B细胞在肿瘤免疫调节中发挥重要作用，研究发现肿瘤驯化下的B细胞可通过分泌抑制性细胞因子和抗体而发挥肿瘤免疫抑制作用，因此，研究肿瘤对B细胞的调控机制对肿瘤免疫治疗具有重要意义。生长诱导配体（APRIL）是TNF超家族成员，可调节B细胞的生长、成熟和分化，特别在抗体类别转换方面发挥重要作用。我们的前期结果表明结肠癌细胞中APRIL的表达明显升高，并能够促进B细胞表面免疫抑制分子的表达，抑制性细胞因子和抗体的分泌。因此，我们提出假设：结肠癌细胞分泌的APRIL可通过结合B细胞表面受体促进B细胞的免疫抑制作用,从而促进肿瘤的进展。本实验希望利用APRIL敲低结肠癌细胞系建立结肠癌小鼠模型，并利用TACI-/-小鼠和μMT B细胞缺陷小鼠模型，研究肿瘤细胞分泌APRIL对B细胞功能的影响，并进一步探讨其发挥作用的具体分子机制。本研究为探讨抗肿瘤免疫效应机制和肿瘤免疫治疗新方法的研发提供理

B cells play important roles in tumor immunology, recent researches has shown that tumor-educated B cells can suppress anti-tumor immunity by secreting inhibitory factors and antibodies, thus regulatory mechanisms of B cells by cancer cells has great significance for cancer immunotherapy.A proliferation-inducing ligand (APRIL) is a member of TNF super family , which can regulate the proliferation and differentiation of B cells, especially in class-switch recombination. Our preliminary results has shown that the expression of APRIL is high in colon cancer cell, and can inhibit the B cell surface markers, promote the expression of inhibitory factors and antibodies. Thus, we hypothesize that APRIL secreted by colon cancer cells can promote B cells immunosuppressive function by binding with APRIL receptor, consequently promote tumor progression. This analysis will establish shAPRIL colon cancer mouse model, TACI-/- mouse model and μMT B cell defect model, to investigate the influence of APRIL on B cells and further explore the molecular mechanisms.This study will provide theoretical basis for the study of anti-tumor immune response and the development of new cancer therapeutic methods.