Identity and their origins of immune cells in the brain

大脑可能是一个免疫特权的部位，因为它缺乏淋巴排水，并且被血脑屏障屏蔽在免疫系统之外。然而，强烈的免疫反应，例如针对病毒的免疫反应，可在中枢神经系统（CNS）局部发生。这些看似矛盾的事实是中枢神经系统中适应性免疫因素的证据。最近，研究表明小鼠脑细胞表达Ia抗原，而几种已建立的人类胶质瘤细胞系表达HLA-DR抗原。与广泛分布于K区和D区的经典移植抗原不同，表面Ia抗原的组织分布有限，主要存在于参与免疫反应的细胞上。来自淋巴组织和非淋巴组织的Ia阳性细胞与免疫功能有关，Ia抗原的存在可能是免疫能力的标志。因此，我们认为，在大脑中识别含ia细胞可能会导致大脑免疫机制的进一步阐明。用hees -buffered Eagle’s （HE）培养基冲洗幼龄B6C3 <F_1>小鼠（H-2b/k）股骨轴获得骨髓悬液。取1 × 108个骨髓细胞与适当稀释的抗thy 1.2抗体在<4^o bb0℃下反应30分钟，然后与兔补体室温孵育45分钟，以去除供者的T细胞。将这些细胞洗净，并将<10^7>细胞静脉注射到退休（6-10月龄）C57BL/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，取出受体脾，制备单悬液。这些脾细胞与小鼠单克隆抗<Ia^k>抗体反应，并用荧光活化细胞分选仪（FACS IV）分析脾细胞的H- <2^(b/k)>表型。移植后约6个月，1 / 3（30只）小鼠存活，且均为嵌合体（<F_1>）小鼠。然后，将所有嵌合体小鼠的大脑置于4%的平台中。脑切片，抗iak抗体染色。然而，免疫荧光染色无法检测到<Ia^k>表型的细胞。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