Brain antigens stimulate proliferation of T lymphocytes with a pathogenic phenotype in multiple sclerosis patients. Brain antigens stimulate proliferation of T lymphocytes with a pathogenic phenotype in multiple sclerosis patients

A method to stimulate T lymphocytes with a broad range of brain antigens would facilitate identification of the autoantigens for multiple sclerosis and enable definition of the pathogenic mechanisms important for multiple sclerosis. In previous work we found the obvious approach of culturing leukocytes with homogenized brain tissue does not work because the brain homogenate suppresses antigen-specific lymphocyte proliferation. We now report a method that substantially reduces the suppressive activity. We used this non-suppressive brain homogenate to stimulate leukocytes from multiple sclerosis patients and controls. We also stimulated with common viruses for comparison. We measured proliferation, selected the responding CD3+ cells with flow cytometry, and sequenced their transcriptomes for mRNA and T cell receptor sequences. The mRNA expression suggested the brain-responding cells from MS patients are potentially pathogenic. The T cell receptor repertoire of the brain-responding cells was clonal with minimal overlap with virus antigens. Overall design: We studied 5 multiple sclerosis patients and 3 controls for a total of 8 subjects. For each subject, we sequenced RNA from T cells responding to stimulation with brain antigens, T cells responding to stimulation with influenza, and peripheral blood cells immediately ex vivo.

一种可利用广谱脑抗原刺激T淋巴细胞（T lymphocyte）的方法，将有助于鉴定多发性硬化（multiple sclerosis）的自身抗原，并明确该病关键的致病机制。既往研究显示，采用脑组织匀浆与白细胞共培养的常规思路并不可行，原因在于脑匀浆会抑制抗原特异性淋巴细胞的增殖。本研究报道了一种可显著降低该抑制活性的方法。我们利用该无抑制活性的脑匀浆，对多发性硬化患者与健康对照的白细胞进行刺激，并以常见病毒作为刺激物开展平行对照实验。我们检测了细胞增殖情况，通过流式细胞术（flow cytometry）分选得到活化的CD3+ T细胞，并对其转录组（transcriptome）进行信使RNA（mRNA）与T细胞受体（T cell receptor）测序。转录组表达分析结果显示，多发性硬化患者体内的脑抗原反应性T细胞具有潜在致病性。脑抗原反应性T细胞的T细胞受体库呈现克隆性特征，且与病毒抗原反应性T细胞的受体库重叠度极低。实验整体设计：本研究共纳入5名多发性硬化患者与3名健康对照，总计8名受试者。针对每名受试者，我们分别对三类细胞进行测序：经脑抗原刺激活化的T细胞、经流感病毒刺激活化的T细胞，以及离体即刻的外周血细胞。