Endogenous dendritic cells required for T cell response by DC vaccines in vivo.

2003 MAY 7 - (NewsRx.com & NewsRx.net) -- Endogenous dendritic cells are required for amplification of T cell responses induced by dendritic cell vaccines in vivo.

According to recent research published in the Journal of Immunology, "Dendritic cells (DCs) loaded in vitro with antigen are used as cellular vaccines to induce antigen-specific immunity. These cells are thought to be responsible for direct stimulation of antigen-specific T cells, which may subsequently mediate immunity. In this study, in transgenic mouse models with targeted MHC class II expression specifically on DO, we show that the DC vaccine is responsible only for partial CD4+ T cell activation, but to obtain optimal expansion of T cells in vivo, participation of endogenous (resident) DO, but not endogenous B cells, is crucial."

"Transfer of antigen to endogenous DO seems not to be mediated by simple peptide diffusion, but rather by DC-DC interaction in lymph nodes as demonstrated by histological analysis," said Petra Kleindienst and Thomas Brocker at Ludwig-Maximilians-Universitat Muenchen in Germany. "In contrast, injection of apoptotic or necrotic DC vaccines does not induce T cell responses, but rather represents an immunological null event, which argues that viability of DC vaccines can be crucial for initial ...