Inflammatory Bowel Disease Center, Division of Gastroenterology, University of California San Diego, La Jolla, CA, USA.
San Diego VA Medical Center, San Diego, CA, USA.
J Crohns Colitis. 2020 Oct 5;14(10):1364-1377. doi: 10.1093/ecco-jcc/jjaa067.
Intestinal biopsy sampling during IBD trials represents a valuable adjunct strategy for understanding drug responses at the tissue level. Given the length and distinctive embryonic origins of the proximal and distal colon, we investigated whether inherent regional differences of immune cell composition could introduce confounders when sampling different disease stages, or pre/post drug administration. Here, we capitalise on novel mass cytometry technology to perform deep immunophenotyping of distinct healthy colonic segments, using the limited numbers of biopsies that can be harvested from patients.
Biopsies [2.8 mm] were collected from the caecum, transverse colon, descending colon, and rectum of normal volunteers. Intestinal leukocytes were isolated, stained with a panel of 37 antibodies, and mass cytometry data acquired.
Site-specific patterns of leukocyte localisation were observed. The proximal colon featured increased CD8+ T cells [particularly resident memory], monocytes, and CD19+ B cells. Conversely, the distal colon and rectum tissues exhibited enrichment for CD4+ T cells and antibody-secreting cells. The transverse colon displayed increased abundance of both γδ T cells and NK cells. Subsets of leukocyte lineages also displayed gradients of expression along the colon length.
Our results show an inherent regional immune cell variation within colonic segments, indicating that regional mucosal signatures must be considered when assessing disease stages or the prospective effects of trial drugs on leukocyte subsets. Precise protocols for intestinal sampling must be implemented to allow for the proper interpretation of potential differences observed within leukocyte lineages present in the colonic lamina propria.
在 IBD 试验中进行肠道活检采样是了解药物在组织水平上反应的一种有价值的辅助策略。鉴于近端和远端结肠的长度和独特的胚胎起源，我们研究了在采样不同疾病阶段或药物给药前后，固有区域免疫细胞组成的差异是否会引入混杂因素。在这里，我们利用新型质谱流式细胞术技术对不同健康结肠段进行深度免疫表型分析，使用可以从患者中采集的有限数量的活检样本。
从正常志愿者的盲肠、横结肠、降结肠和直肠采集[2.8mm]活检。分离肠白细胞，用 37 种抗体进行染色，并获取质谱流式细胞术数据。
观察到白细胞定位的特定部位模式。近端结肠的 CD8+T 细胞[特别是驻留记忆细胞]、单核细胞和 CD19+B 细胞增多。相反，远端结肠和直肠组织富含 CD4+T 细胞和分泌抗体的细胞。横结肠显示γδT 细胞和 NK 细胞的丰度增加。白细胞谱系的亚群也沿着结肠长度表现出表达梯度。
我们的结果显示，结肠段内存在固有区域免疫细胞变异，表明在评估疾病阶段或试验药物对白细胞亚群的潜在影响时，必须考虑区域黏膜特征。必须实施精确的肠道采样方案，以允许对固有层中存在的白细胞谱系中观察到的潜在差异进行适当解释。
