Distinct spatial localization and function of resident dendritic cell subsets in lymph nodes

Wednesday, October 26, 2011 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center	NIAID	IMMUNO/INFLAM-8

* FARE Award Winner

Authors

• M Gerner
• I Ifrim
• W Kastenmuller
• R Germain

Abstract

Dendritic cells (DCs) are essential for uptake and presentation of antigens (Ags) for T-cell activation and can be divided into subsets with varying Ag-presentation capacities. It is not clear whether intrinsic differences or variation in spatial localization and preferential Ag access both contribute to differential Ag-presentation by DC subsets. We thus developed a novel approach of combining multi-parameter confocal microscopy with analytical masking to allow direct in-situ visualization of cellular populations identified by complex phenotypic surface markers. We determined the spatial localization of major resident lymph node (LN) DC subsets and observed preferential positioning of certain populations to distinct LN zones. Some DCs physically associated with lymphatic sinuses (LS) and actively extended dendrites into the LS lumen. Due to particle size restriction, it is currently believed that peripheral DCs that migrate to the LN exclusively present particulate Ags to T cells. Using 2-photon microscopy, we observed the LS-DCs rapidly taking up draining particulate Ags and inducing T-cell clusters in zones proximal to the LS. These results suggest the existence of specialized micro-domains for DC subsets within LN and indicate that LS-DCs are important for T-cell activation to particulate Ags.

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