CHARACTERIZATION AND EXPRESSION OF THE MAREK DISEASE VIRUS SEROTYPE-2GLYCOPROTEIN-E IN RECOMBINANT BACULOVIRUS-INFECTED CELLS - INITIAL ANALYSIS OF ITS DNA-SEQUENCE AND ANTIGENIC PROPERTIES

In Marek's disease virus (MDV) serotype 2 (MDV2) genome, a gene equiva lent to the glycoprotein E (gE) of other alphaherpesviruses was identi fied and sequenced. The primary translation product comprises 488 amin o acids with a M-r of 54.3 kDa. The predicted amino acid sequence poss esses several characteristics typical of membrane glycoproteins, inclu ding a N-terminal hydrophobic signal sequence, C-terminal transmembran e and cytoplasmic domains, and extra-cellular region containing four p otential N-linked glycosylation sites. Compared with other MDV serotyp es, MDV2 gE showed 47.3% identity with MDV1 gE, and 38.9% identity wit h HVT gE at the amino acid level. In transcriptional analyses, a 2.0 k b mRNA which starts between 65 and 86 bps upstream of the potential tr anslational initiation codon of gE was identified as the gE-specific t ranscript. By a recombinant baculovirus, this potential gE coding regi on was expressed as several Specific products from 66 to 72 kDa. These products were susceptible to tunicamycin treatment, indicating that t hey were glycoprotein in nature. Further, the expressed gE reacted wit h al chicken-antisera raised to each of the three serotypes of MDV (st rains GA, SB-1, and FC126), suggesting that gE is expressed by all thr ee serotypes of MDV in infected cells and conserves common antigenic e pitope(s) beyond those that are serotype specific. (C) 1997 Elsevier S cience B.V.