Date of Completion

Spring 5-1-2014

Thesis Advisor(s)

Pramod K Srivastava

Honors Major

Molecular and Cell Biology

Disciplines

Allergy and Immunology | Biochemistry | Biological Engineering | Biological Phenomena, Cell Phenomena, and Immunity | Cancer Biology | Disease Modeling | Genetics | Immunity | Immunoprophylaxis and Therapy | Medical Immunology | Oncology

Abstract

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, while ovalbumin and CFP should only be expressed after a single base pair deletion that can restore the frame, has occurred. Experiments in vitro have been conducted to test whether the transgene behaves they way we expect. Transfection of EL4 cells with the transgene caused cells to express YFP. After growing the transfected cells (thus allowing time for spontaneous mutations), populations of YFP+CFP- and YFP+CFP+ cells were sorted and grown. The YFP+CFP- cells did not present SIINFEKL on H2-Kb on their surfaces, while YFP+CFP+ cells did; this was tested by incubating the cells with B3Z cells, which respond to the SIINFEKL/H2-Kb complex. The mouse model will be used to measure the rate of mutation in the transgene in vivo, investigate the immune response to mutation-generated antigens in a growing tumor in a live host, and test the hypothesis that an immune response to neoantigens on non-transformed somatic cells contributes to aging.