A novel approach to deliver hormones using T cells is shown in mice in Nature Communications this week. The research shows the approach is effective in reducing symptoms of anaemia in mouse models of kidney disease.

Patients affected by hormone deficiencies require the delivery of a recombinant protein, the production of which is costly and which needs to be administered via repeated injections. One example is erythropoietin (EPO), a hormone that regulates production of red blood cells. Previous studies in animal models have used viral-based delivery of EPO, but drawbacks include that this method can produce an immune response, and limited control of EPO production. An alternative approach has used the transfer of cells from transgenic mice, which were modified to express EPO in B lymphocytes, into EPO-deficient mice.

Matthew Wilson and colleagues used a non-viral system to modify T cells directly to express EPO, without the need for their production by a transgenic organism. The cells were then transferred into anaemic mouse models of kidney disease. The treatment succeeded in inducing EPO expression and increasing red blood cell production in the mice for up to 20 weeks. They also demonstrated that the engraftment of T cells and EPO expression could be stimulated by vaccination.

These results show that T cells may represent a suitable system for delivery of EPO, and suggest that they may also be used for the delivery of other peptides for the treatment of different medical conditions.