新型TLR7/9抑制剂对ABC型弥漫大B细胞淋巴瘤的治疗作用及分子机制研究

Diffuse large B-cell lymphoma (DLBCL) is the most common form of Non-Hodgkin’s Lymphoma (NHL), accounting for one-third of mature B-cell neoplasms. Gene expression profiling and analysis of related biomarkers have revealed at least two major histologically indistinguishable molecular subtypes, the germinal center B-cell-like (GCB) subtype and activated B-cell-like (ABC) subtype, which show different cure rates and responsiveness to targeted therapies, independent of clinical variables. In ABC-derived DLBCL, most damaged signaling pathways converge to aberrantly activate the nuclear factor (NF)-κB pathway, leading to the avoidance of cell death and resistance to chemotherapy. Thus, activation of the NF-κB pathway results in poor outcomes for patients with ABC-DLBCL compared to for those with GCB-DLBCL. . Here, we designed a novel immunomodulatory oligodeoxynucleotide (IMO) referred to as HJ901. Our preliminary experiments showed that HJ901 competitively bound to TLR7/9, suppressed activation of TLR7/9 signaling pathways, and selectively inhibited the proliferation of ABC-DLBCL cells with MyD88 mutation. Furtherly, HJ901 could inhibit the tumor growth in a mice model. Constitutive activation of TLR7/9-MyD88 signaling pathways in ABC-DLBCL is complex, involving both “classical” and “alternative” pathways, and can be regulated by many different mechanisms. Aberrant activation of NF-κB can be attributed to a number of different molecular lesions, including tonic signaling of the B-cell receptor (BCR). BCR signaling is essential to B-cell development, antigen selection, and humoral immunity..ABC-DLBCL cell lines and 30% of tissue samples from patients with ABC DLBCL harbor MyD88 gain-of-function mutations in the Toll-interleukin receptor domain. Therefore, we hypothesize that HJ901 targets TLR7/9 and has therapeutic effects on the ABC-DLBCL with abnormal NF-κB pathway activation.. In our future work, the mechanism of the inhibitory effect of HJ901 on ABC-DLBCL in cell culture and animal models will be investigated using various molecular immunology technologies. Furthermore, the regulation among NF-κB-MyD88, BCR signaling and cytokine pathway will be examined. These insights will reveal the role of TLR7/9 pathways in the disease progression of ABC-DLBCL and provide a rationale for ABC-DLBCL treatments.

弥漫大B细胞淋巴瘤（DLBCL）为常见的非霍奇金淋巴瘤，其中活化B细胞样（ABC）亚型患者复发率高，预后差；此亚型主要特征有NF-κB途径持续过度活化和关键分子基因突变等。我们设计并筛选了一种新型免疫调节性寡核苷酸（IMO），命名HJ901。前期研究显示HJ901可竞争性结合TLR7/9，抑制激活剂对TLR7/9信号通路的激活，选择性抑制MyD88突变的ABC型DLBCL细胞增殖。体内实验进一步验证了HJ901对该突变型肿瘤生长的抑制，提示了潜在的治疗前景。我们将进一步明确HJ901对DLBCL不同亚型和突变的作用异同及分子机制，探讨ABC型DLBCL中TLR7/9-MyD88对NF-κB通路的调控作用，揭示其与BCR和细胞因子通路的交互作用。我们的研究将深入阐释TLR7/9通路在ABC型DLBCL疾病进程中的作用，为HJ901作为TLR7/9靶向药物治疗ABC型DLBCL提供理论依据。

弥漫性大B细胞淋巴瘤（diffuse large B cell lymphoma，DLBCL）是一种侵袭性淋巴瘤，预后差。在活化的B细胞样（activated B-cell-like，ABC）DLBCL中，Toll样受体（TLR）7/9/MYD88通路异常激活从而避免细胞死亡并导致化疗抵抗。MYD88的功能增益突变增强了NF-κB和JAK-STAT信号通路，并与ABC型DLBCL发病机制中TLR信号的失调有关。因此，抑制TLR信号通路可能是提高临床疗效的关键。本研究设计了一种新合成的TLR7/9寡核苷酸拮抗剂，称为HJ901，它与TLR7/9竞争性结合。分析了HJ901在不同DLBCL细胞系中的抑制作用，并在异种移植小鼠模型中验证了其对肿瘤的抑制作用。本研究发现HJ901显著抑制了具有MYD88 L265P突变的多种DLBCL细胞系中TLR7和TLR9介导的细胞增殖和细胞因子的产生，呈时间和剂量依赖性。此外，HJ901在具有MYD88 L265P突变的DLBCL异种移植小鼠模型中阻止肿瘤生长并下调NF-κB和JAK2-STAT3信号通路。这些结果阐明了合成的寡核苷酸拮抗剂HJ901与TLR7/9竞争性结合的抗肿瘤作用，其可能与下调NF-κB和JAK2-STAT3信号通路有关，此研究可能为靶向治疗具有MYD88 L265P突变的ABC型DLBCL患者提供新的治疗方案和理论依据。