PubMed Health⌕ Search

Biomedical subjects

Randall L Lindquist

Publications and source records attributed to Randall L Lindquist.

2 recordsLinked to original sources

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

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.

Animals↗

Visualizing dendritic cell networks in vivo.

In the steady state, dendritic cells (DCs) in the lymph node induce T cell tolerance to self antigens. Innate signals trigger the maturation of tissue DCs, which migrate into lymph nodes and activate T cells. To examine DCs in vivo, we produced transgenic mice whose DCs expressed enhanced yellow fluorescent protein. Two-photon microscopy of lymph nodes in live mice showed that most of the steady-state DCs were enmeshed in an extensive network and remained in place while actively probing adjacent T cells with their processes. Mature DCs were more motile than steady-state DCs and were rapidly dispersed and integrated into the sessile network, facilitating their interaction with migrating T cells.

Animals↗