Hajrasouliha Amir R, Sadrai Zahra, Lee Hyung K, Chauhan Sunil K, Dana Reza
Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts.
Mol Vis. 2013 Dec 16;19:2517-25. eCollection 2013.
To identify the role of chemokine receptor 6 (D6) expression by dendritic cells (DCs) and its role in corneal transplant immunity.
Flow cytometry analysis was used to assess the expression level of the D6 chemokine receptor in different leukocyte populations and DC maturation following lipopolysaccharides (LPS) stimulation of bone marrow-derived DCs isolated from wild-type (WT) or D6(-/-) mice (C57BL/6 background). Mixed-lymphocyte reactions and delayed-type hypersensitivity assays were performed with bone marrow-derived DCs from WT or D6(-/-) mice to evaluate T-cell alloreactivity. Adoptive transfer experiments with T cells from WT or D6(-/-) hosts with BALB/c corneal allografts were performed. Graft opacity was assessed over an 8-week period, and graft survival was plotted using Kaplan-Meier survival curves.
Expression of the D6 chemokine receptor was significantly higher in DCs compared to other leukocyte subpopulations, including neutrophils, lymphocytes, and monocytes/macrophages. LPS challenge of D6(-/-) bone marrow-derived DCs elicited significantly lower levels of major histocompatibility complex II and costimulatory molecules (CD40, CD80, and CD86) compared to WT bone marrow-derived DCs, indicating the role of the D6 chemokine receptor in DC maturation. Further, DCs isolated from D6(-/-) mice induced less T-cell proliferation (p≤0.001) and interferon-gamma production in T cells of draining lymph nodes compared to WT mice following corneal transplantation (p≤0.001). Moreover, adoptively transferred T cells from D6(-/-) corneal transplanted mice to WT mice led to impaired graft rejection, compared to the hosts that received T cells from the WT transplanted mice.
We demonstrated D6 chemokine receptor expression by DCs and identified its critical function in multiple aspects of DC biology, including maturation and consequent elicitation of alloreactive T-cell responses that are responsible for corneal allograft rejection.
确定树突状细胞（DC）表达趋化因子受体6（D6）的作用及其在角膜移植免疫中的作用。
采用流式细胞术分析从野生型（WT）或D6基因敲除（D6(-/-)）小鼠（C57BL/6背景）分离的骨髓来源DC在脂多糖（LPS）刺激后，不同白细胞群体中D6趋化因子受体的表达水平以及DC的成熟情况。用WT或D6(-/-)小鼠的骨髓来源DC进行混合淋巴细胞反应和迟发型超敏反应试验，以评估T细胞同种异体反应性。对接受BALB/c角膜异体移植的WT或D6(-/-)宿主的T细胞进行过继转移实验。在8周内评估移植物混浊情况，并用Kaplan-Meier生存曲线绘制移植物存活情况。
与其他白细胞亚群（包括中性粒细胞、淋巴细胞和单核细胞/巨噬细胞）相比，DC中D6趋化因子受体的表达明显更高。与WT骨髓来源DC相比，D6(-/-)骨髓来源DC经LPS刺激后，主要组织相容性复合体II和共刺激分子（CD40、CD80和CD86）的水平明显更低，表明D6趋化因子受体在DC成熟中的作用。此外，与角膜移植后的WT小鼠相比，从D6(-/-)小鼠分离的DC诱导引流淋巴结T细胞的增殖更少（p≤0.001），T细胞中干扰素-γ的产生也更少（p≤0.001）。此外，与接受WT移植小鼠T细胞的宿主相比，将D6(-/-)角膜移植小鼠的T细胞过继转移到WT小鼠中会导致移植物排斥受损。
我们证明了DC表达D6趋化因子受体，并确定了其在DC生物学多个方面的关键功能，包括成熟以及随后引发导致角膜异体移植排斥的同种异体反应性T细胞反应。
