IC50: Imiquimod activates toll-like receptor 7 (EC50 2.1 μM) on immune cells and also enables an OGF-mediated block of cell proliferation (IC50 2 μM) [1].
Toll-like receptor 7, also known as TLR7, is protein that in humans is encoded by the TLR7 gene. It is a member of the toll-like receptor (TLR) family. The TLR family plays an important role in pathogen recognition and activation of innate immunity. Imiquimod is a prescription medication that acts as an immune response modifier activating toll-like receptor 7. It is marketed by Meda AB, Graceway Pharmaceuticals, and iNova Pharmaceuticals under the trade names Aldara and Zyclara, and by Farmacoquímica Médica (FQM) in Brazil as Ixium.
In vitro: Results from a previous study demonstrate that imiquimod were capable of inducing interleukin-12 and interferon-g in mouse and human cell cultures. Imiquimod was also found to inhibit IL-4 and IL-5 production in mouse and human culture systems. These data suggested that imiquimod might have clinical utility in diseases where cellmediated immune responseswere important and in diseases associated with overexpression of IL-4 or IL-5, such as atopic disease. [2].
In vivo: The findings from animal study suggested that imiquimod could inhibit the airway inflammation of asthma animals by reducing GATA-3 mRNA and protein expression and increasing T-bet, STAT(6) mRNA and protein expression [3].
Clinical trial: Imiquimod is a patient-applied cream used to treat certain diseases of the skin, including skin cancers (basal cell carcinoma, Bowen's disease, superficial squamous cell carcinoma, some superficial malignant melanomas, and actinic keratosis) as well as genital warts (condylomata acuminata). However, Imiquimod is generally secondary to surgery, because surgery has a better chance to effectively treat at least some forms of skin cancer. Imiquimod has been tested for treatment of molluscum contagiosum. Two large randomized controlled trials, however, found no evidence of effectiveness of imiquimod in treating children with molluscum contagiosum, and concerning adverse effects were also noted. Imiquimod has also been tested for treatment of vulvar intraepithelial neoplasia, common warts that have proven difficult to treat, and vaginal intraepithelial neoplasia.
IC50: Imiquimod能够激活免疫细胞上的Toll样受体7（EC50为2.1μM），并使OGF介导的细胞增殖受阻（IC50为2μM）[1]。 Toll样受体7，又称TLR7，是人类中由TLR7基因编码的一种蛋白质。它是Toll样受体（TLR）家族的成员。TLR家族在病原体识别和激活先天免疫方面发挥重要作用。Imiquimod是一种处方药，作为免疫反应修饰剂，可以激活Toll样受体7。它由Meda AB、Graceway Pharmaceuticals和iNova Pharmaceuticals在Aldara和Zyclara等品牌下销售，由巴西Farmacoquímica Médica（FQM）作为Ixium销售。
体外研究：以前的研究结果表明，imiquimod能够在小鼠和人类细胞培养中诱导白细胞介素-12和干扰素-g的产生。Imiquimod还发现能够抑制小鼠和人类文化系统中IL-4和IL-5的产生。这些数据表明，imiquimod可能在细胞介导的免疫反应重要和与IL-4或IL-5过度表达相关的疾病（如变应性疾病）的治疗中具有临床效用[2]。
体内：动物研究结果表明，Imiquimod可以通过减少GATA-3 mRNA和蛋白表达以及增加T-bet、STAT（6）mRNA和蛋白表达来抑制哮喘动物的气道炎症 [3]。
临床试验：Imiquimod是一种患者自行使用的乳膏，用于治疗皮肤癌（基底细胞癌、Bowen病、表浅性鳞状细胞癌、某些表浅性恶性黑色素瘤和日光性角化症）以及生殖器疣（尖锐湿疣）。然而，Imiquimod通常是手术的辅助治疗，因为手术有更好的机会有效地治疗至少某些形式的皮肤癌。Imiquimod已经被测试用于治疗软疣。然而，两项大型随机对照试验没有发现Imiquimod在治疗儿童软疣方面的有效性，并且注意到有关不良反应的问题。Imiquimod还被测试用于治疗阴道上皮内瘤变、难以治疗的普通疣和阴道上皮内瘤变。
Reference:
[1] Zagon IS, Donahue RN, Rogosnitzky M, McLaughlin PJ. Imiquimod upregulates the opioid growth factor receptor to inhibit cell proliferation independent of immune function. Exp Biol Med (Maywood). 2008;233(8):968-79.
[2] Wagner TL, Ahonen CL, Couture AM, Gibson SJ, Miller RL, Smith RM, Reiter MJ, Vasilakos JP, Tomai MA. Modulation of TH1 and TH2 cytokine production with the immune response modifiers, R-848 and imiquimod. Cell Immunol. 1999;191(1):10-9.
[3] Yin KS, Jin SX, Bian T, Wu QZ, Wang X, Yao X. The effects of imiquimod on an animal model of asthma. Zhonghua Jie He He Hu Xi Za Zhi. 2007;30(7):509-17.