B.C.B-17scid-beige小鼠免疫学特性及其在LAK前体细胞研究中应用

<正> 重症联合免疫缺陷病(severe combined immu-no-deficient disease,scid)小鼠T、B淋巴细胞功能联合缺陷,可用于构建人-鼠嵌合体(HID)模型,然而该鼠体内存在高活性的NK与LAK细胞功能,并影响到HID模型的完满建立。我们采用杂交-互交-互交-回交系统对scid小鼠引入bg基大(NK细胞缺陷),得到B.C.B-17scid-beige小     

SCID小鼠NK细胞功能及其对异基因移植的影响

重症联合免疫缺陷病小鼠(SCID)由C.B-17纯系小鼠基因突变而来。其突出特点是T、B淋巴细胞功能联合缺陷,能接受人的器官移植物,被称为活体动物试管。接受人体器官移植后的SCID 小鼠称为SCID-人,这种人-鼠嵌和体代表人类生物学研究的新途径,其有可能代替人体而应用于任何在人体上无法进行的实验研究,特别是AIDS 病的研究,但SCID 体内NK 细胞比正常C.B-17小鼠高4倍,经Poly(?)-C 诱导后增强7倍。其脾细胞无成熟T、B 细胞表面标志(Ig,lyt-1,lyt-2)而NK 细胞表面标志高(NK2.1,GM-1,MAC-1)。同时SCID 小鼠LAK 细胞功能也比正常对照高。在异基因组织移植研究中,SCID 小鼠能排斥异基因的骨髓移植物,这种排斥作用是由NK 细胞引起的,因此,SCID 体内的NK、LAK 细胞必然影响SCID-人动物型的完满建立。用进一步缺陷的小鼠有可能替代SCID 小鼠,推动人-鼠嵌合体的研究。     

超重症联合免疫缺陷小鼠体液免疫功能特征研究

本文对超重症联合免疫缺陷小鼠(B.C.B—17scid—beige)的体液免疫功能特征进行了研究,结果如下:1.血清中免疫球蛋白含量低于0.01mg/ml,与正常对照小鼠差异非常显著(p<0.01),2.脾脏发育异常,器官萎缩,B 细胞区细胞稀疏,3.脾脏 B 淋巴细胞缺乏:B220阳性细胞为0.2±0.1%、SmIg 阳性细胞为0.7±0.2%,4.脾淋巴细胞不能针对 B 细胞有丝分裂原细菌脂多糖(LPS)的刺激发生增殖,~3H—Tdr 参入值仅为549.33±146.22cpm,明显低于正常对照小鼠(p<0.01)。上述结果表明该鼠继承了其亲代重症联合免疫缺陷小鼠(scid)的体液免疫缺陷特征,从而为人源单抗及其它基因工程产品的生产提供了更为理想的工具.     

超重症联合免疫缺陷小鼠血清免疫化学特性研究

本文采用多项免疫化学技术对超重症联合免疫缺陷小鼠(B.C,B-17 scid-beige)血清免疫化学特征进行了分析。结果表明: 用免疫双扩散试验、SDS-PAGE和薄层凝胶扫描、以及免疫印迹法均未测出有免疫球蛋白存在,从而表明该品系小鼠血清免疫球蛋白缺失,该鼠体内已导入scid基因。该特征在人源单克隆抗体及其它蛋白质基因工程产品的生产等方面具有重要意义。     

体外扩增的Treg细胞抑制NK细胞介导的抗肿瘤免疫

目的研究CD4+CD25+调节性T细胞(regulatory T cells,Tregs)对NK细胞肿瘤杀伤力的影响及Treg细胞介导的抗肿瘤免疫抑制的机制;初步探讨过继输注NK细胞逆转Treg细胞介导的抗肿瘤免疫抑制的作用。方法免疫磁珠分离法(MACS)分离得小鼠脾脏Treg细胞及NK细胞,用流式细胞术检测其纯度。以CD3/CD28单克隆抗体磁珠和重组小鼠白介素2(rm IL-2)联合刺激体外扩增Treg细胞,重组小鼠白介素15(rm IL-15)、rm IL-2以及氢化可的松联合刺激体外扩增NK细胞。将扩增后Treg细胞及NK细胞按不同比例混合淋巴细胞培养,MTT比色法检测NK细胞的杀伤活性。将B16-F10小鼠黑色瘤细胞输注至Balb/c小鼠体内建立肺移植瘤模型[1],将荷瘤小鼠分为4组:A组单独接种B16-F10小鼠黑色瘤细胞;B组接种Treg细胞+B16-F10黑色素瘤细胞;C组接种B16-F10黑色素瘤细胞+NK细胞;D组接种Treg细胞+B16-F10黑色素瘤细胞+NK细胞。MTT比色法测定各实验组小鼠脾脏NK细胞的杀伤活性,并比较不同处理组小鼠肺部肿瘤结节数目。结果体外扩增后的Treg细胞对新鲜分选及扩增后的NK细胞活性均具有明显抑制作用(P0.05),且抑制作用呈剂量依赖关系;A组荷瘤小鼠NK细胞活性低于正常小鼠,且B组荷瘤小鼠NK细胞活性较A组进一步降低(P0.05);D组荷瘤小鼠NK细胞活性高于A组和B组荷瘤小鼠,但仍低于正常小鼠组(P0.05)。B组荷瘤小鼠肺部移植瘤数目(105.33±10.97)较A组明显增多(17±4.58)(P0.01);C组荷瘤小鼠肺部移植瘤数目(2.00±1.00)较A组(17±4.58)明显减少(P=0.037);D组荷瘤小鼠肺移植瘤数目(79.00±8.54)较B组明显降低(105.33±10.97)(P=0.030),但仍高于A组荷瘤小鼠(17±4.58)(P0.001)。结论体内种植肿瘤会抑制机体NK细胞活性;输注体外扩增Treg细胞能够通过抑制NK细胞发挥抗肿瘤免疫抑制;过继输注体外扩增NK细胞能够部分逆转Treg细胞介导的抗肿瘤免疫抑制。     

猪苓多糖对小鼠NK,LAK活性的影响

猪苓多糖2mg/只,rIL—2 5×1~4U/只,腹腔注射C57BL/6小鼠,连续9天,能明显抑制小鼠皮下移植性B16恶性黑色素瘤的生长,与对照组及单用rIL—2组比较有显著性差异(P<0.05～0.01)。~3H—TdR掺入法检测小鼠脾细胞NK及内源性LAK活性,发现只有猪苓多糖 rIL—2组的NK及内源性LAK活性提高显著(P<0.05),其它单用猪苓多糖与rIL—2两组的NK及内源性LAK活性增加不显著(P>0.05)。说明猪苓多糖与rIL—2有协同作用,猪苓多糖可作为生物反应调节剂(BRM),用于LAK/rIL—2为主的肿瘤生物学疗法。     

米色突变型小鼠T细胞应答的缺陷

人们一直认为,T细胞在免疫监视中起作用,但是由于发现了有T细胞缺陷的裸鼠肿瘤发病率低,人们开始对此观点产生疑问。随后又发现裸鼠的NK细胞水平高,而NK细胞在未预先致敏的情况下有溶解肿瘤细胞的作用。这些发现提示NK细胞组成了预防体内自发肿瘤的第一道防线。曾有报导提出C57BL/5米色突变型小鼠(bg/bg小鼠)有选择性NK细胞缺陷而T细胞功能正常。从而提出可用此型小鼠估价免疫监视中T细胞和NK系统的相对重要性。作者对此     

树突状细胞激活的肿瘤浸润淋巴细胞抗小鼠乳腺癌研究

目的 探讨C127细胞全细胞性抗原致敏的DC激活的TIL体外抗小鼠乳腺癌活性,并将C127细胞全细胞性抗原致敏的DC激活的TIL(C127-DC-TIL)过继免疫荷瘤小鼠,研究其对C127荷瘤小鼠免疫功能的影响及抑瘤作用.方法 从小鼠四肢长骨骨髓中获取DC,应用粒,巨噬细胞集落刺激因子(GM-CSF)、白介素-4(IL-4)和肿瘤全细胞性抗原致敏DC,然后用DC激活TIL,观察TIL在体外对C127细胞、MA782细胞和B16细胞的杀伤活性;检测应用C127-DC-TIL后荷瘤小鼠的脾淋巴细胞的NK、LAK、CTL活性、血清TNF活性、抑瘤作用以及瘤体病理改变,并与对照组相比较.结果 ①C127-DC-TIL具有很强的对C127细胞杀伤活性[杀伤率为(70.21±2.86)%],明显高于其对MA782和B16细胞的杀伤活性[杀伤率分别为(51.31±3.25)%,(31.41±2.65)%],也明显高于未经DC激活的TIL、C127-DC-脾淋巴细胞和未经DC激活的脾淋巴细胞对C127细胞杀伤活性[杀伤率分别为(48.30±2.97)%,(47.76±3.43)%和(17.23±2.56)%]和对MA782细胞杀伤活性[杀伤率分别为(38.52±2.87)%,(36.62±2.75)%和(18.07±2.40)%]以及对B16细胞杀伤活性[杀伤率分别为(25.38±2.63)%,(24.82±2.81)%和(17.34±2.81)%],同时B16细胞全细胞性抗原致敏的DC激活的TIL(B16-DC-TIL,TIL来源于C127瘤体)也可诱导相对较低的对B16细胞的特异性细胞杀伤活性.②C127-DC-TIL可明显诱导提高荷瘤小鼠脾淋巴细胞NK、LAK和CTL活性[活性分别为(32.21±1.24)%、(30.35±1.72)%和(37.43±1.54)%],并可检测到血清TNF水平明显上升[血清TNF水平为(38.41±1.77)U/ml],它们均达正常对照组水平,与未经DC激活的TIL组、C127-DC-脾淋巴细胞组、未经DC激活的脾淋巴细胞组、生理盐水组分别对应比较,差异均有显著性(P＜0.01).该组瘤体内淋巴细胞浸润程度也高于对照组,其瘤体生长明显受到抑制.结论 ①C127-DC-TIL可产生很强的体外针对C127细胞的特异性杀伤活性.②C127-DC-TIL具有很强的特异性抗小鼠乳腺癌作用.     

联合应用IL-2及IL-4基因转染瘤苗对实验性肺转移肿瘤的治疗作用

将IL—2基因转染的高分泌IL—2的B16黑色素瘤细胞株(B2)及IL—4基因转染的高分泌IL—4的B16黑色素瘤细胞株(B4)制备成新型瘤苗,用以治疗实验性肺转移荷瘤小鼠,并辅以低剂量环磷酰胺,结果表明,荷瘤小鼠存活期明显延长;肺部转移结节数明显减少;两种瘤苗联合治疗后的疗效较单独使用明显,当辅以低剂量环磷酰胺时治疗效果更加明显。体内免疫功能检测表明,经两种瘤苗联合治疗的荷瘤小鼠脾细胞NK及CTL杀伤活性升高得更加明显,但对LAK活性及腹腔巨噬细胞杀伤活性无明显协同增强作用;脾细胞经诱导后产生的细胞因子中,IL—2含量有所升高。     

肝脾细胞输注在异种移植中的耐受诱导

目的 :观察肝脾细胞输注诱导异种胰岛移植的免疫耐受性。方法 :采用STZ制备BALB C小鼠糖尿病模型 ,经尾静脉注射供体猪肝细胞和 或脾细胞 3次后 ,腹腔内注射法进行猪胰腺细胞移植。测定血糖浓度变化 ,观察小鼠移植物有功能存活时间。选择常规方法测定小鼠移植后NK细胞活性变化 ,T细胞亚群和B细胞体外抗体形成实验。结果 :肝脾细胞联合胰岛移植组血糖在移植后 2 0d内均处于较低水平 ,并与同期其他各实验组的血糖有明显差异 (P <0 0 5 )。于 35～ 4 5d内出现移植物功能丧失。NK细胞杀伤活性移植后肝脾细胞联合胰岛移植组没有明显变化 (P >0 0 5 )。其他各实验组的NK细胞杀伤活性均明显升高 (P<0 0 5 ) ,T细胞亚群亦与NK细胞杀伤活性一样出现同样变化。脾脏B细胞体外溶血功能均增强 (P<0 0 5 )。结论 :少量多次供体肝细胞和脾细胞提前输注可以诱导异种胰岛细胞移植的免疫耐受性     

B cell maturation and selection at the marrow-periphery interface

More than 95% of newly formed B cells die in the short interval spanning slgM acquisition in the bone marrow and entry into the long-lived pool, suggesting that selective events dictating B cell longevity occur at this stage. These likely include both ligandinduced deletion as well as discrete events that mediate recruitment to the long-lived recirculating pool. We are probing these events through the examination of normal B cell differentiation during this critical period: the characterization of a natural mutation that blocks late maturation, an irradiation/autoreconstitution model of marrow-derived B cell differentiation, and the identification of life span regulatory genes whose expression changes within this window.     

Antibody-independent B cell effector functions in relapsing remitting Multiple Sclerosis: Clues to increased inflammatory and reduced regulatory B cell capacity

The pathogenic role for B cells in the context of relapsing remitting multiple sclerosis (MS) is incompletely defined. Although classically considered a T cell-mediated disease, B cell-depleting therapies showed efficacy in treating the clinical symptoms of RRMS without decreasing plasma cells or total immunoglobulin (Ig) levels. Here, we discuss the potential implications of antibody-independent B cell effector functions that could contribute to autoimmunity with particular focus on antigen presentation, cytokine secretion, and stimulation of T cell subsets. We highlight differences between memory and naïve B cells from MS patients such as our recent findings of hyper-proliferation from MS memory B cells in response to CD40 engagement. We discuss the implications of IL6 overproduction in contrast to limited IL10 production by B cells from MS patients and comment on the impact of these functions on yet unexplored aspects of B cells in autoimmune disease. Finally, we contextualize B cell effector functions with respect to current immunomodulatory therapies for MS and show that glatiramer acetate (GA) does not directly modulate B cell proliferation or cytokine secretion.     

Presence of intragraft B cells during acute renal allograft rejection is accompanied by changes in peripheral blood B cell subsets

B cells have various functions, besides being plasma cell precursors. We determined the presence of intragraft B cells at time of acute rejection (AR) and looked for correlates of B cell involvement in peripheral blood. Renal biopsies at time of AR or stable graft function were analysed for the presence of B cells and B cell-related gene expression, as well as C4d staining. Peripheral blood B cell subset distribution was analysed at various time-points in patients with AR and controls, alongside serum human leucocyte antigen (HLA) antibodies. AR was accompanied by intragraft CD20⁺ B cells, as well as elevated CD20 (MS4A1) and CD19 gene expression compared to controls. B cell infiltrates were proportional to T cells, and accompanied by the chemokine pair C-X-C motif chemokine ligand 13 (CXCL13)–C-X-C motif chemokine receptor 5 (CXCR5) and B cell activating factor (BAFF). Peripheral blood memory B cells were decreased and naive B cells increased at AR, in contrast to controls. While 22% of patients with AR and 5% of controls showed de-novo donor-specific antibodies (DSA), all biopsies were C4d-negative. These results suggest a role for B cells in AR by infiltrating the graft alongside T cells. We hypothesize that the shift in peripheral blood B cell composition is related to the graft infiltration at time of AR.     

人外周血初始B细胞和记忆性B细胞亚群的特征和功能

B淋巴细胞是免疫系统的重要免疫成份，主要功能是介导体液免疫应答。在人外周血中，按照B淋巴细胞的发育阶段及功能的不同，可将B淋巴细胞分为初始成熟B细胞、记忆B细胞和浆细胞。记忆B细胞又可分为IgM记忆B细胞和类型转换的记忆B细胞。近年来的研究表明，B淋巴细胞的亚群远比人想象中的复杂，因此对人B细胞各亚群的起源、发育和功能进行更深入的研究，将有助于治疗自身免疫性疾病，在慢性感染性疾病的治疗过程中找到新的策略，并指导研发安全有效的疫苗。     

Polyreactive antigen-binding B cells in the peripheral circulation are IgD+ and B7−

Polyreactive antibodies are naturally occurring antibodies, primarily of the IgM isotype, that are capable of reacting with a wide variety of different self and non-self antigens. Previously, we reported that a B cell capable of making polyreactive antibody has Ig receptors on its surface that can bind different antigens. The present investigation was initiated to characterize these polyreactive antigen-binding B cells further. A panel of fluorescein isothiocyanate-labeled antigens (insulin, IgG Fc fragment or β-galactosidase) served as probes to select polyreactive antigen-binding B cells by cell sorting. Our experiment revealed that these polyreactive antigen-binding B cells were mainly of the IgD isotype. They expressed high levels of CD40 and major histocompatibility complex class II molecules, but little or no B7-1, B7-2, or Fas. In contrast to the binding of antigens to monoreactive receptors (usually high affinity), the binding of antigens to polyreactive receptors (usually moderate or low affinity) did not up-regulate the expression of B7-1 or B7-2. Antigens that bound to polyreactive receptors, however, were internalized and degraded, although not as efficiently as antigens that bound to monoreactive receptors. Despite the ability of these B7⁻ cells to process antigens, they were not able to activate T cells in a mixed leukocyte reaction. It is concluded that polyreactive antigen-binding B cells have properties that are consistent with the ability to induce immunological tolerance.     

Feedback Inhibition of B Cell Differentiation by Monomeric Immunoglobulin

Polyspecific monomeric immunoglobulin (Ig) isolated from either a commercial source (pooled, > 2000 donors), or an autologous donor was capable of inhibiting both B cell proliferation, induced by T dependent mitogens or T cell factors and B cell differentiation, induced by similar stimuli. These effects appear to be directed at the B cell itself since inhibition of differentiation is detectable when monomeric Ig is added to cultures of B cell lines in the presence of B cell differentiation factor (BCDF). The inhibition of B cell differentiation does not appear to relate to inhibition of B cell proliferation, as no detectable change is seen in thymidine incorporation or cell number in these cultures. Furthermore, the effect of monomeric Ig appears to relate to an early event in B cell differentiation, as there is no effect of IgSRK on spontaneously secreting B cell lines and maturation to cytoplasmic Ig containing cells is markedly impaired. Therefore, monomeric Ig secreted by B cells may serve as an immunoregulator of further Ig secretion.     

Alterations in peripheral B cells and B cell progenitors following androgen ablation in mice

The production of B lymphocytes is regulated in part by physiologic levels of androgens and estrogens. While these sex hormones down-regulate B lymphopoiesis, augmentation of B lymphopoiesis occurs under conditions where androgen or estrogen levels are decreased. In this study we examine the effect of androgen ablation of male mice on B lymphopoiesis and on the phenotypic composition of peripheral B lymphocyte populations. Spleen and thymic weights are significantly increased following castration, as is the total number of peripheral blood lymphocytes. However, the absolute numbers of B cells in the periphery are selectively increased following castration; the numbers of T cells, NK cells and granulocytes remain unchanged. The increase in circulating B cells is due largely to increases in the numbers of recent bone marrow emigrants expressing a B220(lo+)CD24(hi+) phenotype and these cells remain significantly elevated in castrated mice for up to 54 days post-castration. Similar increases in the percentages of newly emigrated B cells are observed in mice that lack a functional androgen receptor (TFM:). Finally, assessments of B cell progenitors in the bone marrow revealed significant increases in the relative numbers of IL-7-responsive B cell progenitors, including cells in Hardy fractions B (early pro-B cells), C (late pro-B cells), D (pre-B cells) and E (immature B cells). These findings demonstrate that androgen ablation following castration significantly and selectively alters the composition of peripheral B cells in mice. Further, these alterations result from the potentiating effects of androgen ablation on IL-7-responsive pro-B cell progenitors.     

Naive B Cells with High-Avidity Germline-Encoded Antigen Receptors Produce Persistent IgM+ and Transient IgG+ Memory B Cells

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Estimation of the B lymphocyte precursor frequencies to herpes simplex type 1 glycoproteins by a limiting dilution assay

The precursor frequency of B lymphocytes from Balb/c mice producing HSV-1 glycoprotein B (gB), glycoprotein C (gC), and glycoprotein D (gD) antibody was determined by limiting dilution analysis under conditions to detect antibody from the clonal progeny of a single B cell precursor. In spleens of naive mice the average gC frequency was 1/48,917 +/- 5,550, while gD was 1/73,330 +/- 15,898, and gB frequency was in excess of 1/100,000. Immunization with live HSV-1 (KOS) increased the B cell frequencies of all three glycoproteins to approximately 1:3,000; however, the serum gB antibody ELISA titer was fivefold higher than gC or gD.     

Selection of stereotyped VH81X-{micro}H chains via pre-B cell receptor early in ontogeny and their conservation in adults by marginal zone B cells

The pre-B cell receptor (preBCR) plays critical roles in early B cell differentiation. It has been shown that not all muH chains are capable of pairing with surrogate light (SL) chains to form preBCR. Here, we established a novel system to differentially identify two types of early pre-B cell populations in bone marrow and fetal liver of mice, one producing SL-pairing muH chains and the other producing SL-non-pairing muH chains. The former population accounted for 80% of all the early pre-B cells in adult bone marrow, while it accounted for only 20% of those in fetal liver. Comparison of the two types of pre-B cell populations in fetal liver revealed the structural difference between SL-pairing and -non-pairing muH chains encoded by the V(H)81X segment that was most frequently utilized in fetal liver pre-B cells but rarely expressed by B cells generated in adults. PreBCR played an important role in the positive selection of V(H)81X-muH chains carrying the characteristic sequences of the complementarity-determining region 3 with little or no nibbling or N nucleotide addition, leading to their predominance in neonatal splenic B cells. These fetal-type V(H)81X-muH chains were also detected in adult spleen, but almost exclusively in marginal zone (MZ) B cells in contrast to the adult-type V(H)81X-muH chains. This strongly suggests that neonatally generated and selected B cells expressing the stereotyped V(H)81X-muH chains are maintained in the adult MZ and could function as innate-like lymphocytes.