Cavatorta Derek J, Erb Hollis N, Felippe M Julia
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Clin Vaccine Immunol. 2012 Oct;19(10):1583-92. doi: 10.1128/CVI.00308-12. Epub 2012 Aug 1.
A defining feature of dendritic cells (DCs) is their ability to induce the proliferation of autologous T cells in the absence of foreign antigen-a process termed the "autologous mixed leukocyte reaction" (AMLR). We report that equine monocyte-derived DCs, but not macrophages, are potent inducers of the AMLR. The response is contact dependent and major histocompatibility complex class II dependent and primarily involves CD3(+) CD4(+) CD8(-) T cells. Upon stimulation with DCs or the mitogen concanavalin A, a subset of the proliferating T cells expresses the regulatory T-cell (Treg) transcription factor FoxP3. Although many of these FoxP3(+) T cells are capable of producing the effector cytokines interleukin-4 (IL-4) and gamma interferon (IFN-γ), they are more likely to produce IL-10 and less likely to produce IFN-γ than equivalent FoxP3(-) cells. Therefore, FoxP3 expression is an inherent component of equine T cell activation and is associated with a more immunosuppressive cytokine profile. These results confirm that FoxP3 expression in the horse, in contrast to the mouse, is regulated similarly to FOXP3 expression in humans and provide evidence that FoxP3 expression by conventional T cells may help regulate the developing immune response.
树突状细胞（DCs）的一个决定性特征是它们能够在没有外来抗原的情况下诱导自体T细胞增殖，这一过程被称为“自体混合淋巴细胞反应”（AMLR）。我们报告称，马单核细胞衍生的DCs而非巨噬细胞是AMLR的有效诱导剂。该反应依赖细胞接触且依赖主要组织相容性复合体II类，主要涉及CD3(+) CD4(+) CD8(-) T细胞。在用DCs或促有丝分裂原伴刀豆球蛋白A刺激后，一部分增殖的T细胞表达调节性T细胞（Treg）转录因子FoxP3。尽管这些FoxP3(+) T细胞中的许多能够产生效应细胞因子白细胞介素-4（IL-4）和γ干扰素（IFN-γ），但与同等的FoxP3(-)细胞相比，它们更有可能产生IL-10且产生IFN-γ的可能性更小。因此，FoxP3表达是马T细胞活化的一个固有组成部分，并且与更具免疫抑制性的细胞因子谱相关。这些结果证实，与小鼠不同，马体内的FoxP3表达与人类FOXP3表达的调控方式相似，并提供了证据表明常规T细胞的FoxP3表达可能有助于调节正在发育的免疫反应。
