Stable transfection of a human lymphoma line by sub‐genomic fragments of Epstein‐Barr virus DNA to measure humoral and cellular immunity to the corresponding proteins

Welinder, Christina; Larsson, Nils‐Göran; Szigeti, Robert; Ehlin‐Henriksson, Barbro; Henle, Gertrude; Henle, Werner; Klein, George; Ricksten, Anne; Rymo, Lars; Sulitzeanu, D.

doi:10.1002/ijc.2910400318

Cited by 12 publications

(5 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There are a number of previous reports that the level of expression of a transfected sequence may vary greatly from one cell to another in a clonal population. Such an observation has been made for a number of proteins, both membrane and cytoplasmic, with several promoters and in several cell types (Welinder et al, 1987;Ernst et al, 1989;Forsayeth et al, 1990;Miyawaki et al, 1990;KO et al, 1990). There is an earlier report that repeated selection can result in the appearance of a clone of mouse L cells expressing high levels of human (a-l,2)-fucosyltranferase (Ernst et al, 1989).…”

Section: Discussionmentioning

confidence: 88%

Selection of stably transfected cells expressing a high level of fetal muscle nicotinic receptors

Chen

Fletcher

Steinbach

1995

J of Neuroscience Research

View full text Add to dashboard Cite

We had earlier found that the numbers of mouse muscle nicotinic receptors expressed on the surface of individual cells of a stably transfected clonal line of quail fibroblasts varied from cell to cell (Kopta and Steinbach: J Neurosci 14:3922-3933, 1994). We have now used repeated selective passages of these clonal cells to produce a population of cells which expresses a greater and more uniform number of surface receptors per cell. The increased level is stable over many cell divisions, and over many half-lives for the metabolic degradation of the surface receptors. Selection was performed by adhesion to a surface coated with a monoclonal antibody to a surface epitope on the muscle receptor, followed by expansion of the most tightly attached population of cells. Studies of the selected cells show that the surface receptors contain all four subunits of the muscle nicotinic receptor, and the functional properties of the receptors appear normal. The metabolic stability of the surface receptors is not altered, while the amount of mRNA for the subunits is increased in the selected population of cells. These observations indicate that the more likely reason for increased expression is a transcriptional effect, and that translational or posttranslational changes are unlikely.

show abstract

Section: Discussionmentioning

confidence: 88%

Selection of stably transfected cells expressing a high level of fetal muscle nicotinic receptors

Chen

Fletcher

Steinbach

1995

J of Neuroscience Research

View full text Add to dashboard Cite

show abstract

“…In order to determine whether Zta is able to drive activation of the BNLF2a promoter, we cloned a region around the transcription start site of the BNLF2a gene into a luciferase reporter vector (BNLF2a 1–5) (Figs S2, S5 and 4a ). We then introduced this into cells that do not contain EBV: a BL cell line DG75 [ 36 ] and the HeLa epithelial cell line [ 37 ]. Co-transfection with Zta drove induction of BNLF2a 1–5 in both cell types ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Mechanism of activation of the BNLF2a immune evasion gene of Epstein-Barr virus by Zta

Almohammed

Osborn

Ramasubramanyan

et al. 2018

Journal of General Virology

View full text Add to dashboard Cite

The human gamma herpes virus Epstein–Barr virus (EBV) exploits multiple routes to evade the cellular immune response. During the EBV lytic replication cycle, viral proteins are expressed that provide excellent targets for recognition by cytotoxic T cells. This is countered by the viral BNLF2a gene. In B cells during latency, where BNLF2a is not expressed, we show that its regulatory region is embedded in repressive chromatin. The expression of BNLF2a mirrors the expression of a viral lytic cycle transcriptional regulator, Zta (BZLF1, EB1, ZEBRA), in B cells and we propose that Zta plays a role in up-regulating BNLF2a. In cells undergoing EBV lytic replication, we identified two distinct regions of interaction of Zta with the chromatin-associated BNLF2a promoter. We identify five potential Zta-response elements (ZREs) in the promoter that are highly conserved between virus isolates. Zta binds to these elements in vitro and activates the expression of the BNLF2a promoter in both epithelial and B cells. We also found redundancy amongst the ZREs. The EBV genome undergoes a biphasic DNA methylation cycle during its infection cycle. One of the ZREs contains an integral CpG motif. We show that this can be DNA methylated during EBV latency and that both Zta binding and promoter activation are enhanced by its methylation. In summary, we find that the BNLF2a promoter is directly targeted by Zta and that DNA methylation within the proximal ZRE aids activation. The implications for regulation of this key viral gene during the reactivation of EBV from latency are discussed.

show abstract

“…Antibodies to EBNA were assayed by anti-complement immunofluorescence (Reedman and Klein, 1973). Monospecifically transfected DG-75 cells were used to detect antibodies against EBNA I, 2A and 6 respectively (Ricksten et al, 1988;Welinder et al, 1987;Lennette et al, 1993). Rat-1 cells, transfected with the BamHI Y fragment of Ag-876 EBV were used as targets for the EBNA 2B assay.…”

Section: Ebv Serologymentioning

confidence: 99%

Detection of two epstein‐barr‐virus (EBV)‐carrying leukemic cell clones in a patient with chronic lymphocytic leukemia (CLL)

Lewin

Avila‐Cariño

Minárovits

et al. 1995

Intl Journal of Cancer

Self Cite

View full text Add to dashboard Cite

The leukemic-cell population of one CLL patient, PG, was found to contain a sub-set of EBV-genome-carrying cells. It was detected directly by the expression of EBNA (EBV-encoded nuclear antigen) and by its capacity to grow in vitro. The proportion of EBNA-positive cells (0.1%) was maintained constantly during the period of this study, the final 3 years of the patient's life. EBV-carrying clonal sibling B-cell lines were established on 5 occasions. They had identically rearranged JH bands and chromosomal markers corresponding to the ex vivo CLL cells. Analysis of the viral episomes in the lines proved that they were the descendants of one cell. On the last occasion of blood sampling, 8 B-cell lines were established; 4 of these contained the same clonal markers as the previous lines, while 4 other lines belonged to another clone with identical JH rearrangement. Their abnormal karyotypes were different from the first clone. The chromosomal markers were only partly identical, suggesting secondary diversifications. The EBV sub-strain carried by this group of lines was different from the sub-strain of the first clone, as judged by the EBNA size distributions (EBNOtype) and EBV-DNA analysis. Analysis of the terminal repeat in the viral episomes also showed that the first and the second set of clones represented 2 independent EBV-infection events in vivo.

show abstract

Stable transfection of a human lymphoma line by sub‐genomic fragments of Epstein‐Barr virus DNA to measure humoral and cellular immunity to the corresponding proteins

Cited by 12 publications

References 37 publications

Selection of stably transfected cells expressing a high level of fetal muscle nicotinic receptors

Selection of stably transfected cells expressing a high level of fetal muscle nicotinic receptors

Mechanism of activation of the BNLF2a immune evasion gene of Epstein-Barr virus by Zta

Detection of two epstein‐barr‐virus (EBV)‐carrying leukemic cell clones in a patient with chronic lymphocytic leukemia (CLL)

Contact Info

Product

Resources

About