Date of Award

Spring 2019

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)

School

Biological, Environmental, and Earth Sciences

Committee Chair

Yan-Lin Guo

Committee Chair School

Biological, Environmental, and Earth Sciences

Committee Member 2

Alex Flynt

Committee Member 2 School

Biological, Environmental, and Earth Sciences

Committee Member 3

Fengwei Bai

Committee Member 3 School

Biological, Environmental, and Earth Sciences

Abstract

Embryonic stem cells (ESCs) have attracted intense interest due to their great potential for regenerative medicine. However, their immune property is an overlooked but a significant issue that needs to be thoroughly investigated not only to resolve the concern for therapeutic applications but also for further understanding the early stage of organismal development. Recent studies demonstrated that ESCs are deficient in innate immune responses to viral/bacterial infections and inflammatory cytokines. Inflammatory conditions generally inhibit cell proliferation, which could be detrimental to ESCs, since cell proliferation is their dedicated task during early embryogenesis. Thus, I hypothesize that the attenuated innate immunity in ESCs could allow them to evade the cytotoxicity caused by immune reactions and is, therefore, a self-protective mechanism during early embryogenesis. We have differentiated mouse ESCs (mESCs) to fibroblast-like cells (mESC-FBs) which were proved to have partially developed innate immunity. Using these cells as a model for comparison with mESCs, the insensitivity of mESCs to the cytotoxic effects from IFNg, which is an inflammatory cytokine highly presented during early embryogenesis, and other inflammatory conditions were demonstrated, including attenuated expressions of inflammatory and signaling molecules, inactivated transcription factor and unaffected cell viability. Furthermore, basal expressions of protein phosphatases that inhibit IFNg pathway were higher in mESCs than mESC-FBs. Treating mESCs with protein phosphatases inhibitor upregulated the expression of IFNg induced signaling molecule. In all, the attenuated inflammatory responses are beneficial for mESCs, and the inhibition effects from protein phosphatases could, at least, partially explain their attenuated responses to IFNg.

ORCID ID

0000-0002-9781-2982

Available for download on Monday, May 10, 2021

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