Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London, UK.
Hepatology. 2011 Feb;53(2):536-47. doi: 10.1002/hep.24039. Epub 2010 Dec 28.
Effector CD4 and CD8 T cell immune responses to cytochrome P450IID6 (CYP2D6), the autoantigen of autoimmune hepatitis type 2 (AIH-2), are permitted by a numerical and functional impairment of CD4(pos) CD25(high) regulatory T cells (T-regs). We aimed to investigate whether T-regs specific for CYP2D6 immunodominant regions and restricted by the appropriate human leukocyte antigen (HLA)-DR molecule can be generated in patients with AIH-2 and can control CD4 and CD8 T cell effectors targeting identical or overlapping CYP2D6 regions. CYP2D6-specific regulatory T cells (CYP2D6 T-regs) were obtained from peptide-pulsed monocyte-depleted peripheral blood mononuclear cells of 17 patients with AIH-2, who were positive for the predisposing HLA-DR7 and/or HLA-DR3 alleles. Their antigen specificity was assessed by cytofluorimetry using HLA class II tetramers and their cytokine profile by intracellular staining. T-reg ability to suppress was ascertained by measuring reduction of CD4(pos) CD25(neg) cell proliferation/effector cytokine secretion and of CD8 T cell cytotoxicity. The most efficient suppression of effector T cell proliferation, inflammatory cytokine release, and cytotoxicity was obtained by coculturing T-regs with CYP2D6-peptide-loaded semimature dendritic cells (smDCs), and smDC-CYP2D6 T-regs also expressed high levels of FOXP3 (forkhead box P3). Possession of the appropriate HLA-DR molecule and recognition of the CYP2D6 autoantigenic sequence were critical to the synergistic smDC-CYP2D6 T-reg immunoregulatory functions, and lack of either element led to poor control of responder cell proliferation and cytokine secretion. Moreover, interferon-γ neutralization significantly boosted the suppressive ability of CYP2D6 T-regs.
T-regs generated under CYP2D6-specific conditions and cocultured with smDCs are highly effective at controlling autoreactive T cells, thus providing the basis for a powerful and tailored form of immunotherapy for AIH-2.
研究自身免疫性肝炎 2 型（AIH-2）患者是否能够产生针对 CYP2D6 免疫优势区域且受适当人类白细胞抗原（HLA）-DR 分子限制的调节性 T 细胞（T-reg），并探讨其是否能控制针对相同或重叠 CYP2D6 区域的 CD4 和 CD8 T 细胞效应器。
采用 HLA Ⅱ类四聚体通过细胞流式术、细胞内染色通过细胞因子谱评估 CYP2D6 特异性调节性 T 细胞（CYP2D6 T-reg）的抗原特异性，通过测量 CD4(pos)CD25(neg)细胞增殖/效应细胞因子分泌和 CD8 T 细胞细胞毒性降低来确定 T-reg 的抑制能力。
从 17 例 HLA-DR7 和/或 HLA-DR3 等位基因阳性的 AIH-2 患者的肽脉冲单核细胞耗竭外周血单个核细胞中获得 CYP2D6 特异性 T-reg。用半成熟树突状细胞（smDC）负载 CYP2D6 肽共培养 T-reg 可获得最有效的抑制效应 T 细胞增殖、炎症细胞因子释放和细胞毒性的效果，smDC-CYP2D6 T-reg 也表达高水平的 FOXP3（叉头框 P3）。拥有适当的 HLA-DR 分子和识别 CYP2D6 自身抗原序列是 smDC-CYP2D6 T-reg 协同免疫调节功能的关键，缺乏任何一个元素都会导致对反应细胞增殖和细胞因子分泌的控制不佳。此外，干扰素-γ 中和显著增强了 CYP2D6 T-reg 的抑制能力。
在 CYP2D6 特异性条件下产生并与 smDC 共培养的 T-reg 可有效控制自身反应性 T 细胞，为 AIH-2 提供了一种强大且针对性的免疫治疗形式的基础。
