Lal Girdhari, Nakayama Yumi, Sethi Apoorva, Singh Amit K, Burrell Bryna E, Kulkarni Neeraja, Brinkman C Colin, Iwami Daiki, Zhang Tianshu, Bromberg Jonathan S
1 National Centre for Cell Science, Pune, MH, India. 2 Departments of Surgery and Microbiology and Immunology, and Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, MD.
Transplantation. 2015 Sep;99(9):1817-28. doi: 10.1097/TP.0000000000000718.
Blocking CD40-CD40L costimulatory signals induces transplantation tolerance. Although B-cell depletion prevents alloantibody formation, nonhumoral functions of B cells in tolerance have not been well characterized. We investigated whether specific subsets of B cell or B cell-derived interleukin (IL)-10 contribute to tolerance.
Wild type C57BL/6, or B cell-specific interleukin (IL)-10 (CD19-Cre::IL-10) mice, received vascularized BALB/c cardiac allografts. BALB/c donor-specific splenocyte transfusion and anti-CD40L monoclonal antibody were used as tolerogen. B cells were depleted with antimouse CD20 monoclonal antibody. Various B-cell subsets were purified and characterized by flow cytometry, reverse transcription polymerase chain reaction, and adoptive transfer.
B-cell depletion prevented costimulatory blockade-induced allogeneic tolerance. Costimulatory blockade increased IL-10 in marginal zone precursor (MZP) B cells, but not other subsets. In particular, costimulatory blockade did not change other previously defined regulatory B-cell subsets (Breg), including CD5CD1d Breg or expression of TIM1 or TIM4 on these Breg or other Breg cell subsets. Costimulatory blockade also induced IL-21R expression in MZP B cells, and IL-21R MZP B cells expressed even more IL-10. B-cell depletion or IL-10 deficiency in B cells prevented tolerance in a cardiac allograft model, resulting in rapid acute cardiac allograft rejection. Adoptive transfer of wild type MZP B cells but not other subsets to B cell-specific IL-10 deficient mice prevented graft rejection.
CD40 costimulatory blockade induces MZP B cell IL-10 which is necessary for tolerance. These observations have implications for understanding tolerance induction and how B cell depletion may prevent tolerance.
阻断CD40 - CD40L共刺激信号可诱导移植耐受。虽然B细胞清除可防止同种抗体形成，但B细胞在耐受中的非体液功能尚未得到充分表征。我们研究了B细胞的特定亚群或B细胞衍生的白细胞介素（IL）-10是否有助于耐受。
野生型C57BL/6或B细胞特异性白细胞介素（IL）-10（CD19 - Cre::IL-10）小鼠接受血管化BALB/c心脏同种异体移植。使用BALB/c供体特异性脾细胞输注和抗CD40L单克隆抗体作为耐受原。用抗小鼠CD20单克隆抗体清除B细胞。通过流式细胞术、逆转录聚合酶链反应和过继转移对各种B细胞亚群进行纯化和表征。
B细胞清除可阻止共刺激阻断诱导的同种异体耐受。共刺激阻断可增加边缘区前体（MZP）B细胞中的IL-10，但其他亚群中未增加。特别是，共刺激阻断并未改变其他先前定义的调节性B细胞亚群（Breg），包括CD5CD1d Breg或这些Breg或其他Breg细胞亚群上TIM1或TIM4的表达。共刺激阻断还可诱导MZP B细胞中IL-21R的表达，并且IL-21R MZP B细胞表达更多的IL-10。B细胞清除或B细胞中的IL-10缺乏可阻止心脏同种异体移植模型中的耐受，导致快速急性心脏同种异体移植排斥反应。将野生型MZP B细胞而非其他亚群过继转移至B细胞特异性IL-10缺陷小鼠可防止移植物排斥。
CD40共刺激阻断可诱导MZP B细胞产生IL-10，这是耐受所必需的。这些观察结果对于理解耐受诱导以及B细胞清除如何可能阻止耐受具有重要意义。
