CD1c-Expression by Monocytes - Implications for the Use of Commercial CD1c+ Dendritic Cell Isolation Kits.

Conventional dendritic cells (cDCs) comprise a heterogeneous population of cells that are important regulators of immunity and homeostasis. CD1c+ cDCs are present in human blood and tissues, and found to efficiently activate naïve CD4+ T cells. While CD1c is thought to specifically identify this subset of human cDCs, we show here that also classical and intermediate monocytes express CD1c.

Characterization of Regulatory T-Cell Markers in CD4+ T Cells of the Upper Airway Mucosa.

CD4+ T regulatory cells (Tregs) comprise a heterogeneous population of cells the regulate immune responses and prevent autoimmunity. Most reports on human Tregs are derived from studies of peripheral blood, although Tregs mainly exert their functions in the periphery. Here we performed a detailed analysis of Tregs in the human upper airway mucosa under non-inflammatory conditions, and found that 10% of all CD4+ T cells expressed the transcription factor FOXP3 and the memory marker CD45RO, as well as high levels of CTLA-4.

A thymic stromal lymphopoietin-responsive dendritic cell subset mediates allergic responses in the upper airway mucosa.

Background: Thymic stromal lymphopoietin (TSLP) controls allergic TH2 inflammatory responses through induction of distinct activation programs in dendritic cells (DCs). However, knowledge about TSLP receptor expression and functional consequences of receptor activation by DCs residing in the human respiratory tract is limited.

Objective: We wanted to identify TSLP-responding DC populations in the human upper airway mucosa and assess the TSLP-mediated effects on such DCs in allergic airway responses.

Human nasal mucosa contains antigen-presenting cells of strikingly different functional phenotypes.

Professional antigen-presenting cells (APCs) constitute a heterogeneous leukocyte population that controls T cell induction. Experimental animal studies have delineated the principal APCs of the airway mucosa as a network of intraepithelial dendritic cells (DCs). Whether the situation is comparable in the human airways is unknown.