肾综合征出血热病毒(HFRSV)抗独特型抗体免疫调节初探

本文应用一株HFRSV抗独特型抗体(Ab_2)观察其对HFRSV感染BALB/c小鼠脾细胞体外增殖的影响,以及部分淋巴因子在其中的作用,旨在探讨抗独特型抗体对免疫应答的调节机理。从感染HFRSV小鼠脾细胞中分离制备单个核细胞悬液体外培养,加入不同剂量Ab_2,用~3H-TdR掺入法测定脾细胞增殖水平。结果Ab_2可明显抑制感染小鼠脾细胞在体外的增殖,并呈剂量依赖关系及具有独特型特异性。早期加入EL-4细胞上清或rHuIL-2可完全逆转此抑制作用,且具有剂量依赖和时间相关性。EL-4细胞上清含有IL-2和IL-6。对抗独特型抗体产生抑制作用的机制进行了讨论。     

裸鼠与正常鼠杂交子一代的免疫功能研究

将BALB/cAnN-nu裸鼠与BALB/cAnN正常鼠杂交的子一代(F_1)与其亲代进行免疫功能比较,单向与双向混合淋巴细胞反应(MLR)。结果表明,F_1与亲代裸鼠在遗传关系上更接近。淋巴细胞转化试验表明F_1由裸鼠遗传获得对ConA诱导T细胞亚群转化活性低、B细胞功能活性高、以及对异种C57BL/6J小鼠MLR反应性低等性状。F_1具有部分细胞免疫功能较亲代裸鼠高而低于亲代BALB/c小鼠的特性,可考虑供细胞免疫功能低下的试验小鼠模型之用。     

Selective Usage of VH Genes in Adult Human B Lymphocyte Repertoires

The authors have compared the VH gene utilization patterns among small resting immunocompetent B cells and large naturally activated B lymphocytes of healthy human adults. They employed a non-radioactive RNA in situ hybridization technique that allows detection of VH gene family expression at the single cell level. Pokeweed mitogen stimulated and unmanipulated mononuclear cells from peripheral blood and spleen of unrelated individuals were hybridized to digoxigenin-labelled antisense RNA probes specific for human VH families 1–6 and for the constant region genes Cμ and Cγ. The observed VH gene family utilization patterns did not correlate with the genomic complexity of human VH genes. The VH3 gene family was most frequently used among resting B cells in both peripheral blood and spleen. Among naturally activated lymphocytes the VH6 gene was markedly over-represented, while expression of the VH1 and VH3 gene families was decreased. The data show that V-region mediated selection participates in shaping the peripheral antibody repertoire in healthy adults.     

Induction of Arthritis in BALB/c Mice by Cartilage Link Protein : Involvement of Distinct Regions Recognized by T and B Lymphocytes

Both type II collagen and the proteoglycan aggrecan are capable of inducing an erosive inflammatory polyarthritis in mice. In this study we provide the first demonstration that link protein (LP), purified from bovine cartilage, can produce a persistent, erosive, inflammatory polyarthritis when injected repeatedly intraperitoneally into BALB/c mice. We discovered a single T-cell epitope, located within residues 266 to 290 of bovine LP (NDGAQIAKVGQIFAAWKLLGYDRCD), which is recognized by bovine LP-specific T lymphocytes. We also identified three immunogenic regions in bovine LP that contain epitopes recognized by antibodies in hyperimmunized sera. One of these B-cell regions is found in the most species-variable domain of LP (residues 1 to 36), whereas the other epitopes are located in the most conserved regions (residues 186 to 230 and 286 to 310). The latter two regions contain an AGWLSDGSVQYP motif shared by the G1 globulin domain of aggrecan core protein, versican, neurocan, glial hyaluronan-binding protein, and the hyaluronan receptor CD44. Our data reveal that the induction of arthritis is associated with antibody reactivities to B-cell epitopes located at residues 1 to 19. Together, these observations show that another cartilage protein, LP, like type II collagen and the proteoglycan aggrecan, is capable of inducing an erosive inflammatory arthritis in mice and that the immunity to LP involves recognition of both T- and B-cell epitopes. This immunity may be of importance in the pathogenesis of inflammatory joint diseases, such as juvenile rheumatoid arthritis, in which cellular immunity to LP has been demonstrated.     

Molecular Analyses of Anti-DNA Antibodies Induced by Polyomavirus BK in BALB/c Mice

In the present experiments, two groups of BALB/c mice (five individuals in each group) were hyperimmunized through four consecutive immunizations with either BK virus (Group 1) or BK dsDNA complexed with methylated BSA (Group 2). All immune sera taken after the fourth immunization from both groups reacted strongly with polyomavirus BK dsDNA as well as with calf thymus dsDNA, and all sera contained antibodies that bound in the Crithidia luciliae assay. This indicates that polyomavirus BK was able to induce antibodies with binding characteristics similar to SLE anti-DNA antibodies. To further characterize these induced anti-DNA responses, 10 monoclonal anti-DNA antibodies (four from Group 1, and six from Group 2) were generated and selected for reactivity with Sl-nuclease digested CT dsDNA. Their specificity for BK and CT dsDNA molecules, as well as their light and heavy chain variable region cDNA nucleotide sequences were analysed to compare them with known SLE derived anti-DNA antibodies. All of the 10 antibodies bound strongly to BK dsDNA, while seven also bound to CT dsDNA in competitive ELISA experiments. V-region analysis revealed that the induced antibodies resembled anti-DNA antibodies characteristic for murine SLE, and all but one contained arginine in the V_H CDR3 region. The arginines present in the monoclonal antibodies originated either from an RF shift from RF1RF3 of the D-genes or from N-sequence additions. Taken together, the data demonstrate that anti-DNA antibodies in response to hyperimmun-ization with polyomavirus BK have the same characteristics as of those occuring spontaneously in SLE. As virus infection/replication in vivo implies expression of immunogenic (non-self) DNA-binding proteins that may render DNA immunogenic, the present results may therefore suggest one physiological mechanism for production of SLE-related anti-DNA antibodies.     

The Pathogenesis of Leishmania aethiopica Infection in BALB/c Mice

A mouse model for L. aethiopica infection is described. BALB/c mice were unable to clear an infection with 1 x 10(7) promastigotes injected into the hind footpad. However, there was no ulceration of the lesion and no development of overt clinical symptoms after 203 days of infection. Spread of viable organisms was evident in the draining lymph node but not in the spleen or liver. The control of the infection was associated with the development of classical delayed hypersensitivity responses to phenolized promastigotes and appeared as a localized granulomtaous infiltration. The infiltration had features of classical tuberculoid granulomas, but superimposed on it was a strong eosinophilic infiltration. The relevance of such cells though unclear is discussed.     

观察链脲佐菌素诱导的BALB/c糖尿病小鼠睾丸微循环损害

目的:观察链脲佐菌素(STZ)诱导的BALB/c糖尿病小鼠睾丸微循环变化。方法:20只BALB/c小鼠,采用完全随机法分为糖尿病组和对照组,每组10只。糖尿病组小鼠连续5天腹腔注射40mg/kg STZ诱导糖尿病模型,对照组注射柠檬酸缓冲液。一周后,应用激光多普勒成像系统(Moor LDLS)检测两组小鼠下腹-外阴部皮肤微循环血流灌注水平;分离腹膜,暴露睾丸,应用激光多普勒血流灌注检测系统(Moor VMS-LDF)检测两组小鼠睾丸微循环血流量及睾丸微血管自律运动。心脏灌流后取两组小鼠睾丸制作组织切片,HE染色观察睾丸微血管形态,免疫组织化学染色两步法观察睾丸微血管内皮细胞抗血小板内皮细胞黏附分子-1(PECAM-1)表达水平。结果:糖尿病组小鼠下腹-外阴部皮肤总血流灌注量低于对照组(P0.01);睾丸平均血流灌注水平和微血管自律运动频率和振幅均显著低于对照组(P0.01);糖尿病组小鼠生精上皮受损,成熟生精细胞减少;睾丸间质微血管增多。睾丸间质微血管内皮细胞PECAM-1表达水平低于对照组(P0.01)。结论:STZ诱导的BALB/c糖尿病小鼠睾丸微循环存在较多损害。     

Antibody Production,Anaphylactic Signs,and T-Cell Responses Induced by Oral Sensitization With Ovalbumin in BALB/c and C3H/HeOuJ Mice

PurposeTwo mouse strains, BALB/c and C3H/HeOuJ, broadly used in the field of food allergy, were compared for the evaluation of the allergenic potential of ovalbumin (OVA).MethodsSensitization was made by administering 2 different OVA doses (1 and 5 mg), with cholera toxin as Th2-polarizing adjuvant. Antibody levels, severity of anaphylaxis, and Th1 and Th2 responses induced by the allergen were assessed. In addition, because the mice selected had functional toll-like receptor 4, the influence of contamination with lipopolysaccharide (LPS) on the immunostimulating capacity of OVA on spleen cells was also evaluated.ResultsBoth strains exhibited similar susceptibility to OVA sensitization. The 2 protein doses generated similar OVA-specific IgE and IgG1 levels in both strains, whereas C3H/HeOuJ mice produced significantly more IgG2a. Oral challenge provoked more severe manifestations in C3H/HeOuJ mice as indicated by the drop in body temperature and the severity of the anaphylactic scores. Stimulation of splenocytes with OVA led to significantly higher levels of Th2 and Th1 cytokines in BALB/c, and these were less affected by protein contamination with LPS.ConclusionsThe antibody and cytokine levels induced by OVA in BALB/c mice and the observation that BALB/c spleen cell cultures were more resistant than those of C3H/HeOuJ mice to the stimulus of LPS make this strain prone to exhibit Th2-mediated food allergic reactions and very adequate for the study of the features of OVA that make it allergenic.     

Inhibition of B Lymphocyte Activation by Interaction with Fc Receptors

Much early work indicated that specific antibody can play an inhibitory role in the immune response. This inhibitory activity was found to be dependent on an intact Fc portion of the antibody used, both in vivo and in vitro. Thus a role for lymphocyte Fc receptors in regulation of the immune response was suggested. However, soluble antigen-antibody complexes, which bind to Fc receptors, do not appear to inhibit B cell activation. Recent experiments have demonstrated that antigen-antibody complexes immobilized on a surface strikingly inhibit LPS induced B cell mitogenesis and polyclonal antibody synthesis. Mechanisms for Fc receptor-mediated inhibition of B cell activation have been considered, and a model proposed to explain many of these findings as well as allow for antigen specific inhibition.     

Inhibition of B Lymphocyte Activation by Interaction with Fc Receptors

Much early work indicated that specific antibody can play an inhibitory role in the immune response. This inhibitory activity was found to be dependent on an intact Fc portion of the antibody used, both in vivo and in vitro. Thus a role for lymphocyte Fc receptors in regulation of the immune response was suggested. However, soluble antigen-antibody complexes, which bind to Fc receptors, do not appear to inhibit B cell activation. Recent experiments have demonstrated that antigen-antibody complexes immobilized on a surface strikingly inhibit LPS induced B cell mitogenesis and polyclonal antibody synthesis. Mechanisms for Fc receptor-mediated inhibition of B cell activation have been considered, and a model proposed to explain many of these findings as well as allow for antigen specific inhibition.     

I. Immunosurveillance and tumorigenesis in 1. BALB/c Mice

Using functional ultrastructure we established the physiology of the cellular immune response in the BALB/c mouse jejunum disseminated lymphoid tissue (JDLT) before and after sequential stimulations withE. coli endotoxin (ECE) (the preceding article in this journal). The functional ultrastructure was established also in this series of BALB/c mice injected i.p. initially with 0.5 ml of mineral oil and then weekly with 5 ng of ECE (EOA). The present series of mice had a pathological immune response and, it is known that they will in time produce plasmacytomas. Differences between the physiologic and pathologic immune responses during the first month of tumorigenesis, are:

1. The T-lymphocyte response was found to be strong but disorganized;
2. As judged from the T∶B ratios, the B-lymphocyte response was found to be very strong, late after the first, early after the second, and late after the fourth injections with ECE, in this EOA model of stimulation.
3. The macrophage cellular response during the EOA stimulation was found to be slightly weaker than that seen in the series of mice stimulated with ECE alone.

At the time of this study, the differences found between the physiologic and pathologic immune responses in the JDLT are not conclusive and they do not elucidate either the mechanisms of tumorigenesis or the role of the immunocompetent cells.     

Comparative Analysis of Natural Antibody Specificities among Hybridomas Originating from Spleen and Peritoneal Cavity of Adult NZB and BALB/c Mice

A preliminary experiment showed that the supernatants of in vitro cultured peritoneal cells (rich in Ly-1 B cell subset shown to secrete most IgM autoantibodies against bromelain-treated mouse red blood cells (BrMRBC) and DNA) from different mouse strains did not contain any significant antibody activity against DNA and cytoskeleton proteins, although the presence of anti-BrMRBC antibodies was clearly evident. Therefore, we investigated comparative natural antibody (NAb) specificities against an antigen panel (DNA, cytoskeleton proteins, IgG, bovine serum albumin (BSA), BrMRBC, trinitrophenyl (TNP), and trimethylammonium (TMA) haptens) among Ig-secreting hybridoma collections from the splenic (158) and peritoneal (230) immune compartments of autoimmune New Zealand black (NZB) and lipopolysaccharide (LPS)-stimulated BALB/c mice. The data showed: (i) isotypic restriction (mu and gamma 3 only), predominance of TMA ion-reactive (including BrMRBC) but negligible anti-DNA-reactive antibody specificities, and lack of simultaneous polyspecific widespread reactivity (i.e. at least four or more antigens) against DNA and cytoskeleton proteins in the peritoneal cavity; (ii) predominance of simultaneous widespread polyspecific reactivity against DNA and cytoskeleton proteins but negligible or no TMA hapten-reactive antibody specificities in the spleen. These observations reflect certain differences in the B cell repertoire of peritoneal cavity (rich in Ly-1 B cells) compared with spleen. The NAb against BrMRBC and those reactive with DNA and cytoskeleton proteins, which have been suggested to be secreted by the Ly-1 B cell subset, are distinguishable on the basis of the presence of separate recurrent idiotypes and preferential localization of B lymphocytes directed against these autoantigens.     

IL-24/MDA-7 Suppressed the Transplantation Tumor in BALB/c Mice

It is well-documented that interleukin-24 （IL-24） can induce apoptosis in a large spectrum of human cancer derived cell lines, but the effect of MDA-7/IL-24 gene transfer on mouse melanoma cells remains unknown. The eukaryotic expressing plasmid of IL-24 （pEGFP-IL-24） was constructed by DNA recombination technique. The recombination plasmid and empty vector were transfected into B16F0 cells and the expressions of IL-24 were determined by LSM, the proliferation of B16F0 cells was measured by MTT assay, and apoptosis rate and cell-cycle distribution of B16F0 cells were measured by FCM. The inhibitory effect of IL-24 gene transfection in mouse solid tumor was observed and measured. Compared with the control, the proliferation of B16F0 cells was inhibited by transfection with pEGFP-IL-24 and the G2/M phase of the transfected cells was also increased. Moreover, the percentage of mice with detectable tumor was decreased after inoculated with B16F0 cells transfected with pEGFP-IL-24. Growth rate of tumor in mouse model was significantly inhibited in IL-24 gene therapy group compared with the control. Proliferation of B16F0 cells was inhibited by pEGFP-IL-24 transfection. The intratumor injection of pEGFP-IL-24 could inhibit the growth of solid tumor in mice remarkably. Cellular ＆ Molecular Immunology.     

Experimental Mycoplasma hominis Infection of the Genital Tract in BALB/c Mice

We studied the ability of laboratory and clinical strains of Mycoplasma hominis to colonize the genital tract mucosa in BALB/c mice. Colonization with mycoplasma occurred only in mice receiving estrogen. Mycoplasma hominis strains obtained after 3-fold passage through the vaginal mucosa in mice and administered intravaginally in a dose of 0.5 x 10(8) CFU/ml caused infection in 100% animals. Inflammation in the lower genital tract was reduced by the 8th week after infection.     

人B细胞激活抗原B7（hB7）基因cDNA的克隆

我们采用Ｎｅｓｔｅｄ ＰＣＲ的方法，成功地从Ｒａｊｉ细胞中扩增出Ｂ７ ｃＤＮＡ，通过单个碱基改变，在两端分别引入单酶切位点（５＇端为ＨｉｎｄⅢ，３＇端为ＥｃｏＲⅠ），经酶切后连入ｐＢｌｕｅｓｃｒｉｐｔ克隆载体，测序证明所得序列与Ｆｒｅｅｍａｎ等报告的完全一致。我们所选用的两个酶切位点ＨｉｎｄⅢ和ＥｃｏｒＩ恰好位于ｐＢｌｕｅｓｃｒｉｐｔ多克隆位点的中央，克隆入Ｂｌｕｅｓｃｒｉｐｔ后，两端有多个单酶切