Human blood contains at least 2 subpopulations of antigen-presenting dendritic cells (DCs) that can be differentiated by their expression of CD11c. Myeloid DCs (myDCs), which are CD11c(+), trap invading pathogens in the tissues and then migrate to lymphoid tissues where they stimulate pathogen-specific T-cell responses. Plasmacytoid DCs (pcDCs), which are CD11c(-), secrete interferon-alpha in r...

Human papillomavirus type-16 (HPV16) L1 virus-like particles (VLPs) activate dendritic cells (DCs) and induce protective immunity. In this study, we demonstrate, using global gene expression analysis, that HPV16 VLPs produce quite distinct innate responses in murine splenic DC subpopulations. While HPV16 VLPs increase transcription of IFN-gamma and numerous Th1-related cytokines and chemokines ...

Background: Leukocyte integrins are involved in cell adhesion, cell migration, and phagocytosis. Results: CD11c/CD18, a leukocyte integrin expressed on monocytes, macrophages, and dendritic cells, is phosphorylated on Ser-1158 of the -chain. Abrogation of phosphorylation results in impaired adhesion and phagocytosis. Conclusion: Integrin inside-out activated adhesion is regulated by a single ph...

In vivo administration of soluble Flt3L increases dendritic cell (DC) numbers to favor improved DC targeting of vaccine antigens, augmenting vaccine efficiency. In addition to confirming the effectiveness of human Flt3L in macaques, we strove to determine the optimal regimen to elevate numbers of functional DCs. Circulating DCs were identified within lineage(-)human leukocyte antigen-DR(+) cell...

BACKGROUND Myeloid cells are central to atherosclerotic lesion development and vulnerable plaque formation. Impaired ability of arterial phagocytes to uptake apoptotic cells (efferocytosis) promotes lesion growth and establishment of a necrotic core. The transcription factor interferon regulatory factor (IRF)-5 is an important modulator of myeloid function and programming. We sought to investig...

Throughout evolution, mammals have co-existed with many harmless organisms such as saprophytic mycobacteria. These “Old Friends” have helped the hosts’ immune system to evolve immunoregulatory mechanisms that prevent inappropriate immune responses. Exposure, once a common occurrence has now become increasingly rare. A revised version of the hygiene hypothesis proposes that this reduced exposure...

Lung dendritic cells (DC) play a fundamental role in sensing invading pathogens (1,2) as well as in the control of tolerogenic responses (3) in the respiratory tract. At least three main subsets of lung dendritic cells have been described in mice: conventional DC (cDC) (4), plasmacytoid DC (pDC) (5) and the IFN-producing killer DC (IKDC) (6,7). The cDC subset is the most prominent DC subset in ...

We report in this study the generation of a novel rat mAb that recognizes mouse plasmacytoid dendritic cells (pDC). This Ab, named 120G8, stains a small subset of CD11c(low) spleen cell with high specificity. This population produces high amounts of IFN-alpha upon in vitro viral stimulation. Both ex vivo- and in vitro-derived 120G8(+) cells display a phenotype identical with that of the previou...

Fms-like tyrosine kinase 3 ligand (Flt3L) administration leads to dramatic increases in dendritic cells (DC) in lymphoid and nonlymphoid tissues. Conversely, mice lacking Flt3L (Flt3L(-)/(-)) show severe reductions in both myeloid (CD11c(+)CD8alpha(-)) and lymphoid-related DC (CD11c(+)CD8alpha(+)) in the thymus and secondary lymphoid organs. In this study marked reductions in CD11c(+) interstit...

Interferon-producing killer dendritic cells (IKDCs) are a recently described subset of CD11c(lo)B220(+) cells that share phenotypic and functional properties of DCs and natural killer (NK) cells (Chan, C.W., E. Crafton, H.N. Fan, J. Flook, K. Yoshimura, M. Skarica, D. Brockstedt, T.W. Dubensky, M.F. Stins, L.L. Lanier, et al. 2006. Nat. Med. 12:207-213; Taieb, J., N. Chaput, C. Menard, L. Apeto...