猴艾滋病的发病和治疗机制初步研究

AIDS是人类严重免疫缺损和自身免疫病的病毒性传染病为害严重。我们通过200多只SIV感染猕猴,进行了发病机制的病理学和免疫学的探讨,获得如下资料。1.猴SIV急性感染:SIV进入CD4+T淋巴细胞进行了复制释放。血浆病毒血症上升。一些带SIVT淋巴细胞进到淋巴组织潜伏。同时SIV抗体上升。CD4+T淋巴细胞减少,淋巴结滤泡生发中心B细胞高度增生。SIV感染2-3个月后,病毒血症略下降,CD4+T淋巴细胞数回升,SIV抗体上升,淋巴结生发中心细胞增生,这一时期淋巴结病理为淋巴结增生病变。2.无症状期:临床上潜伏期,病毒血症维持在较低水平。但C…     

用生物素标记的寡核苷酸探针检测入淋巴组织和淋巴瘤内免疫球蛋白轻链mRNA

本文用生物素标记的κ和λ寡核苷酸探针,在原位杂交的基础上,检测了人淋巴组织,恶性淋巴瘤和浆细胞瘤内轻链 mRNA。结果显示扁桃体和淋巴结内κ和λ轻链 mRNA 主要分布在次级淋巴滤泡的生发中心和浆细胞内,帽状区阴性。初级淋巴滤泡虽然尚无明显生发中心,但也有 mRNA阳性细胞。κ和λ轻链 mRNA 阳性细胞在淋巴组织内混合存在。相反地,淋巴瘤和浆细胞瘤内 mRNA表达则是单一型的。瘤细胞内的 mRNA 含量较多,可能与 mRNA 复制速度增快有关。实践证明经过Formalin 固定和石蜡包埋的组织切片,mRNA 仍被保存,用检测系统四步法能够捕捉到被检 mRNA,而且是特异的。     

滤泡辅助性T细胞分化和功能的研究进展

滤泡辅助性T细胞(Tfollicular helper cells,TFH细胞)是新近发现的一种CD4+辅助性T细胞亚群,具有不同于其他亚群的独特功能:迁移到B淋巴滤泡并辅助B淋巴细胞产生抗体。在短短的几年里面,已有大量针对滤泡辅助性T细胞分化与功能的研究。该文将对滤泡辅助性T细胞的最新研究进展作一综述。     

生发中心的发生与发展

生发中心（germinal centers, GCs）位于次级淋巴组织（secondary lymphoid organs, SLOs）,是淋巴细胞（lymphocytes）与基质细胞(stromal cells)的短暂聚集地,促进体液免疫过程。在生发中心中,B细胞经历了克隆扩增（clonal expansion）、体细胞高频突变（somatic hypermutation,SHM）、亲和力选择（affinity selection）以及分化为浆细胞（plasma cells, PCs）和记忆B细胞(memory B cells, BMEM)等过程。但在生发中心中,亮区（light zone, LZ）和暗区(dark zone, DZ)各自的功能以及亲和力选择的具体机制仍不清楚。在过去10年中,活体镜检法（intravital microscopy, IVM）使人们可以直接地研究生发中心中进行的的一系列动态反应,并取得了一定的进展。表明在暗区进行体细胞高频突变以及B细胞增殖过程,亮区则发生亲和力选择反应。B细胞在暗区与亮区间发生区域流动（interzonal migration）,滤泡辅助性T细胞（T follicular helper cells, T_fh）在调控B细胞从亮区重新回到暗区,促进亲和力选择过程中发挥着重要作用。本文结合最新的研究进展,对生发中心中发生的一系列动态反应,以及其在疫苗设计和疾病治疗中的作用进行综述。     

正常人末梢血淋巴细胞的电泳组分

正常人末梢血淋巴细胞是一不均一的群体。它主要由T淋巴细胞及B淋巴细胞等亚群组成。目前已有多种识别T、B淋巴细胞的方法,如E玫瑰花试验、酸性酯酶染色试验,以及检测细胞表面免疫球蛋白、Fc受体及补体受体等技术,但均因易受多种因素影响而不够完善。用细胞电泳技术分析淋巴细胞亚群国外已研究多年,但国内报道甚少。我们对50例正常人末梢血淋巴细胞进行了电泳研究,重点分析了淋巴细胞的电泳组分及其与T、B淋巴细胞亚群之间的关系。我们认为用这一方法识别淋细胞亚群是可行的。     

淋巴细胞亚群成员研究进展

淋巴细胞是人体重要的免疫细胞,占外周血白细胞总数的20﹪~45﹪,主要分为T细胞、B细胞和NK细胞三大类。根据细胞表面标志及功能特征,将淋巴细胞亚群分为CD3~+CD4~+辅助性T细胞、CD3~+CD8~+的细胞毒性T细胞、CD19~+B细胞、CD16~+CD56~+NK细胞。随着基础免疫学及免疫学技术的不断发展,临床和科研工作者不断地将淋巴细胞亚群细化并发现一些新的亚群,包括γδT细胞、Th1/Th2细胞、Th17细胞、Th9细胞、Tfh细胞、Treg细胞、Breg细胞、NKT细胞和NKB细胞等,淋巴细胞亚群的内容也随之被赋予了新的定义,现将近年来淋巴细胞亚群的研究进展进行综述。     

淋巴细胞的功能亚群与表面抗原

<正>淋巴细胞亚群分析主要指用单克隆抗体(McAb)和流式细胞计(FCM)进行表面标志的分析。作者就淋巴细胞亚群分析的现状和临床应用,概述如下。 一、淋巴细胞亚群分析的现状 淋巴细胞亚群的分析,首先从T细胞、B细胞的分类开始。T细胞又进一步区分为CD_4细胞、CD_8细胞。详细的分析以CD_4细胞内的亚群和CD_8细胞内的亚群为主体。最近也很少单独使用McAb标记的CD_4或CD_8这种大的亚群标志。淋巴细胞的功能亚群标志分析,主要指体外的功能亚群分析。都是在非常限定的条件下进行的,其结果未必具有普遍意义。主要用标记区别亚群,是否确切或仅是偶然与其功能有关,还很难判定。这些亚群实际上作为功能亚群使用,所以有必要进行深入研究和临床评价。基础和临床研究已发现CD_4和CD_8     

生发中心B淋巴细胞活化机制研究进展

B淋巴细胞介导的体液免疫作为机体抵御外界病原微生物的防御机制之一,在维持机体免疫稳态中发挥重要作用。其中,生发中心是体液免疫发生的重要部位,B淋巴细胞在此处的活化受多种因素调控。T细胞的辅助参与、免疫球蛋白的多样性以及充足的能量供应都会影响B淋巴细胞产生特异性抗体的过程以及发挥免疫效应的功能。此外,一些免疫相关疾病也与生发中心B淋巴细胞活化密切相关。本文就B淋巴细胞在生发中心活化的相关机制及其活化异常所导致的相关疾病进行综述。     

协同刺激分子配体ICOSL参与高亲和力抗体筛选生成的新机制

生发中心(germinal center,GC)支持B细胞竞争与亲和力成熟的过程。滤泡辅助T细胞通过与B细胞长时程互作来传递辅助信号并促进生发中心形成。然而,当生发中心形成以后,T细胞如何调控B细胞间的竞争及选择尚不明确。借助骨髓嵌合体和活体成像研究发现,GC里T-B互作短暂而重复,由ICOS-ICOSL分子以一种正反馈的方式调控,而这种正反馈对于迅速、有效地筛选出高亲和力抗体至关重要。这些结果使我们更进一步理解了生发中心亲和力选择的机制。     

带有F_c受体和绵羊红血球(SRBC)受体的双重标志淋巴细胞的研究

淋巴细胞亚群的研究是免疫学研究中一个重要方面,已经显示淋巴细胞有 T 淋巴细胞、B 淋巴细胞、K 细胞等亚群,这些细胞表面都有特征性表面标志。近年亦注意到有些淋巴细胞表面不但有 T 淋巴细胞表面特征,亦同时有 B 细胞或 K 细胞表面特征,这些称为双重标志淋巴细胞。     

A study of lymphocyte subsets in human normal tonsil and lymph node

A series of T and B lymphocyte specific monoclonal antibodies was used to determine the localization of lymphocyte subpopulation in frozen and paraffin tissue sections of human normal tonsil and lymph node by means of immunocytochemical technique. In the paracortical and interfollicular area of tonsil and lymph node, most lymphocytes reacted with Leu 1, Leu 3 a, Leu 4 and OKT4. The numbers of Leu 2 a and OKT8 positive cells were rare in tissue. These cells were not only limited in paracortical area, they also appeared in considerable numbers in medullary cords of lymph nodes. Leu 2 a and OKT 8 positive cells decreased with prominent follicular hyperplasia of tonsils. In addition, substantial leu 3 a and Leu 4 cells were found in the germinal centers. This finding supports the importance of these lymphocyte subsets in regulation of human immune response. In the mantle zone of secondary follicles, the majority of lymphocytes were positive for OKB 2 and BA 1, whereas, the IgM positive cells were predominately observed in the cytoplasma and extracellular substance of B lymphocytes in the germinal centers, but the lymphocytes bearing sIgM were rarely observed. In the mantle zone, the IgM were frequently found on the surface of membrane of small lymphocytes, however, the staining intensity was much than that in the germinal centers.     

Analysis of lymphoid and dendritic cells in human lymph node, tonsil and spleen. A study using monoclonal and heterologous antibodies

The distribution of lymphoid and dendritic cells in human reactive lymph nodes, tonsils and spleens was examined by means of an indirect immunoperoxidase technique, using a panel of monoclonal and heterologous antibodies. The antibodies used were directed against antigens present on T cell subsets (Leu1, leu2a, Leu3a, TA1, OKT6), various types of B cells (BA1, BA2, HLA-DR, CR1) and cells of the mononuclear phagocyte system (alpha HM1, TA1, CR1, OKM1, NA 1/34). In the lymph node and tonsil Leu3a-positive cells (T-helper/inducer phenotype) and Leu2a-positive cells (T-suppressor/cytotoxic phenotype) are found in the thymus-dependent or T-cell area; in the spleen Leu3a-positive cells are found mostly in the periarteriolar lymphocyte sheath (PALS), while Leu2a-positive T-suppressor/cytotoxic cells are almost completely restricted to the cords of Billroth in the red pulp. The cells in the mantle zone of germinal centres and in the primary follicles in lymph nodes, tonsils and spleens have B-cell properties (BA1-, HLA-DR-, and CR1-positive). The cells in the germinal centres show a similar staining pattern (HLA-DR-, and partly CR1-positive). Follicles and T-cell-dependent areas have specific dendritic cells, each with a specific staining pattern: the dendritic reticulum cell (DRC) of the follicle stain with CR1, HLA-DR, BA2 and alpha HM1; the interdigitating cell of the T-cell areas in the lymph node, tonsil and spleen stain with HLA-DR and BA1. Moreover, large dendritic OKT6-positive cells are found in the T-cell areas of some of the peripheral lymph nodes, and are probably Langerhans cells. It is concluded that human lymph nodes and tonsils have an identical compartimentalisation, clearly differing from the spleen in cellular organization.     

Ultrastructural analysis of HNK-1+ cells in human peripheral blood and lymph nodes

HNK-1 positive (HNK-1+) cells in human peripheral blood and lymph nodes were comparatively analysed by means of immunohistochemistry and immunoelectron microscopy. In peripheral blood, the HNK-1+ cells were grouped into large granular lymphocytes (LGLs), small lymphocytes and intermediate forms, all of which had many fine cytoplasmic processes. Except for smooth-surfaced lymphocytes, they could not be distinguished from helper/inducer T (OKT4/Leu3a) cells and suppressor/cytotoxic T (OKT8/Leu2a) cells. In double staining, HNK-1+T3- cells and HNK-1+T3+ cells could not be clearly distinguished in terms of morphology, although the former contained many LGLs. The HNK-1+ cells in the lymph nodes accumulated in the light zones of the germinal centers (GCs). These cells were small to medium-sized lymphocytes with few electron-dense granules and exclusively co-expressed helper/inducer T cell antigens (HNK-1+T4+). Their cytoplasmic projections were interwoven with those of the follicular dendritic cells which trap immune complexes for a long duration. These configurations suggest that HNK-1+T4+ cells in GCs are engaged in an immunological regulation of germinal center cells. On the other hand, large blastic HNK-1+ cells were scattered outside the GCs and some of them were in the process of mitosis. Furthermore, HNK-1+LGL-like cells with a few large electron-dense granules were rarely seen. These observations indicate that the HNK-1+ cells in the lymph nodes may proliferate outside GCs and differentiate into LGLs with a strong natural killer function.     

Improved Immunohistochemical Visualization of Helper/Inducer T-Cells by the Simultaneous Application of two Noncrossblocking Monoclonal Antibodies

We have studied the intensity of staining of helper/inducer T-cells in lymph node and tonsillar tissue using two commercially available monoclonal antibodies (OKT4 and Leu3a) with the indirect immunoperoxidase method. Paracortical and mantle zone helper/inducer T-cells were easily visualized by both monoclonal antibodies, but T-cells in the follicular center, though stained by Leu3a, were hardly demonstrable by OKT4. Excellent staining was obtained in the indirect immunoperoxidase procedure by incubating the sections with a 1:1 mixture of the two monoclonal antibodies which gave bright staining of individual cells throughout the lymphoid tissue. Dilution of the primary antibodies by 1:200 did not affect the results. It is concluded that the simultaneous application of OKT4 and Leu3a as primary antibodies in the indirect immunoperoxidase procedure is the method of choice for the in situ demonstration of helper/inducer T-cells.     

Improved immunohistochemical visualization of helper/inducer T-cells by the simultaneous application of two noncrossblocking monoclonal antibodies

We have studied the intensity of staining of helper/inducer T-cells in lymph node and tonsillar tissue using two commercially available monoclonal antibodies (OKT4 and Leu3a) with the indirect immunoperoxidase method. Paracortical and mantle zone helper/inducer T-cells were easily visualized by both monoclonal antibodies, but T-cells in the follicular center, though stained by Leu3a, were hardly demonstrable by OKT4. Excellent staining was obtained in the indirect immunoperoxidase procedure by incubating the sections with a 1:1 mixture of the two monoclonal antibodies which gave bright staining of individual cells throughout the lymphoid tissue. Dilution of the primary antibodies by 1:200 did not affect the results. It is concluded that the simultaneous application of OKT4 and Leu3a as primary antibodies in the indirect immunoperoxidase procedure is the method of choice for the in situ demonstration of helper/inducer T-cells.     

Use of monoclonal antibodies to human lymphocytes to identify lymphocyte subsets in lymph nodes of the rhesus monkey and the dog

Using commercially available monoclonal antibodies that bind to human lymphocyte subsets, we examined lymph nodes from the rhesus monkey and the dog for their binding ability to these monoclonal antibodies. The avidin biotin-peroxidase immunostaining procedure was used, and the following antibodies were reactive in the rhesus monkey: Leu 4, Leu 3a, OKT4, Leu 2a, OKT8, T8, Leu 5b, T11, Leu 14, B1, and Leu 12. No immunoreactivity was observed in the dog lymph node except for moderate reactivity of OKT8. The following antibodies failed to react in both the rhesus monkey and the dog: OKT3, T1, T2, T1B, T4, T8A, Pan B, and T29/33. Kappa and lambda immunoglobulin light chains were positive in both the dog and monkey.     

Distribution of cells bearing the Tac antigen during ontogeny of human lymphoid tissue

The monoclonal antibody anti-Tac, which binds to the interleukin 2 (IL 2) receptor, was used to identify this antigen in human fetal and adult lymphoid tissue. Liver, spleen, thymus, lymph node, and peripheral blood were examined for Tac-positive cells with the use of frozen sections or cytocentrifuge preparations. The results show that cells in the fetal and neonatal thymus express the Tac antigen; these cells are predominantly located in the medulla. The liver and spleen of both fetus and adult exhibit very few Tac-positive cells. Double staining demonstrates that cells bearing the Tac-antigen stain with Leu-4, an anti-T cell antibody. In adult lymph node tissue, the Tac-bearing cells are predominantly distributed in the interfollicular area, with positive cells also present in the germinal center and mantle zone. The Tac antigen is present on both T and B cells. Few Tac-positive cells are present in the circulating peripheral blood.     

Human follicular dendritic cells express CR1, CR2, and CR3 complement receptor antigens

The expression of complement receptors by human follicular dendritic cells (FDC) was investigated by immunohistochemical techniques by using polyclonal and monoclonal antibodies to antigenic determinants of CR1, CR2, and CR3. Upon optical immunohistochemical examination of frozen sections from human reactive lymph nodes and tonsils by a three-step immunoperoxidase technique, a strong staining of cell bodies and cytoplasmic extensions of FDC was observed in germinal centers with anti-CR1 and anti-CR2 antibodies. Staining for these antigens was also found on cytoplasmic extensions of FDC in the mantle zone and on the plasma membrane of B cells in the entire follicles. Staining of FDC with anti-CR2 antibody was more intense than that of B lymphocytes. Monoclonal antibodies directed against epitopes of the alpha-chain of CR3 weakly stained FDC in follicles in a similar pattern to that which was observed on adjacent sections with mouse monoclonal antibody KIM4 that only recognizes FDC in human lymph nodes. Immunoelectron-microscopy was performed on frozen sections of a lymph node involved with a centroblastic centrocytic B malignant lymphoma and a reactive tonsil with the use of rabbit F(ab')2 anti-CR1 antibodies and mouse monoclonal anti-CR2 antibody. All the plasma membrane of the cell body and cytoplasmic extensions of FDC in germinal centers and in the mantle zones homogeneously stained for CR1 and CR2 antigens. Fibroblastic reticulum cells were negative. The plasma membrane of tumoral B lymphocytes strongly stained with anti-CR1 and weakly stained with anti-CR2 antibodies. The presence of CR1, CR2, and CR3 on FDC is a unique surface characteristic of these cells that should optimally allow the cells to bind antigen/antibody complexes bearing any type of C3 fragment.     

Immunophenotypic characterization of primary and secondary lymphoid follicles

The need for an immunophenotypical referential framework relative to lymphoid follicle has led us to apply a panel of monoclonal and polyclonal antibodies, by means of a sensitive immunostaining method. Lymphoid follicle is an immunophenotypically complex structure made up of three lymphoid populations (B, being its bulk, and a few T and NK cells), dendritic reticulum cells (DRCs) and Flemming's macrophages. Follicular B population is To 15 +, B1+, OKB 7 +, HLA-DR + and C3bR +. In secondary follicles there are differential characteristic reactivities for each topographic compartment: Mantle zone is positive for OKB 2 and surface IgM (sIgM) and IgD (sIgD); germinal center (GC) clear zone (with centrocytic predominance) for OKT 9, sIgM and weakly for OKB 2; and GC dark zone (with centroblastic predominance) only for OKT 9. In sections, OKT 10 allows one to see immunoblasts and plasma cells, the latter being with lymphoplasmacytoid cells the only intracytoplasmic immunoglobulin holders. 10% of GC lymphocytes are T cells, almost exclusively T-helper (Leu 3a +). Another 10% to 15% of lymphoid cells are Leu 7 (HNK-1) +. In histological sections, DRCs are specifically marked with R4/23 and Flemming's macrophages with anti-alpha1-antitrypsin and anti-alpha1-antichymotrypsin antibodies, both populations being negative to OKM 1 and OKM 5.     

Immunohistochemical analysis of human peripheral blood and lymphoid tissues using monoclonal antibodies immunoreactive with non-lymphoid cells

Immunoperoxidase methods were used to study human peripheral blood and lymphoid tissues using a panel of monoclonal antibodies to non-lymphoid cells. The majority of peripheral blood monocytes were immunoreactive for LeuM1, LeuM2, LeuM3 and LeuM5. Rare peripheral blood monocytes were immunoreactive for R4/23. The different antibodies showed characteristic patterns of immunoreactivity in peripheral lymphoid tissues. LeuM1 was immunoreactive with scattered cells in the paracortex of lymph node and tonsil and with many cells in the marginal zone of the spleen. LeuM2 was immunoreactive with endothelial cells in lymph node and tonsil. A few cells in the red pulp of the spleen were immunoreactive for LeuM2. LeuM3 and R4/23 showed distinctive immunoreactivity in germinal centers of secondary follicles, giving a "lacy" pattern. LeuM3 was also immunoreactive with endothelium in lymph node and tonsil and with sinus lining cells in lymph node. LeuM5 was immunoreactive with macrophages in the germinal center, fibroblastic reticulum cells in the mantle zone and interdigitating reticulum cells in the paracortex of lymph node and tonsil.