Protective immunity to malaria: studies with cloned lines of Plasmodium chabaudi chabaudi in CBA/Ca mice. III. Protective and suppressive responses induced by immunization with purified antigens

The protective effect of affinity purified antigen has been investigated in an experimental model for malaria which shows a well marked recrudescence of parasitaemia, a feature of the disease in man. A monoclonal antibody (MoAb) recognizing an epitope common to two genetically distinct cloned lines of Plasmodium chabaudi (AS and CB), was used to purify a Mr250,000 polymorphic schizont antigen (PSA) from these parasites. The purified preparations were then examined for the presence of specific and cross-reactive epitopes by immunoprecipitation with a panel of MoAb raised against P. chabaudi AS. When tested previously on smears of parasitized blood by immunofluorescence, or against lysates of parasitized erythrocytes by immunoprecipitation, most of these MoAb had been found to be AS specific. When either AS or CB affinity purified Mr250,000 PSA was used as the target, these same MoAb immunoprecipitated both antigens, and in some cases, a number of associated polypeptides (AP) which copurify with the Mr250,000 PSA. Subsequently, mice were immunized with either the purified AS or CB antigens in Freund's complete adjuvant (FCA). Prechallenge sera were compared by indirect immunofluorescence and immunoprecipitation. Sera from mice immunized with AS antigen reacted strongly with AS and cross-reacted with CB parasite preparations. Pre-challenge serum from CB antigen immunized mice reacted well with CB, but only faintly with AS preparations. In mice immunized with the AS antigen and then challenged with either AS or CB parasites, the initial parasitaemias were delayed in appearance and the height of the peak parasitaemia reduced, an effect which was most pronounced after challenge with homologous parasites. Only homologous challenge of the mice immunized with CB antigen produced statistically significant modification of the initial parasitaemia. In the immunized mice challenged with homologous parasites, the delayed appearance and slightly reduced peak of the primary parasitaemia was associated with delayed resolution of the patent parasitaemia and significant enhancement of the recrudescence.     

STAT3 couples with 14-3-3σ to regulate BCR signaling,B-cell differentiation,and IgE production

1. Download : Download high-res image (205KB)
2. Download : Download full-size image

     

Expression of the PD-1 antigen on the surface of stimulated mouse T and B lymphocytes

A mAb J43 has been produced against the product of the mousePD-1 gene, a member of the Ig gene superfamily, which was previouslyisolated from an apoptosis-induced T cell hybridoma (2B4.11)by using subtractive hybridization. Analyses by flow cytometryand immunoprecipitation using the J43 mAb revealed that thePD-1 gene product is a 50–55 kDa membrane protein expressedon the cell surface of several PD-1 cDNA transfectants and 2B4.11cells. Since the molecular weight calculated from the aminoacid sequence is 29,310, the PD-1 protein appears to be heavilyglycosylated. Normal murine lymphoid tissues such as thymus,spleen, lymph node and bone marrow contained very small numbersof PD-1⁺ cells. However, a significant PD-1⁺ population appearedin the thymocytes as well as T cells in spleen and lymph nodesby the in vivo anti-CD3 mAb treatment. Furthermore, the PD-1antigen expression was strongly induced in distinct subsetsof thymocytes and spleen T cells by in vitro stimulation witheither anti-CD3 mAb or concanavalin A (Con A) which could leadT cells to both activation and cell death. Similarly, PD-1 expressionwas induced on spleen B cells by in vitro stimulation with anti-IgMantibody. By contrast, PD-1 was not significantly expressedon lymphocytes by treatment with growth factor deprivation,dexamethasone or lipopolysaccharide. These results suggest thatthe expression of the PD-1 antigen is tightly regulated andinduced by signal transduction through the antigen receptorand do not exclude the possibility that the PD-1 antigen mayplay a role in clonal selection of lymphocytes although PD-1expression is not required for the common pathway of apoptosis.     

Infection of human epithelial cells by Epstein-Barr virus (EBV). II. Biochemical characterization of EBV-determined proteins synthesized in epithelial cells

Primary cultures of epithelial cells were grown from tonsils of patients with diseases not related to EBV. The cells were implanted with EBV receptors and exposed to EBV of the transforming (B95-8, AG-876) and nontransforming (P3HR-1) strains. The EBV-infected and control cells were pulsed with [35S]methionine at 18-24 h after infection, and cell extracts were prepared for immunoprecipitation with anti-EBV sera and analysis by gel electrophoresis and autoradiography. About 20 EBV-determined proteins ranging from 22 to 185 kDa were detected in P3HR-1 virus-infected epithelial cells. Only a few polypeptides were detected in extracts of cells infected with AG-876 virus while no EBV-specific proteins were immunoprecipitated from extracts of B95-8 virus-infected cells. These results demonstrate that the system of EBV receptor-implanted normal human epithelial cells can be used for direct biochemical analysis of EBV infection in the epithelial tissue.     

人肝癌组织中p53与HSP70相互作用的初步研究

目的 :探讨人肝癌中热休克蛋白 70 (HSP70 )与 p5 3的相互作用。方法 :用免疫组织化学染色法 ,从 12例肝癌组织中筛选HSP70与 p5 3均呈阳性表达的标本 ,并以免疫共沉淀法提取之。然后用SDS PAGE及Westernblot分析双阳性标本中两种蛋白的存在形式。结果 :用免疫组织化学法检测到 12例肝癌组织中有 3例为双阳性 ,用抗HSP70mAb免疫共沉淀的样品 ,可检测到 p5 3蛋白。用抗p5 3mAb免疫共沉淀的样品也可检测到HSP70蛋白。结论 :人肝癌中p5 3与HSP70以复合物的形式而存在 ,此可为肝癌的发病机制及免疫治疗的研究提供新的思路     

Characterization of the murine interleukin 5 receptor by using a monoclonal antibody

Murine interleukin 5 (IL-5), a lymphokine produced by helper T cells, is involved in the regulation of growth and differentiation of B cells and other hematopoietic cells. The receptor for IL-5 has been identified as two cross-linked complexes on T88-M cells (a murine IL-5-dependent early B cell line). In this study the IL-5 receptor was directly characterized by utilizing an immobilized IL-5 column and a rat monoclonal antibody, designated H7, directed against the IL-5 receptor. H7 completely inhibited specific binding of 35S-labeled IL-5 to T88-M cells, and bound to IL-5-responsive cells, e.g. T88-M, BCL1-B20 (a chronic B-cell leukemia), and MOPC104E (a myeloma), whereas H7 did not bind to IL-5-non-responsive cells, e.g. X5563 (a myeloma), FDC-P1 (an IL-3-dependent line), and MTH (an IL-2-dependent CTLL). H7 could barely bind to T88-M cells in the presence of IL-5, and immunoprecipitated a major band with an Mr of approximately 60 kd from the extract of surface-radioiodinated T88-M cells. The precipitation of this 60 kd molecule was inhibited by the addition of IL-5. Analysis with immobilized IL-5 also revealed that a 60 kd molecule bound specifically to IL-5-coupled beads compared with control beads. Furthermore, no additional molecule with a higher Mr that was recognized by H7 appeared under non-reducing, compared with reducing, conditions. The 60 kd molecule recognized by H7 could be digested with N-glycanase to yield a protein band of approximately 55 kd.(ABSTRACT TRUNCATED AT 250 WORDS)     

A simple quantitative protein A micro-immunoprecipitation method; assay of antibodies to the N and H antigens of poliovirus

Staphylococcus aureus (Cowan strain I) was used to absorb immune complexes from antiserum to poliovirus to which labeled N or H poliovirus antigens had been added, and the radioactivity in the pelleted organisms and in the supernatant was measured. Excellent agreement was obtained between values calculated separately from the pellet and supernatant readings, validating the use of supernatant measurements from a microtitration plate method.     

Production and characterization of monoclonal antibodies to guinea pig lymphoid differentiation antigens

We have prepared 2 mouse monoclonal antibodies which react with differentiation antigens on guinea pig lymphoid cells. Monoclone 5AB2 recognizes an antigen expressed on both T and B lymphocytes and absent on macrophages. It has proven useful in the preparation of populations of antigen presenting cells which are free of T and B lymphocytes. The second monoclonal, 8BE6, is specific for peripheral T cells and 10% of thymocytes. It reacts with a 68,000 dalton molecule which is also expressed on the guinea pig B cell leukemia, EN-L2C. 8BE6 has proven to be lytic for peripheral T cells in the presence of rabbit complement and has been used to deplete T cells from heterogenous cell populations.     

Antigenicity and immunogenicity of the tegumental outer membrane of adult Schistosoma mansoni

The tegumental membranes of adult Schistosoma mansoni have been isolated and purified and shown to function as potent immunogens; they elicit an essentially identical immune response in rabbits, rats and mice. Anti-membrane antisera harvested from these animals consistently recognized common antigens, of relative molecular weight (mol. wt) 32 000 and 20 000, on the surface of young schistosomula, 5 day old lung worms and adult worm purified membranes. An additional molecule of 25 000 mol. wt was present on the surface of lung worms and adult worm membranes and was specifically recognised by serum from chronically infected mice and by serum from rabbits inoculated with adult worm purified membranes. The concept of antigenic identity between developmental stages that parasitize the mammalian host was further substantiated by the observation that anti-membrane antiserum bound to live schistosomula, lung worms and adult parasites as measured by indirect immunofluorescence. In complement-mediated in vitro cytotoxicity assays, the sera from rabbits inoculated with either adult worm purified membranes, or the 32 000 mol. wt antigen partially purified from adult worm membranes, mediated levels of schistosomula killing as high as those obtained with sera from chronically infected mice. These rabbit antisera also promoted eosinophil adherence and killing of newly transformed schistosomula, but lung stage parasites, despite binding the anti-membrane antiserum, were refractory to both humoral and cellular cytotoxicity. The significance of antigenic identity is discussed in relation to the concept of concomitant immunity.