Background: The capacity to activate naïve T cells sets dendritic cells (DCs) apart from other antigen-presenting cells, making them attractive targets for immune intervention during deleterious immune responses. The inherent resistance of terminally differentiated DCs to conventional strategies for genetic modification has, however, greatly limited our understanding of the molecular mechanisms underlying their function.
Methods and results: We report the derivation of long-term cultures of untransformed DCs, uniformly expressing a defined mutant phenotype by the directed differentiation of cloned embryonic stem cells, stably transfected with a reporter gene. Introduction of the gene encoding enhanced green fluorescent protein into pluripotent stem cells demonstrated no observable impact on the phenotype, immunogenicity, or capacity for maturation of DCs differentiated from them.
Conclusions: The production of unlimited numbers of mutant DCs from genetically modified embryonic stem cells paves the way for the systematic elucidation of gene function in this cell type and the rational design of DCs for use in immunotherapy.