Previous Article | Next Article ![]()
Journal of Virology, May 2000, p. 4028-4038, Vol. 74, No. 9
Paul-Ehrlich-Institut, D-63225 Langen,
Germany
Received 29 November 1999/Accepted 8 February 2000
The use of pig xenografts is being considered to alleviate the
shortage of allogeneic organs for transplantation. In addition to the
problems overcoming immunological and physiological barriers, the
existence of numerous porcine microorganisms poses the
risk of initiating a xenozoonosis. Recently, different classes of type C porcine endogenous retoviruses (PERV) which are infectious for human
cells in vitro have been partially described. We therefore examined
whether completely intact proviruses exist that produce infectious
and replication-competent virions. Several proviral PERV
sequences were cloned and characterized. One molecular PERV class B
clone, PERV-B(43), generated infectious particles after transfection
into human 293 cells. A second clone, PERV-B(33), which
was highly homologous to PERV-B(43), showed a G-to-A mutation in the
first start codon (Met to Ile) of the env gene,
preventing this provirus from replicating. However, a genetic
recombinant, PERV-B(33)/ATG, carrying a restored
env start codon, became infectious and could be
serially passaged on 293 cells similar to virus clone PERV-B(43). PERV
protein expression was detected 24 to 48 h
posttransfection (p.t.) using cross-reacting antiserum, and reverse
transcriptase activity was found at 12 to 14 days p.t. The
transcriptional start and stop sites as well as the splice donor
and splice acceptor sites of PERV mRNA were mapped, yielding a
subgenomic env transcript of 3.1 kb. PERV-B(33) and
PERV-B(43) differ in the number of copies of a 39-bp segment in
the U3 region of the long terminal repeat. Strategies to identify and
to specifically suppress or eliminate those proviruses from the pig
genome might help in the production of PERV-free animals.
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Establishment and Characterization of Molecular Clones of Porcine
Endogenous Retroviruses Replicating on Human Cells

and
*
Corresponding author. Mailing address:
Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, D-63225
Langen, Germany. Phone: 49 6103 775304. Fax: 49 6103 771255. E-mail:
toera{at}pei.de.
Present address: Atugen Biotechnology AG, D-13125 Berlin, Germany.
Present address: Robert-Koch-Institut, D-13353 Berlin, Germany.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|