

本研究Western Blot 关键通路验证实验全程使用 Absin HRP 标记二抗 abs20039、abs20040,是解析 Akt、PLCγ 磷酸化信号通路的核心试剂:
T 细胞急性淋巴细胞白血病(T-ALL)是高侵袭血液恶性肿瘤,占儿童 ALL 15%、成人 ALL 25%;成人患者复发率高、化疗耐药、预后极差。现有靶向靶点存在固有缺陷:
CD28 是 T 细胞活化核心共刺激受体;现有免疫治疗多靶向 PD-1/CTLA-4,极少开发 CD28 靶向药物。已有临床样本证实 T-ALL 细胞 CD28 异常过表达,肿瘤微环境内正常 T 细胞 CD28 表达耗竭,存在天然靶向差异窗口,但无 CD28 特异性纳米多肽药物开发报道。
酶指导多肽胞内自组装是近年纳米药物热点,可通过肿瘤特异性酶触发原位纳米结构生成,提升选择性杀伤;但既往多肽缺少特异性肿瘤细胞受体靶向模块,无法精准富集 T-ALL,限制体内疗效。
现有 T-ALL 药物脱靶毒性大、CD28 靶点未被多肽纳米药开发、酶自组装多肽缺乏肿瘤特异性靶向;本文同时解决靶点特异性、多肽酶响应组装、多重细胞毒性机制三大瓶颈,构建 CD28 靶向酶构象开关多肽纳米治疗新策略。
本研究遵循靶点挖掘→分子模块化设计→体外理化表征→细胞水平靶向 / 毒性 / 机制验证→转录组高通量通路筛选→蛋白 WB 通路确证(Absin 二抗支撑)→体内异种移植药效 + 安全性评价→联合化疗增效完整闭环思路:
1.实验思路 构建三功能多肽 SAp-CD28 及三组对照,验证磷酸化位点、靶向序列、组装基序各自功能;通过 ALP 酶处理模拟肿瘤微环境,多手段检测溶解度、组装形貌、二级结构、CD28 结合亲和力。
2.实验结果
3.对应原图
FIGURE 1
Schematic of peptide molecular design and its tumor-killing mechanism. (A) Chemical structure and secondary conformation of SApCD28. (B) Chemical structure and secondary conformation of SA-CD28, generated via alkaline phosphatase-mediated dephosphorylation of SAp-CD28. (C) Schematic illustration of SAp-CD28 inducing nuclear rupture through dysregulation of CD28 downstream signaling and physical damage, and its synergy with the chemotherapeutic agent cytarabine in cancer treatment.
FIGURE 2
Characterization of the four peptide molecules before and after ALP dephosphorylation reactions. (A) Tyndall effects of the four peptides after incubation without ALP or with ALP for 12 h. (B) Conversion rates of the four peptides incubated with ALP (10 U/mL) over time. The HPLC chromatogram (inset images) shows two peaks, corresponding to the peptides before (peak 1) and after ALP dephosphorylation products (peak 2). (C) Transmission electron microscopy (TEM) images of the indicated peptides incubated without ALP or with ALP for 12 h. Scale bar: 200 nm. (D) FTIR spectra of SAp-CD28 and SA-CD28p in the presence or absence of ALP (10 U/mL). The dashed lines represent parallel β-sheets and α-helices, respectively. (E) CD spectrum of SAp-CD28 and SA-CD28p in the presence or absence of ALP (10 U/mL). (F) Secondary structure calculation of SApCD28 and SA-CD28p in the presence or absence of ALP (10 U/mL). (G) Microscale thermophoresis (MST) analysis of SAp-CD28, SA-CD28p and CD28p binding to the recombinant human CD28 proteins before and after ALP dephosphorylation reactions. KD values represent apparent binding affinities calculated from a 16-point titration. Data represent mean ± SD from three independent biological replicates (n = 3).
1.实验思路 以 Jurkat T-ALL 细胞为模型,正常 CD3+T、LO2 肝细胞做安全对照;共聚焦观察细胞摄取、核碎裂;多种内吞抑制剂明确摄取通路;MTT 定量细胞活力;流式区分凋亡 / 坏死比例;Bio 电镜观察核膜超微结构损伤。
2.实验结果
3.对应原图:图 3 共聚焦核染色、内吞抑制剂流式、细胞超微电镜、MTT 活力、Annexin V 流式坏死定量。
FIGURE 3
Nuclear damage and apoptosis triggered by peptide self-assembly at the cellular level. (A) Confocal laser scanning microscopy (CLSM) images of Jurkat cells treated with SAp-CD28 or SA-CD28p. Scale bar: 25 μm. (B) Flow chart of fluorescence intensity of Jurkat cells pretreated with different internalization inhibitors, then incubated with SAp-CD28 for 1 h. (C) Biological electron microscopic (Bio-EM) imaging of Jurkat cells after the indicated treatments for 8 h. Scale bar: 500 nm. (D, E) Relative cell viabilities of (D) Jurkat cells and (E) human CD3+ T cells incubated with different concentrations of the four peptides for 48 h (n = 4). (F) Annexin V-PE/7-AAD apoptosis detection of Jurkat cells after various treatments for 12 h. (G) Quantitative analysis of apoptosis flow cytometry results. Data are presented as mean ± SD (n = 3 independent experiments). Statistical analysis was performed using one-way ANOVA. **p < 0.01.
1.实验思路 PBS、SA-CD28p、SAp-CD28 三组细胞 RNA 测序,差异基因筛选、KEGG 通路富集,定位钙信号、PI3K-Akt、细胞骨架相关失调通路,为 WB 验证提供候选靶点。
2.实验结果 SAp-CD28 处理产生 278 个差异基因,显著富集 PI3K-Akt、钙信号、局灶黏附(细胞骨架)通路,提示存活通路抑制与钙稳态失衡。
FIGURE 4
Transcriptomic profiling of cell apoptosis induced by peptides. (A–C) Volcano plot reveals gene regulation in Jurkat cells: Control vs SAp-CD28 (A), Control vs SAp-CD28 (B), and SA-CD28p vs SAp-CD28 (C). (D) Venn diagram illustrating common and unique deregulated genes in Jurkat cells treated by SAp-CD28 and SA-CD28p compared with PBS control. (E) KEGG pathway enrichment analysis of the differential pathways in Jurkat cells treated with SAp-CD28 versus PBS Control. (F) The heatmap of typical genes associated with apoptosis and nuclear damage in Jurkat cells after SAp-CD28 treatment in comparison with PBS control.
1.实验思路 针对转录组富集的 Akt、PLCγ 核心通路,使用特异性一抗检测总蛋白与磷酸化活化蛋白;采用 Absin HRP 二抗孵育显影,灰度定量,明确 SAp-CD28 对两条促存活通路的抑制作用;配套钙荧光、细胞骨架染色验证下游钙超载与骨架崩解。
2.实验操作含 Absin 产品关键步骤 蛋白电泳转膜后,封闭过夜;孵育兔源一抗(Akt、p-Akt、PLCγ1、p-PLCγ1);洗膜后稀释 Absin abs20039、abs20040 HRP 标记羊抗兔二抗室温孵育 1h;TBST 充分洗涤,HRP 化学发光成像采集条带,ImageJ 定量灰度值。
3.实验结果
Absin 产品关键价值:本模块唯一免疫学检测试剂,直接实现通路蛋白定量可视化,完成转录组数据蛋白水平验证,支撑全文核心杀伤机制推导。
FIGURE 5
SAp-CD28 disrupts CD28 downstream signaling and induces calcium overload and cytoskeletal collapse. (A, B) Representative Western Blot bands (A) and quantitative analysis (B) of phospho-Akt, Akt, phospho-PLCγ, and PLCγ in Jurkat cells treated with SAp-CD28 or SA-CD28p versus PBS controls.
1.实验思路 Jurkat 细胞皮下构建裸鼠移植瘤,分为 PBS、单药阿糖胞苷、SA-CD28p、SAp-CD28 单药、SAp-CD28 + 阿糖胞苷联用 5 组;给药周期 28 天,监测肿瘤体积、小鼠体重;终点检测血清氧化损伤标志物 8-OHdG、肿瘤 H&E 坏死染色、Ki67 增殖染色、心肝肾脾肺脏器病理切片。
2.实验结果
FIGURE 6
Antitumor effects of the self-assembling peptides in Jurkat tumor-bearing nude mice. (A) Schematic illustration of tumor inoculation and treatment in mice. (B) The growth curves of the tumors during the treatments. (C) The variations in mouse weights during the indicated treatments. (D) Tumor inhibition rates are determined by measuring tumor volumes at the end of treatment. (E) The digital images of the dissected tumors after the indicated treatments. (F) The average tumor weight at the end of the treatment. (G) Quantification of serum 8-OHdG as an oxidative stress biomarker in mice at the therapeutic endpoint. (H) Representative hematoxylin and eosin (H&E, top panel; scale bar: 200 μm) and Ki-67 immunohistochemistry (Ki-67, bottom panel; scale bar: 50 μm) staining of tumor tissues at the study endpoint after the indicated treatments. Data are presented as mean ± SD (n = 7 mice per group for B-D, F; n = 3 mice per group for (G)). Statistical significance was determined using two-way ANOVA (B) or one-way ANOVA (F, G). *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.
在本 CD28 靶向多肽治疗 T-ALL 的完整研究体系中,Absin HRP 标记二抗 abs20039、abs20040 是信号通路机制验证的核心支撑试剂,不可替代: