Search results for "Imiquimod"

Regulatory T Cells and IL-10 Independently Counterregulate Cytotoxic T Lymphocyte Responses Induced by Transcutaneous Immunization

2011

Background: The imidazoquinoline derivate imiquimod induces inflammatory responses and protection against transplanted tumors when applied to the skin in combination with a cognate peptide epitope (transcutaneous immunization, TCI). Here we investigated the role of regulatory T cells (Treg) and the suppressive cytokine IL-10 in restricting TCI-induced cytotoxic T lymphocyte (CTL) responses. Methodology/Principal Findings: TCI was performed with an ointment containing the TLR7 agonist imiquimod and a CTL epitope was applied to the depilated back skin of C57BL/6 mice. Using specific antibodies and FoxP3-diphteria toxin receptor transgenic (DEREG) mice, we interrogated inhibiting factors after…

2014

Background Transcutaneous immunization (TCI) approaches utilize skin associated lymphatic tissues to elicit specific immune responses. In this context, the imidazoquinoline derivative imiquimod formulated in Aldara applied onto intact skin together with a cytotoxic T lymphocyte (CTL) epitope induces potent CTL responses. However, the feasibility and efficacy of the commercial imiquimod formulation Aldara is limited by its physicochemical properties as well as its immunogenicity. Methodology/Principal Findings To overcome these obstacles, we developed an imiquimod-containing emulsion gel (IMI-Gel) and characterized it in comparison to Aldara for rheological properties and in vitro mouse skin…

Comparative transcutaneous immunization with imiquimod-containing ointments and potential of in vitro methods to predict effects

2012

This work evaluates the transcutaneous in vitro and in vivo immunization efficacy of five commercially available 5% imiquimod containing formulations. The parameters included micro- scopic analysis, rheological properties, drug permeation across synthetic membranes of molecular weight cutoff 10kDa and ablated murine skin with both 0.1 M HCl and a phthalate buffer pH 3.6 Ph.Eur./methanol 3/7 (v/v) as receiver solutions in a Franz-diffusion cell model. For in vivo formu- lation characterization, the cytotoxic T-cell activity and interferon-g production in C57BL/6 mice was determined ex vivo 24h after transcutaneous administration. OVA257264 (SIINFEKL) from chicken al- bumin served as a target…

la papulosi bowenoide: descrizione di uin caso clinico

2009

UV Exposure Boosts Transcutaneous Immunization and Improves Tumor Immunity: Cytotoxic T-Cell Priming through the Skin

2010

Immunologic approaches to combat cancer aim at the induction of tumor-reactive immune responses to achieve long-term protection. In this context, we recently developed a transcutaneous immunization (TCI) method using the Toll-like receptor (TLR) 7 agonist imiquimod and a peptide epitope. Application onto intact skin induces potent cytotoxic T lymphocyte (CTL) responses and protection against transplanted tumors. The purpose of this study was to explore the effects of UV irradiation on imiquimod-based TCI. Here we show that skin exposure to low-dose UV light before TCI with imiquimod strongly boosts specific CTL responses leading to memory formation and enhanced tumor protection. Toward the …

Hexyl aminolevulinate, 5‐aminolevulinic acid nanoemulsion and methyl aminolevulinate in photodynamic therapy of non‐aggressive basal cell carcinomas:…

2020

Background In the photodynamic therapy (PDT) of non‐aggressive basal cell carcinomas (BCCs), 5‐aminolevulinic acid nanoemulsion (BF‐200ALA) has shown non‐inferior efficacy when compared with methyl aminolevulinate (MAL), a widely used photosensitizer. Hexyl aminolevulinate (HAL) is an interesting alternative photosensitizer. To our knowledge, this is the first study using HAL‐PDT in the treatment of BCCs. Objectives To compare the histological clearance, tolerability (pain and post‐treatment reaction), and cosmetic outcome of MAL, BF‐200 ALA, and low‐concentration HAL in the PDT of non‐aggressive BCCs. Methods Ninety‐eight histologically verified non‐aggressive BCCs met the inclusion criter…

Transcutaneous immunization with imiquimod is amplified by CD40 ligation and results in sustained cytotoxic T-lymphocyte activation and tumor protect…

1999

Transcutaneous immunization (TCI) using ligands of Toll-like receptors (TLRs) and cytotoxic T-lymphocyte (CTL) epitopes lead to the induction of potent T-cell responses. To characterize the efficacy of TCI-mediated CTL activation, we monitored the frequency and functional activity of specific CTL induced with TCI using the ovalbumin-derived epitope SIINFEKL composed in creme containing the synthetic TLR7 ligand R-837. We found that the frequency and activity decayed rapidly 10 d post-TCI. Consistently, no significant memory T-cell formation was detectable. In a prophylactic vaccination setting, TCI was protective against a lethal challenge with ovalbumin expressing EG.7 thymoma cells when t…

Differential Effects of Biologics on Psoriasis-Related Vascular Inflammation and Risk of Thrombosis

2020

Programa Estatal de I+D+i Orientada a los Retos de la Sociedad from Ministerio de Ciencia, Innovación y Universidades and European Regional Development Fund (Spain) [RTI2018-094436-B-I00]; Ministerio de Sanidad y Consumo CIBERehd (Spain) [CB06/04/0071]; Generalitat Valenciana (Spain) [PROMETEO/2018/141]; Proyectos Grupos Emergentes [GV/2019/043]; and Universidad Europea (Spain) (2018/UEM32 and 2019/UEM29]. 8.551 JCR (2020) Q1, 4/69 Dermatology 1.951 SJR (2020) Q1, 54/438 Biochemistry No data IDR 2020 UEV

Transcutaneous Immunization with a Solid Nanoscopic Imiquimod Suspension Enhances Tumor Rejection

2015

Abstract Introduction: Transcutaneous immunization (TCI) is a novel vaccination strategy to induce strong therapeutic cytotoxic T-lymphocyte (CTL) responses by directly targeting skin-resident professional antigen-presenting cells (APC). This vaccination approach is very promising to overcome current limitations of standard vaccination approaches that are mostly effective in prophylaxis, but not in the treatment of diseases. In this context, we have developed a TCI method based on a synthetic TLR7 agonist imiquimod that partial tumor protection in experimental rodent models. In our present work, we describe a novel optimized formulation of imiquimod in a solid suspension of crystalline imiq…

Aldara-Induced Psoriasis-Like Skin Inflammation: Isolation and Characterization of Cutaneous Dendritic Cells and Innate Lymphocytes

2014

Psoriasis is a chronic auto-inflammatory skin disease of unknown etiology affecting millions of people worldwide. Dissecting the cellular networks and molecular signals promoting the development of psoriasis critically depends on appropriate animal models. Topical application of Aldara cream containing the Toll-like receptor (TLR)7-ligand Imiquimod induces skin inflammation and pathology in mice closely resembling plaque-type psoriasis in humans. The particular power of the Aldara model lies in examining the early events during psoriatic plaque formation, which is difficult to achieve in patients. Hence, recent reports using this model have challenged currently prevailing concepts concernin…