Chemokine Receptors and Dendritic Cell Trafficking

Abstract

Dendritic cell (DC) networks dictate peripheral tolerance and immunity in lymph nodes (LNs). The type, timing, location, and interaction of LN-recruited DC subtypes are pivotal and regulated by chemokines. We propose a concept that any DC subtype including myeloid and plasmacy-toid DCs (mDCs and pDCs) is fundamentally categorized by three stages depending on the function and anatomical position: naïve DC, primed DC, and effector DC. Naïve mDC precursors are recruited to infl amed tissues in response to CCR1 and CCR5 ligands to become primed mDCs, remobilized to draining LNs in response to CCR7 ligands, and activated to become effector mDCs to undergo antigen-presenting function. In contrast , pDC precursors directly migrate to LNs in a CXCR3-dependent manner. LN-recruited, primed pDCs are activated to become effector pDCs that produce large amounts of cytokines and chemokines. Concerted recruitment and adequate network formation of distinct effector DCs are pivotal to determine the type and effi cacy of immune response.