Publication Date

2014-04-28

Availability

Embargoed

Embargo Period

2016-04-27

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Microbiology and Immunology (Medicine)

Date of Defense

2014-03-13

First Committee Member

Geoffrey W. Stone

Second Committee Member

Eli Gilboa

Third Committee Member

Eckhard R. Podack

Fourth Committee Member

Samita S. Andreansky

Fifth Committee Member

Margaret A. Fischl

Sixth Committee Member

Jacques Banchereau

Abstract

Dendritic cells are a promising cell type for immunotherapy due to their potent immunostimulatory potential. Nevertheless, improper maturation may account for the limited efficacy of dendritic cells in immunotherapy clinical trials. Latent Membrane Protein-1 (LMP1) of the Epstein-Barr virus was examined for its ability to mature and activate dendritic cells as a gene-based molecular adjuvant. Dendritic cells were transduced with an adenoviral vector expressing LMP1 under the control of a Tet- inducible promoter. LMP1 was found to mature and activate both human and mouse dendritic cells. LMP1 enhanced in vitro migration of dendritic cells toward CCL19, as well as in vivo migration of dendritic cells to the inguinal lymph nodes of mice following subcutaneous injection. LMP1-transduced dendritic cells increased T cell proliferation in a Pmel-1 adoptive transfer model and enhanced survival in a B16-F10 melanoma tumor model. LMP1 also enhanced protection in a vaccinia-gag viral challenge model. Surprisingly, LMP1 generated high levels of IL-12p70 secretion in mouse dendritic cells and failed to induce dendritic cell exhaustion when compared to Mimic maturation. LMP1-transduced human dendritic cells were able to secrete IL-12p70 and TNF alpha in response to restimulation. In contrast, Mimic matured DC were impaired in IL-12p70 secretion following restimulation. We propose that LMP1 is a promising molecular adjuvant for dendritic cell therapy, able to mature and activate dendritic cells while allowing IL-12p70 secretion in response to restimulation in the draining lymph node.

Keywords

Dendritic cells; Immunotherapy; Latent Membrane Protein-1; LMP1; EBV; Epstein-Barr virus; cancer

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