Zeng Ling, Lindstrom Mary J, Smith Judith A
University of Wisconsin Madison, School of Medicine and Public Health, Madison, WI 53792-4108, USA.
Arthritis Rheum. 2011 Dec;63(12):3807-17. doi: 10.1002/art.30593.
Previous studies of the HLA-B27-transgenic rat model of ankylosing spondylitis (AS) suggested that macrophages develop an intracellular stress response called the unfolded protein response (UPR) and, as a result, secrete increased amounts of cytokines in response to Toll-like receptor agonists such as lipopolysaccharide (LPS). Our objective was to determine whether macrophages from AS patients also undergo a UPR and secrete increased cytokines/chemokines in response to LPS.
Peripheral blood monocytes isolated from 10 AS patients and 10 healthy controls were differentiated in vitro with macrophage colony-stimulating factor. Select samples were treated with interferon-γ (IFNγ) to up-regulate class I major histocompatibility complex (HLA-B) expression prior to stimulation with LPS for either 3 hours (for RNA) or 8-24 hours (for supernatant). UPR induction was assessed by measuring the expression of messenger RNA for ERdj4, BiP, and CCAAT/enhancer binding protein homologous protein 10 (CHOP).
Although IFNγ treatment up-regulated HLA-B expression (2-fold; P < 0.0001), neither IFNγ nor LPS substantially enhanced BiP or CHOP expression (<1.3-fold). ERdj4 expression increased weakly, but not significantly, in AS samples treated with IFNγ plus LPS (2.2-fold; P = 0.31). In response to LPS, AS macrophages secreted more CXCL9, interleukin-10 (IL-10), IL-12p70, IL-23, and tumor necrosis factor α than did control macrophages (P ≤ 0.025). The most striking difference was observed for IL-23 (median 265 pg/ml in AS patients versus 9 pg/ml in controls; P = 0.0007). We did not detect significant differences in IL-6, IL-8, or IFNβ production.
The greater production of IL-23 by AS patient macrophages in response to LPS provides further support for the development of Th17/IL-23-directed therapy. Since significant UPR induction was not detected in AS patient macrophages, the relationship between UPR and inflammatory cytokine production remains unclear.
先前对强直性脊柱炎（AS）的HLA - B27转基因大鼠模型的研究表明，巨噬细胞会产生一种称为未折叠蛋白反应（UPR）的细胞内应激反应，因此，在对脂多糖（LPS）等Toll样受体激动剂作出反应时会分泌更多的细胞因子。我们的目的是确定AS患者的巨噬细胞是否也会经历UPR，并在对LPS作出反应时分泌更多的细胞因子/趋化因子。
从10例AS患者和10名健康对照者中分离出外周血单核细胞，在体外使用巨噬细胞集落刺激因子进行分化。在用LPS刺激3小时（用于RNA）或8 - 24小时（用于上清液）之前，选择的样本用干扰素 - γ（IFNγ）处理以上调I类主要组织相容性复合体（HLA - B）的表达。通过测量ERdj4、BiP和CCAAT/增强子结合蛋白同源蛋白10（CHOP）的信使RNA表达来评估UPR诱导情况。
尽管IFNγ处理上调了HLA - B的表达（2倍；P < 0.0001），但IFNγ和LPS均未显著增强BiP或CHOP的表达（<1.3倍）。在用IFNγ加LPS处理的AS样本中，ERdj4表达微弱增加，但不显著（2.2倍；P = 0.31）。与对照巨噬细胞相比，AS巨噬细胞在对LPS作出反应时分泌更多的CXCL9、白细胞介素 - 10（IL - 10）、IL - 12p70、IL - 23和肿瘤坏死因子α（P≤0.025）。IL - 23的差异最为显著（AS患者中位数为265 pg/ml，对照者为9 pg/ml；P = 0.0007）。我们未检测到IL - 6、IL - 8或IFNβ产生的显著差异。
AS患者巨噬细胞对LPS产生更多的IL - 23，这为Th17/IL - 23导向治疗的发展提供了进一步支持。由于在AS患者巨噬细胞中未检测到显著的UPR诱导，UPR与炎性细胞因子产生之间的关系仍不清楚。
