Salazar Lorena, Aravena Octavio, Contreras-Levicoy Juan, Pesce Barbara, Catalan Diego, Zuniga Roberto, Iruretagoyena Mirentxu, Kalergis Alexis M, Aguillón Juan C
Programa Disciplinario de Inmunología, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Eur Cytokine Netw. 2007 Jun;18(2):78-85. doi: 10.1684/ecn.2007.0089. Epub 2007 Jun 26.
Dendritic cells (DCs) are professional, antigen-presenting cells, which induce and regulate T cell reactivity. DCs are crucial in innate and adaptive immune responses, and are also involved in central and peripheral tolerance induction. Tolerance can be mediated by immature and semi-mature DCs expressing low levels of co-stimulator and major histocompatibility complex (MHC) molecules. The aim of this study was to investigate the ability of short-term lipopolysaccharide (LPS) stimulation to modulate the stage of differentiation of bone marrow-derived DCs. For this purpose, DCs obtained from DBA1/lacJ mice were stimulated for four (4hLPS/DCs) or 24 (24hLPS/DCs) hours with LPS, using DCs without stimulation (0hLPS/DCs) as a control. Flow cytometry analysis of 4hLPS/DCs showed intermediate CD40 and MHC class II expression, lower than that of 24hLPS/DCs (fully mature), and greater than that of 0hLPS/DCs (immature). A functional assay showed that 4hLPS/DCs displayed increased endocytotic ability compared to 24hLPS/DCs, indicating a semi-mature state. 4hLPS/DCs were greater producers of IL-10 protein and TGFbeta1 mRNA than 24hLPS/DCs and immature DCs, displaying a cytokine production pattern that is characteristic of tolerogenic DCs. An assay for antigen-presenting capacity demonstrated that 4hLPS/DCs induced secretion of IL-2 from an OTH4 T cell hybridoma, indicating a functional presenting activity. Finally, the tolerogenic phenotype of 4hLPS/DCs was demonstrated by their ability to interfere with the progression of bovine type II collagen (bII)-induced arthritis (CIA) when they were loaded with bCII antigen and injected into mice with established CIA. We conclude that the stimulation of murine bone marrow-derived DCs with LPS for four hours generates semi-mature DCs with tolerogenic capability.
树突状细胞（DCs）是专业的抗原呈递细胞，可诱导和调节T细胞反应性。DCs在先天性和适应性免疫反应中至关重要，也参与中枢和外周耐受的诱导。未成熟和半成熟的DCs表达低水平的共刺激分子和主要组织相容性复合体（MHC）分子，可介导耐受。本研究的目的是调查短期脂多糖（LPS）刺激调节骨髓来源DCs分化阶段的能力。为此，用LPS刺激从DBA1/lacJ小鼠获得的DCs 4小时（4hLPS/DCs）或24小时（24hLPS/DCs），以未刺激的DCs（0hLPS/DCs）作为对照。对4hLPS/DCs进行的流式细胞术分析显示，其CD40和MHC II类分子的表达处于中间水平，低于24hLPS/DCs（完全成熟），高于0hLPS/DCs（未成熟）。功能分析表明，与24hLPS/DCs相比，4hLPS/DCs的内吞能力增强，表明其处于半成熟状态。4hLPS/DCs比24hLPS/DCs和未成熟DCs产生更多的IL-10蛋白和TGFβ1 mRNA，呈现出耐受性DCs特有的细胞因子产生模式。抗原呈递能力检测表明，4hLPS/DCs可诱导OTH4 T细胞杂交瘤分泌IL-2，表明其具有功能性呈递活性。最后，当用bCII抗原负载并注射到已患牛II型胶原（bII）诱导性关节炎（CIA）的小鼠体内时，4hLPS/DCs能够干扰疾病进展，从而证明了其耐受性表型。我们得出结论，用LPS刺激小鼠骨髓来源的DCs 4小时可产生具有耐受性的半成熟DCs。
