前 言
CD63也被称为溶酶体相关膜蛋白3（LAMP3），属于四次跨膜蛋白超家族成员，与细胞的活化、黏附、变异及肿瘤的侵袭、转移等有关。CD63是外泌体特异性标志蛋白，为新型药物递送及靶向外泌体提供契机，还可作为肿瘤的潜在标志物（如卵巢癌、肺癌等）。研究人员利用重组CD63蛋白开发多种适配体，用于非侵入型外泌体的检测。CD63靶点的多面性为治疗、诊断和生物医学研究带来新希望。
01 CD63生理学和病理学意义
CD63参与多种细胞进程，在晚期内体和多泡体的细胞蛋白分选中发挥关键作用，促进外泌体形成。通过靶向CD63介导外泌体药物的精准递送有助于实现靶向治疗。在免疫反应中，表达CD63的外泌体有助于抗原呈递并激活CD4+T细胞进行免疫调控。这凸显了CD63在免疫治疗中的重要性及其作为小分子抑制剂靶点的潜力。此外，它与整合素的相互作用控制细胞粘附和迁移。
除了在细胞稳态中的发挥基本功能外，CD63在多种肿瘤中均有表达，可促进肿瘤生长并调节肿瘤微环境，可作为癌症治疗的潜在靶标。此外，研究证明CD63外泌体在卵巢癌和肺癌等特定癌症中差异表达，表明其作为诊断生物标志物的潜在用途，对早期诊断和个性化治疗方案的制定产生影响。
CD63 作为诊断及治疗一体化靶点
（源自：doi.org/10.1002/adbi.202300078）
02 CD63从实验室到临床应用
CD63靶点的多样性为治疗干预提供了广阔的应用前景。在个性化医疗和靶向治疗中，直接或间接地将治疗药物添加到外泌体中已成为一种新的策略。这一创新的方案为精确治疗和疗效改善奠定了基础。值得一提的是，作为创新药物递送载体--细胞来源的胞外囊泡（EVs）已在癌症治疗的研究中如火如荼地开展，其表面表达CD9、CD63、CD81和CD82标记物。这些源自植物细胞、间充质细胞、T细胞和树突状细胞的外泌体具有作为有效药物载体的潜力，对多种疾病的治疗发挥作用。除了其治疗潜力外，CD63存在于外泌体和循环囊泡中，使其适用于从生物体液中进行非侵入性检测。这一先天优势为疾病早期诊断和持续监测开辟了新的途径。截至2023年8月，已有2项针对CD63的临床前研究。
临床试验中CD63靶向药物列表
药物 | 药物类型 | 适应证 | 临床阶段 |
AAV-GAA gene therapy (Pompe disease)
| 腺病毒相关病毒、酶、 重组病毒、抗体
| II型糖原累积病 | 临床前
|
anti-CD63 fusion protein | 抗体偶联、融合蛋白、重组酶 | 溶酶体贮积症（LSD） | 临床前 |
来源：data.pharnexcloud。com/
03 CD63在研究中的应用
CD63重组蛋白可用于新型核酸适体的开发。张振团队开发了一种无需分离纯化、基于适体的荧光偏振检测外泌体的方法（AFPExo）。AFPExo通过荧光偏振检测外泌体，为临床研究分析外泌体提供了一种可靠的方案。刘静团队进行的另一项研究，鉴定出一种新的核酸适体LL4A，用于CD63高表达的PLX4032耐药黑色素瘤患者的预后及靶向治疗。通过抗体或抑制剂阻断CD63的表达，并使用LL4A作为CD63 siRNA的递送工具，有望成为威罗菲尼（Vemurafenib）的新型联合疗法一个潜在新选择。
A. AFPExo法测定外泌体的选择性。使用5.0 μg/mL的CD63和BSA进行检测，结果显示外泌体特异性结合CD63。B. 荧光偏振随CD63浓度变化的曲线图（插图为荧光偏振对ΔFP的线性图），结果显示外泌体对CD63表现出高灵敏度，随CD63浓度的增加而增加。（源自：doi.org/10.1039/C9NR01589B）
通过一系列实验证实CD63是LL4A的结合靶点，图为酶联寡核苷酸测定法（ELONA）测定纯化的CD63重组蛋白（货号：11271-H08H，His标签，义翘神州）与LL4A的解离常数。（源自：doi.org/10.1016/j.omtn.2019.10.005）
✦义翘神州CD63明星产品
高纯度：
CD63 Protein, Mouse, Recombinant (His Tag), HPLC-verified, Cat: 50557-M08H
Purity ≥ 95 % as determined by SDS-PAGE, ≥ 95 % as determined by SEC-HPLC.
CD63 Protein, Human, Recombinant ( hFc Tag), HPLC-verified, Cat: 11271-H02H
Purity ≥ 95 % as determined by SDS-PAGE, ≥ 95 % as determined by SEC-HPLC.
相关应用: FCM, ICC/IF
Anti-CD63 Antibody, Mouse MAb, Cat: 11271-MM03
Immunofluorescence staining of CD63 in MCF7 cells.
相关应用: IHC-P
Anti-CD63 Antibody, Mouse MAb, Cat: 11271-MM01
Immunochemical staining of human CD63 in human malignant melanoma.
【参考文献】
1. Cheerathodi, M, et al. Epstein-Barr Virus LMP1 Modulates the CD63 Interactome. Viruses, 2021. doi.org/10.3390/v13040675
2. Yu, D, et al. Exosomes as a new frontier of cancer liquid biopsy. Molecular cancer, 2022. doi.org/10.1186/s12943-022-01509-9
3. Mosquera-Heredia, et al. Exosomes: Potential Disease Biomarkers and New Therapeutic Targets. Biomedicines, 2021. doi.org/10.3390/biomedicines9081061
4. Z. Song, et al. Development of a CD63 aptamer for efficient cancer immunochemistry and Immunoaffinity-Based exosome Isolation. Molecules, 2020. doi: 10.3390/molecules25235585.
5. Zhang, Z., et al. Aptamer-based fluorescence polarization assay for separation-free exosome quantification. Nanoscale, 2019. doi.org/10.1039/c9nr01589b
6. Li, H., et al. A Novel Aptamer LL4A Specifically Targets Vemurafenib-Resistant Melanoma through Binding to the CD63 Protein. Molecular therapy. Nucleic acids, 2019. doi.org/10.1016/j.omtn.2019.10.005
7. S. Tugues et al. Tetraspanin CD63 promotes vascular endothelial growth factor receptor 2-Β1 integrin complex formation, thereby regulating activation and downstream signaling in endothelial cells in vitro and in vivo. Journal of Biological Chemistry, 2013. doi: 10.1074/jbc.m113.468199.
8. Lema, D. A., & Burlingham, W. J. Role of exosomes in tumour and transplant immune regulation. Scandinavian journal of immunology, 2019. doi.org/10.1111/sji.12807
9. Valencia, J. C., Egbukichi, N., & Erwin-Cohen, R. A. Autoimmunity and Cancer, the Paradox Comorbidities Challenging Therapy in the Context of Preexisting Autoimmunity. Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research, 2019. doi.org/10.1089/jir.2018.0060
10. W. Sun, J. Luo, H. Jiang, and D. Duan, Tumor exosomes: a double-edged sword in cancer therapy. Acta Pharmacologica Sinica, 2018. doi: 10.1038/aps.2018.17.
11. Akbari, A.,et al. Engineered Exosomes for Tumor-Targeted Drug Delivery: A Focus on Genetic and Chemical Functionalization. Pharmaceutics, 2022. doi.org/10.3390/pharmaceutics15010066
12. B. De Goeij et al. Efficient payload delivery by a bispecific Antibody–Drug conjugate targeting HER2 and CD63. Molecular Cancer Therapeutics, 2016. doi: 10.1158/1535-7163.mct-16-0364.
13. Dai, X., Ye, Y., & He, F. Emerging innovations on exosome-based onco-therapeutics. Frontiers in immunology, 2022. doi.org/10.3389/fimmu.2022.865245
14. Kim, J. H., Lee, C. H., & Baek, M. C. Dissecting exosome inhibitors: therapeutic insights into small-molecule chemicals against cancer. Experimental & molecular medicine, 2022. doi.org/10.1038/s12276-022-00898-7
15. Herrmann, I. K., Wood, M. J. A., & Fuhrmann, G. Extracellular vesicles as a next-generation drug delivery platform. Nature nanotechnology, 2021. doi.org/10.1038/s41565-021-00931-2
16. Rezaie, J., Feghhi, M., & Etemadi, T. A review on exosomes application in clinical trials: perspective, questions, and challenges. Cell communication and signaling : CCS, 2022. doi.org/10.1186/s12964-022-00959-4
17. H. Odaka, et al. CD63-positive extracellular vesicles are potential diagnostic biomarkers of pancreatic ductal adenocarcinoma. BMC Gastroenterology, 2022. doi: 10.1186/s12876-022-02228-7.
