B7-1抗体阻断B7/CD28信号通路对Pristane肾病的治疗作用

目的:探讨B7-1抗体阻断B7-1/CD28信号通路对小鼠Pristane肾病的治疗作用。方法:将8周龄雌性C57BL/J6小鼠随机分为3组,正常对照组予生理盐水0.5ml/只,造模组与治疗组予Pristane0.5ml/只后,分别予鼠同型IgG抗体(造模组)或鼠抗人B7-1抗体(治疗组)200μg/只,第10天分别检测局部淋巴结和脾脏中吞噬细胞、树突状细胞的活化及脾脏B细胞表面活化分子的变化;每月定期检测血清中抗核抗体(ANA)及尿蛋白,七个月后处死动物HE染色观测肾脏病理变化和冰冻切片直接免疫荧光法观察免疫复合物(IC)的沉积情况。结果:第10天,相对于正常对照组、治疗组和造模组小鼠局部淋巴结和脾脏中吞噬细胞、树突状细胞均有不同程度的活化,治疗组活化程度明显低于造模组(P0.05),脾脏B细胞表面CD21、CD40、CD86等分子上调程度低于造模组(P0.05);4个月后治疗组和造模组小鼠血清均检测到ANA,但治疗组的血清抗体滴度较造模组低(P0.05);治疗组7个月后,尿蛋白含量低于造模组,肾脏HE结果显示治疗组小鼠肾脏病理改变轻于造模组,直接免疫荧光检测可见治疗组免疫复合物荧光强度弱于造模组,正常对照组小鼠肾脏没有明显的病理改变。结论:鼠抗人B7-1抗体对Pristane肾病具有一定的治疗效果。     

Interleukin-1-like activity produced by hybrids constructed with Epstein-Barr-virus-transformed human B lymphocytes and mouse myeloma cells

Peripheral blood B lymphocytes from a donor with positive tuberculin skin test reaction were transformed into lymphoblastoid cell lines by Epstein-Barr virus and then fused by polyethylene glycol with mouse myeloma cells. Human-mouse hybrid cells producing human IgM monoclonal antibody to purified protein derivative of tuberculin were isolated, and the concentrated supernatant of one of these cell hybrids was tested for the capacity of interfering with DNA synthesis of human and mouse lymphocytes. The hybrid cell supernatant was found to contain soluble factors that increased DNA synthesis in unstimulated human and mouse lymphocytes and that, conversely, decreased DNA synthesis in concanavalin-A-stimulated cells. Gel filtration experiments showed that these antagonistic activities were due to at least two different factors, one of which resembled human interleukin-1 in biochemical and biological properties.     

Human monoclonal antibody to purified protein derivative of tuberculin produced by hybrids constructed with Epstein-Barr virus-transformed B lymphocytes and mouse myeloma cells

A method of producing human monoclonal antibody by combining somatic cell hybridization technology with the capability of Epstein-Barr virus (EBV) to transform human B lymphocytes is described. Peripheral blood lymphocytes from a donor with positive tuberculin skin test reaction were transformed by EBV and then tested for antibody production to mycobacterial purified protein derivative (PPD) by an enzyme-linked immunosorbent assay. Two EBV-transformed lymphoblastoid cell lines making IgM antibodies to PPD were obtained. One of these cell lines was fused by polyethylene glycol with a murine hypoxanthine-guanine phosphoribosyl transferase-deficient myeloma cell line that had been selected for resistance to ouabain. The human-mouse hybrids were selected in ouabain-containing HAT medium and 11 heterohybridomas producing IgM antibody to PPD were obtained. one of these was cloned by limiting dilution with efficiency at least 20-fold higher than parent EBV-transformed cell line. Heterohybridoma subclones reached levels of IgM antibody as high as 75.0 μg/ml of culture medium, whereas IgM production of EBV-transformed B cell clones ranged between 3.0 and 4.0 μg/ml.     

Identical forms of the CD2 antigen expressed by mouse T and B lymphocytes

A monoclonal antibody (12-15) reactive with the mouse CD2 was used to study the expression of the antigen in different lymphoid cell subsets. By two-color immunofluorescence using B or T cell-specific reagents and cell sorting in combination with biochemical analysis we provide evidence that the CD2 antigen is present on mouse B and T cells. The antigen is expressed by both subsets at similar density and appears to be biochemically indistinguishable.     

Activation of human B lymphocytes through CD40 and interleukin 4

We have produced and characterized a new CD40 monoclonal antibody, mAb 89, which in the presence of anti-IgM antibodies co-stimulates to induce B cell proliferation. mAb 89 activates resting B cells as shown by an increase in cell volume and an enhanced subsequent proliferation of B cells in response to anti-IgM antibody. However, mAb 89 does not prepare B cells to respond to the growth-promoting activity of interleukin (IL) 2 or IL 4. Unlike IL 2 and IL 4, mAb 89 only weakly stimulates the proliferation of anti-IgM pre-activated B cells. Thus, the activating properties of anti-CD40 are likely to explain its co-stimulatory effect on B cells. Interestingly, the anti-CD40 mAb 89 was found to act in synergy with IL 4, but not with IL 2, in co-stimulation and restimulation assays. In this respect, anti-CD40 does not induce a significant increase of B cell surface IL 4 receptors while IL 4, but not IL 2, induces a twofold increase of the CD40 antigen expression. Thus the synergistic interaction between IL 4 and anti-CD40 may be related to the IL 4-dependent increase of CD40 antigen expression.     

CD47 deficiency ameliorates autoimmune nephritis in Faslpr mice by suppressing IgG autoantibody production

CD47, a self‐recognition marker, plays an important role in both innate and adaptive immune responses. To explore the potential role of CD47 in activation of autoreactive T and B cells and the production of autoantibodies in autoimmune disease, especially systemic lupus erythematosus (SLE), we have generated CD47 knockout Fas^lpr (CD47^?/??Fas^lpr) mice and examined histopathological changes in the kidneys, cumulative survival rates, proteinuria, extent of splenomegaly and autoantibodies, serum chemistry and immunological parameters. In comparison with Fas^lpr mice, CD47^?/??Fas^lpr mice exhibit a prolonged lifespan and delayed autoimmune nephritis, including glomerular cell proliferation, basement membrane thickening, acute tubular atrophy and vacuolization. CD47^?/??Fas^lpr mice have lower levels of proteinuria, associated with reduced deposition of complement C3 and C1q, and IgG but not IgM in the glomeruli, compared to age‐matched Fas^lpr mice. Serum levels of antinuclear antibodies and anti‐double‐stranded DNA antibodies are significantly lower in CD47^?/??Fas^lpr than in Fas^lpr mice. CD47^?/?–Fas^lpr mice also display less pronounced splenomegaly than Fas^lpr mice. The mechanistic studies further suggest that CD47 deficiency impairs the antigenic challenge‐induced production of IgG but not IgM, and that this effect is associated with reduction of T follicular cells and impairment of germinal centre development in lymphoid tissues. In conclusion, our results demonstrate that CD47 deficiency ameliorates lupus nephritis in Fas^lpr mice via suppression of IgG autoantibody production. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Expression of CD6 and the UCHL1-defined CD45 (p180) antigen by human colonic T lymphocytes

Cryostat sections of histologically normal human colon were studied by double-label immunofluorescence techniques using a panel of monoclonal antibodies to T-lineage antigens and activation markers, with particular reference to the CD6 antigen. In the lamina propria, the majority population of T cells was of the CD3+, CD6+, CD4+ subset, of which virtually all were of the UCHL1+, CD45R-, Leu 8- phenotype of antigen-committed helper T cells. This majority lamina propria population did not express markers associated with blastogenesis (CD7), activation (MHC class II, CD25, CD38) or proliferation (OKT9, Ki67). In both intra-epithelial and lamina propria compartments, a subpopulation of CD3+ T cells was identified which did not express either the CD6 or CD5 peripheral 'pan T' markers. Most of the CD3+, CD6- cells were of the CD8+ (cytotoxic-suppressor) subset which co-expressed the CD7 antigen with a much higher frequency than did the CD6+ subpopulation. Expression of CD25, CD38 and HLA-D antigens, although infrequent, was confined to this CD8+, CD5-, CD6- population. Our data thus imply that the colonic mucosa is largely populated by mature, antigen-committed resting T cells of the helper-inducer phenotype.     

Monoclonal antibody to MALA-2 (ICAM-1) reduces acute autoimmune nephritis in kdkd mice.

Hereditary tubulointerstitial nephritis is a prominent cause of renal failure in humans. A variety of animal models utilizing immunologically induced nephritis have been developed. The kdkd congenic variant of the CBA/Ca mouse has normal kidneys at birth but develops progressive, lethal autoimmune nephritis beginning at approximately Week 8. The destruction of renal tubular epithelium in mediated by a population of antigen-specific, H-2Kk-restricted, Lyt-2+, L3T4- T cells. The present experiments demonstrate that systemic treatment with anti-ICAM-1 monoclonal antibody reduces kidney disease in kdkd mice. Anti-ICAM-1 mab localizes to inflammatory sites in the kidney and effects a significant reduction in leukocyte infiltration. Concomitantly, urine protein levels of anti-ICAM-1-treated mice are significantly reduced. The use of anti-adhesion molecule monoclonal antibodies that alter leukocyte activity and/or trafficking may be useful therapies for certain autoimmune disorders.     

Triggering of B lymphocytes through CD23: epitope mapping and studies using antibody derivatives indicate an allosteric mechanism of signalling.

By using five monoclonal antibodies in reciprocal cross-locking studies, a minimum of three epitope clusters have been defined for the B-cell restricted, activation-associated CD23 antigen. Two of the five antibodies were capable of replacing low molecular weight B-cell growth factor (BCGF) in B-cell co-stimulation assays. These two antibodies belonged to the same epitope group, while non-stimulatory antibodies fell outside this cluster. By prior coating of activated B lymphocytes at 4 degrees, all five CD23 antibodies interfered with the subsequent uptake of BCGF activity onto the cells. However, only the two stimulatory antibodies were capable of inhibiting the absorption of BCGF completely. From one of these antibodies, F(ab')2 and Fab fragments were generated and both were found to be equivalent to whole antibody in their ability to mimic BCGF. Immobilized antibody, however, failed to stimulate over a wide range of concentrations. These findings demonstrate that the ability of certain CD23 antibodies to deliver a growth-promoting signal to activated B cells is independent not only of the Fc portion of the molecule but also of receptor cross-linking. The latter observation is indicative of an allosteric mechanism of triggering, a notion supported by the epitope specificity of activation through CD23. The findings are discussed in relation to the putative natural ligands for CD23 and the way they may influence B-cell function through this receptor.     

抗CD71人-鼠嵌合抗体对活化淋巴细胞的效应

目的　通过体外实验探讨抗CD71人 鼠嵌合抗体对活化淋巴细胞效应的影响 ,并与其鼠源性单克隆抗体进行比较。方法　以丝裂原诱导的人外周血单个核细胞 (PBMC)为靶细胞 ,测定嵌合抗体和鼠源性单抗对其增殖抑制率 ;在新鲜补体存在下 ,测定补体依赖性嵌合抗体介导的细胞毒效应(CDC)。以EBV转化的B细胞为刺激细胞 ,测定两种抗体对其诱导的同种异体PBMC的增殖抑制率 ;以同种异体的PBMC为刺激细胞 ,测定两种抗体在单向、双向混合淋巴细胞培养 (MLC)中的增殖抑制率。结果　嵌合抗体和鼠源性单抗均可明显抑制丝裂原诱导的PBMC的增殖反应 ,且二者抑制率差异无显著性(P >0 .0 5 ) ,其抑制作用随抗体浓度增加而增强 ,PBMC和丝裂原共同孵育 12h后加入抗体的增殖抑制效应最明显 ;在新鲜补体存在下 ,嵌合抗体对丝裂原诱导增殖的PBMC具有CDC作用 ,而鼠源性单抗CDC作用较弱 ;两种抗体对混合淋巴细胞培养反应有明显的抑制作用 ,且嵌合抗体组抑制率明显高于鼠源性单抗组 (P <0 .0 5 )。结论　抗CD71人 鼠嵌合抗体在体外实验中可抑制淋巴细胞的活化及其效应 ,其作用明显强于抗CD71鼠源性单克隆抗体。     

CD19 regulates Src family protein tyrosine kinase activation in B lymphocytes through processive amplification

CD19 regulates constitutive and antigen receptor-induced signaling thresholds in B lymphocytes through its unique cytoplasmic domain. Herein, we demonstrate a novel molecular mechanism where interactions between CD19 and Lyn amplify basal and antigen receptor-induced Src family kinase activation. Lyn expression was required for CD19 tyrosine phosphorylation in primary B cells. Experiments with purified proteins demonstrated that CD19-Y513 was Lyn's initial phosphorylation and binding site. This led to processive phosphorylation of CD19-Y482, which recruited a second Lyn molecule, allowing for transphosphorylation and amplification of Lyn activation. In vivo, CD19 deficiency impaired, and CD19 overexpression enhanced, Lyn kinase activity. Thus, CD19 functions as a specialized adapter protein for the amplification of Src family kinases that is crucial for intrinsic and antigen receptor-induced signal transduction.     

Surface immunoglobulin ligands and cytokines differentially affect proliferation and antibody production by human CD5+ and CD5- B lymphocytes.

Normal human peripheral blood B lymphocytes were separated into CD19+ CD5+ and CD19+ CD5- subsets by dual-color FACS sorting. In most experiments the cells were activated with Staphylococcus aureus Cowan I (SAC) and cultured in the absence or presence of recombinant human IL-1 alpha, IL-2, or IL-6, or combinations of these cytokines. Unstimulated CD5+ and CD5- B cells showed a comparable, low level of incorporation of [3H]thymidine into DNA. SAC stimulated proliferation of CD5+ and CD5- B cells, and this proliferation was augmented by IL-2 in the case of CD5- B cells. Anti-mu beads stimulated some proliferation of the CD5- subset and augmented SAC-induced proliferation of these cells. In contrast, anti-mu beads did not stimulate proliferation of the CD5+ subset and had no effect on SAC-induced proliferation of these cells. CD5+ B cells activated by anti-mu beads were stimulated to proliferate in the presence of IL-4, but not in the presence of IL-2. These observations support the interpretation that two signals are required for proliferation of CD5+ B cells. Using a two-step culture system, SAC activation itself did not induce Ig production by either subset of purified B cells. However, it primed the cells for antibody production in the presence of IL-2. IL-1 and IL-6 by themselves augmented antibody formation by these cells slightly, if at all. However, IL-6, and to a lesser extent IL-1, augmented antibody production in the presence of IL-2. Under the culture conditions used CD5- B cells produced IgM, IgG, and IgA whereas the CD5+ B cells produced almost exclusively IgM. The expression on B cells of surface activation markers was analyzed after culture for 2 days with SAC or anti-mu beads. In both subsets expression of Leu-23 and Leu-21 was increased, with some differences in intensity (Leu-23 greater in CD5+ cells, Leu-21 greater in CD5- cells). SAC increased IL-2R expression to a greater extent than anti-mu beads. In neither subset was expression of CD23 increased. These observations are discussed in the context of the possible role of the CD5+ subset of B lymphocytes as components of a system of natural immunity.     

Development of lupus-like autoimmune diseases by disruption of the PD-1 gene encoding an ITIM motif-carrying immunoreceptor.

PD-1, a 55 kDa transmembrane protein containing an immunoreceptor tyrosine-based inhibitory motif, is induced in lymphocytes and monocytic cells following activation. Aged C57BL/6(B6)-PD-1(-/-) congenic mice spontaneously developed characteristic lupus-like proliferative arthritis and glomerulonephritis with predominant IgG3 deposition, which were markedly accelerated by introduction of a Fas mutation (lpr). Introduction of a PD-1 null mutation into the 2C-TCR (anti-H-2Ld) transgenic mice of the H-2(b/d) background resulted in the chronic and systemic graft-versus-host-like disease. Furthermore, CD8+ 2C-TCR+ PD-1(-/-) T cells exhibited markedly augmented proliferation in vitro in response to H-2d allogenic cells. Collectively, it is suggested that PD-1 is involved in the maintenance of peripheral self-tolerance by serving as a negative regulator of immune responses.     

肿瘤浸润B淋巴细胞产生的IgG对肺癌生长的抑制作用

机体的免疫功能与肺肿瘤的发生发展有着密切的关系.机体通过细胞免疫和体液免疫两方面发挥抗肿瘤的作用.目前多数学者认为,在抗肿瘤免疫中,T细胞介导的细胞免疫占主导地位.但在临床上却经常可以观察到在肺癌组织中有B淋巴细胞浸润.国外学者研究发现,肿瘤浸润B淋巴细胞(TIB)可以产生一种IgG,可以识别肺癌组织中的某种抗原,使其对肺癌的生长起到一定的抑制作用.     

Feedback regulation of antibody formation by suppressive B cell factor: preferential suppression of high-affinity antibody production by memory B lymphocytes

Cloned TS4.44 cells, which were hybridized HAT-sensitive 3T3-4E cells with B cells stimulated by immune complexes produce a lymphokine, biochemical and biological characteristics of which are identical with those of conventional suppressive B cell factor (SBF) synthesized by Fc receptor bearing B cells stimulated with immune complexes. This factor is known to suppress B cell responses to antigen/mitogen. The present studies were carried out by using this hybridoma-derived SBF to characterize the large proportion of B cells sensitive to SBF and the small proportion of B cells resistant to it in terms of affinities of antibodies which these cells are able to produce. The treatment of normal spleen cells with SBF resulted in a 50-70% decrease in anti-dinitrophenyl (DNP) antibody production when the cells were transferred into X-ray-irradiated mice along with alum-precipitated dinitrophenyl-conjugated keyhole limpet hemocyanin (DNP-KLH). The affinity of anti-DNP antibody molecules produced in these mice was significantly lower than that of the controls, even if immunization was repeated. The target cells for SBF were B, and not helper T cells which might be involved in the process of affinity maturation. A single treatment of spleen cells in vitro with SBF was sufficient to abrogate the precursors committed to mediate high-affinity anti-DNP antibody responses, since the retreatment with SBF in vitro and transfer into the second irradiated recipients along with antigens of spleen cells of mice to which SBF-treated spleen cells were transferred 3 weeks before resulted in almost the same level of plaque-forming-cell-responses as in mice which received medium-treated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cooperation by mouse T lymphocytes: the role of antibody in T cell specificity

Mouse thymus cells were educated in vivo with horse red blood cells (RBC) and tested for their ability to cooperate in the response of bone marrow cells to sheep RBC. Significant cooperation was observed only when anti-sheep serum was injected into the educating mouse. We suggest that cooperation and some other properties of the T cell are mediated by passively acquired antibody.     

Features of peripheral CD8+CD57+ lymphocytes in patients with autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AIHA) is an acquired condition characterized by the presence of autoantibodies recognizing erythrocyte-related antigens. Several components of the immune system are involved in disease pathogenesis. Among them, as for other autoimmune disorders, a role for specific CD8⁺CD57⁺ regulatory cells subset could be hypothesized. We evaluated this lymphocyte subset by flow cytometry in 18 AIHA patients randomly selected in a retrospective population of 29 cases. Secondary forms were observed in 65.5% of cases, whereas frequencies of warm, cold, mixed, and atypical forms were similar. Cold agglutinins and cryoglobulins tested positive in 44.8% and 10.3% of cases, respectively. These patients exhibited a higher frequency of peripheral vascular symptoms (odds ratio?=?8.2, p?=?.04) and complement consumption (odds ratio?=?7.2, p?=?.02). Frequency of CD8⁺CD57⁺ cells resulted significantly higher in AIHA patients than in control group (17.0?±?15.8% vs 8.2?±?5.0%, p?=?.04). Regardless of therapeutic schedule, patients with partial or no response to therapy (8/18) showed higher frequencies of CD8⁺CD57⁺ cells as compared with controls (23.6?±?21.3% vs 8.9?±?4.9%, p?=?.01), whereas 10/18 complete responders (CR) showed lower levels of CD8⁺CD57⁺ cells (11.7?±?6.9%, p?=?.11). CR and controls showed similar values (p?=?.24). This study suggests that monitoring this lymphocyte subset before and after treatment administration might have a prognostic value. Moreover, CD8⁺CD57⁺ cells may represent a possible therapeutic target to restore the normal balance between lymphocyte populations.     

The CD19/CD81 complex physically interacts with CD38 but is not required to induce proliferation in mouse B lymphocytes

In B lymphocytes, the cell surface receptor CD38 is involved in apoptosis of immature B cells, proliferation and differentiation of mature B cells. Although CD38 has been establish as a receptor, its signaling has been only partially characterized. As a result of the lack of signaling motifs in the cytoplasmic domain, CD38 must use a co-receptor to induce signaling within the cell. Accordingly, CD38 has been associated with different receptors such as the T-cell receptor/CD3 complex on T cells, CD16 on natural killer cells and MHC class II molecules on monocytes. The CD19/CD81 complex has been proposed as a co-receptor for CD38 in human B lymphocytes, but little or no characterization has been performed in mice. In this study the contribution of the CD19/CD81 complex in murine CD38 signaling was evaluated. Proliferation assays were performed using CD19(-/-) or CD81(-/-) deficient mice; CFSE-labeled B lymphocytes from wild-type mice and CD19(-/-) , CD81(-/-) and CD38(-/-) deficient mice were stimulated with agonistic antibodies against CD38. Immunoprecipitation and immunofluorescence were also performed to detect protein-protein interactions. Our results indicate that the CD19/CD81 complex interacts with CD38 but this interaction is not required to induce proliferation in mouse B lymphocytes, suggesting that other receptors may contribute to the proliferation induced by CD38 in B lymphocytes.