Reactivity of Two Selected Antigens of Neisseria gonorrhoeae

Two antigen preparations, the soluble antigen and a fraction 1 thereof, isolated in the course of a systematic study of the various antigens of the virulent gonococcus, have been investigated for their ability to serve as antigens for the detection of antibody in patients infected with the gonococcus. The soluble antigen was reactive with 88.2% of the sera from infected females, and fraction 1 was reactive with 71.6% of the sera. Of sera from infected males, only 27.6% reacted with the soluble antigen and only 20.4% with fraction 1. Of sera from individuals presumed free of gonococcal infection, approximately 4% reacted with the soluble antigen; none reacted with fraction 1. This study suggests that these antigens might be adaptable to the detection of human gonococcal antibody, especially in the female.     

Antigenic Structure of Treponema pallidum, Nichols Strain II. Extraction of a Polysaccharide Antigen with “Strain-specific” Serological Activity

An ultracentrifugally homogeneous heat-stable polysaccharide preparation free from serologically reactive rabbit testicular tissue antigen, including cardiolipin, was extracted from the Nichols strain of Treponema pallidum, and found to react by complement-fixation with homologous rabbit sera but not with human syphilitic sera. In addition, the reactive "strain-specific" component was found to be distinct from a second reactive component within the preparation related to an antigen of T. reiteri.     

Reactivity of Two Gonococcal Antigens in an Automated Microhemagglutination Procedure

In studies of several hundred sera, a passive-hemagglutination technique with soluble antigen of sonically treated gonococci as the sensitizing material for tanned erythrocytes and Neisseria sicca sonically treated material as an absorbent detected gonococcal antibodies in 77% of males and 88% of females infected with uncomplicated gonorrhea. However, 6% of the sera from individuals in celibate religious orders and 18% of the sera from a group of females having cervical cultures negative for gonococci were also reactive with this procedure. Erythrocytes sensitized with an alkaline extract of gonococci reacted with 23% of the sera from infected males, 49% of the sera from infected females, and 2% of the sera from celibate females.     

Isolation of an Antigen of Neisseria gonorrhoeae Involved in the Human Immune Response to Gonococcal Infection

Ion-exchange chromatography was used to isolate a fraction from disrupted gonococci which reacts with sera from patients with gonococcal disease in complement-fixation and gel-diffusion tests. This antigenic fraction was shown to be the same as that previously described as having been isolated by gel filtration. The method reported here has the advantage of greater rapidity of isolation together with some improvement in purity.     

Serological Response of Rhesus Monkeys to Histoplasma, Blastomyces, and Coccidioides Antigens

Fifteen adult rhesus monkeys were inoculated with nonviable Histoplasma capsulatum, Blastomyces dermatitidis, or Coccidioides immitis. Antibody assays were made periodically during a 2-year period by use of a complement-fixation (CF) test employing four antigens and a latex-agglutination test. Selected sera were also studied in an immunodiffusion test and a coccidioidin-precipitin test. The serological patterns obtained with the anti-Histoplasma, anti-Blastomyces, and anti-Coccidioides monkey sera were comparable to those of sera from patients with diseases caused by the respective organisms. Rhesus monkeys should provide a good laboratory model for additional studies, including the influence of multiple antigenic stimuli on serologic response and patterns. Monkeys could also be used for the production of antisera required for studies to improve the specificity of the currently available CF antigens.     

Comparative Studies of Antigens from Mycoplasma mycoides and Escherichia coli

Extracts of sonically disrupted Mycoplasma mycoides and Escherichia coli were fractionated by sucrose density gradient centrifugation. The presence of antigen in each of the fractions was determined by complement-fixation and agar-gel diffusion precipitin tests, in which cow, pig, and rabbit anti-M. mycoides sera and rabbit anti-E. coli serum were used. Fractions of M. mycoides, with a buoyant density of 1.225 or lower, fixed complement with cow and pig anti-M. mycoides sera. These fractions also formed precipitin lines with pig antiserum. Fractions in the buoyant density range of 1.10 to 1.20 fixed complement with rabbit anti-E. coli serum, but precipitin lines were not formed. All E. coli fractions fixed complement and gave precipitin lines with homologous serum. But fractions in the buoyant density range of 1.10 to 1.20 had minimal complement fixation with heterologous M. mycoides sera. The cross-reacting antigens in M. mycoides and E. coli had a buoyant density of 1.10 to 1.20; the specific antigens were isolated from M. mycoides at a buoyant density of 1.08 to 1.02.     

Toxoplasmosis II. Studies of Animal Sera Using Complement-Fixation Tests

Serological studies were performed in guinea pigs, a sheep, calf, goat and two pigs experimentally infected with toxoplasmosis. The direct complement-fixation method was effective in detecting antibodies in guinea-pig, goat and sheep sera. The modified complement-fixation technique supplementing complement with normal bovine serum fraction, was required when testing bovine serum. With swine sera best reactions occurred in the indirect complement-fixation test and definite but low grade reactions were produced in the direct test after pro-complementary activity was removed by pH treatment of the sera. Allergic skin reactions were produced in the experimental animals but improvement in the antigen is necessary before the test could be used generally in the field as a diagnostic method for animal toxoplasmosis.     

Isolation of an antigen fromBlastomyces dermatitidis that is specific for the diagnosis of blastomycosis

The A antigen ofBlastomyces dermatitidis has been isolated and purified by DEAE column chromatography. In the complement-fixation test, the antigen reacted with 10 of 16 sera from patients with proven cases of blastomycosis and was negative with known positive sera from 7 cases of histoplasmosis, 5 cases of coccidioidomycosis, 5 cases of candidiasis, and 5 cases of cryptococcosis. In the enzyme-immunoassay test, 25 of 27 sera from cases of blastomycosis were positive, but all heterologous and normal sera tested were negative. The antigen gave a positive skin test with guinea pigs sensitized with killed yeast-phase cells ofB. dermatitidis and negative skin tests with guinea pigs sensitized with killed yeast-phase cells ofHistoplasma capsulatum.     

Antígenos del paracoccidioides brasiliensis para las Reacciones serológicas

Summary The sera from normal subjects gave negative results with the following antigens used in the complement-fixation tests: 1) polysaccharide prepared according toFava Netto's technic; 2) a filtrate of shaked cultures followingAjello et al.'s technic; 3) an aqueous extract of mechanically disrupted yeast cells ofP. brasiliensis.The sera from patients of S.A. blastomycosis gave positive c.f. tests with the three antigens with titer ranging from 1/20 to 1/5, 160. Antigen No 2 gave in 11/18 cases higher titers than the other antigens.Immunodiffusion tests gave positive results with the antigen no 2. The sera from 10 cases of histoplasmosis gave cross reactions with the antigen No 3, in 5/10 cases with the antigen No 2 and in not any case with the antigen No 1.     

Immunodiffusion Analysis of Yaba Poxvirus Structural and Associated Antigens

Yaba poxvirus virions were extracted and purified from Rhesus monkey tumors. A saline-soluble virion fraction (Y-xp), obtained by mechanical fractionation of purified virions with an X-press, contained seven components in acrylamide gel electrophoresis; five of these components were reactive in immunodiffusion with whole virion and Y-xp antisera produced in rabbits and monkeys. The saline-insoluble residue remaining after X-press treatment was hydrolyzed with sodium dodecyl sulfate, urea, and 2-mercaptoethanol (SUM). This fraction, Y-sum, contained five components, four of which were demonstrable by immunodiffusion. There was no evidence of antigenic relationships between Y-xp and Y-sum antigens in immunodiffusion. In acrylamide gel electrophoresis, one Y-xp and one Y-sum component had similar mobilities. Y-xp but not Y-sum antisera contained viral-neutralizing antibodies. Virus-free saline extracts of Yaba tumor prepared with Genetron (YS) were essentially devoid of virion structural antigens. They failed to induce precipitating antibodies for virion antigens, were nonreactive in immunodiffusion with virion antisera, and gave low complement-fixation titers with virion antisera. Yaba virion antigens were recovered from the Genetron tumor sediment by SUM and alkaline hydrolysis. Antisera prepared to YS extracts gave a maximum of 17 precipitin lines in immunodiffusion with YS extracts; none was identified as a virion structural antigen. Saline extracts of tumor prepared without Genetron contained immunogenic amounts of 5 virion antigens and 12 to 14 associated antigens. Animals immunized with infected cell culture extracts (virus-free) formed antibodies to six to seven virion antigens. The implications of using extracts of Yaba poxvirus-infected tissues in complement-fixation tests to measure virion antibodies were discussed.     

Agar-Gel Precipitin-Inhibition Test for Coccidioidomycosis: I. Preliminary Evaluation of the Complement-Fixation and Agar-Gel Precipitin Tests in the Serodiagnosis of Human Coccidioidomycosis

The agar-gel precipitin-inhibition serological test for coccidioidomycosis was a more sensitive indicator of Coccidioides immitis antibodies than the tube precipitin, the agar-gel immunodiffusion, in the complement-fixation tests in assaying monkey sera, whether these sera were from prechallenge-vaccinated or postchallenged animals. When applying this technique to the assay of human sera, an analogous finding generally persisted. However, some human sera were positive by the complement-fixation test and negative by the agar-gel precipitin-inhibition test. These sera were diffused in agar-gel against various coccidioidin complement-fixation, tube precipitin, and agar-gel precipitin-inhibition test antigens with essentially negative results.     

Proteins of Vesicular Stomatitis Virus: II. Immunological Comparisons of Viral Antigens

The antigens of the nucleoprotein core and the coat of vesicular stomatitis virus (VSV) particles of the Indiana serotype were prepared and purified by sucrose gradient fractionation. Antibody was prepared separately to each of the two antigen fractions. By immunological procedures, it was shown that soluble antigens of VSV preparations sedimenting at 20S and in the leading edge of the 6S region are antigenically related to VP3, the protein of the virus core, whereas the 6S soluble antigen cross-reacts only with viral coat antibodies. These results confirm previous results obtained by polyacrylamide gel analysis of the antigens. It has further been demonstrated that the 6S antigen is a glycoprotein. Comparing antigens of the New Jersey and Indiana serotype showed that the coat antigens of virus particles and the 6S antigen are immunologically distinct in the two serotypes. In complement-fixation tests, the core antigens and the soluble 20S antigens from one serotype showed a cross-reaction with antiserum prepared against core proteins of the other serotype.     

Variability of the lytic susceptibility of Neisseria gonorrhoeae to human sera.

The bactericidal activity of human sera for Neisseria gonorhoeae was studied. Sera were obtained from a group of patients with gonococcal infections who had acute urethritis, acute pelvic inflammatory disease, disseminated gonococcal infection, or who were asymptomatic carriers. The homologous and heterologous strains were tested with these sera. The development of serum bactericidal antibodies was not a universal event. With few exceptions, the susceptibility of a particular strain to human antibody and complement appeared to be largely independent of the particular person from whom the serum was obtained and was due instead to antigenic properties intrinsic to each individual strain. Lipopolysaccharide appeared to be the predominant antigen against which bactericidal antibodies were directed. The principal bactericidal antibody class was IgM. Blocking antibodies were not found to account for the lack of lytic activity. A correlation of bactericidal antibodies with protection from developing gonococcal infection could not be demonstrated in three pateints.     

Induction of reaginic (IgE) gonococcal antibodies in the rat by a common antigen of Neisseria gonorrhoeae.

An antigen (ZAB) common to Neisseria gonorrhoeae was prepared by stepwise elution of a crude gonococcal antigen (ZA) from columns of diethylaminoethyl cellulose employing 0.02 M phosphate buffers, pH 7.6, containing increasing concentrations of sodium chloride. Rats immunized with ZAB produced reaginic (IgE) antibody which cross-reacted with ZA prepared from eight gonococcal strains by the passive cutaneous anaphylaxis (PCA) test. Heating of the sera at 56 degrees C for 4 h destroyed the PCA activity. The PCA activity of the anti-ZAB rat serum was removed after absorption with ZAB antigen or with rabbit anti-rat IgE but not after absorption with gonococcal lipopolysaccharide or with heat-killed or formalinized gonococci. Treatment of ZAB with trypsin or heating at 100 degrees C for 30 min destroyed or reduced the antigenic activity respectively. Further purification of ZAB by filtration through Sephadex G-100 gave a preparation (ZAB2) which contained the common antigen as shown by the cross-reactivity of anti-ZAB2 rat serum with seven stains of N. gonorrhoeae. Fraction ZAB2 contained material which had a molecular weight less than 13,700 and was associated with the presence of material absorbing at 260 nm. The results of this study indicate that a low molecular weight antigen, which appears to be protein in nature and associated with nuclei acid, is common to the gonococcus and is the main antigenic component inducing reaginic (IgE) antibody in the rat.     

Antigens of Pichinde virus I. Relationship of soluble antigens derived from infected BHK-21 cells to the structural components of the virion.

Antigens detected by the complement-fixation (CF) test were prepared from BHK-21 cells infected with Pichinde virus.The preparations contained two antigens demonstrable by immunodiffusion. The antigen present in abundance was heat stable, Pronase resistant, and had a molecular weight of 20,000 to 30,000 as estimated by gel filtration. Polyacrylamide gel electrophoresis of purified antigen demonstrated two low-molecular-weight polypeptides. An identical antigenic determinant was found by disrupting purified virus with Nonidet P-40; however, none of the viral polypeptides co-migrated with the polypeptides derived from purified CF antigen. Pronase digestion of disrupted virus did not alter antigenicity but degraded the viral peptides to sizes similar to those associated with the major CF antigen. These observations suggest that the major CF antigen of Pichnide virus is a cleavage product of the structural proteins of the virus.     

Comparison of Schistosoma mansoni Soluble Cercarial Antigens and Soluble Egg Antigens for Serodiagnosing Schistosome Infections

A Schistosoma mansoni cercarial antigen preparation (cercarial transformation fluid – SmCTF) was evaluated for detection of anti-schistosome antibodies in human sera in 4 collaborating laboratories. The performance of SmCTF was compared with that of S. mansoni egg antigens (SmSEA) in an indirect enzyme-immunoassay (ELISA) antigen assay, the latter being used routinely in 3 of the 4 participating laboratories to diagnose S. mansoni and S. haematobium infections. In the fourth laboratory the performance of SmCTF was compared with that of S. japonicum egg antigens (SjSEA) in ELISA for detection of anti-S. japonicum antibodies. In all 4 laboratories the results given by SmCTF in ELISA were very similar to those given by the antigen preparation routinely used in the respective laboratory to detect anti-schistosome antibodies in human infection sera. In so far as the ELISA results from SmCTF are thus so little different from those given by schistosome egg antigens and also cheaper to produce, the former is a potentially useful new diagnostic aid for schistosomiasis.     

Estudio comparativo de las reacciones serologicas cuantitativas con un antigeno metabolico de Aspergillus fumigatus

Summary The following quantitative serologic reactions: agar-gel immunodiffusion, complement-fixation, opposite electrophoresis and latex particle agglutination tests have been performed in 38 sera from mycologically proved pulmonary aspergillosis cases. A metabolic antigen from a strain ofAspergillus fumigatus according toAjello et al technic modified by us, has been employed. Sera from 120 subjects suffering from non-mycotic lung conditions, as well as 10 sera from histoplasmosis cases, 10 sera from S. A. blastomycosis and 2 sera from patients with lung aspergillosis produced byA. niger, gave negative results with the above mentioned seroligic reactions.One hundred per cent of positive results were obtained with the complement-fixation test (titre ranging from 1/20 to 1/1280), agar-gel immunodiffusion test (titre up to 1/64) and the opposite immunoelectrophoresis (titre ranging from 1/2 to 1/256). Twenty five per cent negative and 4 non-specific results were registered with the latex particle agglutination test.A correlation of the number of serum precipition bands obtained by the electrophoresis technic with the titre of the quantitative serologic reactions, as well as a correlation of the titre of the circulating antibodies with the severity of the clinical form of aspergillosis seems to be present.Electrophoretic motility of the specific antibody performed in 10 sera showed results like the IgM in 1 instance and an intermediate position between IgA and IgG in 9 samples.     

Complement-Fixing Antigens Produced by Varicella-Zoster Virus in Tissue Culture

The complement-fixing antigens present in tissue cultures infected with varicella-zoster virus were separated into four components. There were (i) a cell-free soluble antigen, (ii) a cell-associated soluble antigen, (iii) a cell membrane-associated antigen, and (iv) a virion antigen. All four antigens were reactive with sera from patients with varicella or zoster, and about 90% of the total complement-fixing activity was found to be nonvirion associated.     

梅毒螺旋体重组抗原酶联免疫吸附试验的建立及应用

建立梅毒螺旋体重组抗原酶联免疫吸附试验（ELISA）,用于梅素血清学诊断和调查。其法,用表达的重组抗原IPN17和TmpA,建立检测血清特异抗体的间接ELISA,并与其它检测方法比较,分别检测梅毒参比血清、病人及献血员血清。其结果,敏感性、特异性均为100％。新建ELISA与TPHA的总符率为95．7％,明显高于RPR与TPHA的总符合率（89．1％）。献血员人群抗体阳性率为0．3％－0．69％,健康人群中抗体阳性率较低。     

Interactions of Standard Antibody with Australia Antigens in Au Ag-Ab Radioimmunoassay

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of (125)I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of (125)I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of (125)I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens. Without free Au antigen or antibody in the resultant mixtures there was no inhibition or enhancement; the mixtures presumably contained immunoreactively equivalent proportions of Au antigen and antibody. RIA data for diagnostic specimens indicated an end-point sensitivity which was proportional to the dilution of the standard anti-Au sera used in the test. High concentrations of the standard antibody permitted detectable inhibition of (125)I-Au antigen precipitation at lower antigen specimen concentrations. Similarly, low concentrations of the standard antibody permitted detectable enhancement of (125)I-Au antigen precipitation at lower antibody specimen concentrations. Omitting the standard antibody altogether resulted in a more sensitive RIA for Au antibody in test sera.