Fiore Nathan T, Willcox Kendal F, Grieco Anamaria R, Dayani Dorsa, Zuberi Younus A, Heijnen Cobi J, Grace Peter M
Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, United States.
Department of Psychological Sciences, Rice University, Houston, TX, United States.
Pain. 2025 Jul 18. doi: 10.1097/j.pain.0000000000003734.
B cells contribute to the development of pain after sciatic nerve chronic constriction injury (CCI) through binding of immunoglobulin G (IgG) to Fc gamma receptors (FcγRs) in the lumbar dorsal root ganglia (DRG) and spinal cord. Yet the contribution of B cells to pain after different types of peripheral nerve injury is uncertain. Using male and female mice, we demonstrate a divergent role for B cell-IgG-FcγR signaling underlying mechanical allodynia between CCI, nerve crush (NC), spared nerve injury (SNI), and spinal nerve ligation (SNL). Depletion (monoclonal anti-CD20) or genetic deletion (muMT mice) of B cells prevented development of allodynia after NC and CCI, but not SNI or SNL. In apparent contradiction, circulating levels of autoreactive IgG and circulating immune complexes were increased in all models, although more prominent after NC and CCI. Passive transfer of IgG from SNI donor mice induced allodynia in CCI muMT recipient mice, demonstrating that IgG secreted after SNI is pronociceptive. To investigate why pronociceptive IgG did not contribute to mechanical allodynia after SNI, we evaluated the levels of the Fc receptor γ subunit. Spared nerve injury or spinal nerve ligation did not increase γ subunit levels in the DRG and spinal cord, whereas CCI and NC did, in agreement with B cell-dependent allodynia in these models. Together, the results suggest that traumatic peripheral nerve injury drives secretion of autoreactive IgG from B cells. However, levels of cognate FcγRs are increased after sciatic nerve constriction and crush, but not transection, nerve injury.
B细胞通过免疫球蛋白G(IgG)与腰段背根神经节(DRG)和脊髓中的Fcγ受体(FcγRs)结合,促进坐骨神经慢性压迫性损伤(CCI)后疼痛的发展。然而,B细胞在不同类型的周围神经损伤后对疼痛的作用尚不确定。我们使用雄性和雌性小鼠,证明了在CCI、神经挤压(NC)、保留神经损伤(SNI)和脊髓神经结扎(SNL)之间,B细胞-IgG-FcγR信号传导在机械性异常性疼痛中发挥不同作用。B细胞的耗竭(单克隆抗CD20)或基因缺失(muMT小鼠)可预防NC和CCI后异常性疼痛的发展,但不能预防SNI或SNL后的异常性疼痛。明显矛盾的是,所有模型中自身反应性IgG和循环免疫复合物的循环水平均升高,尽管在NC和CCI后更为显著。将SNI供体小鼠的IgG被动转移到CCI muMT受体小鼠中可诱导异常性疼痛,表明SNI后分泌的IgG具有伤害感受性。为了研究为什么伤害感受性IgG在SNI后对机械性异常性疼痛没有作用,我们评估了Fc受体γ亚基的水平。保留神经损伤或脊髓神经结扎并未增加DRG和脊髓中的γ亚基水平,而CCI和NC则增加了,这与这些模型中B细胞依赖性异常性疼痛一致。总之,结果表明创伤性周围神经损伤驱动B细胞分泌自身反应性IgG。然而,坐骨神经压迫和挤压后,而非横断性神经损伤后,同源FcγRs的水平会升高。