Ectopic lymphokine gene expression in human peripheral blood lymphocytes in vivo

An animal model to study the effects of ectopic expression of cytokines involved in cell growth and differentiation has been established. Retrovirus vectors containing the human interleukin 6 cDNA were used to produce high titer virus-producing lines. Human peripheral blood lymphocytes (hPBLs) were successfully infected with the retrovirus and engrafted into severe combined immunodeficient mice. The majority of the animals were engrafted with hPBLs, as determined by the presence of human glucose phosphate isomerase. Furthermore, six of seven mice engrafted with hPBLs infected with high titer virus and detectable hPBLs present in the spleen expressed the retroviral human interleukin 6 gene. Importantly, human interleukin 6 protein was expressed at physiologically significant levels in these mice. These results demonstrate that models for human disease and immunotherapy involving retrovirus-mediated gene transfer into human cells can be developed in mice.