A human B cell differentiation antigen selectively expressed on mature B cells identified by a monoclonal antibody (HB-2)

A monoclonal IgM antibody (HB-2), produced against a membrane antigen on the Raji, B cell line, reacted by indirect immunofluorescence with 2 to 40% of lymphoblasts from the B cell lines, Raji, Daudi, SN-1036, and SB but not with other types of cell lines, including pre-B, myeloid, melanoma, or T cells. HB-2 antibody reacted with 10 ± 3% of normal blood mononuclear cells, and was unreactive with monocytes, granulocytes, platelets, or erythrocytes. Two-color immunofluorescence revealed that HB-2 antigen expression was confined to cells bearing surface Ig. An interesting finding was the fact that 25% of plasmablasts induced by pokeweed mitogen also expressed the HB-2 antigen. However, pre-B and plasma cells from normal bone marrow did not express the HB-2 antigen either on their membrane surface or in their cytoplasm. Analysis of 85 leukemias revealed that the HB-2 antigen was expressed on acute and chronic B cell leukemias and Burkitt's lymphomas, but not on malignacies of pre-B, T, myelocytic, or plasma cells. The results suggest that expression of the HB-2 antigen is confined to mature B cells.     

重组人bFGF的原核表达及其高效价抗血清的制备

目的 以重组人碱性成纤维生长因子为免疫原，制备高效价抗hbFGF抗血清。方法通过PCR方法改造5’编码区的12个密码子，构建hbFGF’原核表达载体并在大肠杆菌(E．coli)中表达，以纯化的hbFGF、免疫新西兰兔，制备高效价抗血清，用于重组hbFGF、的免疫印迹分析。结果经过改造的hbFGF基因在E．coli中获得较高水平表达。从可溶性部分纯化得到纯度95％以上的重组hbFGF，以该重组蛋白免疫兔子，在二次加强后以间接ELISA检测抗血清效价可达1：512000。免疫印迹分析显示该抗血清与E．coli中表达的重组hbFGF、和标准hbFGF、均有特异性反应，但与某些细菌蛋白存在弱交叉反应，经E．coli菌体蛋白吸附的抗血清，与菌体蛋白的弱交叉反应消失。结论以纯化的重组hbFGF为免疫原制备了高效价的特异性抗血清，经菌体蛋白吸附可消除存在的交叉反应性。     

Heterogeneity of CD3 antigen expression in T-cell lymphoma

CD 3 antigen expression was studied in a series of 98 T-cell lymphomas, using polyclonal antibodies which recognize this molecule in routinely processed, paraffin-embedded, tissue. We identified 40 cases in which CD3 was present on only a proportion of the neoplastic cells. This phenomenon of heterogeneous CD3 expression was commonest in pleomorphic T-cell lymphomas (22/42 cases) and in CD30 (Ki-1)-positive lymphomas (5/11 cases), and was less frequently observed in mycosis fungoides (4/18 cases) and not seen in T-cell lymphoblastic lymphoma (0/9 cases). CD3 expression was often related to cell morphology, with CD3 antigen being present on the smaller neoplastic cells but absent from the larger ones. The diagnostic significance of these observations is that, on occasion, it may be possible to diagnose a lymphoma as being of T-cell origin in paraffin sections by demonstrating a minor subpopulation of CD3-positive neoplastic cells.     

Placental site trophoblastic tumor of the mediastinum

Choriocarcinoma has been described as the most frequent subtype of mediastinal germ cell tumors showing trophoblastic differentiation. We report a unique case of a placental site trophoblastic tumor, which developed in the mediastinum of a 14-year-old boy 2 years after the resection of a mature teratoma. The recurrent tumor was composed of a grossly hemorrhagic and necrotic mass. Histologically, diffusely infiltrating large polygonal cells with focal nodular growth and a teratomatous part containing mature intestinal, respiratory, and squamous epithelium with adjacent cutaneous adnexal structures were found. The typical morphologic features included vessel wall infiltration by the neoplastic cells with fibrinoid deposits and geographic necroses within the tumor masses. Characteristic diffuse positivity for melanoma cell adhesion molecule and human leucocyte antigen G was found on immunohistochemical investigation, confirming the diagnosis of placental site trophoblastic tumor. The patient died 1 year later after polychemotherapy. The outcome of this rare tumor is similar to the reported poor clinical outcome in patients with mediastinal choriocarcinomas.     

Transport of Proteins Across the Human Placenta

PROBLEM: The transport of various proteins across the human placenta was investigated by comparing maternal and fetal concentrations of tetanus antigen (TT-AG), anti-tetanus (TT)-immunoglobulin G (IgG) (following maternal vaccination), IgA, human chorionic gonadotropin (hCG), human placental lactogen (hPL), and alpha-fetoprotein (AFP) at term. METHOD OF STUDY: The concentrations of the six proteins were determined using enzyme-linked immunosorbent assay in serum of maternal venous and umbilical (fetal) vein samples obtained at delivery from uncomplicated term pregnancies (n = 16). RESULTS: The ratios (mean ± standard deviation) of fetal (umbilical) to maternal level were 1.41 ± 0.33 (anti-TT-IgG), 0.91 ± 0.37 (TT-AG), 0.002 ± 0.001 (IgA), 0.003 ± 0.001 (hCG), and 0.008 ± 0.004 (hPL), while the maternal:fetal concentration ratio of AFP was 0.002 ± 0.002. IgA, hCG, hPL, and AFP showed a close correlation between maternal and fetal levels varying between r² = 0.47 to 0.73 (P < 0.004–0.0001). Because AFP is produced by the fetus while IgA originates in the mother, the appearance of small amounts of these two proteins in the maternal or fetal compartment, respectively, suggests a slow rate of diffusion following a high concentration gradient. The detection of hCG and hPL in fetal serum is also interpreted as diffusion from the maternal into the fetal blood. Anti-TT-IgG has a significantly higher concentration in the fetal as compared with the maternal serum, which is in line with the well-documented active transfer of IgG. Fetal TT-antigen levels were similar to maternal concentrations, showing a close correlation (r² = 0.74, P < 0.0001) between the two proteins. CONCLUSIONS: The correlation between maternal and fetal concentrations of various proteins like IgA (150,000 Da), hCG (42,000 Da), and hPL (21,000 Da) suggests passive diffusion of these macromolecules across the placenta from the maternal to the fetal side, albeit at a slow rate. A similar process is postulated for AFP (70,000 Da) diffusing in the opposite direction from the fetus to the mother. There was no significant difference between the transplacental fetomaternal gradient of IgA and hCG and the maternal-fetal gradient of AFP. In view of the substantially larger volume of circulating maternal as compared with fetal blood, a significantly higher rate of crossing of AFP as compared with the other proteins must be assumed. It is uncertain whether a difference in the rate of transplacental transfer in the two directions or an additional source of AFP production in the maternal compartment explains the high maternal level. Anti-TT-IgG concentration is significantly higher in fetal than in maternal serum suggesting active transfer from the mother to the fetus. Furthermore, there is considerable transfer of TT-AG and a close correlation of fetal:maternal ratios of anti-TT-IgG (150,000 Da) and TT-AG (150,000 Da) could be an indication for a specific transfer of the antigen antibody complex.     

Identification of parasite proteins in a membrane preparation enriched for the surface membrane of erythrocytes infected with Plasmodium knowlesi

A subcellular fraction enriched in erythrocyte membranes has been isolated from rhesus monkey erythrocytes infected with Plasmodium knowlesi. Infected cells were lysed by centrifugation through a zone of hypotonic buffer and membranes isolated by equilibrium density gradient centrifugation in the same tube. The purified membrane fraction was shown to include the erythrocyte surface membrane by several methods: electron microscopy, identification of Coomassie Blue stained erythrocyte membrane proteins, identification of band 3 with a monoclonal antibody, and identification of radioiodinated cell surface proteins. The resulting ghosts were shown to be specifically reactive with monkey sera against the variant surface antigens of P. knowlesi by indirect immunofluorescence and membrane agglutination. No reactivity was seen with a monoclonal antibody (13C11) against the intracellular schizont surface. A number of metabolically labelled parasite proteins were enriched in this membrane function, including peptides of 277, 208, 173, 153, 134, 109, 80, 60 and 48 kDa and the variant surface antigens of variable molecular mass (180-207 kDa). These proteins were distinct from the major parasite proteins of total infected erythrocytes and isolated merozoites. The major glucosamine labelled glycoprotein of the internal schizont (230 kDa) was not found in this fraction. Moreover, no fragment of this parasite glycoprotein was found in this membrane fraction, indicating that no part of this molecule is transported to the erythrocyte surface. In contrast, the variant antigen of P. knowlesi, known to be on the erythrocyte surface, could be readily identified as peptides unique to specific cloned parasite lines. We propose that the other nine parasite proteins found within this membrane fraction represent a starting point for the identification of other parasite proteins transported to the surface membrane of the infected erythrocyte.     

Action of allogeneic and syngeneic splenic extracts on primary cell cultures from inbred mice

The effect of allogeneic and syngeneic extracts from the spleens of male and female inbred mice on primary cultures of fibroblasts obtained from the subcutaneous connective tissues of fetuses of CBA and C57BL/6J mice was studied. The cytotoxic and growth-inhibiting action on the cultures was successively enhanced by the use of extracts from syngeneic male and allogeneic female and male tissues. Consequently, an increase in the degree of antigenic difference between the target cells and extracts led to enhancement of the phenomenon of allogeneic inhibition. It was shown for the first time that in a syngeneic system extracts from male tissues (containing the weak H-Y antigen) have a cytotoxic action on cells from female inbred mice, i.e., that they induce a reaction of the allogeneic inhibition type.Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi biologii i meditsiny, Vol. 86, No. 10, pp. 486–488, October, 1978.     

Dendritic cell number is related to IL-4 expression in the airways of atopic asthmatic subjects

BACKGROUND: Airway dendritic cells are essential for stimulating naive T cells in response to inhaled antigen and for the development of allergic sensitization. IL-4 in vitro can distinguish dendritic cell lines from peripheral blood mononuclear cells. Our study had the following aims: 1) to compare the distribution of CD1a+ dendritic cells and IL-4+ cells, in the bronchial mucosa of asthmatics and controls 2) to determine the relationship between the numbers of CD1a+ dendritic cells and IL-4+ cells in the bronchial mucosa of asthmatics 3) to determine whether CD1a+ cells express the IL-4 receptor. METHODS: Twenty atopic asthmatic and eight normal subjects were studied. In each subject, bronchoscopy with bronchial biopsies was performed. CD1a, IL-4, and IL-4 receptor expressions were evaluated by immunohistochemistry. RESULTS: The number of CD1a+ and IL-4+ cells was significantly higher in asthmatics than controls. The number of CD1a+ cells was positively correlated to the number of IL-4 + cells. Bronchial biopsy serial section studies showed that CD1a+ cells express the receptor for IL-4. CONCLUSIONS: These results suggest that an increased amount of IL-4 may play a physiopathologic role in maintaining the dendritic cell pool in vivo. Therefore, because of possible IL-4 activity on antigen-presenting cells in T-cell immune responses to allergens, an important new role of IL-4 in asthma inflammation can be envisaged.     

Anti-neutrophil cytoplasmic antibodies (ANCA) in ulcerative colitis: anti-cathepsin G and a novel antibody correlate with a refractory type

We analysed the clinical significance of ANCA in patients with ulcerative colitis. On either an indirect immunofluorescence assay or an ELISA with fixed neutrophils, 71% (25/35) of the patients were positive for ANCA. However, only half of them reacted with either cathepsin G or lactoferrin. Western blot assays revealed positive bands in 40% (10/25) of the antibody-positive patients. The sizes of the bands detected were ≈58, 47, 44, 40, and 28 kD. No significant correlation was found between the ANCA positivity and various variables, i.e. disease activity, extent of lesion, or treatment of the disease. The anti-cathepsin G and 28-kD positivity, however, significantly correlated with a refractory type of ulcerative colitis.