Predominant role for directly transfected dendritic cells in antigen presentation to CD8+ T cells after gene gun immunization.
Predominant role for directly transfected dendritic cells in antigen presentation to CD8+ T cells after gene gun immunization.
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DOI：
10.1084/jem.188.6.1075
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发表时间：
1998-09-21
影响因子：
15.3
通讯作者：
Germain, R N
中科院分区：
文献类型：
--
作者：
Porgador, A;Irvine, K R;Iwasaki, A;Barber, B H;Restifo, N P;Germain, R N
皮肤基因(DNA)轰击导致编码的抗原在表皮层大量表达，并在引流淋巴结(LNS)的树突状细胞(DC)中可检测到表达。在这种情况下，DC抗原递呈给初始CD8+T细胞可能存在两种方式：(A)通过基因转染树突状细胞运输到局部淋巴结直接递呈，以及(B)未转染树突状细胞交叉递呈从转染表皮细胞释放的抗原或与其相关的抗原。这些不同的抗原提呈方式对启动细胞毒性T细胞(CTL)反应的相对贡献尚未明确确定。在这里，我们发现直接表达DNA编码抗原的LN细胞很少；在五次腹部皮肤轰击后24小时，这些细胞的数量在单个引流LN中不超过50-100个细胞。然而，在同一时间段，CD11c+DC的总数增加了两倍多，每个主要引流节点平均增加了20,000-30,000个DC。这种增强是由金轰击引起的，并且不依赖于质粒DNA的存在。在引流DNA传递部位的LNS中，大多数携带抗原的细胞似乎是DC，并且可以被由共转染DNA编码的完整表面蛋白的抗体耗尽。这一发现也与抗原和CD86编码DNA共转染研究的数据一致，表明单次免疫启动抗突变流感核蛋白CTL依赖于编码核蛋白和B7.2的DNA在同一细胞中的共表达。这些观察结果揭示了基因直接表达和交叉呈现在使用基因枪免疫的CD8+T细胞启动中的相对作用，并提示增强DC基因的直接表达可能会增强这种启动。
Cutaneous gene (DNA) bombardment results in substantial expression of the encoded antigen in the epidermal layer as well as detectable expression in dendritic cells (DC) in draining lymph nodes (LNs). Under these conditions, two possible modes of DC antigen presentation to naive CD8+ T cells might exist: (a) presentation directly by gene-transfected DC trafficking to local lymph nodes, and (b) cross-presentation by untransfected DC of antigen released from or associated with transfected epidermal cells. The relative contributions of these distinct modes of antigen presentation to priming for cytotoxic T cell (CTL) responses have not been clearly established. Here we show that LN cells directly expressing the DNA-encoded antigen are rare; 24 h after five abdominal skin bombardments, the number of these cells does not exceed 50–100 cells in an individual draining LN. However, over this same time period, the total number of CD11c+ DC increases more than twofold, by an average of 20,000–30,000 DC per major draining node. This augmentation is due to gold bombardment and is independent of the presence of plasmid DNA. Most antigen-bearing cells in the LNs draining the site of DNA delivery appear to be DC and can be depleted by antibodies to an intact surface protein encoded by cotransfected DNA. This finding of predominant antigen presentation by directly transfected cells is also consistent with data from studies on cotransfection with antigen and CD86-encoding DNA, showing that priming of anti-mutant influenza nucleoprotein CTLs with a single immunization is dependent upon coexpression of the DNAs encoding nucleoprotein and B7.2 in the same cells. These observations provide insight into the relative roles of direct gene expression and cross-presentation in CD8+ T cell priming using gene gun immunization, and indicate that augmentation of direct DC gene expression may enhance such priming.