Department of Animal and Food Sciences, College of Agriculture and Natural Resources, University of Delaware, Newark 19717-1303.
Department of Biological Sciences, University of Delaware, Newark 19717-1303.
J Dairy Sci. 2019 Apr;102(4):3452-3468. doi: 10.3168/jds.2018-15156. Epub 2019 Feb 22.
Inconsistent evidence of inflammatory immune cell infiltrates in adipose tissues with extensive triglyceride mobilization raises the possibility that regulatory or anti-inflammatory immune cell populations reside within the mesenteric adipose tissue (MAT) and mesenteric lymph nodes (MLN). These resident immune cell populations may be involved in attenuating the inflammatory response. We explored the immune cell population of MAT and MLN collected from lean, lactating Holstein cows without apparent disease in an abattoir (n = 42). Lean cows had a body condition score of 2.6 ± 0.1 (mean ± SD) with a greater frequency of adipocyte area occurring in small rather than large adipocytes. Cells were labeled with monoclonal antibodies specific to bovine leukocyte antigens for enumeration by flow cytometry. Within both lymph node and adipose tissues, relatively large subpopulations of cells expressed the β2 integrins CD11b and CD11c, class II major histocompatibility antigens (MHCII), and the SIIRP-1α receptor (CD172a) typical of dendritic cells and macrophages. Macrophage/dendritic cell heterogeneity was marked by β2 integrin expression alone or in conjunction with CD172a or MHCII across subpopulations from both tissues; CD209, the DC-SIGN c-type lectin receptor of dendritic cells, was not detected by fluorescence-activated cell sorting in either tissue. Lymphocytes comprised 74.1 ± 3.7% and 13.7 ± 3.7% of the MLN and MAT cell populations, respectively, and CD3CD4 lymphocytes accounted for 49.8 ± 9.9% of the MLN and 6.13 ± 1.23% of the MAT cells. Fox P3 regulatory lymphocytes comprised 15.3 ± 1.1% and 6.73 ± 0.52% of the MLN and MAT cells, whereas γδ lymphocytes accounted for 6.65 ± 0.74% and 3.91 ± 0.43% of the MLN and MAT cells, respectively. Subpopulations of CD3CD8 cytotoxic T cells and CD3CD11c innate lymphocytes were present in MLN but not MAT. These results show that subpopulations of resident tissue macrophages, dendritic cells, T helper lymphocytes, regulatory T lymphocytes (Tregs), and γδ lymphocytes reside in mesenteric lymph nodes and adipose tissues. Balance in the innate and adaptive immune functions embedded in these tissues could support metabolic health.
在大量甘油三酯动员的脂肪组织中，炎症免疫细胞浸润的证据不一致，这使得人们产生了这样的可能性，即在肠系膜脂肪组织（MAT）和肠系膜淋巴结（MLN）中存在调节性或抗炎免疫细胞群体。这些常驻免疫细胞群体可能参与减轻炎症反应。我们从屠宰场中没有明显疾病的瘦泌乳荷斯坦奶牛（n = 42）中探索了 MAT 和 MLN 的免疫细胞群体。瘦奶牛的体况评分为 2.6 ± 0.1（平均值 ± SD），脂肪细胞面积较大的频率较高，而较小的脂肪细胞面积较大。细胞用针对牛白细胞抗原的单克隆抗体标记，通过流式细胞术进行计数。在淋巴结和脂肪组织中，相对较大的细胞亚群表达 β2 整合素 CD11b 和 CD11c、II 类主要组织相容性抗原（MHCII）和 SIIRP-1α 受体（CD172a），这些典型的树突状细胞和巨噬细胞。巨噬细胞/树突状细胞异质性在两个组织的亚群中均以 β2 整合素表达为特征，或与 CD172a 或 MHCII 结合；荧光激活细胞分选术在两种组织中均未检测到树突状细胞的 DC-SIGN c 型凝集素受体 CD209。淋巴细胞分别占 MLN 和 MAT 细胞群的 74.1 ± 3.7%和 13.7 ± 3.7%，CD3CD4 淋巴细胞占 MLN 的 49.8 ± 9.9%，MAT 细胞的 6.13 ± 1.23%。FoxP3 调节性淋巴细胞分别占 MLN 和 MAT 细胞的 15.3 ± 1.1%和 6.73 ± 0.52%，而 γδ 淋巴细胞分别占 MLN 和 MAT 细胞的 6.65 ± 0.74%和 3.91 ± 0.43%。CD3CD8 细胞毒性 T 细胞和 CD3CD11c 固有淋巴细胞的亚群存在于 MLN 中，但不存在于 MAT 中。这些结果表明，驻留组织巨噬细胞、树突状细胞、辅助性 T 淋巴细胞、调节性 T 淋巴细胞（Tregs）和 γδ 淋巴细胞的亚群存在于肠系膜淋巴结和脂肪组织中。这些组织中固有和适应性免疫功能的平衡可能支持代谢健康。
