Dendritic cells help prime T cells by immune-stimulating complexes in vivo.

2003 AUG 6 - (NewsRx.com & NewsRx.net) -- Dendritic cells participate in the priming of antigen-specific CD4+ and CD8+ T lymphocytes by immune-stimulating complexes in vivo.

"Immune-stimulating complexes (ISCOMS) are adjuvant vectors which are unusual in being able to prime both CD4+ and CD8+ T cells by parenteral and mucosal routes. However, their mode of action is unclear and to define better the cellular interactions involved we have studied the ability of ISCOMS containing ovalbumin (OVA) to prime TCR transgenic CD4+ or CD8+ T cells in vivo," scientists in Scotland report.

"Immunization with OVA ISCOMS caused activation and clonal expansion of CD4+ and CD8+ T cells in the T cell areas of the draining lymph nodes, followed by the migration of both CD4+ and CD8+ T cells into the B cell follicle," stated Helen Beacock-Sharp and colleagues at the University of Glasgow. "The T cells were primed to proliferate and secrete IFN-gamma after re-stimulation in vitro with the appropriate OVA peptide and CD8+ T cell priming occurred in the absence of CD4+ T cells."

"Increasing the number of dendritic cells (DC) in vivo with flt3 ligand augmented the expansion and ...