Immune response and resistance to Rous sarcoma virus challenge of chickens immunized with cell-associated glycoproteins provided with a recombinant avian leukosis virus

Abstract

The Rous-associated virus 1 env gene, which encodes the envelope gp85 and gp37 glycoproteins, was isolated and inserted in place of the v-erbB oncogene into an avian erythroblastosis virus-based vector, carrying the neo resistance gene substituted for the v-erbA oncogene, to generate the pNEA recombinant vector. A helper-free virus stock of the pNEA vector was produced on an avian transcomplementing cell line and used to infect primary chicken embryo fibroblasts (CEFs) or quail QT6 cells. These infected cells, selected with G418 (CEF/NEA and QT6/NEA, respectively) were found to be resistant to superinfections with subgroup A retroviruses. The CEF/NEA preparations were used as a cell-associated antigen to inoculate adult chickens by the intravenous route compared with direct inoculations of NEA recombinant helper-free viruses used as a cell-free antigen. Chickens injected with the cell-associated antigen (CEF/NEA) exhibited an immune response demonstrated by induction of high titers of neutralizing antibodies and were found to be protected against tumor production after Rous sarcoma virus A challenge. Conversely, no immune response and no protection against Rous sarcoma virus A challenge were observed in chickens directly inoculated with cell-free NEA recombinant virus or in sham-inoculated chickens.

Experimental infection of Mouflon-domestic sheep hybrids with caprine arthritis-encephalitis virus

“…Mouflon hybrids-Serum neutralization tests were performed as described, 29 with minor modifications. Briefly, 1,000 TCID 50 of CAEV-pBSCA and of maedi-visna virus 1514 were incubated with 100 µl of undiluted serum from the Mouflon hybrids and with 10 -1 , 10 -2 , and 10 -3 dilutions.…”

Usage of retrovirus vectors for gene transfer into birds

“…Для создания животных, устойчивых к инфек ции ALV и образованию опухолей, позднее исполь зовали репликативно-дефектный вектор pNE-A, несущий пео-ген под контролем LTR птичьего эритробластоза и env-ген ALV А-подгрупповой спе цифичности [60]. Цыплята, инфицированные этим…”

Packaging cells for avian leukosis virus-based vectors with various host ranges

“…ALV-derived genomes have provided an interesting source of replication-competent (23) or helper-free (2, 7, 13, 34) gene transfer vectors. These vectors have proved useful for a variety of studies either with cell culture (1, 15) or with animals or embryos (6,7,16,21,35,36). Until now, the helper-free vectors were produced as particles of subgroup * Corresponding author.…”