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In vivo detection of dendritic cell antigen presentation to CD4(+) T cells.

Ingulli E, Mondino A, Khoruts A, Jenkins MK - J. Exp. Med. (1997)

Bottom Line: DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells.These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell-rich regions of lymph nodes.This interaction results in T cell activation and disappearance of the DC.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.

ABSTRACT
Although lymphoid dendritic cells (DC) are thought to play an essential role in T cell activation, the initial physical interaction between antigen-bearing DC and antigen-specific T cells has never been directly observed in vivo under conditions where the specificity of the responding T cells for the relevant antigen could be unambiguously assessed. We used confocal microscopy to track the in vivo location of fluorescent dye-labeled DC and naive TCR transgenic CD4(+) T cells specific for an OVA peptide-I-Ad complex after adoptive transfer into syngeneic recipients. DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells. In contrast, the OVA peptide-specific T cells formed large clusters around paracortical DC that were pulsed in vitro with the OVA peptide before injection. Interactions were also observed between paracortical DC of the recipient and OVA peptide-specific T cells after administration of intact OVA. Injection of OVA peptide-pulsed DC caused the specific T cells to produce IL-2 in vivo, proliferate, and differentiate into effector cells capable of causing a delayed-type hypersensitivity reaction. Surprisingly, by 48 h after injection, OVA peptide-pulsed, but not unpulsed DC disappeared from the lymph nodes of mice that contained the transferred TCR transgenic population. These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell-rich regions of lymph nodes. This interaction results in T cell activation and disappearance of the DC.

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Detailed analysis of  a DC–T cell cluster. A series of  optical sections was taken at 1-μm  intervals through a dendritic cell  that appeared to be surrounded  by T cells 24 h after the injection  of OVA peptide-pulsed DC. At  this magnification, the optical  thickness of each image is ∼0.6  μm. Bar, 10 μm.
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Figure 4: Detailed analysis of a DC–T cell cluster. A series of optical sections was taken at 1-μm intervals through a dendritic cell that appeared to be surrounded by T cells 24 h after the injection of OVA peptide-pulsed DC. At this magnification, the optical thickness of each image is ∼0.6 μm. Bar, 10 μm.

Mentions: Although the high degree of coincidence between OVA peptide-pulsed DC and DO11.10 T cell clusters at 24 h made it likely that the clusters represented bona fide interactions between the two cell types, the ∼5-μm-thickness of the optical sections made it formally possible that the dendritic cells were not centrally located within the clusters, but rather were situated immediately above or below the clusters. Serial optical sectioning through individual cluster-associated, OVA peptide-pulsed dendritic cells was performed at high power (optical section thickness = 0.6 μm) to assess this possibility. As shown in Fig. 4, interactions between the dendritic cell and several DO11.10 T cells were observed in each serial plane of focus through the dendritic cell body. Similar results were observed for all clusters examined in this way (n = 5). These results demonstrate that OVA peptide-pulsed dendritic cells are centrally located within the clusters at the 24-h time point, and are simultaneously interacting with many DO11.10 T cells.


In vivo detection of dendritic cell antigen presentation to CD4(+) T cells.

Ingulli E, Mondino A, Khoruts A, Jenkins MK - J. Exp. Med. (1997)

Detailed analysis of  a DC–T cell cluster. A series of  optical sections was taken at 1-μm  intervals through a dendritic cell  that appeared to be surrounded  by T cells 24 h after the injection  of OVA peptide-pulsed DC. At  this magnification, the optical  thickness of each image is ∼0.6  μm. Bar, 10 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196354&req=5

Figure 4: Detailed analysis of a DC–T cell cluster. A series of optical sections was taken at 1-μm intervals through a dendritic cell that appeared to be surrounded by T cells 24 h after the injection of OVA peptide-pulsed DC. At this magnification, the optical thickness of each image is ∼0.6 μm. Bar, 10 μm.
Mentions: Although the high degree of coincidence between OVA peptide-pulsed DC and DO11.10 T cell clusters at 24 h made it likely that the clusters represented bona fide interactions between the two cell types, the ∼5-μm-thickness of the optical sections made it formally possible that the dendritic cells were not centrally located within the clusters, but rather were situated immediately above or below the clusters. Serial optical sectioning through individual cluster-associated, OVA peptide-pulsed dendritic cells was performed at high power (optical section thickness = 0.6 μm) to assess this possibility. As shown in Fig. 4, interactions between the dendritic cell and several DO11.10 T cells were observed in each serial plane of focus through the dendritic cell body. Similar results were observed for all clusters examined in this way (n = 5). These results demonstrate that OVA peptide-pulsed dendritic cells are centrally located within the clusters at the 24-h time point, and are simultaneously interacting with many DO11.10 T cells.

Bottom Line: DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells.These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell-rich regions of lymph nodes.This interaction results in T cell activation and disappearance of the DC.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.

ABSTRACT
Although lymphoid dendritic cells (DC) are thought to play an essential role in T cell activation, the initial physical interaction between antigen-bearing DC and antigen-specific T cells has never been directly observed in vivo under conditions where the specificity of the responding T cells for the relevant antigen could be unambiguously assessed. We used confocal microscopy to track the in vivo location of fluorescent dye-labeled DC and naive TCR transgenic CD4(+) T cells specific for an OVA peptide-I-Ad complex after adoptive transfer into syngeneic recipients. DC that were not exposed to the OVA peptide, homed to the paracortical regions of the lymph nodes but did not interact with the OVA peptide-specific T cells. In contrast, the OVA peptide-specific T cells formed large clusters around paracortical DC that were pulsed in vitro with the OVA peptide before injection. Interactions were also observed between paracortical DC of the recipient and OVA peptide-specific T cells after administration of intact OVA. Injection of OVA peptide-pulsed DC caused the specific T cells to produce IL-2 in vivo, proliferate, and differentiate into effector cells capable of causing a delayed-type hypersensitivity reaction. Surprisingly, by 48 h after injection, OVA peptide-pulsed, but not unpulsed DC disappeared from the lymph nodes of mice that contained the transferred TCR transgenic population. These results demonstrate that antigen-bearing DC directly interact with naive antigen-specific T cells within the T cell-rich regions of lymph nodes. This interaction results in T cell activation and disappearance of the DC.

Show MeSH
Related in: MedlinePlus