Identity and their origins of immune cells in the brain

大脑可能是免疫特权部位，因为它缺乏淋巴引流，并通过血脑屏障与免疫系统屏蔽。然而，强烈的免疫反应，例如，抗病毒，可以发生在局部的中枢神经系统（CNS）。这些看似矛盾的事实是CNS中适应性免疫因素的证据。最近，已经显示小鼠脑细胞表达Ia抗原，并且几种已建立的人脑胶质瘤细胞系表达HLA-DR抗原。与广泛分布在K和D区的经典移植抗原不同，表面Ia抗原具有有限的组织分布，并且主要在参与免疫应答的细胞上发现。来自淋巴组织和非淋巴组织的Ia阳性细胞与免疫功能相关，Ia抗原的存在可能是免疫能力的标志。因此，我们推断，在大脑中识别出带有Ia的细胞可能会导致 关于我们 通过<F_1>用Hepes缓冲的Eagle’s（HE）培养基冲洗年轻B6 C3小鼠（H-2b/k）的股骨干获得骨髓悬液。将1 × 108个骨髓细胞与适当稀释的抗-Thy1.2抗体在4 ℃下反应30分钟。然后将这些细胞与兔的补体在室温下孵育45分钟，以去除供体的T细胞。清洗这些细胞，并将&lt;10^7&gt;个细胞静脉注射到退休（6-10月龄）C57 BL/6小鼠中，这些小鼠在静脉注射前1-2小时接受了950拉德的全身照射。约6个月后，取出受体的脾脏，并从这些脾脏制备单细胞悬液。这些脾细胞与小鼠单克隆抗&lt;Ia^k&gt;抗体反应，用荧光激活细胞分选仪（FACS IV）分析脾细胞的H- &lt;2^（B/k）&gt;表型。骨髓移植后约6个月，三分之一（30只小鼠）的受体存活，它们都是嵌合体（<F_1>进入母体）小鼠。然后，将嵌合体小鼠的所有脑置于4%的多聚甲醛中。将脑切片并用抗Iak抗体染色。然而，&lt;Ia^k&gt;表型携带细胞不能通过免疫荧光染色检测。少

The brain may be an immunologically privileged site, in that it lacks lymphatic drainage and is shielded from the immune system by the blood-brain barrier. However, intense immune reactions, e.g., against viruses, can take place locally in the central nervous system (CNS). These seemingly contradictory facts are evidence for adaptive immunologic elements in the CNS. Recently, it has been shown that murine brain cells express Ia antigens, and that several established human glioma cell lines express HLA-DR antigens. Unlike the widely distributed classical transplantation antigens mapping in the K and D regions, surface Ia antigens have limited tissue distribution and are found predominantly on cells involved in immune responses. Ia-positive cells from both lymphoid and nonlymphoid tissues are associated with immune function, and the presence of Ia antigens might be a marker for immune competency. Therefore, we reasoned that the identification of Ia-bearing cells in the brain may lead to … More the elucidation of immune mechanisms within the brain.Bone marrow suspensions were obtained by flushing femoral shafts of young B6C3 <F_1> mice (H-2b/k) with Hepes-buffered Eagle's (HE) medium. 1 x 108 bone marrow cells were reacted with appropriately diluted anti-thy 1.2 antibody for 30 minutes at <4^o> C. And then these cells were incubated with rabbit's complement for 45 minutes at room temperature, in order to remove donor's T cells. These cells were washed and <10^7> cells were injected intravenously into retire (6-10 month of age) C57BL/6 mice that had received 950 rads of whole body irradiation 1-2 hr prior to intravenous injection. After about 6 months, the recipients' spleens were removed and sigle suspensions were prepared from these spleens. These spleen cells were reacted with mouse monoclonal anti- <Ia^k> antibody and H- <2^(b/k)> phenotype of spleen cells were analyzed with a fluorescence-activated cell sorter (FACS IV). About 6 months after transplantation of the bone marrow, one-third (30 mice) of the recipients were alive and they were all chimera ( <F_1> into parent) mice. Then, all brains of chimera mice were placed in 4% paraform. The brains were sectioned and stained with anti-Iak antibody. However, <Ia^k> phenotype-bearing cells were unable to detect by immunofluorescence staining. Less