Construction of hu-PBL/SCID chimeras and development of EBV-related lymphomas.
OBJECTIVE
To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV).


METHODS
Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient (SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experimental animals and induced neoplasms.


RESULTS
In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence.


CONCLUSIONS
EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.
Gan
Run-liang
RL
Cancer Research Institute, School of Medicine, Nanhua University, Hengyang 421001. gan998@yahoo.com
Lan
Ke
K
Yin
Zhi-hua
ZH
Wang
Li-jiang
LJ
Song
Ying
Y
Yao
Kai-tai
KT
D000328:Adult; D000818:Animals; D018951:Antigens, CD20 / Q000378:metabolism; D002678:Chimera; D020031:Epstein-Barr Virus Infections / Q000276:immunology / Q000821:virology*; D006086:Graft vs Host Disease / Q000517:prevention & control* / Q000821:virology; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D017493:Leukocyte Common Antigens / Q000378:metabolism; D017708:Leukocyte Transfusion / Q000379:methods; D016393:Lymphoma, B-Cell / Q000276:immunology / Q000821:virology*; D052118:Lysosomal-Associated Membrane Protein 1 / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID
D018951:Antigens, CD20; D052118:Lysosomal-Associated Membrane Protein 1; D017493:Leukocyte Common Antigens