TLR9 ligand induces the generation of CD20+ plasmablasts and plasma cells from CD27+ memory B-cells.

Plasma cells (PCs) have a heterogeneous phenotype in humans. While bone marrow PCs are CD20-CD138+, tonsil PCs are CD20+CD138+/- and peripheral plasmablasts (PBs) are CD20-CD138-. In vitro, PCs are mainly generated by the activation of CD27+ memory B-cells through transient stimulation of CD40, and their phenotype appears similar to that of bone marrow PCs.

Osteoclasts support the survival of human plasma cells in vitro.

The aim of this in vitro study was to evaluate if osteoclasts (OCs) and dendritic cells (DCs), both of monocyte origin, can support the survival of normal human plasma cells (PCs). PCs differentiate from plasmablasts (PBs) arising from activated B cells, essentially memory B cells. To study the survival of both PBs (CD20(low)CD38(high)CD138(neg)) and PCs (CD20(neg)CD38(bright)CD138(bright)), we generated pre-PBs (CD20(low)CD38(pos)CD138(neg)) from CD40-activated B cells (CD20(high)CD38(neg)CD138(neg)) and cultured them on DCs or OCs in the presence of added IL-6.

Mcl-1L cleavage is involved in TRAIL-R1- and TRAIL-R2-mediated apoptosis induced by HGS-ETR1 and HGS-ETR2 human mAbs in myeloma cells.

We evaluated the ability of 2 human mAbs directed against TRAILR1 (HGS-ETR1) and TRAILR2 (HGS-ETR2) to kill human myeloma cells. HGS-ETR1 and HGS-ETR2 mAbs killed 15 and 9 human myeloma cell lines (HMCLs; n = 22), respectively. IL-6, the major survival and growth factor for these HMCLs, did not prevent their killing.

Allogeneic T lymphocytes as a source of peptide-dependent T cells specific for myeloma cells.

We investigated the generation of myeloma-specific CTLs from normal donors HLA mismatched with the myeloma cell line SBN. The T-cell line obtained was cloned and each CTL was assessed against SBN and SBN-EBV (a B-EBV cell line obtained by EBV infection of B cells from SBN patient) simultaneously. Among >270 clones evaluated, 2 CTLs (Vbeta13.