A human CD4 transgene rescues CD4−CD8+ cells in β2-microglobulin-deficient mice

The specificity of the αβ T cell receptor for class I or class II major histocompatibility complex (MHC) molecules determines whether a mature T cell will be of the CD4^?CD8⁺ or CD4⁺CD8^? phenotype, respectively. We show here that a human CD4 transgene can rescue a significant fraction of CD4^?CD8⁺ T cells in β2-microglobulin-deficient mice. Cells with this phenotype could be induced to become potent killers of targets expressing allogeneic MHC antigens, indicating that lineage commitment can precede the rescue of developing cells by the T cell receptor for antigen and the CD4 coreceptor.     

Thymic selection and peptide-induced activation of T cell receptor-transgenic CD8 T cells in interleukin-2-deficient mice

The requirement for interleukin-2 (IL-2) in repertoire selection and peripheral activation of CD8 T cells was tested in mice rendered IL-2 deficient by gene targeting and expressing a transgenic T cell receptor (TcR) (F5) specific for influenza nucleoprotein (NP) 366-374 + H-2D^b. Positive selection of the transgenic F5 TcR into the CD8 compartment proceeded normally. Both in vivo and in vitro, the antigenic peptide induced depletion of immature thymocytes and proliferation of mature CD8 T cells regardless of the presence of an intact IL-2 gene. In contrast, cytotoxic T lymphocyte (CTL) activity was only generated by T cells from IL-2⁺ F5 transgenic mice. Exogenous IL-2 was able to fully restore the CTL response of IL-2^?/? responder cells in vitro. Thus, both in vivo and in vitro, clonal expansion of CD8 T cells can proceed in the absence of IL-2, whereas in peptide-immunized F5 transgenic mice, induction of cytotoxic effector function is IL-2 dependent.     

Protein-G binding material from synovial fluid of rhematoid arthritis patients induces unorthodox autoantibodies (IgG1 rheumatoid factor) in NZB,NZW and (NZB x NZW)F1 mice

Our previous studies have demonstrated that injection of rheumatoid arthritis (RA) synovial fluid (SF) induces a marked increase mainly of IgG1 antibody-producing cells in autoimmune disease prone (NZB X NZW)F1 mice but not in CBA mice. In the present study, the in vivo effect of RA-SF on autoantibody production was tested in different strains of mice. Injection of RA-SF induced the production of unorthodox autoantibodies (IgG1 rheumatoid factor, RF) in young (NZB X NZW)F1 mice as well as in their parental strains NZB and NZW, but not in normal mice (CBA) or in mice with severe combined immunodeficiency, indicating that the response is not caused by a conventional immune response against RA-SF material. IgG1 RF production was rapidly induced and reached high levels already on day 7 and lasted for more than 90 days. The induction of IgG1 RF was not the result of polyclonal activation, since RA-SF did not stimulate the production of other antibodies, such as autoantibodies against double-stranded DNA, bromelain-treated mouse red blood cells, myosin, transferrin, cytochrome c, thyroglobulin or myoglobin or antibodies reactive with the hapten TNP. To elucidate the identity of the active substance in RA-SF, responsible for IgG1 RF production, bound and unbound material of RA-SF, eluted from a protein-G column was injected into (NZB X NZW)F1 mice. Only the protein-G binding material was active, indicating that the effect is mediated by autoantibodies or immune complexes in the synovial fluid. Further studies demonstrated that identical concentrations of protein obtained from a pool of normal human IgG or SF from seronegative RA and non-RA arthritides patients did not contain the same activity.     

Maturation of medullary thymic epithelium requires thymocytes expressing fully assembled CD3-TCR complexes

Unlike meduilary thymic epithelial cells (TEC) of normal mice,meduilary TEC of TCR^– SCID mice are immature and disorganized.In order to assess directly the role of TCR⁺ cells in the developmentof medullary TEC, we bred mice which co-expressed the SCID geneticdefect and transgenes encoding clonotypic TCR chains. Immunohistologicexamination revealed that meduilary thymic epithelial cellsfrom TCRß transgenic SCID mice, whose thymocytes onlyexpress TCRß chains that inefficiently associate withCD3 and , components, remained immature and disorganized. Incontrast, meduilary TEC from TCRß transgenic SCIDmice, whose thymocytes express fully assembled CD3--TCRßcomplexes were mature and organized. Interestingly, the abilityof TCRß⁺-⁺-CD3³ thymocytes to induce maturation ofmeduilary TEC appeared not to be related to the antigen specificityof the TCR as thyml from positively selecting, negatively selectingand non-selecting TCRß transgenic SCID mice all possessedinduced meduilary thymic epithelial cells. In addition, we foundthat induction of meduilary TEC cells was associated with thepresence of meduilary thymocytes, including those of the CD4-CD8-TCRß⁺phenotype. The present findings demonstrate that fully assembledCD3--TCR complexes are required to induce maturation of meduilarythymic epithelial cells and indicate that thymocyte inductionof meduilary thymic epithelial cells may result from signalingindependently of their clonotyplc chains.     

Development and proliferation of lymphocytes in mice deficient for both interleukins-2 and -4

Interleukin (IL)-2 and IL-4 are considered as important regulators of growth and differentiation of lymphocytes. We report that in mice made deficient for both IL-2 and IL-4 by gene targeting all major T cell subsets and B cells were normal, indicating that IL-2 and IL-4 are not essential for development of the immune system. Paradoxically, proliferation of T cells was increased in both IL-2- and IL-4-deficient homozygous mice.     

FAP在胃癌间质中的表达及其与微血管密度的关系

目的 探讨FAP在胃癌间质中的表达及其与微血管密度(microvessel density,MVD)的关系.方法 收集162例胃癌组织,同时建立人胃癌细胞系SGC-7901裸鼠皮下移植瘤模型,采用免疫组织化学染色法检测FAP和CD34的表达.结果 在人胃癌组织中,FAP表达于问质成纤维细胞,表达阳性率为90.74%(147例),而胃癌细胞和正常胃组织中无表达,且FAP表达和MVD分别与胃癌的分化程度(χ2=51.882,P<0.01;χ2=46.383,P<0.01)、侵袭深度(χ2=40.193,P<0.01;χ2=21.617,P<0.01)及淋巴结转移(χ2=24.232,P<0.01;χ2=13.393,P<0.01)有关.在15例裸鼠皮下移植瘤中,所有肿瘤中FAP均不同程度在间质成纤维细胞呈阳性表达.在人胃癌组织(χ2=97.710,P<0.01)和裸鼠皮下移植瘤组织(χ2=11.100,P<0.01)中,不同强度的FAP表达组间肿瘤间质MVD的差异具有统计学意义,且随着FAP表达水平的增高,MVD也随之增加.结论 FAP的表达与胃癌的分化程度、侵袭深度及淋巴结转移有关.FAP可能通过促进肿瘤的微血管生成,加快肿瘤的生长、侵袭和转移.     

Short term treatment with estradiol decreases the rate of newly generated cells in the subventricular zone and main olfactory bulb of adult female mice

Adult neurogenesis occurs most notably in the subgranular zone (SGZ) of the hippocampal dentate gyrus and in the olfactory bulb (OB) where new neurons are generated from neural progenitors cells produced in the subventricular zone (SVZ) of the forebrain. As it is well known that gonadal steroid hormones, primarily estradiol, modulate neurogenesis in the hippocampus of adult female rodents, we wanted to determine whether estradiol would also affect the proliferation of progenitor cells in the SVZ and by consequence the rate of newly generated cells in the main OB. Thus a first group of adult female C57Bl6/J mice was ovariectomized and received a short term treatment with estradiol (single injection of 1 or 10 μg 17β-estradiol or Silastic capsule of estradiol during 2 days) before receiving a single injection with BrdU to determine whether estradiol would modulate the cell proliferation in the SVZ. A second group of adult ovariectomized female mice was submitted to the same estradiol treatment before receiving four BrdU injections, and was sacrificed 21 days later to determine whether a modulation in cell proliferation actually leads to a modulation in the number of newborn cells in the main OB. We observed a decrease in cell proliferation in the SVZ following either dose of estradiol compared to the controls. Furthermore, 21 days after their generation in the SVZ, the number of BrdU labeled cells was also lower in the main OB, both in the granular and periglomerular cell layers of estradiol-treated animals. These results show that a short term treatment with estradiol actually downregulates cell proliferation leading to a decreased number of newborn cells in the OB.     

An active CD8α/pMHCI interaction is required for CD8 single positive thymocyte differentiation

Recognition of viral antigenic peptides bound to major histocompatibility complex class I molecules (MHCI) by TCR is critical for initiating the responses of CD8⁺ T cells that ultimately lead to elimination of virus‐infected cells. This antigen recognition is enhanced by the CD8 coreceptor through its interaction with the peptide‐MHCI complexes (pMHCI). Mouse CD8αβ can form two different complexes with pMHCI via either the CD8α‐ or CD8β‐dominated interaction. To understand the functional significance of these complexes in vivo, we generated Tg mice carrying a variant CD8αβ (CD8α^m3β) capable of forming only the CD8β‐dominated CD8αβ/pMHCI complex. These mice show sub‐optimal thymic differentiation with reduced populations of CD8⁺ single‐positive thymocytes. Tg CD8⁺ T cells exhibit a compromised developmental capacity when competing with CD8⁺ T cells from B6 mice in mixed bone marrow chimera experiments. However, once these CD8⁺ T cells have emigrated to the peripheral lymphoid organs, they exhibit normal effector function against viral infection. Our observations indicate that, in addition to the CD8 activity conferred by CD8β‐dominated CD8αβ/pMHCI complexes, full thymocyte differentiation requires additional coreceptor activities conferred by CD8αα and/or CD8αβ with CD8α‐dominated CD8/pMHCI complexes.     

C57BL/6小鼠上皮性卵巢癌模型的建立及其生物学特性

目的在免疫功能正常的C57BL/6小鼠体内建立上皮性卵巢癌腹腔转移瘤模型及皮下瘤模型,为卵巢癌的诊断、治疗及预防的相关研究提供基础。方法体外培养近交系C57BL/6小鼠卵巢上皮低分化腺癌细胞株ID-8,将对数生长期的ID-8细胞按1×10^7、5×10^6、1×10^6和1×10^5个细胞/只的剂量,分别接种于6～8周雌性SPF级C57BL/6小鼠腹腔及左侧肩部皮下,共8组,每组6只。观察腹腔瘤及皮下瘤的成瘤时间、成瘤率、腹水、腹腔肿瘤转移情况及小鼠生存期;处死小鼠时留取主要脏器、腹腔肿瘤及皮下肿瘤标本,行病理学检查。另外6只小鼠接种5×10^6个ID-8细胞,分别在4、8、16周后处死进行系统解剖,做常规病理学检查。结果将不同数量的ID-8细胞接种C57BL/6小鼠腹腔及皮下后,成瘤率均为100%,腹腔瘤模型组：腹腔注射1×10^5,1×10^6,5×10^6,1×10^7个ID-8细胞,平均生存时间分别为（141±6.7）d、（122.8±4.5）d、（83.4±7.2）d和（74.4±4.5）d,随着肿瘤细胞接种负荷增加,动物生存期明显缩短（P〈0.05）。皮下瘤组：1×10^7细胞组和5×10^6细胞组,1周左右成瘤;1×10^6细胞组,3周左右成瘤;1×10^5细胞组,6周左右成瘤。随着肿瘤接种负荷的增加,肿瘤直径和体积明显增大（P〈0.05）。结论 C57BL/6小鼠腹腔瘤模型类似人类Ⅲ、Ⅳ期卵巢上皮癌患者的临床特点。皮下瘤模型更易于观察免疫治疗或药物治疗的疗效。在免疫功能正常的C57BL/6小鼠建立的ID-8细胞卵巢癌肿瘤模型,是适合于卵巢癌分子和免疫治疗研究的模型。     

泛福舒短期口服对哮喘小鼠免疫调节作用的影响

目的研究泛福舒（roncho-Vaxom）对哮喘小鼠免疫功能的调节和影响,是否影响树突状细胞（DC细胞）的成熟,探讨哮喘的免疫调节治疗。方法将60只BABL/c小鼠随机分为3组,每组20只,对照组正常饲养1个月后建立哮喘模型;试验1组,泛福舒0.1mg/kg口服1个月后停药,建立小鼠哮喘模型;试验2组,泛福舒口服1个月后建立哮喘模型,在建模过程中继续服药,前后总共服药2个月。末次激发后收集各组小鼠血清,ELISA检测细胞因子IL-4、IL-13、IL-2、IFN-γ。WesternBlot法检测哮喘小鼠骨髓来源的树突状细胞成熟标志物酪氨酸蛋白激酶SyK的含量。结果试验1组和试验2组小鼠骨髓来源树突状细胞酪氨酸蛋白激酶SyK表达水平较对照组下调。对照组细胞因子IL-4、IL-13水平明显高于试验1组和试验2组,试验1组细胞因子IL-4、IL-13水平高于于试验2组,试验1组和试验2组IL-2、IFN-γ水平较对照组明显升高,且试验2组高于试验1组。各组数据差别有统计学意义。结论泛福舒短期口服可以抑制树突状细胞的成熟,抑制Th0细胞向Th2方向的分化,减少哮喘小鼠细胞因子IL-4、IL-13的产生,调节哮喘小鼠免疫功能。