Presentation Title

Genetic Engineering of Immune Cells for Specificity and Costimulation in the Glioblastoma Tumor Microenvironment

Start Date

November 2016

End Date

November 2016

Location

MSE 103

Type of Presentation

Oral Talk

Abstract

Adoptive immunotherapy is a field of study involving genetic alteration of the immune system to enhance its effectiveness in eliminating cancer. While T cells have the ability to combat cancer when antigen specific and co-stimulatory signals are provided, cancer cells often engage in immunoregulatory interaction in order to avoid immune detection and rejection by the immune system. This immune evasion involves a down-regulation of co-stimulatory signals and an up-regulation of inhibitory ligands, such as Programmed Death Ligand 1 (PD-L1), which causes T cells to be functionally ineffective following engagement with Programmed Death 1 (PD-1) on their cell surface. In order to counter the PDL1-PD1 interaction, a chimera containing the extracellular portion of PD-1 fused to the intracellular signaling domain of co-stimulatory CD28 was developed and provided moderate co-stimulation as a result of PD-L1 engagement. The current study aims to improve these results by incorporating intracellular domains of co-stimulatory molecules 4-1BB and OX40, in addition to a chimeric antigen receptor (CAR) to specifically target interleukin-13 receptor a2, which is highly expressed on glioblastoma. Upon engagement of the chimera and CAR, it is hypothesized that T cells will show increased proliferation and cytotoxic potential as measured by levels of ERK phosphorylation, cytokine secretion, and Granzyme B expression. Thus far, three novel chimeras were created containing the extracellular portion of PD-1 fused to combinations of the intracellular domains of CD28, 4-1BB, and OX40 in a pcDNA vector, which enabled stable cell line development via antibiotic selection. These chimeras have been tested in T cells by a 24-hour co-culture with tumor cells and found to produce increased levels of cytokine production as compared to parental T cells or T cells expressing the original PD1:CD28 chimera. Ultimately, this study will determine the optimal combination of co-stimulation to overcome PD1-mediated immunosuppression in the glioblastoma tumor microenvironment.

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Nov 12th, 10:15 AM Nov 12th, 10:30 AM

Genetic Engineering of Immune Cells for Specificity and Costimulation in the Glioblastoma Tumor Microenvironment

MSE 103

Adoptive immunotherapy is a field of study involving genetic alteration of the immune system to enhance its effectiveness in eliminating cancer. While T cells have the ability to combat cancer when antigen specific and co-stimulatory signals are provided, cancer cells often engage in immunoregulatory interaction in order to avoid immune detection and rejection by the immune system. This immune evasion involves a down-regulation of co-stimulatory signals and an up-regulation of inhibitory ligands, such as Programmed Death Ligand 1 (PD-L1), which causes T cells to be functionally ineffective following engagement with Programmed Death 1 (PD-1) on their cell surface. In order to counter the PDL1-PD1 interaction, a chimera containing the extracellular portion of PD-1 fused to the intracellular signaling domain of co-stimulatory CD28 was developed and provided moderate co-stimulation as a result of PD-L1 engagement. The current study aims to improve these results by incorporating intracellular domains of co-stimulatory molecules 4-1BB and OX40, in addition to a chimeric antigen receptor (CAR) to specifically target interleukin-13 receptor a2, which is highly expressed on glioblastoma. Upon engagement of the chimera and CAR, it is hypothesized that T cells will show increased proliferation and cytotoxic potential as measured by levels of ERK phosphorylation, cytokine secretion, and Granzyme B expression. Thus far, three novel chimeras were created containing the extracellular portion of PD-1 fused to combinations of the intracellular domains of CD28, 4-1BB, and OX40 in a pcDNA vector, which enabled stable cell line development via antibiotic selection. These chimeras have been tested in T cells by a 24-hour co-culture with tumor cells and found to produce increased levels of cytokine production as compared to parental T cells or T cells expressing the original PD1:CD28 chimera. Ultimately, this study will determine the optimal combination of co-stimulation to overcome PD1-mediated immunosuppression in the glioblastoma tumor microenvironment.