Induction of antibodies to the Epstein-Barr virus glycoprotein gp85 with a synthetic peptide corresponding to a sequence in the BXLF2 open reading frame

1998

The Epstein-Barr virus (EBV) homolog of the conserved herpesvirus glycoprotein gN is predicted to be encoded by the BLRF1 open reading frame (ORF). Antipeptide antibody to a sequence corresponding to residues in the predicted BLRF1 ORF immunoprecipitated a doublet of approximately 8 kDa from cells expressing the BLRF1 ORF as a recombinant protein. In addition, four glycosylated proteins of 113, 84, 48, and 15 kDa could be immunoprecipitated from virus-producing cells by the same antibody. The 15-kDa species was the mature form of gN, which carried α2,6-sialic acid residues. The remaining glycoproteins which associated with gN were products of the BBRF3 ORF of EBV, which encodes the EBV gM homolog. The 8-kDa doublet seen in cells expressing recombinant gN comprised precursors of the mature 15-kDa gN. Coexpression of EBV gM with EBV gN was required for authentic processing of the 8-kDa forms to the 15-kDa form.

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

The Epstein-Barr Virus (EBV) gN Homolog BLRF1 Encodes a 15-Kilodalton Glycoprotein That Cannot Be Authentically Processed unless It Is Coexpressed with the EBV gM Homolog BBRF3

Lake

Molesworth

1998

“…Antibodies. Monoclonal antibodies F-2-1 (22) and E1D1 (17) were obtained from spent culture medium of hybridoma cells. Three antipeptide antibodies were made to synthetic peptides corresponding to residues 518 to 533 of the BXLF2 ORF (anti-gH), to residues 125 to 137 of the BKRF2 ORF (anti-gL), and to residues 71 to 88 of the BZLF2 ORF (anti-BZLF2).…”

Section: Methodsmentioning

confidence: 99%

“…Among these are the involvement of the herpes simplex virus gH and its homologs in virus penetration (4-7, 14, 18) and the requirement for gH homologs to associate with a second conserved glycoprotein, gL, in order to be correctly folded and transported within the infected cell (3,9,10,12,20,21). The Epstein-Barr virus (EBV) gH homolog is gp85, the product of the BXLF2 open reading frame (ORF) (8,17), and in many respects this glycoprotein mirrors the behavior of its counterparts in other viruses. Two monoclonal antibodies, F-2-1 and E1D1, have been used to characterize the molecule biochemically and implicate the EBV gH as playing a role in virus penetration.…”

mentioning

confidence: 99%

The Epstein-Barr virus (EBV) BZLF2 gene product associates with the gH and gL homologs of EBV and carries an epitope critical to infection of B cells but not of epithelial cells

Turk

1995

Self Cite

180

125

Glycoprotein gp85, the product of the BXLF2 open reading frame (ORF), is the gH homolog of Epstein-Barr virus (EBV) and has been implicated in penetration of virus into B cells. Like its counterparts in other herpesviruses, it associates with a gL homolog, gp25, which is the product of the BKRF2 ORF. Unlike the gH homologs of other herpesviruses, however, gp85 also complexes with two additional glycoproteins of 42 and 38 kDa. Glycoproteins gp42 and gp38 were determined to be alternatively processed forms of the BZLF2 gene product. Coexpression of EBV gH and gL facilitated transport of gH to the cell surface and resulted in formation of a stable complex of gH and gL. It also restored expression of an epitope recognized by monoclonal antibody E1D1, which immunoprecipitates the native gH complex but not recombinant gH expressed in isolation. Coexpression of gH, gL, and the BZLF2 ORF restored expression of an epitope recognized by a second monoclonal antibody, F-2-1, which immunoprecipitates the native gH-gL-gp42/38 complex but not the complex of recombinant gH and gL alone. The epitope recognized by antibody F-2-1 was mapped to the BZLF2 gene product itself. Antibody F-2-1 inhibited the ability of EBV to infect B lymphocytes but had no effect on the ability of the virus to infect the epithelial cell line SVK-CR2. In contrast, antibody E1D1 had no effect on infection of the B-cell line but inhibited infection of the epithelial cell line. These results indicate that penetration of the two cell types by EBV involves differential use of the gH-gL-gp42/38 complex and suggest the hypothesis that the BZLF2 gene product has evolved as a unique adaptation to infection of B lymphocytes by EBV.

“…The envelope of Epstein-Barr virus (EBV), like that of all herpesviruses, includes multiple unique glycoprotein species. Among those mapped to their open reading frames (ORFs) in the virus genome (1) and characterized at least biochemically are gp350/220, the product of the BLLF1 ORF (2); glycoproteins gp85, gp42, and gp25, respective products of the BXLF2 (7,21), BZLF2 (14), and BKRF2 ORFs (33), which make up the EBV gH-gL-gp42 complex; gp78, the product of the BILF2 ORF (16); gN, the product of the BLRF1 ORF (12); gM, the product of the BBRF3 ORF (12); and gp150, the product of the BDLF3 ORF (11,20). Functions have been ascribed to gp350/220, which is the viral attachment protein that binds the virus to CR2 or CD21 (19,30), and to the gH-gL-gp42 complex, which interacts with HLA class II molecules on B cells (27) and is involved in virus penetration through the membranes of both B cells and epithelial cells (6,13,17,31,32).…”

mentioning

confidence: 99%

Epstein-Barr Virus Recombinant Lacking Expression of Glycoprotein gp150 Infects B Cells Normally but Is Enhanced for Infection of Epithelial Cells

Borza

1998

Glycoprotein gp150 is a highly glycosylated protein encoded by the BDLF3 open reading frame of Epstein-Barr virus (EBV). It does not have a homolog in the alpha- and betaherpesviruses, and its function is not known. To determine whether the protein is essential for replication of EBV in vitro, a recombinant virus which lacked its expression was made. The recombinant virus had no defects in assembly, egress, binding, or infectivity for B cells or epithelial cells. Infection of epithelial cells was, however, enhanced. The glycoprotein was sensitive to digestion with a glycoprotease that digests sialomucins, but no adhesion to cells that express selectins that bind to sialomucin ligands could be detected.