Disease relevance of orf3

• By using porcine immune sera to select a library of phage-displayed random peptides, we identified an antigenic sequence (RKASLSTS) in the C-terminus of the ORF 3 structural glycoprotein of European-type porcine reproductive and respiratory syndrome virus (PRRSV) [1].
• Emergence of porcine reproductive and respiratory syndrome virus deletion mutants: correlation with the porcine antibody response to a hypervariable site in the ORF 3 structural glycoprotein [1].
• The specificity of another MAb, WBE2, was found to be for a 45 kDa protein, determined to be the product of ORF3 and demonstrated to be present in purified virion preparations [2].
• The hydrophilic carboxyterminal 199 amino acids encoded by the ORF 3 of a European (Lelystad) isolate of PRRSV were expressed as a recombinant fusion protein (BP03-P) in a baculovirus gene expression system [3].
• By Western-immunoblotting with PRRSV-infected cell extracts, the ORF3 encoded protein had an estimated molecular mass (M(r)) of 42 kDa, similar to that of the protein expressed by the adenovirus vector [4].

High impact information on orf3

• Through the use of overlapping reading frames, the same PRRSV genetic locus codes for the ORF 3 "RKASLSTS" sequence, and a previously described ORF 4 epitope (Meulenberg, J. J. M., Van Nieuwstadt, A. P., Van Essen-Zandbergen, A., and Langeveld, J. P. M., 1997, J. Virol. 71, 6061-6067) [1].
• The nucleic acid homology with corresponding ORFs of the European PRRSV isolate Lelystad virus (LV) was 65% for ORF 2, 64% for ORF 3 and 66% for ORF 4 [5].

Biological context of orf3

• Antigenic differences between European and American isolates of porcine reproductive and respiratory syndrome virus (PRRSV) were revealed by serologic analysis of a recombinant protein derived from PRRSV open reading frame 3 (ORF 3) [3].

Analytical, diagnostic and therapeutic context of orf3

• Together, our results show that ORF3 sequencing is a valuable epidemiologic tool for examining the emergence and spread of PRRSV in Europe. As such, the panel of well-characterized and highly divergent ORF3 sequences described in this study provides a reference point for future molecular epidemiologic studies [6].
• The ORF3 and ORF7 regions of the individual viruses were amplified by the polymerase chain reaction (PCR) and their sequences were determined using internal sense and antisense primers [7].
• Tested convalescent pig sera that were found to be seropositive to PRRSV by indirect immunofluorescence reacted positively with the recombinant GST-ORF3 fusion protein by immunoblotting [4].
• Based on the size of the ORF 3, 3-1 and 4 RT/PCR products, TGEV and PRCV strains could be quickly and easily differentiated into three groups designated TGEV Miller, Purdue types and PRCV [8].

References