Lumazine synthase protein cage nanoparticles as antigen delivery nanoplatforms for dendritic cell-based vaccine development

PURPOSE: Protein cages are promising nanoplatform candidates for efficient delivery systems due to their homogenous size and structure with high biocompatibility and biodegradability. In this study, we investigate the potential of lumazine synthase protein cage as an antigen delivery system to dendritic cells (DCs), which induce antigen-specific T cell proliferation. MATERIALS AND METHODS: Ovalbumin (OVA) peptides OT-1 (SIINFEKL) and OT-2 (ISQAVHAAHAEINEAGR) were genetically inserted to lumazine synthase and each protein cage was over-expressed in Escherichia coli as a soluble protein. The efficiency of antigen delivery and the resulting antigen-specific T cell proliferation by DCs was examined in vitro as well as in vivo. RESULTS: We successfully generated and characterized OVA peptides carrying lumazine synthase protein cages. The OT-1 and OT-2 peptides carried by lumazine synthases were efficiently delivered and processed by DCs in vitro as well as in vivo, and induced proliferation of OT-1-specific CD8+T cells and OT-2-specific CD4+T cells. CONCLUSION: Our data demonstrate the potential of lumazine synthase protein cage being used as a novel antigen delivery system for DC-based vaccine development in future clinical applications.

CKbeta8-1 alters expression of cyclin E in colony forming units-granulocyte macrophage (CFU-GM) lineage from human cord blood CD34 + cells

A C6 beta-chemokine, CKbeta8-1, suppressed the colony formation of CD34 + cells of human cord blood (CB). Molecular mechanisms involved in CKbeta8-1-medicated suppression of colony formation of CD34 + cells are not known. To address this issue, the level of various G1/S cell cycle regulating proteins in CKbeta8-1-treated CD34 + cells were compared with those in untreated CD34 + cells. CKbeta8-1 did not significantly alter the expression of the G1/S cycle regulation proteins (cyclin D1, D3, and E), CDK inhibitor (p27and Rb), and other cell proliferation regulation protein (p53) in CB CD34 + cells. Here we describe an in vitro system in which CB CD34 + cells were committed to a multipotent progenitor lineage of colony forming units-granulocyte/macrophage (CFU-GM) by a simple combination of recombinant human (rh) GM-CSF and rhIL-3. In this culture system, we found that cyclin E protein appeared later and disappeared faster in the CKbeta8-1-treated cells than in the control cells during CFU-GM lineage development. These findings suggested that cyclin E may play a role in suppressing the colony formation of CFU-GM by CKbeta8-1.

The Effect of Vasoactive Intestinal Peptide on Cord Blood CD34 (+) Cells / 대한소아혈액종양학회지

PURPOSE: We investigated the expression of vasoactive intestinal peptide (VIP), VIP receptor 1 (VPAC1), VIP receptor 2 (VPAC2) genes in the human umbilical cord blood CD34 cells, and the ability of VIP to stimulate human primitive as well as monopotent hematopoietic progenitors. METHODS: We isolated RNA from umbilical cord blood CD34 cells, and then performed RT-PCR, and sequencing. The umbilical cord blood CD34 cells were cultured with the various concentrations of VIP for burst-forming unit of erythrocyte (BFU-E), colony-forming unit of granulocyte/monocyte (CFU-GM), colony-forming unit of graulocyte/erythrocyte/monocyte/megakaryocyte (CFU-GEMM), and colony-forming unit of megakaryocyte (CFU-Mk). RESULTS: The RNA coding for VPAC1 was detected in human umbilical cord blood CD34 cells. VIP significantly stimulated the growth of CFU-GEMM and CFU-Mk. CONCLUSION: The present results suggest that VIP is an important neuropeptide in the early proliferation of human primitive as well as megakaryocyte progenitors.