Transgenic Mouse Model Of IFNβ Induced MCherry Using A Transposon System

In the immune system of higher organisms,the innate immune and acquired immune systems work together to resist the invasion of foreign pathogens and maintain the body health.As the first line of defense against the invasion of exogenous pathogens,innate immunity is indispensable and stands in the breach.In innate immunity,interferon,as a kind of highly active natural glycoprotein,plays an important role in antiviral,anti-proliferation and immune regulation.Currently known innate immune pathways include TLRs,RIG-I and cGAS-STING pathways all of which are able to induce type Ⅰ interferon production and its down stream responses.In addition,IFN is also involved in the immune function against tumors.Since interferon is an important indicator of innate immune response,it is important to detect its expression sites and levels.However,interferon is only expressed in some cell types and will be diluted once released into the blood,making detection more difficult.On the other hand,due to the high background of green fluorescence,it is inconvenient to observe accurately.Therefore,we selected red fluorescence mCherry as the expression protein induced by IFN promoter to construct the transgenic mouse model for use in the studies of interferon-induced immune functions.In this dissertation,we constructed a recombinant vector system to express mCherry proteins linked to the truncated IFN promoter using the Sleeping beauty transposon/transposon enzyme system and demonstrated IFN promoter driven mCherry protein expression in vitro cells.Then the above plasmid was microinjected into mouse embryos,and the injected embryos were transplanted into the pseudo pregnant mice.The genotype was determined by PCR amplification and sequencing of the genome of offspring mice.The results showed that we successfully constructed the transgenic model mice with mCherry expression under the IFN promoter.Then,the offspring were mated to establish a stable transgenic mouse line.By isolating the primary lung fibroblasts of transgenic mice and stimulating them accordingly,the results showed that the transgenic mice could respond to the corresponding stimuli and express mCherry.The expression of mCherry was synchronous with the expression of IFN,indicating that we successfully constructed a transgenic mouse model of IFN-induced mCherry expression.This mouse model can be used to to study the regulatory mechanism of innate immune signal transduction related pathways.