43: Administration of rhIL-7 Increases TCR Repertoire Diversity Through Preferential Expansion of Naive T Cells

Abstract

Interleukin-7 (IL-7) is a multifunctional cytokine with critical and non-redundant roles in thymopoiesis and peripheral T-cell homeostasis. We previously reported preliminary results of the first Phase I study of recombinant human IL-7 (rhIL-7), demonstrating that two weeks of alternate day treatment with rhIL-7 produced a marked increase in the number of CD4+ and CD8+ T cells. This increase was maintained in follow up assays at 6 to 12 weeks post treatment. Furthermore, rhIL-7 therapy disproportionately increased CD27+CD45RA+ naive cells, which represent the most diverse elements of the mature T cell receptor (TCR) repertoire, at the expense of CD27-CD45RA+/- effector populations, which are often oligoclonal.