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Biomedical subjects

L Boguszaková

Publications and source records attributed to L Boguszaková.

3 recordsLinked to original sources

Epstein-Barr virus nuclear antigen type 1 binding: electron microscopy.

Epstein-Barr virus (EBV) nuclear antigen type-1 (EBNA-1) was extracted and purified from Raji cells by chromatography on DNA-Sepharose and Blue-dextran Sepharose. Its complexes with plasmid pM765-10 derived from EBV (strain M-ABA) DNA were visualized by electron microscopy. The criteria of specificity were as follows: (1) preferential binding of EBNA-1 to the ori-P region of pM765-10; (2) specific enlargement of EBV DNA/EBNA-1 complexes with anti-EBNA-1 (IR-3) IgG antibody; and (3) resistance of the resulting EBV DNA/EBNA-1/anti-EBNA-1 antibody complexes to treatment with 1.5 M NaCl. The optimal conditions for the formation of EBV DNA/EBNA-1 complexes were 50 to 150 mM NaCl and pH 6.0. A balanced equilibrium of EBNA-1 and pM765-10 was necessary to achieve both a high yield and specificity of EBV DNA/EBNA-1 complexes.

Antigens, Viral↗

Absence of cytomegalovirus, Epstein-Barr virus, and papillomavirus DNA from adenoma and adenocarcinoma of the colon.

Biopsy specimens from 13 patients with adenocarcinoma of the colon and from 10 patients with endoscopic polypectomies for colon adenoma were examined for the presence of the DNA of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human papillomavirus (HPV) types 2, 6, 16 and 18. The specific activities of viral DNA probes obtained by nick--translation ranged from 10(7) to 10(8) cpm/micrograms DNA. By Southern blot hybridization with an estimated sensitivity of 10 pg virus DNA which corresponded to 0.05 virus genome equivalents per cell we failed to detect any virus DNA in the biopsy material tested.

Adenocarcinoma↗

Relationship between Epstein-Barr virus nuclear antigen and DNA genome number in superinfected and induced lymphoblastoid cell lines.

The relative contents of Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA) and average numbers of EBV genome equivalents per cell were determined (i) in Raji cells superinfected with P3HR-1 virus, (ii) in Raji cells induced by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and sodium n-butyrate and (iii) in P3HR-1 cells induced by TPA and sodium n-butyrate. This treatment was followed by increases in the percentage of early antigen (in both Raji and P3HR-1 cells) and virus capsid antigen-positive cells (in P3HR-1 cells) and increases of approximately 20-fold in the average number of EBV DNA equivalents in superinfected Raji cells and in TPA- and sodium n-butyrate-induced P3HR-1 cells. However, the content of EBNA in these cells dropped. This was revealed by a decrease in both the complement-fixing antigen content and in the proportion of EBNA-positive cells as determined by anti-complement immunofluorescence. Thus, the positive correlation found previously between the content of EBNA and the number of EBV genome equivalents per cell in proliferating lymphoblastoid cultures does not seem to apply to the situation in either superinfected Raji cells or in P3HR-1 cells induced by TPA and sodium n-butyrate.

Antibody Specificity↗