Topical imiquimod yields systemic effects due to unintended oral uptake.
Ontology highlight
ABSTRACT:
SUBMITTER: Grine L
PROVIDER: S-EPMC4730190 | biostudies-other | 2016 Jan
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Topical imiquimod cream (trade name: Aldara) is a Toll-like receptor (TLR) 7 agonist that is approved for the treatment of cutaneous tumors. Aldara is also used as a vaccine adjuvant in clinical trials in patients with glioma and other tumors. The main mechanism of action ascribed to Aldara has been the local activation of TLR7(+) cells near the application site. Here we report the unexpected finding that Aldara has therapeutic and immunomodulatory activity as a single agent in mice bearing intracranial tumors. Repeated administration of Aldara onto the skin significantly increased the survival of mice bearing intracranial GL261 glioma and EMT6 breast carcinoma. Aldara treatment was associated with a reduction in the number CD4(+)Foxp3(+) regulatory T cells in the blood and brain tumor site. Mice treated with Aldara exhibited a generalized lymphopenia in the blood amidst an increase in brain tumor infiltrating CD4(+) and CD8(+) T cells and dendritic cells. Brain-infiltrating CD8(+) T cells were tumor reactive as demonstrated by degranulation and interferon-? secretion in a GL261-dependent manner. In addition, soluble imiquimod directly inhibited the proliferation of GL261 cells in a TLR7-independent manner. This is the first report demonstrating that topical application of imiquimod can enhance T-cell responses to intracranial tumors as a single agent. The results must be interpreted with caution considering anatomical and biological differences between mice and humans. Nevertheless, Aldara that is being used as a vaccine adjuvant in clinical trials may have direct antitumor effects that are independent of exogenous antigen. Further studies in humans are warranted.
| S-EPMC3073686 | biostudies-literature
Project description:Topical application of Aldara cream, containing the Toll-like receptor 7/8 agonist Imiquimod, is a widely used mouse model for investigating the pathogenesis of psoriasis. We have previously used this model to study the effects of peripheral inflammation on the brain, and reported a brain-specific response characterised by increased transcription, infiltration of immune cells and anhedonic-like behavior. Here, we perform a more robust characterisation of the systemic response to Aldara application and find a potent but transient response in the periphery, followed by a prolonged response in the brain. Mass spectrometry analysis of plasma and brain samples identified significant levels of Imiquimod in both compartments at molar concentrations likely to evoke a biological response. Indeed, the association of Imiquimod with the brain correlated with increased Iba1 and GFAP staining, indicative of microglia and astrocyte reactivity. These results highlight the potency of this model and raise the question of how useful it is for interpreting the systemic response in psoriasis-like skin inflammation. In addition, the potential impact on the brain should be considered with regards to human use and may explain why fatigue, headaches and nervousness have been reported as side effects following prolonged Aldara use.
| S-EPMC5707416 | biostudies-literature
Project description:Chromoblastomycosis is a subcutaneous mycosis that remains a therapeutic challenge, with no standard treatment and high rates of relapse. On the basis of our recent discoveries in mouse models, we tested the efficacy of topical applications of imiquimod to treat patients afflicted with this chronic fungal infection. We report results of treatment for the first 4 recipients of topical imiquimod, all of whom displayed a marked improvement of their lesions, both with and without concurrent oral antifungal therapy.
| S-EPMC4036686 | biostudies-literature
Project description:Introduction:Oral mucositis, the most common adverse effect of radiotherapy (RT) and/or chemotherapy is observed in almost 97% of patients with head and neck cancer. Although several agents like corticosteroids, lidocaine and vitamins are available for its prevention or management, results are often disappointing. Here we report on the effects of a topically applied, highly purified natural deoxyribonucleic acid from sturgeon gonads on three cases of moderate to severe oral mucositis in patients with head and neck cancer. Case Description:Three patients who had undergone RT and/or chemotherapy received an oral spray containing sodium salt-based natural deoxyribonucleic acid (PDRN) for Grade 3 oral mucositis. Treatment continued for one month after the end of RT. No patient reported any allergic reactions. RT and chemotherapy were not interrupted and opioid therapy was not given to any patient. Pain was relieved about 2-3?days after starting treatment and oral mucositis was reduced to G2 within one week. Conclusions:Outcomes in all 3 cases showed topical use of the sodium salt-based PDRN derived from sturgeon gonads was acceptable and safe when used topically for therapeutic and regenerative purposes.Present results are encouraging and suggest a more in-depth study is warranted on its use in a larger patient cohort with RT-induced oral mucositis.
| S-EPMC7033775 | biostudies-literature
Project description:Introduction: Infiltration of cancers by T-cells is associated with improved patient survival and response to immune therapies; however, optimal approaches to induce T-cell infiltration of tumors are not known. This study tests the hypothesis that topical treatment of melanoma metastases with the TLR7 agonist imiquimod treatment plus administration of a multipeptide cancer vaccine will improve immune cell infiltration of melanoma metastases. Patients and Methods: Eligible patients were immunized with a vaccine comprised of 12 melanoma peptides and a tetanus toxoid-derived helper peptide, and imiquimod was applied topically to tumors daily. Adverse events (AE; CTCAE v4.03) were recorded and effects on the tumor microenvironment (TME) were evaluated from sequential tumor biopsies. T-cell responses were assessed by IFNgamma ELIspot assay, and T-cell tetramer staining. Patient tumors were evaluated for immune cell infiltration, cytokine and chemokine production, and gene expression. Results and Conclusions: Four eligible patients were enrolled, and administration of imiquimod and vaccination was well tolerated in these patients. Circulating T-cell responses to the vaccine were detected by ex vivo ELIspot assay in 3 of 4 patients. Treatment of metastases with imiquimod induced immune cell infiltration and favorable gene signatures in the patients with circulating T-cell responses. This study supports further study of topical imiquimod combined with vaccines or other immune therapies for the treatment of melanoma. Precis: This clinical trial tested topical application of imiquimod to melanoma metastases combined with a melanoma vaccine. The regimen dramatically upregulated immune rejection gene signatures in melanoma metastases and increased T-cell infiltrate.
2017-04-01 | GSE80028 | GEO
Project description:Enteric infections caused by Chlamydia (C.) psittaci are frequent in ducks, but mostly remain subclinical under field conditions. To emulate natural infection, we investigated the pathogenic potential of a C. psittaci field strain in orally inoculated 4-day-old ducklings. Three different challenge doses were tested and seven contact animals were also mock-inoculated with buffer in each group. Over the course of ten days, the birds were monitored for clinical symptoms and chlamydial dissemination before final examination of tissues using histopathology and immunohistochemistry. While the challenge strain disseminated systemically to all internal organs, mild signs of diarrhea were confined to ducklings inoculated with the highest dose (4.3 x 108 IFU/mL, Group 1). No other clinical symptoms or histopathological lesions were seen. The chlamydial load in internal organs as measured by PCR depended on the challenge dose and was unevenly distributed, i.e. high loads in spleen, liver, and distal small and large intestinal tract (ileum, cecum and rectum) vs. ten times lower values in lungs and proximal small intestinal tract (duodenum and jejunum). Notably, the C. psittaci infection of contact birds became evident on day 10 post-infection, with bacterial loads comparable to those of experimentally-infected animals, thus suggesting rapid bird-to-bird transmission of the challenge strain.
| S-EPMC4864072 | biostudies-literature
Project description:Imiquimod, an immune-modulating imidazoquinoline compound, has been approved in topical formulation for the treatment of actinic keratoses, superficial basal cell carcinomas, and external genital warts. Its use in the treatment of field cancerization, in particular, has been rapidly evolving. With the recent approval of a new drug application for a new concentration, as well as generic formulations, this drug has emerged at the forefront of treatment for actinic keratoses, with improved dosage scheduling and more patients having access to generic options. In the nearly 15 years since its original approval by the Food and Drug Administration for the treatment of actinic keratoses in 1997, topical imiquimod has been reviewed and studied extensively, not only for its safety and efficacy, but also for its tolerability in patients. This paper provides an indepth review of the literature, and provides clinical evidence for its inclusion in the arsenal of treatment options for patients with actinic keratoses.
| S-EPMC3114604 | biostudies-other
Project description:BackgroundThe objective of this study was to identify the molecular processes responsible for the anti-lesional activity of imiquimod in subjects with actinic keratosis using global gene expression profiling.MethodsA double-blind, placebo-controlled, randomized study was conducted to evaluate gene expression changes in actinic keratosis treated with imiquimod 5% cream. Male subjects (N = 17) with > or = 5 actinic keratosis on the scalp applied placebo cream or imiquimod 3 times a week on nonconsecutive days for 4 weeks. To elucidate the molecular processes involved in actinic keratosis lesion regression by imiquimod, gene expression analysis using oligonucleotide arrays and real time reverse transcriptase polymerase chain reaction were performed on shave biopsies of lesions taken before and after treatment.ResultsImiquimod modulated the expression of a large number of genes important in both the innate and adaptive immune response, including increased expression of interferon-inducible genes with known antiviral, anti-proliferative and immune modulatory activity, as well as various Toll-like receptors. In addition, imiquimod increased the expression of genes associated with activation of macrophages, dendritic cells, cytotoxic T cells, and natural killer cells, as well as activation of apoptotic pathways.ConclusionData suggest that topical application of imiquimod stimulates cells in the skin to secrete cytokines and chemokines that lead to inflammatory cell influx into the lesions and subsequent apoptotic and immune cell-mediated destruction of lesions.
| S-EPMC1796543 | biostudies-literature
Project description:Endothelin-1 (ET-1) is well known as the most potent vasoconstrictor, and can evoke histamine-independent pruritus. Recently, its involvement in cutaneous inflammation has begun to draw attention. The upregulation of ET-1 expression in the epidermis of human psoriasis patients has been reported. It was also demonstrated that ET-1 can stimulate dendritic cells to induce Th17/1 immune responses. However, the role of the interaction between ET-1 and ET-1 receptors in the pathogenesis of psoriasis remains elusive. Here, we investigated the effects of ET-1 receptor antagonist on imiquimod (IMQ) -induced psoriasiform dermatitis in mouse. Psoriasis-related cytokines such as IL-17A and TNF-α induced ET-1 expression in human keratinocytes. Topical application of selective endothelin A receptor (ETAR) antagonist ambrisentan significantly attenuated the development of IMQ-induced psoriasiform dermatitis and also significantly inhibited the histological inflammation and cytokine expression (TNF-α, IL-12p40, IL-12 p19, and IL-17) in the lesional skin of the mouse model. Furthermore, topical application of ambrisentan suppressed phenotypic and functional activation of dendritic cells in lymph nodes. Our findings indicate that the ET-1 and ETAR axis plays an important role in the pathogenesis of psoriasis and is a potential therapeutic target for treating psoriasis.
| S-EPMC7289852 | biostudies-literature
Project description:Received wisdom in the field of fungal biology holds that the process of editing a genome by transformation and homologous recombination is inherently mutagenic. However, that belief is based only on circumstantial evidence. We provide the first direct measurement of the effects of transformation on the genome by sequencing the genomes of 29 transformants and 30 untransformed controls to high coverage. Contrary to the received wisdom, our results show that transformation of DNA flanked by long targeting sequences, followed by homologous recombination and selection on a drug marker, is extremely safe. Gene deletion may select for a few mutations that occur after transformation, but even then we found fewer than two point mutations per gene deletion strain. We also tested these strains for changes in gene expression and found only a few genes that were consistently differentially expressed between wild types and strains with a drug resistance marker inserted. As part of this process, we provide the first published genome sequence of the commonly used laboratory strain Cryptococcus neoformans var. grubii strain KN99.
2017-09-26 | GSE104198 | GEO