Tolerogenic dendritic cells (tDCs) play a central role in the development of paternal antigen-specific regulatory T cells (Tregs) during pregnancy. We examined whether uterine CD11c+ antigen presenting cells (APC) induced paternal antigen-specific tolerance in allogeneic pregnant mice. Female BALB/c mice were mated with male DBA/2 mice, and their surface markers of APCs were studied using flow cytometry. After allogeneic mating, the uterine APCs exhibited significantly decreased expression of major histocompatibility complex (MHC) class II on day 3.5 post-coitus (pc) and day 5.5 pc. To analyze how seminal fluid affects surface markers of APCs, female BALB/c mice were mated with male mice that had undergone seminal vesicle excision (SVX). No reductions of MHC class II expression on APCs were seen in these mice. To analyze APC functions, a mixed lymphoid reaction (MLR) assay to paternal splenocytes was performed. Uterine APCs from allogeneic pregnant mice significantly suppressed the MLR reaction, but APCs from SVX mated mice did not suppress the MLR reaction Uterine APCs induced paternal antigen (Mls1a)-specific Treg development in vitro, but not in mice that mated with allogeneic SVX mice. These findings suggest that seminal fluid priming expands the paternal antigen-specific Treg population by inducing APCs development.

中文翻译：

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子宫 CD11c+ 细胞通过精浆启动诱导父本抗原特异性 Treg 的发育。

致耐受性树突状细胞 (tDC) 在怀孕期间父本抗原特异性调节性 T 细胞 (Treg) 的发育中发挥核心作用。我们检查了子宫 CD11c+ 抗原呈递细胞 (APC) 是否在同种异体怀孕小鼠中诱导了父本抗原特异性耐受性。雌性 BALB/c 小鼠与雄性 DBA/2 小鼠交配，并使用流式细胞术研究它们的 APC 表面标志物。同种异体交配后，子宫 APC 在性交后第 3.5 天和第 5.5 天表现出显着降低的主要组织相容性复合体 (MHC) 类 II 的表达。为了分析精液如何影响 APC 的表面标志物，将雌性 BALB/c 小鼠与接受过精囊切除 (SVX) 的雄性小鼠交配。在这些小鼠中未观察到 APC 上 MHC II 类表达的减少。要分析 APC 功能，对父本脾细胞进行了混合淋巴样反应 (MLR) 检测。来自同种异体怀孕小鼠的子宫 APC 显着抑制 MLR 反应，但来自 SVX 交配小鼠的 APC 不会抑制 MLR 反应 子宫 APC 在体外诱导父本抗原 (Mls1a) 特异性 Treg 发育，但在与同种异体 SVX 小鼠交配的小鼠中则不然。这些发现表明，精液引发通过诱导 APC 发育扩大了父本抗原特异性 Treg 群体。