This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Katano, H. Articles by Sata, T. Search for Related Content PubMed PubMed Citation Articles by Katano, H. Articles by Sata, T.

(American Journal of Pathology. 1999;155:47-52.)
© 1999 American Society for Investigative Pathology

Short Communication

High Expression of HHV-8-Encoded ORF73 Protein in Spindle-Shaped Cells of Kaposi's Sarcoma

Harutaka Katano^*, Yuko Sato^*, Takeshi Kurata^*, Shigeo Mori and Tetsutaro Sata^*

From the Department of Pathology^*
and Laboratory of Pathology,
AIDS Research Center, National Institute of Infectious Diseases, and Department of Pathology,
Institute of Medical Science, University of Tokyo, Tokyo, Japan

	Abstract

Top Abstract Introduction Materials and Methods Results Discussion References

 
Human herpesvirus 8 (HHV-8) has been demonstrated previously in Kaposi's sarcoma (KS) tissues by immunohistochemistry, in situ polymerase chain reaction, and in situ hybridization. The HHV-8-encoded protein ORF73 is a 222- or 234-kd protein named latent nuclear antigen (LNA) or latency-associated nuclear antigen (LANA) that is identified in HHV-8-infected cell lines by immunofluorescence assay. In the present study, a rabbit antibody against a recombinant ORF73 protein was developed. Immunofluorescent staining of a HHV-8-infected cell line, TY-1, showed that the staining pattern of the anti-ORF73 antibody overlapped completely the LANA staining pattern obtained using KS patients' sera. Immunoblotting analysis showed that the anti-ORF73 antibody reacted specifically with 222- and 234-kd proteins that were present in TY-1 and BCBL-1 cell lysates. Immunohistochemistry using a catalyzed signal amplification system demonstrated that the anti-ORF73 antibody reacted exclusively with the majority of KS spindle-shaped cells, showing a nuclear dot-like staining pattern. Some of the ORF73 protein-positive cells also expressed CD34 and vimentin but not CD68 or factor-VIII-related antigen. These data indicate that the anti-ORF73 antibody recognizes LANA and that most KS cells are infected with HHV-8 in the latent phase. Our findings also suggest that ORF73 protein plays an important role in the pathogenesis of KS.

	Introduction

Top Abstract Introduction Materials and Methods Results Discussion References

The newly identified human herpesvirus-8 (HHV-8; also called KS-associated herpesvirus, KSHV) has been demonstrated in over 90% of KS lesions by polymerase chain reaction (PCR), regardless of the human immunodeficiency virus (HIV) infection status and the clinical type.^3-7 HHV-8 has also been identified in primary effusion lymphoma (PEL; also called body-cavity-based lymphoma, BCBL),^8,9 in PEL cell lines,^10-16 and in patients with a subset of multicentric Castleman's disease.¹⁷

The HHV-8 genome was first detected in KS tissues, in both spindle-shaped cells and endothelial cells, by in situ PCR.¹⁸ In situ hybridization (ISH) has also been used to detect HHV-8 mRNA in KS tissues.^7,19-25 HHV-8 was identified in the intranuclear inclusions of spindle-shaped cells and of mononuclear cells in KS tissues using a T1.1 riboprobe.²¹ HHV-8 ORF26 expression by macrophages in KS tissues has also been detected by ISH using an ORF26 riboprobe.²⁵ In these studies, however, the positive cells were few in numbers because the probes recognize early lytic or lytic genes that are expressed in the infected cells. Concerning latent genes, mRNA of ORF72 (viral cyclin D) was first detected in KS spindle cells using a radioisotope-labeled probe; however, the resolution was not enough to demonstrate the clear localization.¹⁹ Recently, mRNAs of ORF72 and ORFK12 (T0.7, kaposin) were detected in many KS spindle-shaped cells using the catalyzed signal amplification system²⁴ or riboprobes.²⁰ The sensitivity of the HHV-8-specific probes is crucial for these studies.

In immunofluorescence assay (IFA), the sera of HHV-8-infected patients react with a nuclear antigen to produce a dot-like staining pattern in latently infected PEL cell lines; the nuclear antigen is known as latency-associated nuclear antigen (LANA).^26,27 Western blotting of nuclear extracts of the BC-1 cell line show that 222- to 234-kd doublet bands of protein were labeled by KS patient sera, and the labeled protein has been designated as latent nuclear antigen (LNA).²⁸ It has since been shown that an antibody that was affinity purified from KS patients' sera using a recombinant ORF73 protein binds to both LNA and LANA in IFA and Western blotting, which indicates that LNA and LANA are the same protein encoded by ORF73.²⁹ It has been also indicated that the LNA was expressed in some KS tumor cells in the immunohistochemical examination using the affinity-purified patient's antibody.²⁹ Despite intensive studies, little immunohistological evidence of the expression of latent proteins has been gathered so far. In the present study, a rabbit polyclonal antibody against HHV-8 ORF73 protein was developed, and the distribution of the protein in AIDS- or immunodeficiency-associated KS tissues was investigated.

	Materials and Methods

Top Abstract Introduction Materials and Methods Results Discussion References

 
Synthesis and Purification of Recombinant HHV-8 ORF73 Protein

A DNA fragment corresponding to amino acids 35 to 291 of the ORF73 gene (GenBank accession number KSU75698) was amplified from the total DNA of TY-1 cells¹⁵ by PCR. The forward primer sequence was 5'-CTC gga tcc TTG GCG ATG ACC TAC ATC TA-3', and the reverse primer was 5'-CTC gaa ttc TGC AAT CTC CGC AAG GAG CAC-3' (the cloning sites are underlined and lowercase).³⁰ The TY-1 cell line is HHV-8 positive and Epstein-Barr virus (EBV) negative. It was established from an AIDS patient with PEL.¹⁵ After purification by agarose gel electrophoresis, the PCR product was cloned into the BamHI and XhoI sites of the bacterial expression vector pGEX5X-2 (Pharmacia, Uppsala, Sweden). The expression vector produced 257 amino acids of ORF73 as a fusion protein with glutathione-S transferase (GST) in Escherichia coli (JM109, Toyobo, Toyama, Japan). The fusion protein (GST-ORF73) was affinity purified using glutathione-Sepharose as described previously.³¹ The purity and concentration of the eluted protein was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Bradford assay (Protein Assay, BioRad, New York, NY), respectively.

Production of an Anti-ORF73 Antibody (PA1–73N)

Purified GST-ORF73 in Freund's complete adjuvant (Difco Laboratories, Detroit, MI) was used to immunize New Zealand White rabbits to produce anti-ORF73 polyclonal antibodies. Immune sera were collected from the rabbits and partially purified twice by ammonium sulfate precipitation, and the precipitates were dissolved in PBS. The protein solution was passed through a GST-Sepharose column to remove the anti-GST antibodies before the desired antibody was affinity purified using GST-ORF73 coupled to activated CH-Sepharose (Pharmacia). The purified antibody, designated PA1–73N, was used in the following experiments.

Immunofluorescent Assay (IFA) Using PA1–73N and Sera from KS Patients

To detect the LANA protein of HHV-8, IFA of cell smears was carried out as described previously.^26-28 Sera from AIDS-KS patients and PA1–73N were mixed and diluted to 1:200 in PBS/1% bovine serum albumin (BSA) and used as the primary antibodies. TY-1 cells smeared on spotted slides and fixed in acetone were incubated with the primary antibodies for 60 minutes at 37°C and then washed extensively in PBS. The secondary antibodies, fluorescein isothiocyanate (FITC)-conjugated goat anti-human IgG (Tago Immunologicals, Camarillo, CA) and Texas-red-conjugated goat anti-rabbit IgG (Cappel, Organon Teknika Co., Durham, NC), were applied at a dilution of 1:50 in PBS for 30 minutes. The slides were then washed extensively in PBS and mounted with buffered glycerin. Imaging was performed using a confocal microscope equipped with an argon-krypton laser (LSM-MicroSystem, Zeiss, Germany). Texas red was excited at 568 nm, and FITC was excited at 488 nm. The emission patterns of the two fluorescent labels were collected separately, and the data were overlaid by a computer to create two-color images.

Western Blot Assay

Western blotting was carried out using PA1–73N and sera from AIDS-KS patients. The cell lines examined for GST and GST-ORF73 expression were BCBL-1 (HHV-8 positive and EBV negative, kindly provided by Dr. Brian Herndier),¹⁶ TY-1 (HHV-8 positive, EBV negative)¹⁵ , Raji (HHV-8 negative, EBV positive), and Molt-4 (HHV-8 negative, EBV negative). To assess the specificity of PA1–73N, excess GST-ORF73 (100 µg/ml) was added to the dilution buffer.

Immunohistochemistry

To investigate the expression of ORF73 protein in tissues, 26 KS biopsy specimens from 25 cutaneous lesions and one lymph node, together with 30 specimens from non-KS tissues, were fixed in 10% buffered formalin and embedded in paraffin. Twenty-one of the cutaneous KS specimens were in the nodular stage and four were in the patchy stage. Sections (4 µm) were deparaffinized by sequential immersion in xylene and ethanol and rehydrated in distilled water. They were then irradiated for 15 minutes in a microwave oven for antigen retrieval. Endogenous peroxidase activity was blocked by immersing the sections in methanol/0.6% H₂O₂ for 30 minutes at room temperature. Affinity-purified PA1–73N antibody, diluted 1:3000 in PBS/5% BSA, was then applied, and the sections were incubated overnight at 4°C. After washing in PBS twice, the second and third reactions and the amplification procedure were performed using kits according to the manufacturer's instructions (catalyzed signal amplification system kit, DAKO, Copenhagen, Denmark). The signal was visualized using 0.2 mg/ml diaminobenzidine and 0.015% H₂O₂ in 0.05 mol/L Tris-HCl, pH 7.6. Double immunostaining was performed as described previously.³² Mouse monoclonal antibodies against CD34 (DAKO), factor-VIII-related antigen (DAKO), vimentin (DAKO), and CD68 (KP-1, DAKO) were each used as the first primary antibody followed by PA1–73N. To detect one of the lytic proteins of HHV-8, a rabbit polyclonal antibody against an HHV-8-encoded ORF59 protein was used.^33,34

	Results

Top Abstract Introduction Materials and Methods Results Discussion References

 
IFA of HHV-8-Infected Cells

IFA of the HHV-8-infected cell line TY-1 using PA1–73N (the anti-ORF73 antibody) produced a dot-like pattern of nuclear staining (Figure 1a) . This staining pattern overlapped the staining pattern produced by sera from patients with KS (Figure 1, b and c) . Close observation showed that the staining pattern of the KS sera was broader than that of PA1–73N because patient sera recognized other HHV-8 antigens in addition to LANA. These data suggest that PA1–73N recognizes LANA.

View larger version (22K): [in this window] [in a new window]   Figure 1. Immunofluorescence assay using a rabbit antibody to recombinant ORF73 protein, PA1–73N, and AIDS-KS serum. Double labeling of IFA was carried out on TY-1 cells by using PA1–73N (a) and AIDS-KS serum (b). Texas-red-conjugated anti-rabbit and FITC-conjugated anti-human IgG antibodies were used as secondary antibodies. c: A dual image indicated that the staining of PA1–73N was overlapped completely on that of AIDS-KS serum.

PA1–73N reacted with GST-ORF73 and with several proteins, ranging from 120 to 222 and 234 kd, that were present in the lysates of both BCBL-1 and TY-1 cells (Figure 2a) . PA1–73N did not recognize GST or any proteins from the HHV-8-negative cell lines Raji and Molt-4 (Figure 2a) . Preincubation with excess GST-ORF73 blocked these positive reactions completely (Figure 2b) . By contrast, AIDS-KS sera reacted with many protein bands from 120 to 222 and 234 kd. These findings indicate that PA1–73N identified LNAs that are present in BCBL-1 and TY-1 cells and that these proteins are specific to HHV-8-infected cells.

View larger version (27K): [in this window] [in a new window]   Figure 2. Western blot analysis of PA1–73N and AIDS-KS serum. Lane 1, BCBL-1 (HHV-8-positive, EBV-negative cell line); lane 2, TY-1 (HHV-8-positive, EBV-negative cell line); lane 3, Raji (HHV-8-negative, EBV-positive B-cell line); lane 4, Molt-4 (HHV-8-negative, EBV-negative T-cell line); lane 5, GST protein (26 kd, open arrowhead); lane 6, recombinant GST-ORF73 protein (approximately 53 kd, closed arrowhead). a: PA1–73N recognized several proteins ranging from 120 to 234 kd. These bands were detected in the cell lysates of two HHV-8-infected PEL cell lines, BCBL-1 and TY-1, but not in two HHV-8-negative cell lines, Raji and Molt-4. The recombinant GST-ORF73 was stained with PA1–73N, whereas GST protein was not stained. b: The recombinant GST-ORF73 protein blocked the reaction of anti-ORF73 rabbit antibody with the 53-kd protein and recombinant GST-ORF73 protein completely. c: AIDS-KS serum reacted with several proteins, including 120- to 234-kd proteins in BCBL-1 and TY-1 cells. AIDS-KS serum also reacted with a recombinant GST-ORF73 protein.

The expression of ORF73 protein in KS tissues was examined by staining tissue sections with PA1–73N. Specific positive reactions were noted in the nuclei of KS cells (Figure 3c) . High-power views showed that PA1–73N produced a dot-like nuclear staining pattern on over 90% of the spindle-shaped cells (Figure 3d) . A positive signal was not observed in non-tumor endothelial cells, fibroblasts, or macrophages or in lymphocytes infiltrating in the KS lesions. On the other hand, ORF59 protein, which is a lytic protein encoded by HHV-8, was expressed by only a small proportion of the KS tumor cells (Figure 3b) . Furthermore, the ORF59-positive cells did not react with PA1–73N (data not shown). The PA1–73N nuclear staining pattern was similar in all 24 KS tissue specimens from AIDS-KS patients and in the two specimens from KS patients without HIV infection, whereas PA1–73N did not label the normal tissues of various organs (skin, gastrointestinal tract, liver, lung, kidney, and spleen) or non-KS lesions (angiosarcoma, hemangioma, scar tissue, and granulation tissue; data not shown). The KS330₂₃₃³ or KS330₁₅₃³⁵ DNA products were amplified successfully by PCR from the total DNA of each immunohistochemically positive case (data not shown). The lymph node specimen showed ORF73 antigen exclusively in the nuclei of the KS tumor cells (Figure 3, e and f) . Double staining of the KS sections showed that a small number of the ORF73-positive cells also expressed CD34 and vimentin. However, most of the KS cells did not express any of the cell-specific markers tested: CD34, vimentin, CD68, and factor-VIII-related antigen (data not shown). These data indicate that ORF73 protein is specifically expressed by most KS spindle-shaped cells, which suggests that the majority of KS spindle-shaped cells are infected with HHV-8 in the latent phase.

View larger version (173K): [in this window] [in a new window]   Figure 3. Immunohistochemistry of ORF73 in KS. a: Hematoxylin and eosin staining of a biopsy specimen of nodular KS. b: Demonstration of the HHV-8 lytic protein. ORF59 antigen is detected in a small number of KS cells. c and d: Stained with affinity-purified rabbit antibodies to ORF73. A large proportion of KS tumor cells expressed ORF73 antigen in their nuclei. e and f: ORF73 antigen is demonstrated exclusively in KS lesion in an inguinal lymph node. Any lymphocytes do not express ORF73 antigen.

	Discussion

Top Abstract Introduction Materials and Methods Results Discussion References

We have confirmed that PA1–73N binds specifically to ORF73 protein: 1) PA1–73N IFA staining completely overlapped the LANA distribution pattern in TY-1 cells, 2) similar results were obtained when Western blotting was performed using PA1–73N and the serum of a patient with AIDS-KS, and 3) PA1–73N labeled only KS tumor cells, not other cell types.

In our Western blot analysis PA1–73N recognized not only the 222- or 234-kd proteins of LNA but also several proteins ranging from 120 to 220 kd in size, which were also recognized by sera from patients with AIDS-KS. Two groups^20,37 reported the presence of mRNA splice variants that are produced using a common promoter by a cluster of latently expressed genes encoding ORF K13, ORF72, and ORF73. ISH has shown that these RNAs are present in at least 70% of the spindle-shaped cells in KS tumors.²⁰ Although the sizes of these mRNAs were reported as 1.7, 5.4, and 5.7 kb, no splicing site was detected in ORF73. Therefore, we think that the small sizes of bands from 120 to 222 kd were generated by degradation of LNA, which differ in size from the reported ones (222 and 234 kd).

The results of our immunohistochemical examination indicate that ORF73 protein is specifically expressed in KS spindle-shaped cells and not in non-tumor endothelial cells or macrophages in KS lesions. Some previous studies have demonstrated that macrophages in KS lesions were infected with HHV-8,²⁵ but we could not obtain any evidence for the infection to macrophages in the present study. Generally, immunohistochemical localization is superior to and far cleaner than ISH studies. Thus, the present study clearly confirmed that HHV-8 infected spindle tumor cells and was not detected in non-tumor endothelial cells or the majority of macrophages infiltrating KS lesions. It is known that some KS tumor cells are positive for CD34, CD68, factor-VIII-related antigen, vimentin, and smooth muscle actin. However, these antigens are not specific to KS and cannot be used as markers of this disease.² Our immunohistochemical data suggest that the ORF73 protein can be used as a diagnostic marker for KS and that the antibody PA1–73N is a useful tool for detecting HHV-8-infected cells in the latent phase.

The findings of the present study indicate that HHV-8 infects most KS cells. Based on the findings for other oncogenic viruses, ie, EBV, human papillomavirus, human T-cell leukemia/lymphoma virus type 1, hepatitis B virus, and hepatitis C virus, we believe that the association of KS with HHV-8 infection has been confirmed by this immunohistochemical study of KS tumor cells.

	Acknowledgements

 
We thank Dr. Brian Herndier, University of California at San Francisco, for providing an HHV-8 cell line, BCBL-1. We acknowledge the following doctors for providing KS specimens: R. Muraki, National Kasumigaura Hospital; S. Fuyama, Yamagata University; M. Kawashima, Tokyo Women's University; M. Hoshikawa, St. Marianna University; S. Saiki, St. Lukes International Hospital; T. Tsuruoka, Toho University; A. Honda and I. Sakurai, Nippon University; H. Koizumi, Hokkaido University; and N. Wada, Keio University.

	Footnotes

 
Address reprint requests to Dr. T. Sata, Laboratory of Pathology, AIDS Research Center, and Department of Pathology, National Institute of Infectious Diseases, 1–23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan. E-mail: tsata{at}nih.go.jp

Supported by a Grant-in-Aid for Scientific Research from the Ministry of Health and Welfare.

Accepted for publication March 31, 1999.

	References

Top Abstract Introduction Materials and Methods Results Discussion References

 

1. Kaposi M: Idiopatiches multiples pigment sarcom der Haut. Arch Dermatol Syphil 1872, 4:265-272
2. Buchbinder A, Huang YQ, Cockerell CJ, Friedman-Kien AE: Clinical manifestations and histopathologic features of classic, endemic African, and epidemic AIDS-associated Kaposi's sarcoma. Friedman-Kien AE Cockerell CJ eds. Color Atlas of AIDS. 1996, :pp 35-80 WB Saunders, Philadelphia
3. Chang Y, Cesarman E, Pessin MS, Lee F, Culpepper J, Knowles DM, Moore PS: Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi's sarcoma. Science 1994, 266:1865-1869[Abstract/Free Full Text]
4. Huang YQ, Li JJ, Kaplan MH, Poiesz B, Katabira E, Zhang WC, Feiner D, Friedman KA: Human herpesvirus-like nucleic acid in various forms of Kaposi's sarcoma. Lancet 1995, 345:759-761[Medline]
5. Dupin N, Grandadam M, Calvez V, Gorin I, Aubin JT, Havard S, Lamy F, Leibowitch M, Huraux JM, Escande JP, Agut H: Herpesvirus-like DNA sequences in patients with Mediterranean Kaposi's sarcoma. Lancet 1995, 345:761-762[Medline]
6. Moore PS, Chang Y: Detection of herpesvirus-like DNA sequences in Kaposi's sarcoma in patients with and without HIV infection. N Engl J Med 1995, 332:1181-1185[Abstract/Free Full Text]
7. Staskus KA, Zhong W, Gebhard K, Herndier B, Wang H, Renne R, Beneke J, Pudney J, Anderson DJ, Ganem D, Haase AT: Kaposi's sarcoma-associated herpesvirus gene expression in endothelial (spindle) tumor cells. J Virol 1997, 71:715-719[Abstract]
8. Nador RG, Cesarman E, Chadburn A, Dawson DB, Ansari MQ, Said J, Knowles DM: Primary effusion lymphoma: a distinct clinicopathologic entity associated with the Kaposi's sarcoma-associated herpes virus. Blood 1996, 88:645-656[Abstract/Free Full Text]
9. Cesarman E, Chang Y, Moore PS, Said JW, Knowles DM: Kaposi's sarcoma-associated herpesvirus-like DNA sequences in AIDS-related body-cavity-based lymphomas. N Engl J Med 1995, 332:1186-1191[Abstract/Free Full Text]
10. Arvanitakis L, Mesri EA, Nador RG, Said JW, Asch AS, Knowles DM, Cesarman E: Establishment and characterization of a primary effusion (body cavity-based) lymphoma cell line (BC-3) harboring Kaposi's sarcoma-associated herpesvirus (KSHV/HHV-8) in the absence of Epstein-Barr virus. Blood 1996, 88:2648-2654[Abstract/Free Full Text]
11. Carbone A, Cilia AM, Gloghini A, Canzonieri V, Pastore C, Todesco M, Cozzi M, Perin T, Volpe R, Pinto A, Gaidano G: Establishment of HHV-8-positive and HHV-8-negative lymphoma cell lines from primary lymphomatous effusions. Int J Cancer 1997, 73:562-569[Medline]
12. Carbone A, Cilia AM, Gloghini A, Capello D, Todesco M, Quattrone S, Volpe R, Gaidano G: Establishment and characterization of EBV-positive and EBV-negative primary effusion lymphoma cell lines harbouring human herpesvirus type- 8. Br J Haematol 1998, 102:1081-1089[Medline]
13. Gaidano G, Cechova K, Chang Y, Moore PS, Knowles DM, Dalla F: Establishment of AIDS-related lymphoma cell lines from lymphomatous effusions. Leukemia 1996, 10:1237-1240[Medline]
14. Said W, Chien K, Takeuchi S, Tasaka T, Asou H, Cho SK, de VS, Cesarman E, Knowles DM, Koeffler HP: Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8) in primary effusion lymphoma: ultrastructural demonstration of herpesvirus in lymphoma cells. Blood 1996, 87:4937-4943[Abstract/Free Full Text]
15. Katano H, Hoshino Y, Morishita Y, Nakamura T, Satoh H, Iwamoto A, Herndier B, Mori S: Establishing and characterizing a CD30-positive cell line harboring HHV-8 from primary effusion lymphoma. J Med Virol 1999 (in press)
16. Renne R, Zhong W, Herndier B, McGrath M, Abbey N, Kedes D, Ganem D: Lytic growth of Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) in culture. Nature Med 1996, 2:342-346[Medline]
17. Soulier J, Grollet L, Oksenhendler E, Cacoub P, Cazals-Hatem D, Babinet P, d'Agay MF, Clauvel JP, Raphael M, Degos L, Sigaux F: Kaposi's sarcoma-associated herpesvirus-like DNA sequences in multicentric Castleman's disease. Blood 1995, 86:1276-1280[Abstract/Free Full Text]
18. Boshoff C, Schulz TF, Kennedy MM, Graham AK, Fisher C, Thomas A, McGee JO, Weiss RA, O'Leary JJ: Kaposi's sarcoma-associated herpesvirus infects endothelial and spindle cells. Nature Med 1995, 1:1274-1278[Medline]
19. Davis MA, Sturzl MA, Blasig C, Schreier A, Guo HG, Reitz M, Opalenik SR, Browning PJ: Expression of human herpesvirus 8-encoded cyclin D in Kaposi's sarcoma spindle cells. J Natl Cancer Inst 1997, 89:1868-1874[Abstract/Free Full Text]
20. Dittmer D, Lagunoff M, Renne R, Staskus K, Haase A, Ganem D: A cluster of latently expressed genes in Kaposi's sarcoma-associated herpesvirus. J Virol 1998, 72:8309-8315[Abstract/Free Full Text]
21. Orenstein JM, Alkan S, Blauvelt A, Jeang KT, Weinstein MD, Ganem D, Herndier B: Visualization of human herpesvirus type 8 in Kaposi's sarcoma by light and transmission electron microscopy. AIDS 1997, 11:F35-F45[Medline]
22. Li JJ, Huang YQ, Cockerell CJ, Friedman KA: Localization of human herpes-like virus type 8 in vascular endothelial cells and perivascular spindle-shaped cells of Kaposi's sarcoma lesions by in situ hybridization. Am J Pathol 1996, 148:1741-1748[Abstract]
23. Sturzl M, Blasig C, Schreier A, Neipel F, Hohenadl C, Cornali E, Ascherl G, Esser S, Brockmeyer NH, Ekman M, Kaaya EE, Tschachler E, Biberfeld P: Expression of HHV-8 latency-associated T0.7 RNA in spindle cells and endothelial cells of AIDS-associated, classical and African Kaposi's sarcoma. Int J Cancer 1997, 72:68-71[Medline]
24. Reed JA, Nador RG, Spaulding D, Tani Y, Cesarman E, Knowles DM: Demonstration of Kaposi's sarcoma-associated herpes virus cyclin D homolog in cutaneous Kaposi's sarcoma by colorimetric in situ hybridization using a catalyzed signal amplification system. Blood 1998, 91:3825-3832[Abstract/Free Full Text]
25. Blasig C, Zietz C, Haar B, Neipel F, Esser S, Brockmeyer NH, Tschachler E, Colombini S, Ensoli B, Sturzl M: Monocytes in Kaposi's sarcoma lesions are productively infected by human herpesvirus 8. J Virol 1997, 71:7963-7968[Abstract]
26. Simpson GR, Schulz TF, Whitby D, Cook PM, Boshoff C, Rainbow L, Howard MR, Gao SJ, Bohenzky RA, Simmonds P, Lee C, de RA, Hatzakis A, Tedder RS, Weller IV, Weiss RA, Moore PS: Prevalence of Kaposi's sarcoma associated herpesvirus infection measured by antibodies to recombinant capsid protein and latent immunofluorescence antigen. Lancet 1996, 348:1133-1138[Medline]
27. Kedes DH, Ganem D, Ameli N, Bacchetti P, Greenblatt R: The prevalence of serum antibody to human herpesvirus 8 (Kaposi sarcoma-associated herpesvirus) among HIV-seropositive and high-risk HIV-seronegative women. J Am Med Assoc 1997, 277:478-481[Abstract]
28. Gao SJ, Kingsley L, Hoover DR, Spira TJ, Rinaldo CR, Saah A, Phair J, Detels R, Parry P, Chang Y, Moore PS: Seroconversion to antibodies against Kaposi's sarcoma-associated herpesvirus-related latent nuclear antigens before the development of Kaposi's sarcoma. N Engl J Med 1996, 335:233-241[Abstract/Free Full Text]
29. Rainbow L, Platt GM, Simpson GR, Sarid R, Gao SJ, Stoiber H, Herrington CS, Moore PS, Schulz TF: The 222- to 234-kilodalton latent nuclear protein (LNA) of Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) is encoded by orf73 and is a component of the latency-associated nuclear antigen. J Virol 1997, 71:5915-5921[Abstract]
30. Russo JJ, Bohenzky RA, Chien MC, Chen J, Yan M, Maddalena D, Parry JP, Peruzzi D, Edelman IS, Chang Y, Moore PS: Nucleotide sequence of the Kaposi sarcoma-associated herpesvirus (HHV8). Proc Natl Acad Sci USA 1996, 93:14862-14867[Abstract/Free Full Text]
31. Smith DB, Johnson KS: Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene 1988, 67:31-40[Medline]
32. Katano H, Morishita Y, Cui LX, Watanabe T, Hirai K, Mori S: Expression of latent membrane protein 1 in clinically isolated cases and animal models of AIDS-associated non-Hodgkin's lymphomas. Pathol Int 1996, 46:568-574[Medline]
33. Chan SR, Bloomer C, Chandran B: Identification and characterization of human herpesvirus-8 lytic cycle- associated ORF 59 protein and the encoding cDNA by monoclonal antibody. Virology 1998, 240:118-126[Medline]
34. Katano H, Sata T, Suda T, Nakamura T, Tachikawa N, Nishizumi H, Sakurada S, Hayashi Y, Koike M, Iwamoto A, Kurata T, Mori S: Expression and antigenicity of human herpesvirus 8 encoded ORF59 protein in AIDS-associated Kaposi's sarcoma. J Med Virol 1999 (in press)
35. Mitsuishi T, Sata T, Matsukura T, Kawashima M: HHV8 is rarely found in Bowen's disease of the hands. Br J Dermatol 1997, 136:803-804
36. Said JW, Chien K, Tasaka T, Koeffler HP: Ultrastructural characterization of human herpesvirus 8 (Kaposi's sarcoma-associated herpesvirus) in Kaposi's sarcoma lesions: electron microscopy permits distinction from cytomegalovirus (CMV). J Pathol 1997, 182:273-281[Medline]
37. Sarid R, Wiezorek JS, Moore PS, Chang Y: Characterization and cell cycle regulation of the major Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) latent genes and their promoter. J Virol 1999, 73:1438-1446[Abstract/Free Full Text]

This article has been cited by other articles:

				J. Liu, H. Martin, M. Shamay, C. Woodard, Q.-Q. Tang, and S. D. Hayward Kaposi's Sarcoma-Associated Herpesvirus LANA Protein Downregulates Nuclear Glycogen Synthase Kinase 3 Activity and Consequently Blocks Differentiation J. Virol., May 1, 2007; 81(9): 4722 - 4731. [Abstract] [Full Text] [PDF]

				Y. Murakami, S. Yamagoe, K. Noguchi, Y. Takebe, N. Takahashi, Y. Uehara, and H. Fukazawa Ets-1-dependent Expression of Vascular Endothelial Growth Factor Receptors Is Activated by Latency-associated Nuclear Antigen of Kaposi's Sarcoma-associated Herpesvirus through Interaction with Daxx J. Biol. Chem., September 22, 2006; 281(38): 28113 - 28121. [Abstract] [Full Text] [PDF]

				S. Sakakibara, K. Ueda, K. Nishimura, E. Do, E. Ohsaki, T. Okuno, and K. Yamanishi Accumulation of Heterochromatin Components on the Terminal Repeat Sequence of Kaposi's Sarcoma-Associated Herpesvirus Mediated by the Latency-Associated Nuclear Antigen J. Virol., July 15, 2004; 78(14): 7299 - 7310. [Abstract] [Full Text] [PDF]

				K Kamiyama, T Kinjo, K Chinen, T Iwamasa, H Uezato, J-i Miyagi, N Mori, and N Yamane Human herpesvirus 8 (HHV8) sequence variations in HHV8 related tumours in Okinawa, a subtropical island in southern Japan J. Clin. Pathol., May 1, 2004; 57(5): 529 - 535. [Abstract] [Full Text] [PDF]

				S. C. Verma and E. S. Robertson ORF73 of Herpesvirus Saimiri Strain C488 Tethers the Viral Genome to Metaphase Chromosomes and Binds to cis-Acting DNA Sequences in the Terminal Repeats J. Virol., December 1, 2003; 77(23): 12494 - 12506. [Abstract] [Full Text] [PDF]

				S.-J. Gao, J.-H. Deng, and F.-C. Zhou Productive Lytic Replication of a Recombinant Kaposi's Sarcoma-Associated Herpesvirus in Efficient Primary Infection of Primary Human Endothelial Cells J. Virol., September 15, 2003; 77(18): 9738 - 9749. [Abstract] [Full Text] [PDF]

				C. Tomescu, W. K. Law, and D. H. Kedes Surface Downregulation of Major Histocompatibility Complex Class I, PE-CAM, and ICAM-1 following De Novo Infection of Endothelial Cells with Kaposi's Sarcoma-Associated Herpesvirus J. Virol., September 1, 2003; 77(17): 9669 - 9684. [Abstract] [Full Text] [PDF]

				M. Fujimuro and S. D. Hayward The Latency-Associated Nuclear Antigen of Kaposi's Sarcoma-Associated Herpesvirus Manipulates the Activity of Glycogen Synthase Kinase-3{beta} J. Virol., July 15, 2003; 77(14): 8019 - 8030. [Abstract] [Full Text] [PDF]

				B.-S. Lee, M. Connole, Z. Tang, N. L. Harris, and J. U. Jung Structural Analysis of the Kaposi's Sarcoma-Associated Herpesvirus K1 Protein J. Virol., July 15, 2003; 77(14): 8072 - 8086. [Abstract] [Full Text] [PDF]

				T. Watanabe, M. Sugaya, A. M. Atkins, E. A. Aquilino, A. Yang, D. L. Borris, J. Brady, and A. Blauvelt Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen Prolongs the Life Span of Primary Human Umbilical Vein Endothelial Cells J. Virol., June 1, 2003; 77(11): 6188 - 6196. [Abstract] [Full Text] [PDF]

				F.-C. Zhou, Y.-J. Zhang, J.-H. Deng, X.-P. Wang, H.-Y. Pan, E. Hettler, and S.-J. Gao Efficient Infection by a Recombinant Kaposi's Sarcoma-Associated Herpesvirus Cloned in a Bacterial Artificial Chromosome: Application for Genetic Analysis J. Virol., May 13, 2002; 76(12): 6185 - 6196. [Abstract] [Full Text] [PDF]

				L. J. Coulter and H. W. Reid Isolation and expression of three open reading frames from ovine herpesvirus-2 J. Gen. Virol., March 1, 2002; 83(3): 533 - 543. [Abstract] [Full Text] [PDF]

				K. Mattsson, C. Kiss, G. M. Platt, G. R. Simpson, E. Kashuba, G. Klein, T. F. Schulz, and L. Szekely Latent nuclear antigen of Kaposi's sarcoma herpesvirus/human herpesvirus-8 induces and relocates RING3 to nuclear heterochromatin regions J. Gen. Virol., January 1, 2002; 83(1): 179 - 188. [Abstract] [Full Text] [PDF]

				S. Sakurada, H. Katano, T. Sata, H. Ohkuni, T. Watanabe, and S. Mori Effective Human Herpesvirus 8 Infection of Human Umbilical Vein Endothelial Cells by Cell-Mediated Transmission J. Virol., August 15, 2001; 75(16): 7717 - 7722. [Abstract] [Full Text] [PDF]

				C. Rivas, A.-E. Thlick, C. Parravicini, P. S. Moore, and Y. Chang Kaposi's Sarcoma-Associated Herpesvirus LANA2 Is a B-Cell-Specific Latent Viral Protein That Inhibits p53 J. Virol., January 1, 2001; 75(1): 429 - 438. [Abstract] [Full Text]

				D. R. Schwam, R. L. Luciano, S. S. Mahajan, L. Wong, and A. C. Wilson Carboxy Terminus of Human Herpesvirus 8 Latency-Associated Nuclear Antigen Mediates Dimerization, Transcriptional Repression, and Targeting to Nuclear Bodies J. Virol., September 15, 2000; 74(18): 8532 - 8540. [Abstract] [Full Text]

				H. Katano, T. Iwasaki, N. Baba, M. Terai, S. Mori, A. Iwamoto, T. Kurata, and T. Sata Identification of Antigenic Proteins Encoded by Human Herpesvirus 8 and Seroprevalence in the General Population and among Patients with and without Kaposi's Sarcoma J. Virol., April 15, 2000; 74(8): 3478 - 3485. [Abstract] [Full Text]

This Article Abstract Full Text (PDF) Purchase Article View Shopping Cart Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Katano, H. Articles by Sata, T. Search for Related Content PubMed PubMed Citation Articles by Katano, H. Articles by Sata, T.