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Nanoparticles represent a new generation of drug delivery systems that can be engineered to harness optimal target selectivity for specific cells and tissues and high drug loading capacity, allowing for improved pharmacokinetics and enhanced bioavailability of therapeutics. The spontaneous propensity of both organic and colloidal nanoparticles to be captured by the cells of the reticuloendothelial system encouraged their utilization as passive targeting systems that can be preferentially directed to innate immune cells, such as macrophages, dendritic cells and neutrophils. The natural affinity for phagocytic cells suggests the possible implementation of nanoparticles as an immunotherapeutic platform for inflammatory diseases and autoimmune disorders. Here we discuss the recent advances in the application of nanotechnology to induce antigen-specific tolerance in autoimmunity and the use of nanoparticles for anti-inflammatory therapies, including treatment of inflammatory bowel diseases, psoriasis and rheumatoid arthritis., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Blood to skin recirculation could play a role in the pathogenesis of psoriasis. To investigate this possibility we dissected the phenotype of circulating T cells in psoriasis patients, calculated the correlation the clinical parameters of the disease and performed a parallel bioinformatics analysis of gene expression data in psoriatic skin. We found that circulating CCR6 + CD4 + T EM and T EFF cells significantly correlated with systemic inflammation. Conversely, the percentage of CXCR3 + CD4 + T EM cells negatively correlated with the severity of the cutaneous disease. Importantly CLA + CD4 + T CM cells expressing CCR6 + or CCR4 + CXCR3 + negatively correlated with psoriasis severity suggesting recruitment to the skin compartment. This assumption was reinforced by gene expression data showing marked increase of CCR7 and CLA-encoding gene SELPLG expression in psoriatic skin and strong association of their expression. The data enlightens a role for CD4 + T cells trafficking between blood and skin in cutaneous and systemic manifestations of psoriasis., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Recent results have identified critical components of the T cell response involved in the initiation and amplification phases of psoriasis. However the link between T cell responses arising in the skin and the systemic inflammation associated with severe psoriasis is largely unknown. We hypothesized that specific subsets of memory T cells recirculating from the skin could play a role. We therefore dissected the circulating memory T cell compartment in patients by analyzing the TCM, TEM and Teff phenotype, the pattern of CCR4 and CCR5 chemokine receptor expression and the expression of the tissue homing molecule CD103. For each subset we calculated the correlation with the Psoriasis Area and Severity Index (PASI) and with the extent of systemic inflammation measured as serum level of the prototypic short pentraxin, C reactive protein (CRP). Validation was performed by comparison with gene expression data in psoriatic plaques. We found that circulating CD103(+)CCR4(+)CCR5(+) and CCR4(+)CCR6(-) CD8(+) Teff cells, were highly correlated with CRP levels as well as with the validated index PASI, reflecting a link between skin involvement and systemic inflammation in patients with severe psoriasis. In addition we observed a contraction of circulating CCR5(+) T cells in psoriasis patients, with a highly significant inverse correlation between CCR5(+)CD4 T cells and the PASI score. Increased expression of CCR5 and CCL5 genes in psoriatic skin lesions was consistent with an accumulation of CCR5(+) cells in psoriatic plaques indicating a role for CCR5/CCL5 axis in disease pathogenesis., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Dendritic cells (DCs) are a special type of leukocytes able to alert the immune system to the presence of infections. They play a central role in the initiation of both innate and adaptive immune responses. This particular DC feature is regulated by the activation of specific receptors at the cell surface called Toll-like receptors (TLRs) that bind a number of microbial products collectively referred to as microbial-associated molecular patterns (MAMP). TLRs initiate a cascade of events, which together define the process of DC maturation. This phenomenon allows DCs to progressively acquire varying specific functions. DC maturation depends on the nature of the perturbation and permits unique and efficient immune responses for each pathogen. In this review the discussion is focused on DCs in the context of interactions with pathogens and DC-specific functions are highlighted.

Dendritic cells (DCs) are professional antigen presenting cells that hold the key to the induction of T-cell responses. Therefore, the use of DCs for immunotherapy to stimulate immune responses has recently raised a great deal of interest. Many clinical trials using DCs have been initiated to stimulate immune responses against tumors or infectious agents. Several issues need to be considered before DCs can be used successfully as natural adjuvants: DCs have to be generated in sufficient numbers; they should display morphological, phenotypical, and functional properties of DCs; and they should be able to present antigens. In the present review we focus on methods for the purification of DCs from human bone marrow and peripheral blood and for the optimization of in vitro cell culture systems. Methods to generate growth factor-dependent mouse DC lines are also described., (Copyright 1999 Academic Press.)