RNA of Australia Antigen

ALTHOUGH the exact nature of Australia (Au) antigen is not resolved, increasing evidence suggests that it is the causal agent of viral hepatitis. This supposition is based chiefly on the frequent occurrence of Au antigen in the sera of patients with viral hepatitis^1–4 and on its virus-like appearance under the electron microscope^5–7. Biochemical studies have shown that Au antigen consists largely of protein, with a minor lipid moiety^{8, 9}. So far, however, no genetic material has been detected in the Au antigen and it has been suggested that the Au antigen might be “a unique infectious particle with little or no nucleic acid”¹⁰. We wish to present evidence, however, that RNA is an essential component of Au antigen.     

Biophysical Properties of Australia Antigen

Biophysical studies with Australia complement-fixing (CF) antigen showed it to be a particle with a buoyant density of 1.20 g/cm(3) in CsCl, a sedimentation coefficient of 110, and an average diameter of 25 nm. The CF antigen was not inactivated by ether, 1% deoxycholate, 1% Tween 80 or overnight heating at 56 C. The antigen was unstable when treated with 1% sodium dodecyl sulfate. A procedure is described for the isolation and partial purification of Australia antigen from serum by using isopycnic banding and rate separation techniques. Treatment of the 1.20 g/cm(3) Australia antigen with 1% Tween 80 yielded a minor peak of CF activity with a buoyant density of 1.39 g/cm(3) in CsCl.     

New Specificity of Australia Antigen

THE immunodiffusion laboratory at the Institute for Cancer Research frequently acts as a reference laboratory to test anti-Australia antigen sera for our colleagues in many parts of the world. Because Australia antigen is known to possess different antigenic specificities^1–4, a panel was established which consisted of Australia antigen specimens selected from hepatitis and Down's syndrome patients and from clinically normal residents of the Lau area in Malaita, British Solomon Islands. Sera from normal blood donors without Australia antigen were included as negative controls. All antisera received after August 1971 were tested against this panel to detect heterogeneity among both the antibodies tested and the antigens included in the panel. Immunodiffusion was performed in a seven-hole Ouchterlony pattern with the antiserum in the centre well and a positive Australia antigen control serum from a Pennsylvania Down's syndrome patient in the top and bottom wells. The patterns were cut in a layer of 1.1% agarose in veronal buffer, pH 8.2, on glass lantern slides^6,7.     

抗SEA鸡卵黄抗体用于血吸虫循环抗原检测的初步研究

目的:探讨抗可溶性虫卵抗原(SEA)鸡卵黄抗体(Immunoglobulin Y,IgY)用于血吸虫循环抗原检测的可行性。方法:以纯化的鸡抗SEA卵黄抗体为捕捉抗体,以酶标抗SEA单克隆抗体NP28-5B进行双抗体夹心酶联免疫吸附试验法(S-ELISA)检测急、慢性血吸虫病病人和健康人血清,并与常规检测抗体的酶联免疫吸附试验(SEA-ELISA)法做比较。结果:S-ELISA法测得SEA浓度(y)与A450值(x)呈明显的正相关(r=0.9481,y=459.22x-108.14)。S-ELISA法检测急性血吸虫病人循环抗原的阳性率为100%,慢性血吸虫病人循环抗原的阳性率为84.40%,健康人的特异性为96%。两种方法对血吸虫病的检出率差异无统计学意义(P>0.05)。结论:S-ELISA可用于血吸虫病的免疫诊断。     

用Vero细胞制备马抗狂犬病血清抗原

以Vero细胞为基质制备马抗狂犬病血清用抗原,以期建立有效、经济、简便的抗原制备方法。用含10％马血清营养液对Vero细胞作适应性培养,接种狂犬病毒,以含1％～3％马血清营养液作维持液培养病毒,于第5,8天收获病毒液,经灭活、浓缩、离心等制成抗原。第5,8天收获病毒滴度可稳定在7．010gLD50／mL以上,灭活抗原具良好的抗原性,用NIH法测定效价达6．0IU／mL以上,可用作抗原生产抗狂犬病血清。     

用Vero细胞制备马抗狂犬病血清抗原

以Vero细胞为基质制备马抗狂犬病血清用抗原,以期建立有效、经济、简便的抗原制备方法.用含10%马血清营养液对Vero细胞作适应性培养,接种狂犬病毒,以含1%～3%马血清营养液作维持液培养病毒,于第5,8天收获病毒液,经灭活、浓缩、离心等制成抗原.第5,8天收获病毒滴度可稳定在7.0logLD50/mL以上,灭活抗原具良好的抗原性,用NIH法测定效价达6.0IU/mL以上,可用作抗原生产抗狂犬病血清.     

Australia Antigen and Hepatitis in Accra,Ghana

Viral hepatitis in young adults in Accra, Ghana, is associated with Australia antigen (H.A.A.). Sera from 85 patients in hospital with viral hepatitis were available for determinations of H.A.A. Of the 16 patients whose serum was obtained within the first week of symptoms, 15 were positive. The only factor related to finding H.A.A. was the time between onset of symptoms and the collection of the serum sample. Persistence of H.A.A. was associated with persistence of jaundice in men but not in women. Previous epidemiological studies in Accra found no evidence for parenteral transmission of viral hepatitis and showed a shanty-town predilection pointing to faecal-oral transmission. It thus seems that H.A.A.-associated hepatitis is transmitted in West Africa either faecal-orally or by shanty-town associated arthropods. The finding that H.A.A. hepatitis is the usual hepatitis in young adults in Accra is in accord with the high prevalence of H.A.A. elsewhere in the general population in Africa and may be related to the high rate of cirrhosis and hepatoma in Africa.     

Australia Antigen: Large-Scale Purification from Human Serum and Biochemical Studies of Its Proteins

Biophysical techniques are described for the large-scale isolation of Australia antigen (Au) from unit quantities of human serum by using the batch-type zonal centrifuge rotors. A three-step procedure involving isopycnic banding of the particle in CsCl density gradients and rate-zonal centrifugation on sucrose gradients resulted in a highly purified Au preparation which was used for biochemical studies of Au proteins and as immunizing antigen for the production of reagent antiserum in animals. The spherical form of Au, which was devoid of detectable nucleic acid, was composed of two major proteins (AuP1 and AuP2) and a minor protein (AuP3) of 26,000, 32,000, and 40,000 molecular weight, respectively, as determined by acrylamide gel electrophoresis. The significance of these findings to the possibility of Au subtypes is discussed.     

A Material History of Australia

This article presents an analysis of the material history of Australia in the period 1975–2005. The values of economy‐wide indicators of material flow roughly trebled since 1975, and we identify the drivers of this change through structural decomposition analysis. The purpose of this work is to delve beneath the top‐level trends in material flow growth to investigate the structural changes in the economy that have been driving this growth. The major positive drivers of this change were the level of exports, export mix, industrial structure, affluence, and population. Only improvements in material intensity offered retardation of growth in material flow. Other structural components had only small effects at the aggregate level. At a more detailed level, however, the importance of the mineral sectors became apparent. Improvements in mining techniques have reduced material requirements, but increased consumption within the economy and increased exports have offset these reductions. The full roll out of material flow accounting through Australian society and business and a systematic response to its implications will require change in the national growth focus of the last two generations, with serious consideration needed to reverse the current volume‐focused growth of the economy and also to recast neoliberal and globalized trade policies that have dominated the globe for the past decades.     

Antigen Binding Characteristics of Immunoglobulin Free Light Chains: Crosslinking by Antigen is Essential to Induce Allergic Inflammation

Beside the production of complete immunoglobulins IgG, IgE, IgA, IgM and IgD, consisting of tetrameric heterodimers of immunoglobulin heavy and light chains, B cells also secrete immunoglobulin free light chains (Ig-fLC). Previous studies showed that Ig-fLCs are able to induce immediate hypersensitivity reactions. It is apparent that recognition and binding of antigen are crucial steps in the onset of these inflammatory responses. In this study, the binding characteristics of Ig-fLC to antigen were further investigated using various biochemical approaches. In addition, we investigated whether antigen-mediated crosslinking of Ig-fLC is required to initiate allergic skin inflammation in vivo. Our study shows that binding of Ig-fLCs to antigen can be measured with different experimental setups. Surface plasmon resonance analysis showed real-time antigen binding characteristics. Specific antigen binding by Ig-fLCs was further detected using immunoblotting and ELISA. Using the ELISA-based assay, a binding affinity of 76.9±3.8 nM was determined for TNP-specific Ig-fLC. Antigen-induced ear swelling in mice passively sensitized with trinitrophenol-specific Ig-fLC was inhibited when multivalent antigen was combined with excess of monovalent antigen during challenge. We conclude that Ig-fLCs are able to interact with antigen, a prerequisite for antigen-specific cellular activation. In analogy to antigen-specific Fc receptor-induced mast cell activation, crosslinking of Ig-fLCs is necessary to initiate a local allergic response.     

Preparation and Standardization of an Australia Antigen Antibody of Equine Origin

A horse has been immunized with Australia antigen (Au/SH) purified 20-fold by a procedure employing gel filtration of Cohn fraction IV derived from an Au/SH-positive human plasma pool. Hyperimmunization was initiated by the intramuscular injection of 20 ml of a mixture of equal parts of purified Au/SH and complete Freund's adjuvant. The 20-ml volume was divided into four 5-ml doses, two of which were administered on each side of the horse's neck. Booster doses of antigen alone were given as follows: 10 ml intravenously 30 days later and 5 ml intramuscularly on each of days 77 and 205. Au/SH antibody formed readily, beginning on day 17, and was demonstrated by the agar gel double-diffusion technique and the complement fixation test during the subsequent 6 months. Antihuman plasma protein antibodies were effectively removed from the horse serum by one absorption with 1 to 3 volumes of normal human plasma. Abrupt rises in anticomplementary activity observed shortly after the third and fourth antigen injections, when the horse had developed elevated and steady levels of Au/SH antibody, could possibly be due to formation of antigen-antibody complexes. After optimal conditions were determined, an Au/SH antibody reagent pool which met official requirements was prepared. It was found equally suitable for the agar gel double-diffusion, complement fixation, and counterimmunoelectrophoresis test procedures.     

Material Flows and Material Productivity in China,Australia, and Japan

This article presents material flows and material productivity data and indicators for Australia, China, and Japan for the period 1970 to 2005. The main data used come from a new material flows database for the Asia‐Pacific region that was assembled using up‐to‐date standardized methodologies of material flow accounting and significantly extends the knowledge base available for studies on resource use dynamics in the region. We show that the three nations studied here have diverging patterns of resource use, and that these patterns can be linked to interdependencies between them and the very different roles each nation plays within a globalized system of natural resource exploitation. We also conduct a brief analysis of the most important drivers of changes in their resource use over the period, using an IPAT framework (Impact = Population × Affluence × Technology). The fundamentally different economic structures and trading roles of each country, that is, primary resource provider (Australia), mature and advanced manufacturer (Japan), and rapidly industrializing developing country (China), lead to starkly different contexts in which appropriate policies to encourage sustainable resource use must be formulated.     

Expression of Immunoglobulin Receptors with Distinctive Features Indicating Antigen Selection by Marginal Zone B Cells from Human Spleen

Marginal zone (MZ) B cells, identified as surface (s)IgM^highsIgD^lowCD23^low/−CD21⁺CD38⁻ B cells, were purified from human spleens, and the features of their V(D)J gene rearrangements were investigated and compared with those of germinal center (GC), follicular mantle (FM) and switched memory (SM) B cells. Most MZ B cells were CD27⁺ and exhibited somatic hypermutations (SHM), although to a lower extent than SM B cells. Moreover, among MZ B-cell rearrangements, recurrent sequences were observed, some of which displayed intraclonal diversification. The same diversifying sequences were detected in very low numbers in GC and FM B cells and only when a highly sensitive, gene-specific polymerase chain reaction was used. This result indicates that MZ B cells could expand and diversify in situ and also suggested the presence of a number of activation-induced cytidine deaminase (AID)-expressing B cells in the MZ. The notion of antigen-driven expansion/selection in situ is further supported by the VH CDR3 features of MZ B cells with highly conserved amino acids at specific positions and by the finding of shared (“stereotyped”) sequences in two different spleens. Collectively, the data are consistent with the notion that MZ B cells are a special subset selected by in situ antigenic stimuli.     

Atypical Antigen Recognition Mode of a Shark Immunoglobulin New Antigen Receptor (IgNAR) Variable Domain Characterized by Humanization and Structural Analysis

The immunoglobulin new antigen receptors (IgNARs) are a class of Ig-like molecules of the shark immune system that exist as heavy chain-only homodimers and bind antigens by their single domain variable regions (V-NARs). Following shark immunization and/or in vitro selection, V-NARs can be generated as soluble, stable, and specific high affinity monomeric binding proteins of ∼12 kDa. We have previously isolated a V-NAR from an immunized spiny dogfish shark, named E06, that binds specifically and with high affinity to human, mouse, and rat serum albumins. Humanization of E06 was carried out by converting over 60% of non-complementarity-determining region residues to those of a human germ line Vκ1 sequence, DPK9. The resulting huE06 molecules have largely retained the specificity and affinity of antigen binding of the parental V-NAR. Crystal structures of the shark E06 and its humanized variant (huE06 v1.1) in complex with human serum albumin (HSA) were determined at 3- and 2.3-Å resolution, respectively. The huE06 v1.1 molecule retained all but one amino acid residues involved in the binding site for HSA. Structural analysis of these V-NARs has revealed an unusual variable domain-antigen interaction. E06 interacts with HSA in an atypical mode that utilizes extensive framework contacts in addition to complementarity-determining regions that has not been seen previously in V-NARs. On the basis of the structure, the roles of various elements of the molecule are described with respect to antigen binding and V-NAR stability. This information broadens the general understanding of antigen recognition and provides a framework for further design and humanization of shark IgNARs.