Molecularly cloned porcine endogenous retroviruses replicate on human cells

Porcine Endogenous Retrovirus Transmission Characteristics of an Inbred Herd of Miniature Swine

“…Although the majority of PERV loci in porcine DNA are most likely noninfectious (3,4,8,9), human-tropic viruses have been isolated from porcine cell lines as well as primary tissues (2, 11-13, 16, 18, 21). Interestingly, all clones of replication-competent PERV-A and PERV-B classes with significant infectious titers have been isolated from PK15 cells or cell lines infected by viruses released from PK15 cells (6,8,19). Conversely, all PERV clones derived from primary pig cells have had extremely low titers and limited replication competence (6,8,19).…”

Sequence Analysis of Porcine Endogenous Retrovirus Long Terminal Repeats and Identification of Transcriptional Regulatory Regions

“…Gammaretroviruses from cell lines of swine origin have been characterized previously (2,16,29,46) and shown to be infectious for human cells in vitro (36,41,47,51). The laboratories which initially detected the human tropism of some of these porcine retroviruses have identified three classes of infectious endogenous gammaretroviruses (PERV-A, PERV-B, and PERV-C) by nucleotide sequence analysis (25) and receptor interference studies (44).…”

Characterization of Chromosomally Assigned Replication-Competent Gamma Porcine Endogenous Retroviruses Derived from a Large White Pig and Expression in Human Cells

“…All clones showed a close relationship to proviral PERV sequences described previously (5,12,27). In particular, Bac-PERV-A(130A12), Bac-PERV-A(151B10), Bac-PERV-A(463H12), and Bac-PERV-B(192B9) were compared to PK15-PERV-A(58) and PK15-PERV-B(213) (5,12).…”

“…Integration of PERV was tested by amplification of pro/pol sequences using oligonucleotide primers PK1 (5Ј-TTG ACT TGG CAG TGG GAC GGG TAA C-3Ј, nucleotides (nt) 2927 to 2949) and PK6 (5Ј-GAG GGT CAC CTG AGG GTG TTG GAT-3Ј, nt 3739 to 3716) for a first PCR and primers PK2 (5Ј-GGT AAC CCA CTC GTT TCT GGT CA-3Ј, nt 2954 to 2966) and PK5 (5Ј-CTG TGT AGG GCT TCG TCA AAG ATG-3Ј, nt 3696 to 3673) for a nested amplification. Nucleotide positions refer to 293-PERV-B(33) (5,27).…”

“…We have previously reported the isolation of replicationcompetent molecular PERV clones derived from human embryonic kidney cells infected with PERV (293 PERV-PK) (5,27). Subsequently, we described functional proviral PERV isolated from porcine kidney cell line PK15 (12).…”