Expression of human herpesvirus 8 (HHV-8)-encoded immediate early protein,open reading frame 50, in HHV-8-associated diseases

Citation
H. Katano et al., Expression of human herpesvirus 8 (HHV-8)-encoded immediate early protein,open reading frame 50, in HHV-8-associated diseases, J HUMAN VIR, 4(2), 2001, pp. 96-102
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF HUMAN VIROLOGY
ISSN journal
1090-9508 → ACNP
Volume
4
Issue
2
Year of publication
2001
Pages
96 - 102
Database
ISI
SICI code
1090-9508(200103/04)4:2<96:EOHH8(>2.0.ZU;2-D
Abstract
Objectives: To investigate the expression of the open reading frame (ORF) 5 0 protein, a human herpesvirus 8 (HHV-8)encoded immediate early protein, in HHV-8-associated diseases. Study Design/Methods: We developed a rabbit anti-ORF50 protein polyclonal a ntibody, and investigated the ORF50 protein expression by immunohistochemis try using primary effusion lymphoma (PEL) cell lines and tissue sections of Kaposi's sarcoma (KS), HHV-8-associated solid lymphoma, and multicentric C astleman's disease (MCD). Results: Western blot analysis revealed that this antibody reacted with a 1 10-kd protein in the lysate of phorbolester-stimulated HHV-8-infected PEL c ell lines. Immunohistochemistry revealed that a very small population of ce lls expressed the ORF50 protein in KS and HHV-8-associated solid lymphoma c ells, and almost all these cells expressed HHV-8-encoded latency-associated nuclear antigen. The ORF50 protein expression was also rare in the cells o f PEL cell lines, and the staining pattern was diffuse or dot-like in the n uclei, overlapping partially with that of promyelocytic leukemia protein. I n MCD, however, the ORF50 protein was expressed in some cells of the mantle zone of the lymphoid follicle. Conclusions: The ORF50 protein expression in vivo was considerably rare in KS, HHV-8-associated solid lymphoma, and PEL, but was more frequent in MCD. Rare expression of this transactivator protein in HHV-8-associated maligna ncies causes low expression levels of other lytic proteins and may play a r ole in the maintenance of the latent infection. This is the first report de scribing the expression of an immediate early protein of HHV-8 in cases of HHV-8-associated diseases.