scholarly journals Inhibitory Effect of Natural Carotenoids on Epstein-Barr Virus Activation Activity of a Tumor Promoter in Raji Cells. A Screening Study for Anti-tumor Promoters.

1995 ◽  
Vol 18 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Miyuki TSUSHIMA ◽  
Takashi MAOKA ◽  
Masaaki KATSUYAMA ◽  
Mutsuo KOZUKA ◽  
Takao MATSUNO ◽  
...  
Intervirology ◽  
1981 ◽  
Vol 16 (1) ◽  
pp. 29-32 ◽  
Author(s):  
Y. Zeng ◽  
H.M. Zhou ◽  
S.P. Xu

1999 ◽  
Vol 73 (12) ◽  
pp. 9858-9866 ◽  
Author(s):  
Tobias Ragoczy ◽  
George Miller

ABSTRACT Initiation of the Epstein-Barr virus (EBV) lytic cycle is controlled by two immediate-early genes, BZLF1 and BRLF1. In certain epithelial and B-cell lines, their protein products, ZEBRA and Rta, stimulate their own expression, reciprocally stimulate each other’s expression, and activate downstream viral targets. It has been difficult to examine the individual roles of these two transactivators in EBV-infected lymphocytes, as they are expressed simultaneously upon induction of the lytic cycle. Here we show that the Burkitt lymphoma cell line Raji represents an experimental system that allows the study of Rta’s role in the lytic cycle of EBV in the absence and presence of ZEBRA. When expressed in Raji cells, exogenous Rta does not activate endogenous BZLF1 expression, yet Rta remains competent to transactivate certain downstream viral targets. Some genes, such as BaRF1, BMLF1, and a late gene, BLRF2, are maximally activated by Rta itself in the absence of detectable ZEBRA. The use of the Z(S186A) mutant form of ZEBRA, whose transactivation function is manifest only by coexpression of Rta, allows identification of a second class of lytic cycle genes, such as BMRF1 and BHRF1, that are activated in synergy by Rta and ZEBRA. It has already been documented that of the two activators, only ZEBRA stimulates the BRLF1 gene in Raji cells. Thus, there is a third class of viral genes activated by ZEBRA but not Rta. Moreover, ZEBRA exhibits an inhibitory effect on Rta’s capacity to stimulate the late gene, BLRF2. Consequently ZEBRA may function to repress Rta’s potential to activate some late genes. Raji cells thus allow delineation of the combinatorial roles of Rta and ZEBRA in control of several distinct classes of lytic cycle genes.


1996 ◽  
Vol 102 (1-2) ◽  
pp. 223-226 ◽  
Author(s):  
Govind J. Kapadia ◽  
Shekhar C. Sharma ◽  
Harukuni Tokuda ◽  
Hoyoku Nishino ◽  
Shinichi Ueda

2012 ◽  
Vol 56 (3) ◽  
pp. 271-274
Author(s):  
Joanna Krzowska-Firych ◽  
Hanna Fota-Markowska ◽  
Barbara Marzec-Kotarska ◽  
Roma Modrzewska ◽  
Jacek Wojcierowski

Abstract The aim of the study was to assess the expression of TNFRp55 mRNA and to examine if the antisense inhibition of Epstein-Barr virus (EBV) encoded EBNA1 gene product alters the expression of gene encoding TNFRp55 in lymphoblastoid cell line (LCL). The experiment was performed on LCL derived from EBV infected human peripheral blood B lymphocytes. The lymphocytes were isolated and cultured. RNA was isolated and examined according to the RNase protection assay. The hybridisation was done with HCR-4 probe. RNA was quantified by densitometry and presented in extinction units. The level of expression was calculated with TotaILab software programme. The results of the study suggest that EBV gene, responsible for the synthesis of EBNA1 protein, has an inhibitory effect on human TNFRp55 gene expression in LCL.


1999 ◽  
Vol 139 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Yukiko Iwase ◽  
Yuko Takemura ◽  
Motoharu Ju-ichi ◽  
Satoru Kawaii ◽  
Masamichi Yano ◽  
...  

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