Genomic and functional characterization of human T cell responses to co-stimulation with an agonistic anti-CD27 mAb, 1F5 (Varlilumab). Homo sapiens

CD27, a member of the tumor necrosis factor receptor super family (TNFRSF7), is constitutively expressed on the majority of mature T cells, memory B cells, and a portion of NK cells. Here we report on the 1F5-induced immune modulation of isolated human T cells. In vitro activation of peripheral blood-derived T cells from different healthy volunteers with mAb 1F5 showed that crosslinking of CD27 in the presence of CD3 stimulation (OKT3 mAb) was essential to elicit proliferation and broad spectrum of cytokine release. Analysis of this response on a multiplex cytokine array system revealed a Th1-biased cytokine profile (IFN-gamma, IL-2 and TNF-alpha). Transcriptional profiling by microarray RNA hybridization is underway to map specific and global gene expression changes following 1F5 modulation of T cells. Overall design: T cells were enriched using magnetic beads and stimulated with plate bound anti-CD3 mAb and anti-CD27 mAb, 1F5 (or control mAb) for 72 hours (late) or 4 hours (early) and characterized for functional responses that included cytokine release (ELISA), proliferation (CFSE dilution) and immunophenotyping (flow cytometry). Microarray analysis of treated T cells was used to further explore the universe of genes affected by costimulatory signals provided by mAb 1F5.