Gene expression signatures of human plasma cells isolated from different territories

In vivo antigen (Ag)-induced differentiation of B lymphocytes into plasma cells (PCs) takes place in extra-follicular foci and germinal centers of the secondary lymphoid organs (SLOs). Most of these SLO PCs are short-living and only relatively few PCs, characterized by secreting high-affinity antibodies (Ab), travel through the circulation and finally home in specialized survival niches of the bone marrow (BM) and, at a lesser extent, in the SLOs, where they become long-living Ab-secreting PCs. We have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish between human circulating Ag-induced PCs in comparison with tonsil and BM PCs distinctively regulate genes involved in cell proliferation. Gene expressions in human plasma cells isolated from tonsil (7 samples), blood (6 samples) and bone marrow (7samples) were measured. Each sample was isolated from a different donor.