噬菌蛭弧菌简易保存方法的研究

本文报道了噬菌蛭弧菌在自来水宿主软琼脂中,于4℃环境(冰箱)存活的时间.发现噬菌蛭弧菌在自来水宿主软琼脂中,于4℃冰箱中保存,至少可以存活3个月以上,一般为5～8个月左右,最长时间可达18个月。但在自来水宿主双层琼脂平板上形成的噬斑数目,随着保存时间的延长,则有不同程度的减少。     

脆弱拟杆菌BF839治疗寻常型银屑病：一项单臂、开放初步临床试验

银屑病被认为是一种T细胞主导的炎症性疾病,其发病与肠道菌群失调密切相关。脆弱拟杆菌 (Bacteroides fragilis,BF) 可通过调节T细胞的细胞因子表达起抗炎作用。目前尚无脆弱拟杆菌用于治疗银屑病的相关报道,文中率先探究脆弱拟杆菌BF839对银屑病的治疗效果。选择2019年4月至2019年10月广州医科大学附属第二医院就诊的27例银屑病患者,维持原治疗不变,口服脆弱拟杆菌BF839 12周,对比治疗前后银屑病皮损面积与严重程度指数 (Psoriasis area and severity index,PASI) 评分,统计治疗12周后药物减停率。结果表明,12周试验完成率为96.3% (26/27),12周PASI30 (PASIN定义为治疗后PASI评分下降≥N%的患者比例) 为65.4%,PASI50为42.3%,PASI75为19.2%;治疗前PASI评分为9.1±5.9,治疗12周后PASI评分为5.8±4.9,具有显著统计学差异 (P<0.01);治疗12周后皮肤瘙痒程度用视觉模拟量表 (Visual analog scale,VAS) 评分有效率为42.3%,治疗前VAS评分为2.9±2.2,治疗12周后VAS评分为2.3±2.1,无显著统计学差异 (P>0.05)。患者治疗12周内不良反应率为3.8% (1/26),其中便秘1例,药物减停率为60.0%。以上结果提示脆弱拟杆菌BF839可能对银屑病治疗有一定疗效,可降低PASI评分及药物使用率,不良反应少,值得进一步研究。     

Minimal Erythema Dose (MED) Testing

Ultraviolet radiation (UV) therapy is sometimes used as a treatment for various common skin conditions, including psoriasis, acne, and eczema. The dosage of UV light is prescribed according to an individual''s skin sensitivity. Thus, to establish the proper dosage of UV light to administer to a patient, the patient is sometimes screened to determine a minimal erythema dose (MED), which is the amount of UV radiation that will produce minimal erythema (sunburn or redness caused by engorgement of capillaries) of an individual''s skin within a few hours following exposure. This article describes how to conduct minimal erythema dose (MED) testing. There is currently no easy way to determine an appropriate UV dose for clinical or research purposes without conducting formal MED testing, requiring observation hours after testing, or informal trial and error testing with the risks of under- or over-dosing. However, some alternative methods are discussed.     

CARD14/CARMA2sh and TANK differentially regulate poly(I:C)–induced inflammatory reaction in keratinocytes

CARD14/CARMA2sh (CARMA2sh) is a scaffold protein whose mutations are associated with the onset of human genetic psoriasis and other inflammatory skin disorders. Here we show that the immunomodulatory adapter protein TRAF family member-associated NF-κB activator (TANK) forms a complex with CARMA2sh and MALT1 in a human keratinocytic cell line. We also show that CARMA2 and TANK are individually required to activate the nuclear factor κB (NF-κB) response following exposure to polyinosinic-polycytidylic (poly [I:C]), an agonist of toll-like receptor 3. Finally, we present data indicating that TANK is essential for activation of the TBK1/IRF3 pathway following poly (I:C) stimulation, whereas CARMA2sh functions as a repressor of it. More important, we report that two CARMA2sh mutants associated with psoriasis bind less efficiently to TANK and are therefore less effective in suppressing the TBK1/IRF3 pathway. Overall, our data indicate that TANK and CARMA2sh regulate TLR3 signaling in human keratinocytes, which could play a role in the pathophysiology of psoriasis.     

Secukinumab,a novel anti–IL-17A antibody,shows low immunogenicity potential in human in vitro assays comparable to other marketed biotherapeutics with low clinical immunogenicity

Secukinumab is a human monoclonal antibody that selectively targets interleukin-17A and has been demonstrated to be highly efficacious in the treatment of moderate to severe plaque psoriasis, starting at early time points, with a sustained effect and a favorable safety profile. Biotherapeutics—including monoclonal antibodies (mAbs)—can be immunogenic, leading to formation of anti-drug antibodies (ADAs) that can result in unwanted effects, including hypersensitivity reactions or compromised therapeutic efficacy. To gain insight into possible explanations for the clinically observed low immunogenicity of secukinumab, we evaluated its immunogenicity potential by applying 2 different in vitro assays: T-cell activation and major histocompatibility complex–associated peptide proteomics (MAPPs). For both assays, monocyte-derived dendritic cells (DCs) from healthy donors were exposed in vitro to biotherapeutic proteins. DCs naturally process proteins and present the derived peptides in the context of human leukocyte antigen (HLA)-class II. HLA-DR–associated biotherapeutic-derived peptides, representing potential T–cell epitopes, were identified in the MAPPs assay. In the T-cell assay, autologous CD4⁺ T cells were co-cultured with secukinumab-exposed DCs and T-cell activation was measured by proliferation and interleukin-2 secretion. In the MAPPs analysis and T-cell activation assays, secukinumab consistently showed relatively low numbers of potential T-cell epitopes and low T-cell response rates, respectively, comparable to other biotherapeutics with known low clinical immunogenicity. In contrast, biotherapeutics with elevated clinical immunogenicity rates showed increased numbers of potential T-cell epitopes and increased T-cell response rates in T-cell activation assays, indicating an approximate correlation between in vitro assay results and clinical immunogenicity incidence.     

Dietary iron restriction increases plaque stability in apolipoprotein-E-deficient mice

Accumulative evidence has supported the role of iron in the development of atherosclerosis. To test whether iron-mediated oxidative stress influences plaque stability, apoliporotein-E (ApoE)-deficient mice (3 months old) were placed on a chow diet or a low-iron diet for 3 months, and the abundance of interstitial collagen and the expression of the matrix degradation-associated enzyme, matrix metalloproteinase-9 (MMP-9), in vascular lesions were assessed. A low-iron diet appeared to reduce iron deposition while substantially increasing collagen content of lesions in mice. Immunostaining demonstrated lower expression of MMP-9 in lesions of iron-restricted animals. Likewise, SDS-PAGE zymography revealed lower gelatinolytic activities in aortic tissues and sera of the same group of animals. When older ApoE-deficient mice (5 months old) received a low-iron diet for 2 months, development of the lesion area was not significantly affected. However, the lesional collagen content was much higher in the iron-restricted group of animals, and MMP-9 expression in aortic tissues from the same group of mice was significantly lower. Treatment of murine J774 macrophages with increasing concentrations of ferric ammonium citrate significantly enhanced the amount of MMP-9 secreted. Together, these data indicate that decreased vascular iron content following dietary iron restriction in ApoE-deficient mice leads to lower matrix degradation capacity and increased plaque stability.