AEGiS-14IAC: Construction of infectious EIAV vaccine and chimeric clones.

14th International AIDS Conference

Barcelona, Spain - July 7-12, 2002

Construction of infectious EIAV vaccine and chimeric clones.

Int Conf AIDS 2002 Jul 7-12; 14:(abstract no. A10054)

He X, Fan XJ, Jia B, Xue F, Liu ZY, Zhao QB, Shen RX, Shao YM
National Center for AIDS Prevention and Control, Beijing, China

BACKGROUND: A Chinese live attenuated EIAV vaccine was developed in 1977. The vaccine had put the disease under control in China by immunizing more than 70 millions horses and donkeys in the last 2 decades. Being one of the 7 lentiviruses, the EIAV vaccine is used as a model to study the pathogenesis and the correlates of immune protection of lentiviruses, which could also be helpful to HIV vaccine research.

METHODS: Three overlapping proviral DNA fragments covering full-length of the Chinese EIAV attenuated vaccine strain were amplified by PCR and a full-length clone pFD3 was constructed. On the basis of the clone pFD3, we construct another full-length clone pLGFD3 with low copy number. The Nco I-Nru I fragment from wild type proviral DNA was inserted to the corresponding position of pLGFD3 and constructed a new clone sFDLN. Based on the comparative results between env genes of wild type strains and vaccine strains, 2 mutated env genes were inserted to the corresponding positions of pLGFD3 and constructed another 2 new infectious clones named mFD7-2 and mFD5-4. These clones were used to transfect fetal donkey dermal (FDD) cell and to monitor their infectious characteristics using PCR test and RT activity assay.

RESULTS: The provirus DNA could be detected in cell culture after 3 generations passaged in fetal donkey dermal cells. The level of RT activity in the cell culture increased along with the rise of generations. Obvious cytopathic effect (CPE) could be observed 5 generations after passaged in FDD cell. The EIAV particles could be observed under electron microscope in cell culture.

CONCLUSIONS: We have obtained 5 infectious clones of EIAV, included 2 vaccine clones and 3 chimeric clones. The viruses derived from these clones have inoculated to the animals to study the biological functions and the animal challenge work is on going. The results, which may be of great significance for the design of new HIV vaccine, will be recorded in the next few months.

Keywords: AEGIS, Infectious Anemia Virus, Equine, Vaccines, Genes, env, Equidae, Viral Vaccines, Polymerase Chain Reaction, Horses, AIDS Vaccines, China, Animal, genetics

020707
A10054