A cassette vector for high-level reporter expression driven by a hybrid invariant chain promoter in transgenic mice

A plasmid cassette vector was designed to generate transgenic mice expressing reporter cDNAs at high levels in antigen-presenting cells under the control of the murine invariant chain (Ii) promoter. Analysis of several transgenic mice harboring a chimeric Ii cDNA placed in this vector showed that it can drive expression of the reporter protein to levels comparable to those of endogenous Ii. Furthermore, its expression pattern overlaps quite well with that of endogenous Ii. This vector should therefore be a convenient and versatile tool for the generation of transgenic mouse lines in which a desired protein may be expressed in Ii-positive cells at levels similar to those of endogenous Ii. Such a vector would be ideal for complementation studies of Ii-deficiency by specific Ii variants.