scholarly journals Granulocytes, macrophages, and dendritic cells arise from a common major histocompatibility complex class II-negative progenitor in mouse bone marrow.

1993 ◽  
Vol 90 (7) ◽  
pp. 3038-3042 ◽  
Author(s):  
K. Inaba ◽  
M. Inaba ◽  
M. Deguchi ◽  
K. Hagi ◽  
R. Yasumizu ◽  
...  
2010 ◽  
Vol 78 (7) ◽  
pp. 2956-2965 ◽  
Author(s):  
Marlena M. Westcott ◽  
Curtis J. Henry ◽  
Jacqueline E. Amis ◽  
Elizabeth M. Hiltbold

ABSTRACT Dendritic cells (DC) provide a suboptimal niche for the growth of Listeria monocytogenes, a facultative intracellular bacterial pathogen of immunocompromised and pregnant hosts. This is due in part to a failure of large numbers of bacteria to escape to the cytosol, an essential step in the intracellular life cycle that is mediated by listeriolysin O (LLO). Here, we demonstrate that wild-type bacteria that failed to enter the cytosol of bone marrow-derived DC were retained in a LAMP2+ compartment. An isogenic L. monocytogenes strain that produces an LLO protein with reduced pore-forming activity had a severe escape and growth phenotype in DC. Few mutant bacteria entered the cytosol in the first 2 h and were instead found in LAMP2+, major histocompatibility complex class II+ (MHC-II+) H2-DM vesicles characteristic of MHC-II antigen loading compartments (MIIC). In contrast, the mutant had a minor phenotype in bone marrow-derived macrophages (BMM) despite the reduced LLO activity. In the first hour, DC phagosomes acidified to a pH that was, on average, half a point higher than that of BMM phagosomes. Unlike BMM, L. monocytogenes growth in DC was minimal after 5 h, and consequently, DC remained viable and matured late in infection. Taken together, the data are consistent with a model in which phagosomal maturation events associated with the acquisition of MHC-II molecules present a suboptimal environment for L. monocytogenes escape to the DC cytosol, possibly by limiting the activity of LLO. This, in combination with an undefined mechanism that controls bacterial growth late in infection, promotes DC survival during the critical maturation response.


1997 ◽  
Vol 186 (9) ◽  
pp. 1481-1486 ◽  
Author(s):  
Sofia Casares ◽  
Kayo Inaba ◽  
Teodor-Doru Brumeanu ◽  
Ralph M. Steinman ◽  
Constantin A. Bona

Intramuscular and intracutaneous immunization with naked DNA can vaccinate animals to the encoded proteins, but the underlying mechanisms of antigen presentation are unclear. We used DNA that encodes an A/PR/8/34 influenza peptide for CD4 T cells and that elicits protective antiviral immunity. DNA-transfected, cultured muscle cells released the influenza polypeptide, which then could be presented on the major histocompatibility complex class II molecules of dendritic cells. When DNA was injected into muscles or skin, and antigen-presenting cells were isolated from either the draining lymph nodes or the skin, dendritic, but not B, cells presented antigen to T cells and carried plasmid DNA. We suggest that the uptake of DNA and/or the protein expressed by dendritic cells triggers immune responses to DNA vaccines.


Blood ◽  
2011 ◽  
Vol 117 (24) ◽  
pp. 6562-6570 ◽  
Author(s):  
Andreas Schlitzer ◽  
Jakob Loschko ◽  
Katrin Mair ◽  
Roger Vogelmann ◽  
Lynette Henkel ◽  
...  

Abstract Whereas the final differentiation of conventional dendritic cells (CDCs) from committed precursors occurs locally in secondary lymphoid or peripheral tissues, plasmacytoid dendritic cells (PDCs) are thought to fully develop in the bone marrow from common DC progenitors before migrating to the periphery. In our study, we define, for the first time, a subpopulation of CCR9− major histocompatibility complex class IIlow PDCs in murine bone marrow, which express E2-2 and are immediate precursors of CCR9+ fully differentiated PDCs. However, CCR9− PDCs have the plasticity to acquire the phenotype and function of CD11b+ CD8α− major histocompatibility complex class IIhigh CDC-like cells under the influence of soluble factors produced by intestinal epithelial cells or recombinant GM-CSF. This deviation from the PDC lineage commitment is regulated on the level of transcription factors reflected by down-regulation of E2-2 and up-regulation of ID2, PU.1, and BATF3. Thus, CCR9− PDCs are immediate PDC precursors that can be reprogrammed to differentiate into CDC-like cells with higher antigen-presenting and cytokine-producing capacity under the influence of the local tissue microenvironment.


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