GSBS Dissertations and Theses

Approval Date

June 1995

Document Type

Doctoral Dissertation

Department

Graduate School of Biomedical Sciences, Program in Immunology/Virology

Subjects

T-Lymphocytes, Cytotoxic; Virus Diseases; Academic Dissertations; Dissertations, UMMS

Abstract

Epstein-Barr virus (EBV) is associated with a spectrum of benign and malignant lymphoproliferative disorders, including acute infectious mononucleosis (IM), Burkitt's lymphoma (BL) and immunosuppression-associated B cell lymphoproliferative disease (LPD). Immunosurveillance mediated by virus-specific cytotoxic T lymphocytes is believed to protect immunocompetent hosts from EBV-associated lymphoma and LPD. Due to the lack of an adequate animal model, however, the precise immunologic mechanisms which provide this protection have not been directly demonstrated in vivo.

Human peripheral blood mononuclear cell-reconstituted C.B.-17-scid/scid mice (hu-PBMC-SCID mice) develop EBV-positive LPD following intraperitoneal injection of PBMC from EBV-seropositive donors. The SCID mouse disease mirrors human EBV-associated LPD in morphology, presence of the EBV genome, clonality, and patterns of expression of latent viral cellular differentiation antigens. The hu-PBMC-SCID mouse provides a unique small animal model of EBV+ LPD, and it was used in this study to examine the role of CD8+ CTL in controlling LPD. Survival time increase significantly when EBV-specific cytotoxic T-cell lines (CTL) are adoptive transferred into hu-PBMC-SCID mice, demonstrating suppression of LPD in vivo by a CTL-mediated virus-specific mechanism. Survival time also increases significantly with administration of alloreactive CTL lines, suggesting that a non-virus-specific mechanism also contributes to control of EBV-associated LPD by CTL.

NOD-SCID mice reconstituted with PBMC from donors with latent EBV infection develop EBV+ LPD with significantly less frequency than do C.B.17-SCID mice reconstituted with PBMC from the same donors. Administration of anti-CD8 mAb to these mice depletes human CD8+ cells and increases the incidence of LPD to 100%, demonstrating that CD8+ T cells are neccessary for protection from EBV-associated LPD. Adoptive transfer of human CD8+ T cells, but not CD4+ T cells, prevents LPD in CD8-depleted NOD-SCID mice. In vivo depletion of CD4+ T cells prevents engraftment of human T cells, and LPD does not develop in most mice after CD4+ cell depletion. These studies are the first to directly demonstrate both the protective role of CD8+ T cells and a requirement for CD4+ T cells in EBV -associated LPD in an in vivo model.

Comments

Some images did not scan well, especially color photos on pages 33 and 64. Please consult original document.

Rights and Permissions

Copyright is held by the author, with all rights reserved.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.