Open Access Research

The adapter protein ADAP is required for selected dendritic cell functions

Mauro Togni1, Swen Engelmann1, Dirk Reinhold1, Burkhart Schraven1,2 and Annegret Reinhold1*

Author Affiliations

1 Institute for Molecular and Clinical Immunology, Otto von Guericke University Magdeburg, Leipziger Strasse 44, 39120 Magdeburg, Germany

2 Department of Immune Control, Helmoltz Center for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany

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Cell Communication and Signaling 2012, 10:14 doi:10.1186/1478-811X-10-14

Published: 6 June 2012

Abstract

Background

The cytosolic adaptor protein ADAP (adhesion and degranulation promoting adapter protein) is expressed by T cells, natural killer cells, myeloid cells and platelets. ADAP is involved in T-cell-receptor-mediated inside-out signaling, which leads to integrin activation, adhesion and reorganization of the actin cytoskeleton. However, little is known about the role of ADAP in myeloid cells. In the present study, we analyzed the function of ADAP in bone-marrow-derived dendritic cells (BMDCs) from ADAP-deficient mice.

Results

ADAP-deficient BMDCs showed almost normal levels of antigen uptake, adhesion, maturation, migration from the periphery to the draining lymph nodes, antigen-specific T-cell activation, and production of the proinflammatory cytokines IL-6 and TNF-∝. Furthermore, we provide evidence that the activation of signaling pathways after lipopolysaccharide (LPS) stimulation are not affected by the loss of ADAP. In contrast, ADAP-deficient BMDCs showed defects in CD11c-mediated cellular responses, with significantly diminished production of IL-6, TNF-∝ and IL-10. Actin polymerization was enhanced after CD11c integrin stimulation.

Conclusions

In summary, we propose that the adapter molecule ADAP is critical for selected CD11c integrin-mediated functions of dendritic cells.

Keywords:
Adapter protein; ADAP; Dendritic cell; Integrin; Inside-out signaling