A Study on the Tropism of Epstein-Barr Virus

Chung, Choon Hae; Lee, Mi Ja; Jeon, Ho Jong

Abstract

PURPOSE: The Epstein-Barr Virus (EBV) is associated with a variety of human lymphocytic and epithelial malignancies. EBV is thought to display exclusive tropism for B lymphocytes, follicular dendritic cells, and pharyngeal epithelia via specific receptors (C3d receptors, CR2, CD21). Recent evidence, however, challenged this belief. We designed this experiment to determine the incidence of EBV receptor in various malignant tumor cell lines and normal lymphocyte subsets.
MATERIALS AND METHODS
We have examined the incidence of EBV receptor, CD21 on the 10 healthy adult peripheral blood (PB), 10 umbilical cord blood (CB), 4 immortalized lymphoblastoid B cells by EBV infection (CSUP-1, CSUP-2, CSUP-3, CSUP-4), 3 EBV-positive B cell lymphoma cell lines (Jiyoye, IM-9, PTLC-1), 1 EBV-negative B cell lymphoma cell line (JeKo-1), 3 T cell lymphoma and leukemia cell lines (CCRF-CEM, H9, CEM-CM3), one histiocytic lymphoma cell line (U-937) and 5 gastric cancer cell lines (KATO III, AGS, SNU-1, SNU-5, and SNU-16). EBV receptor, C3d receptor was identified by flow cytometry (FACSCalibur) using FITC-conjugated or PE-conjugated CD21 monoclonal antibody. Also we investigated the expression of CD3, CD5, CD7, CD19, CD20, IgM, IgG, Ig and Ig by using FITC-conjugated or PE-conjugated monoclonal antibody, on above cell lines.
RESULTS
The expressions of CD21 molecule were 10.99 3.84% and 9.22 5.39% in adult PB lymphocytes and CB lymphocytes, respectively. The anti-human CD21 antibody was positive for CD19-positive or CD20-positive B lymphocytes. The CD3-positive or CD7-positive T lymphocytes were negative for anti-human CD21 antibody in PB and CB. But, CD21 antibody was weakly positive for CD5-positive lymphocytes. EBV-positive cell lines expressed variable ranges from 0.9% to 5.2% for CD21 antigen, while EBV-negative lymphoma cell line, JeKo-1 expressed 5.5%. All T lymphoma and leukemia cell lines and gastric cancer cell lines did not express CD21 antigen. But U-937 expressed 14.4% for CD21 antigen.
CONCLUSION
These results suggested that the CD21 antigen was expressed in CD20 or CD19-positive mature B cells, CD5-dim positive lymphocytes, some EBV-positive and negative B cell lymphoma cell lines, and a histiocytic lymphoma cell line. Further evaluation on the nature of CD5-dim positive cells, which was expressing CD21 molecule, is revealed, especially in reference to EBV association in some peculiar subtypes of peripheral T cell lymphoma.