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CD14+ dendritic cells (DCs) present in the dermis of human skin represent a large subset of dermal DCs (dDCs) that are considered macrophage-like cells with poor antigen (cross)-presenting capacity and limited migratory potential to the lymph nodes. CD14+ dDC highly express DC-specific ICAM-3-grabbing non-integrin (DC-SIGN), a receptor containing potent endocytic capacity, facilitating intracellular routing of antigens to major histocompatibility complex I and II (MHC-I andII) loading compartments for the presentation to antigen-specific CD8+ and CD4+ T cells. Here we show using a human skin explant model that the in situ targeting of antigens to DC-SIGN using glycan-modified liposomes enhances the antigen-presenting capacity of CD14+ dDCs. Intradermal vaccination of liposomes modified with the DC-SIGN-targeting glycan LewisX, containing melanoma antigens (MART-1 or Gp100), accumulated in CD14+ dDCs and resulted in enhanced Gp100- or MART-1-specific CD8+ T-cell responses. Simultaneous intradermal injection of the cytokines GM-CSF and IL-4 as adjuvant enhanced the migration of the skin DCs and increased the expression of DC-SIGN on the CD14+ and CD1a+ dDCs. These data demonstrate that human CD14+ dDCs exhibit potent cross-presenting capacity when targeted in situ through DC-SIGN. [ABSTRACT FROM AUTHOR]

Over the past decades advances in bioengineering and expanded insight in tumor immunology have resulted in the emergence of novel bispecific antibody (bsAb) constructs that are capable of redirecting immune effector cells to the tumor microenvironment. (Pre-) clinical studies of various bsAb constructs have shown impressive results in terms of immune effector cell retargeting, target dependent activation and the induction of anti-tumor responses. This review summarizes recent advances in the field of bsAb-therapy and limitations that were encountered. Furthermore, we will discuss potential future developments that can be expected to take the bsAb approach successfully forward. [ABSTRACT FROM AUTHOR]

Langerhans cells (LCs) migrate after topical exposure of the skin to irritants, despite the supposed independence of irritant contact dermatitis from adaptive immunity. Whereas allergen-activated LCs are known to migrate to the draining lymph nodes (LNs), the fate of migrated LCs upon topical irritant exposure is unknown. Here, we identified a phenotypic switch of LCs after their migration into the dermis upon irritant exposure. With the aid of ex vivo intact human skin and epidermal sheets, we show that dermal fibroblasts are necessary for an IL-10-dependent postmigrational phenotypic switch of LCs into macrophage-like cells. Exposure of ex vivo skin to a panel of seven irritants resulted in a decrease in the number of CD1a+ cells and an increase in CD14+/CD68+ cells in the dermis. Neutralizing antibodies against IL-10 totally inhibited the phenotypic LC-to-macrophage transition, but did not influence the migration of CD1a+ cells. Exposure of epidermal sheets to irritants resulted in a fibroblast-dependent LC-to-CD14+/CD68+ switch coinciding with migration, which could be totally inhibited by neutralizing antibodies against either IL-10 or CCL2/CCL5 (two chemokines responsible for epidermal-to-dermal migration). We have thus identified an IL-10-dependent phenotypic switch of LCs into macrophage-like cells upon irritant exposure and emigration from the epidermis. [ABSTRACT FROM AUTHOR]

An abstract of the article "A Single-Component CD40-Targeted Adenoviral Vector for Efficient Transduction and Activation of Cutaneous Dendritic Cells," by Nikolay Korokhov and colleagues is presented.