Stable T cell–dendritic cell interactions precede the development of both tolerance and immunity in vivo

Abstract

The maturation status of dendritic cells (DCs) determines whether they prime or tolerize T cells. We targeted ovalbumin peptide exclusively to DCs in situ using an antibody to DEC-205 and studied the interaction of DCs with naive CD4(+) T cells in tolerizing or priming conditions. We used two-photon microscopy to simultaneously track antigen-specific OT-II T cells, nonspecific T cells and DCs in lymph nodes of living mice. In both tolerance and immunity, OT-II cells arrested on DCs near high endothelial venules beginning shortly after extravasation and regained their baseline speed by 18 h. Thus, early antigen-dependent T cell arrest on DCs is a shared feature of tolerance and priming associated with activation and proliferation.

Visualizing dendritic cell migration within the skin

“…DCs in these mice exhibit high Xuorescence, and are readily identiWable by both Xuorescence microscopy and Xow cytometry. These mice have not only greatly improved our understanding of the behavior of endogenous DCs in the LN (Lindquist et al 2004;Shakhar et al 2005), but also their roles in various models of infection (Aoshi et al 2008;Hapfelmeier et al 2008;Veres et al 2007). They also enabled the visualization of intestinal DCs (Flores-Langarica et al 2005) and the identiWcation of a previously uncharacterized population of DCs in the brain (Bulloch et al 2008).…”

The Biophysics of T Lymphocyte Activation In Vitro and In Vivo

“…It was during this phase that T cell divisions became detectable [28]. These findings were essentially confirmed for CD4 + T cell activation in vivo [52] and in an explanted lymph node model [50]. In addition, the group of Amigorena showed that CD8 + T cells contacting DC under a regime inducing tolerance rather that activation displayed short-lived interactions at any time point, while Mempel's three phase model with long interactions in a middle phase [28] could be confirmed for an activatory situation [77].…”

“…3, [28,[47][48][49][50]). When a firm contact is established, the T cell can give up its migratory morphology and round up again or remain stationary [51,52]. However, it may also maintain a dynamic state of motility and crawl along the APC surface with substantial velocities of up to 10 µm per minute [28,34,49,53].…”

Imaging Interactions Between the Immune and Cardiovascular Systems In Vivo by Multiphoton Microscopy

“…track velocity, displacement, meandering index, motility co-efficient. 4. It is also possible to measure the interaction between DC and T cell using the colocalization tool to identify green and red voxels.…”