Andrieu Muriel, Desoutter Jean-François, Loing Estelle, Gaston Jésintha, Hanau Daniel, Guillet Jean-Gérard, Hosmalin Anne
Département d'Immunologie, Unité INSERM 567, UMR CNRS 8104, IFR 116, Institut Cochin, Paris, France.
J Virol. 2003 Jan;77(2):1564-70. doi: 10.1128/jvi.77.2.1564-1570.2003.
An efficient vaccine against human immunodeficiency virus (HIV) must induce good cellular immune responses. To do this, it must be processed and presented by dendritic cells, which are required for primary T-lymphocyte stimulation. We have previously shown that a model lipopeptide containing a short epitopic peptide from HIV-1 was endocytosed and presented in association with major histocompatibility complex class I molecules by human dendritic cells to specific CD8(+) T lymphocytes, but the cross-presentation pathway needed to be precisely determined. We have studied a longer lipopeptide (Pol(461-484)) and another lipopeptide (Nef(66-97)) currently being used in vaccine trials. Like the shorter lipopeptide, the rhodamine-labeled Pol(461-484) lipopeptide was internalized by endocytosis, as assessed by confocal microscopy. The lipopeptides were processed by dendritic cells and presented to CD8(+) T cells specific for the HLA-A0201-restricted Pol(476-484) and the HLA-A0301-restricted Nef(73-82) epitope, respectively. Presentation of both lipopeptides was inhibited by brefeldin A. Presentation of the Pol lipopeptide was inhibited by epoxomycin, a proteasome-specific inhibitor, but not by monensin. This shows that it gained access to the cytosol to be digested by the proteasome. In contrast, presentation of the Nef lipopeptide was not inhibited by epoxomycin but was inhibited by monensin, a classical inhibitor of acid-dependent endosomal enzyme activity, indicating an endocytic processing pathway yielding to major histocompatibility complex class I-restricted presentation. Therefore, the two lipopeptides followed different cross-presentation pathways, both resulting in efficient presentation to CD8(+) T lymphocytes.
一种有效的抗人类免疫缺陷病毒（HIV）疫苗必须能诱导良好的细胞免疫反应。要做到这一点，它必须由树突状细胞进行处理和呈递，而树突状细胞是初始T淋巴细胞刺激所必需的。我们之前已经表明，一种包含来自HIV-1的短表位肽的模型脂肽被人树突状细胞内吞，并与主要组织相容性复合体I类分子结合呈递给特异性CD8(+) T淋巴细胞，但交叉呈递途径需要精确确定。我们研究了一种更长的脂肽（Pol(461 - 484)）和另一种目前正在疫苗试验中使用的脂肽（Nef(66 - 97)）。与较短的脂肽一样，通过共聚焦显微镜评估，罗丹明标记的Pol(461 - 484)脂肽通过内吞作用被内化。这些脂肽由树突状细胞处理，并分别呈递给针对HLA-A0201限制的Pol(476 - 484)和HLA-A0301限制的Nef(73 - 82)表位的CD8(+) T细胞。两种脂肽的呈递均被布雷菲德菌素A抑制。Pol脂肽的呈递被蛋白酶体特异性抑制剂环氧霉素抑制，但不被莫能菌素抑制。这表明它进入了胞质溶胶以被蛋白酶体消化。相比之下，Nef脂肽的呈递不被环氧霉素抑制，但被莫能菌素抑制，莫能菌素是一种经典的酸依赖性内体酶活性抑制剂，表明其通过内吞加工途径进行主要组织相容性复合体I类限制的呈递。因此，这两种脂肽遵循不同的交叉呈递途径，两者都能有效地呈递给CD8(+) T淋巴细胞。
