果表明，表达的重组基因产物的分子量大小约为90kD-94kD。用这些重组基因产物免疫鸡可以诱导鸡导鸡产生出高滴度的抗ALV－J特异性抗体。这一结果提示，这种杆状病毒表达的重组基因产物有助于ALV－J env基因生物学特性的深入研究。

Cloning and Expression of Envelope Gene of Subgroup J Avian Leukosis Virus

Avian leukosis viurs subgroup J(ALV-J)was identified in 1990's, which causes myelocytic myeloid leukosis(ML)in meat-type chicken. The envelope(env)gene of ADOL-4817 strain of ALV-J was amplified by polymerase chain reaction(PCR)and cloned into TA vector. The size of env gene is about 1.7kb. A transfer vector pBac4817-env was constructed by ligation of env gene DNA and pBlue-Bac4 plasmid DNA. By cotransfecting Sf9 cells with both Bac-N-Blue baculovirus DNA and pBac4817-env DNA, a recombinant baculovirus, rBac4817-env-2 was obtained. Immunofluorescence assay showed that the recombinant env gene products were expressed in Sf9 cells infected with rBac4817-env-2. The molecular weight of expressed protein was 90 kD-94 kD by Western blotting. The recombinant gene products induced antibodies to ALV-J virus in chickens. These results suggested that the expressed recombinant env gene products will be very useful in studying the biological characterization of env gene in the future.