A quantitative ELISA for antigen-specific IgG subclasses using equivalence dilutions of anti-kappa and anti-subclass specific secondary reagents Application to the study of the murine immune response against the capsular polysaccharide of Neisseria meningitidis serogroup B

We have developed an enzyme-linked immunosorbent assay (ELISA) to measure murine antigen-specific IgG antibodies of defined subclass using precalibrated equivalence dilutions of anti-κ (in the standard) and each anti-IgG subclass-specific polyclonal secondary antibody (in the test sample). The calibration of secondary reagents could be carried out easily with a set of monoclonal antibodies (MoAbs) specific for all IgG subclasses. These MoAbs do not require purification or standardization. In addition the MoAbs can be of different antigenic specificity. Once the equivalence dilutions have been determined, they can be applied in a quantitative ELISA using the same antigen in the standard and sample, and using only one IgG subclass standard for the determination of all the IgG subclasses. The method is easy to standardize for many antigenic systems. It is particularly useful when the only standard available is one standardized MoAb of the appropriate specificity, and it could be adapted to use with standard polyclonal antibodies having a known content of total antigen-specific IgG bearing κ chains but unknown IgG subclass composition. The use of this method to quantitate IgG specific for the capsular polysaccharide of Neisseria meningitidis serogroup B (CpsB) gave highly reproducible measures with an interbatch CV of 5–6% similar for all IgG subclasses and low detection limits ranging from 0.3 ng/well for IgG3 to 0.8 ng/well for IgG2a. The IgG subclass response observed after immunization with live meningococci was mainly IgG2a (74%) and IgG2b (18%). Hyperimmunization modified this IgG distribution to one of mainly IgG3 (62%) and IgG1 (28%) which was maintained in the response to a single immunization 4 weeks later, possibly indicating the generation of resting B cells during continuous stimulation.     

猪苓多糖对S180细胞培养上清免疫抑制作用影响的研究

目的 :研究猪苓多糖对肿瘤细胞系S180培养上清免疫抑制作用的影响。方法 :用MTT比色法检测有或无猪苓多糖作用的肿瘤细胞S180培养上清 (简称肿瘤上清 ) ,对ConA诱导的小鼠脾细胞增殖和IL 2产生 ,对小鼠脾细胞的杀伤活性 ,以及对CTLL 2细胞对IL 2反应性的影响。用流式细胞仪检测该培养上清对小鼠脾细胞表面IL 2Rα表达的影响。结果 :无猪苓多糖作用的肿瘤上清可强烈抑制上述 5项指标 ;而猪苓多糖作用的肿瘤上清则可明显上调上述方法中所测 5项指标。若先用含猪苓多糖培养液培养肿瘤细胞 2 4h或 48h ,而后洗去或不洗去猪苓多糖 ,再培养肿瘤细胞 2 4h ,所获肿瘤上清也可明显上调上述 5项指标。结论 :猪苓多糖可抵消肿瘤上清的免疫抑制作用 ,下调肿瘤细胞S180合成和 /或分泌免疫抑制物质     

The advantage of mucosal immunization for polysaccharide-specific memory responses in early life

The aim of vaccination is to rapidly elicit protective immunity and generate memory for sustained protection. We studied the induction and persistence of polysaccharide (PS)-specific memory in neonatal and infant mice primed with pneumococcal conjugate (Pnc1-TT) by assessing the response to native pneumococcal PS (PPS-1), the kinetics of the PPS-1-specific IgG response to a second Pnc1-TT dose and affinity maturation. A subcutaneous (s.c.) Pnc1-TT booster induced a rapid increase in PPS-1-specific IgG, indicating efficient priming for memory by a single dose of Pnc1-TT already at 1 week of age. High levels were maintained for >12 weeks. However, a PPS-1 booster induced no response in neonatal or infant mice. The adjuvant LT-K63 significantly enhanced the IgG response and affinity to Pnc1-TT by both the s.c. and the intranasal (i.n.) route in all age groups. In neonatal and infant mice, PPS-1 and LT-K63 induced a booster response only when given i.n. following either s.c. or i.n. priming with Pnc1-TT and LT-K63. In contrast, PPS-1 with or without LT-K63 administered s.c. compromised the ongoing PPS-1-specific response elicited in neonatal mice by either s.c. or i.n. priming with Pnc1-TT and LT-K63. These results demonstrate the advantage of the mucosal route for elicitation of PS-specific memory responses in early life.     

重组卡介苗及猪苓多糖对荷瘤小鼠巨噬细胞NO释放量的影响

目的 观察重组卡介苗（rBCG)和中药猪苓多糖（PPS），对荷瘤小鼠空巨噬细胞释放NO的影响。方法 将黑色素瘤细胞株B16接种于小鼠左大腿外侧皮下，建立荷瘤小鼠模型，分别用rBCG－IL-2,rBCG-IL-2 PPSPPS进行局部治疗。于给药后第1，2，3和5wk处死小鼠，用NO酶法测定小鼠腹腔巨噬细胞释放NO的水平，并观察不同实验组瘤体的变化。结果 rBCG－IL－2组小鼠腹腔巨噬细胞释放NO的水平最高。与对照组相比较，PPS组小鼠腹腔巨噬细胞释放NO的水平在第1wk与第2wk增高，第3wk起与对照组释放的NO水平没有差异。rBCG－IL－2组小鼠随给药时间的延长，皮下瘤体逐渐缩小。PPS组小鼠瘤体在给药后第1wk和第2wk生长缓慢，第3wk起瘤体生长速度明显增加。结论 rBCG－IL－2与PPS能提高小鼠腹腔巨噬细胞释放NO的水平，rBCG－IL－2能明显抑制肿瘤生长。     

Antibodies to pneumococcal polysaccharides in pneumonia and response to pneumococcal vaccination in young children in Papua New Guinea.

Antibodies against pneumococcal polysaccharides were measured by ELISA in Papua New Guinean children with pneumonia aged 0-14 months, in age-matched healthy Papua New Guinean controls and in healthy expatriate children living in Papua New Guinea. At 0-5 months of age, the IgG antibody titres against six of the eight polysaccharides measured were significantly lower in pneumonia patients than in both control groups. Antibody titres in 6-14-month-old Papua New Guinean controls were significantly lower than in control Papua New Guineans aged 0-5 months for five of the eight polysaccharides tested. In the 6-14-months age group the antibody titre was significantly lower in pneumonia patients than in controls for only one polysaccharide. For seven of the eight serotypes tested, antibody levels in expatriate controls did not decline with age. Antibody responses of Papua New Guinean children aged 6-18 months to a 23-valent pneumococcal vaccine were serotype dependent. Fold increases in response to the vaccine were greatest for the IgA isotype. IgG antibody responses were greater than three fold to four of the eight serotypes tested.     

硫酸酯化葡甘聚糖凝胶颗粒的微观形貌及其吸附行为研究

制备了硫酸酯化魔芋葡甘聚糖凝胶颗粒血液低密度脂蛋白吸附剂，扫描电镜观察产物呈交联网状多孔结构。体外静态吸附实验表明：在37℃振荡吸附2h后，对总胆固醇（TC）、低密度脂蛋白及超低密度脂蛋白胆固醇（LDL＋VLDL-C）、高密度脂蛋白胆固醇（HDL-C）的吸附率分别为52．68％、54．76％、27．78％。通过吸附动力学曲线和吸附等温线分析，吸附剂对LDL＋VLDL-C的作用包括类似分子筛的吸附和电荷间静电相互作用两种方式。     

Effect of injection ofCryptococcus heteropolysaccharide injection into bone marrow donors and recipients on structure of a heterotopic focus of hematopoiesis

Academician I. P. Pavlov First Leningrad Medical Institute. Leningrad Pharmaceutical Chemical Institute. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 3, pp. 352–353, March, 1988.     

Anticoagulant Activity of Fucoidan from Brown Algae Fucus evanescens of the Okhotsk Sea

In vitro and in vivo experiments showed that anticoagulant activity of sulfated polysaccharide from Fucus evanescens (brown algae of the Okhotsk Sea) was similar to that of heparin. Anticoagulant properties of fucoidan are determined by thrombin inhibition mediated via plasma antithrombin III.     

Chronic mucocutaneous candidiasis. II. Class and subclass of specific antibody responses in vivo and in vitro

Patients with chronic mucocutaneous candidiasis (CMC) succumb to persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been repeatedly reported while antibody responses were mostly found to be normal. The underlying defect remains poorly understood. It has recently been shown that CMC patients are also susceptible to infections with encapsulated bacteria, and may have associated IgG2 and IgG4 deficiency. Our previous studies demonstrated altered cytokine production in CMC patients. As cytokines can influence production and isotype of specific antibody, in 10 patients with CMC we measured the levels and isotype distributions of serum antibodies to Candida antigens (CAg), pneumococcal polysaccharide (PPS) and tetanus toxoid (TT) antigens. Peripheral blood lymphocytes were also stimulated in culture and the antibodies made in vitro were measured. Our data demonstrated that in vivo, CMC patients had very high levels of IgG and IgA CAg-specific antibodies. CAg-specific and PPS-specific IgG1 was markedly higher than in controls. Children but not adults with CMC had significantly lower levels of IgG2-specific antibody to CAg and PPS compared with age-matched controls. Patients had significantly higher levels of IgG3-specific antibody to all three antigens tested. These findings were in accordance with increased total IgG and IgG3 levels seen in CMC patients. In vitro, CMC patients, particularly children, did not respond as frequently to antigen stimulation as did their healthy controls. The level of specific antibody produced was also lower to all antigens tested, as was the amount of total immunoglobulins following antigenic and particularly mitogenic stimulation. Addition of interferon-alpha (IFN-α) or IFN-γ to cultures had variable, sometimes marked, effects. Our results demonstrate that CMC patients manifest subtle alterations in specific antibody responses to CAg, PPS and TT, which are most pronounced in children. This may relate to altered cytokine production also seen in these patients.