Subclassification of murine T cells by computerized microphotometric analysis

Splenocytes separated by physical means and classified as T cells by immunologic tests and computerized microphotometric analysis are differentiated into subgroups by analysis of the distribution patterns of Feulgen-positive nuclear DNA. In like fashion T cells obtained as purified preparations after separation on a nylon column, and accepted as T cells by micromorphometric analysis were subjected to further computerized morphometric analysis of nuclear DNA to form subgroups of cells. In each case, the number and composition of the detected subgroups were consistent. The classification does not appear to reflect any obvious phases of the cell cycle and is not dependent upon the sex and strain of mice from which the cells were obtained.     

Separation of T and B lymphocytes from various mouse strains by density gradient electrophoresis

T and B mouse spleen lymphocytes were separated by density gradient electrophoresis on the basis of their surface charge. In all strains examined, the T lymphocytes were found in the high mobility fractions and the B in the low. The T and B cells were separated completely in most fractions, with some overlapping in the middle. Significant differences were found in the electrophoretic distribution profiles between the strains: C57BL/6j, C57BL/10j, (BALB/cXC57BL/6j)F₁, and all the following: B₆·C-H-2^d/cBy (congenic to C57BL/6j), BALB/c, CBA/H/T6j, C57BL/10Sn, and C3H. The C57BL/6j and the (BALB/cXC57BL/6j)F₁ cells appear more heterogeneous as far as electrophoretic mobility is concerned. Almost all the other strains give two major peaks. Moreover, the high mobility areas are less populated in the C57BL/6j and the (BALB/cXC57BL/6j)F₁ animals than in all the others. The above differences were found consistently when cells prepared by different methods were electrophoresed. It is concluded that the surface charge of lymphocytes may be genetically determined. Possible dependency on the H-2 complex or non-H-2 areas is discussed.     

长链非编码RNA的免疫调节机制研究进展

真核生物的基因表达受多个层面调控,包括染色体水平、DNA水平、转录水平和转录后水平的调控等.长链非编码RNA(lnc RNA)是一类转录本超过200 nt的非编码RNA,其对基因表达的调控涉及上述各个层面,如组蛋白修饰、DNA甲基化的调控、转录的促进和抑制、m RNA的剪辑及对转录因子的调控等.其作用方式复杂多样,可与DNA、mRNA和蛋白质等相互作用而发挥调节作用.LncRNA保守性较差,但其表达却有较高的细胞、组织和分化阶段特异性.免疫系统的发育和分化受到精密的调控,且具有较高的阶段性和特异性.因此研究lnc RNA的功能及作用机制,免疫系统是较好的选择,这能促进我们对免疫调控的理解,为免疫性疾病的治疗提供新的思路和方法.本文主要介绍lnc RNA的分类和lnc RNA作用的一般分子机制,及其对T细胞、B细胞、固有免疫细胞和炎症因子的分子调控机制及其进展.     

IL‐21 has a critical role in establishing germinal centers by amplifying early B cell proliferation

The proliferation and differentiation of antigen‐specific B cells, including the generation of germinal centers (GC), are prerequisites for long‐lasting, antibody‐mediated immune protection. Affinity for antigen determines B cell recruitment, proliferation, differentiation, and competitiveness in the response, largely through determining access to T cell help. However, how T cell‐derived signals contribute to these outcomes is incompletely understood. Here, we report how the signature cytokine of follicular helper T cells, IL‐21, acts as a key regulator of the initial B cell response by accelerating cell cycle progression and the rate of cycle entry, increasing their contribution to the ensuing GC. This effect occurs over a wide range of initial B cell receptor affinities and correlates with elevated AKT and S6 phosphorylation. Moreover, the resultant increased proliferation can explain the IL‐21‐mediated promotion of plasma cell differentiation. Collectively, our data establish that IL‐21 acts from the outset of a T cell‐dependent immune response to increase cell cycle progression and fuel cyclic re‐entry of B cells, thereby regulating the initial GC size and early plasma cell output.     

Generation of megakaryocytes and platelets from preadipocyte cell line 3T3-L1, but not the parent cell line 3T3, in vitro

Platelets are produced from megakaryocytes (MKs), although the pathway leading from stem cells to MK lineages are not yet fully understood. Recently, we reported to obtain abundant MKs and platelets from human subcutaneous adipose tissues. Adipose tissues contain various cell types, most of which are lineage cells from mesenchymal or adipocyte-derived stem cells, distinct from hematopoietic cells. To identify the cells responsible for the differentiation MK lineages in adipose tissues, this study examined whether the preadipocyte cell line 3T3-L1 and fibroblast cell line 3T3 differentiated into MK lineages in vitro. Cells were cultured in megakaryocyte lineage induction medium. By day 4, most of 3T3 cell-derived cells leaded to cell death. In contrast, 3T3-L1-derived cells on days 8 showed to have typical characterizations of MK lineages in analyses for specific marker, DNA ploidy, transmission electro micrograph. 3T3-L1-derived platelet-sized cells on day 12 could be stimulated by ADP and PAR4-activating peptide. This study clearly shows in vitro differentiation from 3T3-L1 cells, not from 3T3 cells, into MK lineages.     

Ontogeny of lymphatic structures in the pig omentum

Summary The development of lymphoid populations in the omentum majus during the prenatal and postnatal life of the pig was studied. T lymphocytes, monocytes and mast cells were first found on the 40th day of gestation. B lymphocytes appeared on the 72nd day of gestation when the first macrophage aggregates were formed. Macrophages appeared to be the prerequisite for the formation of dense lymphatic areas (DLA's). At later stages T cells were observed only in the omentum of germfree pigs. DLA's of conventional pig omentum are filled exclusively with B cells.     

Human B-cell activation in vitro. T cell-dependent pokeweed mitogen-induced differentiation of blood B lymphocytes.

Human blood lymphocytes were separated into T and non-T cells and cultured with pokeweed mitogen (PWM). It was found that in the absence of T cells no differentiation of B cells into immunoglobulin-containing blasts and plasma cells took place. Moreover, the cell yields and the rate of DNA synthesis and blast transformation were very low. The influence of T cells on PWM-induced B-lymphocyte differentiation was studied in mixtures of T/non-T cells at various ratios. Addition of even a few T lymphocytes caused a considerable stimulation of B cells by all parameters used. The responses of T/non-T mixtures of the original cellular composition were of the same order as those of cultures of unseparated cells. It is concluded that the differentiation of human blood B lymphocytes into cells actively synthesizing immunoglobulins, as induced by PWM, is strongly dependent upon the presence of T cells.     

IL-27:保持免疫平衡的重要因子

由EBI-3和p28组成的IL-27是IL-12家族的新成员,主要来源于树突状细胞(dendritic cells,DCs)的分泌。当DCs表面的Toll样受体(Toll like receptor,TLR)受到外界信号刺激的时候,通过激活下游因子MyD88、IRF3、c-Rel以及JNK等通路介导IL-27表达。IL-27受体由WSX-1和gp130两个亚基组成,表达于多种免疫细胞和非免疫细胞表面。IL-27对这些细胞的发育、分化和功能都发挥着不可或缺的作用。IL-27与其受体结合后,通过激活下游的STAT1/STAT3途径诱导na?veT细胞向Th1方向分化,同时抑制其向Th2、Th17和Foxp3+Treg方向分化。B细胞抗体类型的转换、DCs表面共刺激分子的表达和促进Th1反应的能力也受到IL-27的调节。另外,IL-27还可以诱导一些非免疫细胞的表面表达MHC分子,使其具有抗原呈递的功能。更具有临床意义的是,IL-27在许多感染性疾病、自身免疫病和肿瘤中都发挥了重要作用,是相关疾病潜在的作用靶点。     

Cooperation of dendritic cells with naïve lymphocyte populations to induce the generation of antigen-specific antibodies in vitro

The production of monoclonal antibodies by hybridoma technology is dependent on lymphocytes taken from vertebrates which have to be immunized against the corresponding antigen. We present here our first experiments which should allow the replacement of this in vivo immunization step by an in vitro immunization procedure. This work provides new possibilities for the specific activation of immune cells in order to use them for the generation of antibodies which are not of murine origin. Bone marrow-derived dendritic cells were loaded with antigen and co-cultured with naïve T and B lymphocytes of non-immunized mice. The interaction and activation of the different cell types were investigated by measuring the expression of specific cell surface markers, the release of activation-dependent interleukins and the secretion of antigen-specific antibodies. We could demonstrate that dendritic cells process and present antigen fragments and activate T cells, that T cells proliferate and release activation-induced interleukins, and that B cells maturate under the influence of activated T cells and secrete antigen-specific antibodies.     

Subclassification of murine T cells by computerized microphotometric analysis.

Splenocytes separated by physical means and classified as T cells bay immunologic tests and computerized microphotometric analysis are differentiated into subgroups by analysis of the distribution patterns of Feulgen-positive nuclear DNA. In like fashion T cells obtained as purified preparations after separation on a nylon column, and accepted as T cells by micromorphometric analysis were subjected to further computerized morphometric analysis of nuclear DNA to form subgroups of cells. In each case, the number and composition of the detected subgroups were consistent. The classification does not appear to reflect any obvious phases of the cell cycle and is not dependent upon the sex and strain of mice from which the cells were obtained.     

蚁属（膜翅目：蚁科）4种的形态测量学分析

运用形态测量学分析方法,对蚁属Formica中的光亮黑蚁F.candida、亮腹黑褐蚁F.gagatoides、北京凹头蚁F.beijingensis和满洲蚁F.manchu 4种共296头蚂蚁标本进行研究。选取头长(HL)、头宽(HW)、复眼最大直径(ED)、触角柄节长(SL)、并腹胸长(AL)、前胸背板宽(PW)、并胸腹节宽(DPW)和体长(TL)8个度量数据为变量进行相关性、配对T检验、均值±SD与主成分散点分布图分析,探讨形态测量学方法在蚁科昆虫分类中的应用。结果表明:形态测量学方法能够将4种蚂蚁进行有效识别区分,可作为形态分类学研究的一种有效、快速的辅助方法。     

Development of antigenic heterogeneity in the splenic meshwork of severe combined immunodeficient (SCID) mice after reconstitution with T and B lymphocytes

Recently, we produced monoclonal antibodies reacting specifically with the reticular meshwork (RM) of lymphoid tissues, and demonstrated that, in the splenic white pulp of normal mouse, the antigenic heterogeneity of RM was associated with the segregation of the T and B lymphocytes. In the present study, we attempted to visualize further the interaction between splenic RM and T and B lymphocytes transferred into severe combined immunodeficient (SCID) mice. The splenic white pulp of naive SCID mice, containing a few T and B cells, showed little tendency for T-B segregation and antigenic diversity of RM. Transfer of spleen or bone marrow cells from normal mice resulted in complete recovery of lymphocyte populations, showing not only a clear segregation of T and B lymphocytes but also a remarkable antigenic diversity of RM. The same results were obtained following the transfer of spleen or bone marrow cells from the nude mouse. Next, we transferred purified T lymphocytes to one group of SCID mice and B cells to another. In mice given T cells, a few B cells were observed in the white puop; T lymphocytes lodged not only in the inner periarterial lymphatic sheath (PALS) but also in the outer PALS and follicles. In the animals to which B cells were transferred, T cells were few and the homing of B cells occurred only into their proper compartments, such as the outer PALS, follicles and marginal zone, but not in the inner PALS. Thus, B cells can home into their proper compartments of the splenic white pulp independently of T lymphocytes.     

The function of BAFF on T helper cells in autoimmunity

B cell-activating factor belonging to the TNF family (BAFF) exerts its pathogenic role in supporting the survival and proliferation of B cells, regulating class switch recombination as well as the selection of autoreactive B cells. Overexpression of BAFF induces a dramatic expansion of activated B cells, particularly marginal zone B cells, as well as hypergammaglobulinemia, autoantibody production and immune complex deposition. However, in addition to its effect on B cells, recent work has also demonstrated that BAFF can promote T cell activation, proliferation and differentiation. In this review, we have discussed the recent progress on the function and role of BAFF on T cells and T cell-mediated diseases.