Granzyme B–producing B cells have been reportedly reported to be an important regulatory B cell subset in the pathogenesis of many diseases. However, its role in liver transplant recipients with acute rejection has never been well elucidated. Seventeen liver transplant recipients with acute rejection and 25 controls with stable liver function were enrolled in this study to determine the function of granzyme B–producing B cells via flow cytometry. Liver transplant recipients with acute rejection had higher expression of granzyme B in CD19⁺B cells when compared with controls. Following rejection, the granzyme B production was even elevated although comparison failed to reach significance. The percentages of CD27⁺granzyme B⁺CD19⁺B cells and CD138⁺granzyme B⁺CD19⁺B cells were lower than those of CD27⁻granzyme B⁺CD19⁺B cells and CD138⁻granzyme B⁺CD19⁺B cells in patients with acute rejection, respectively. While the production of CD27 and CD138 was not different between liver transplant recipients with and without acute rejection but increased expression of the two surface markers was observed following rejection. Furthermore, the frequency of granzyme B⁺CD19⁺B cells correlated with the level of alanine aminotransferase instead of tacrolimus. CD19⁺B cells could produce granzyme B when stimulated with IgG + IgM and CpG in the presence of the supernatant of activated CD4⁺CD25⁻T cells. In return, granzyme B⁺CD19⁺B cells could suppress the proliferation of CD4⁺CD25⁻T cells in a granzyme B– and contact-dependent manner. The increased expression of granzyme B in CD19⁺B cells from liver transplant recipients with acute rejection might function as a feedback loop for the activation of the CD4⁺CD25⁻T cells.

据报道，产生颗粒酶 B 的 B 细胞是许多疾病发病机制中重要的调节性 B 细胞亚群。然而，它在具有急性排斥反应的肝移植受者中的作用从未得到很好的阐明。本研究招募了 17 名急性排斥的肝移植受者和 25 名肝功能稳定的对照者，通过流式细胞术确定产生颗粒酶 B 的 B 细胞的功能。与对照组相比，患有急性排斥反应的肝移植受者在 CD19 ^{+ B 细胞中具有更高的颗粒酶 B 表达。}拒绝后，颗粒酶 B 的产生甚至升高，尽管比较未能达到显着性。CD27 ⁺颗粒酶 B ⁺ CD19 ^{+的百分比}急性排斥反应患者的B细胞和CD138 ^+颗粒酶B ⁺ CD19 ⁺ B细胞分别低于CD27-颗粒^酶B ⁺ CD19 ⁺ B细胞和CD138-颗粒酶B ⁺ CD19 ^{+ B细胞。}虽然 CD27 和 CD138 的产生在有和没有急性排斥反应的肝移植受者之间没有差异，但在排斥反应后观察到两种表面标志物的表达增加。^{此外，颗粒酶 B +} CD19 ⁺ B 细胞的频率与丙氨酸氨基转移酶水平相关，而不是与他克莫司相关。CD19 ^{+在活化的 CD4 +} CD25 ^- T 细胞的上清液存在下，用 IgG + IgM 和 CpG 刺激 B 细胞可以产生颗粒酶 B。作为回报，颗粒酶 B ⁺ CD19 ⁺ B 细胞可以颗粒酶 B- 和接触依赖性方式抑制 CD4 ⁺ CD25 ^{- T 细胞的增殖。来自具有急性排斥反应的肝移植受者的 CD19 +} B 细胞中颗粒酶 B 的表达增加可能充当激活 CD4 ⁺ CD25 ^- T 细胞的反馈回路。