Major Cross-reactivity Research Articles

Non-A, Non-B hepatitis virus: identification of a core antigen-antibody system that cross reacts with hepatitis B core antigen and antibody.

Using immunodiffusion, a major cross-reactivity had been previously demonstrated between hepatitis B(HBe/3 Ag) and the antigen reported in the serum on non A, non-B hepatitis patients, therefore redesignated NANBe Ag. By direct immunofluorescence a new antigen associated with, but distinct from, NANBe Ag has now been identified in the liver of 14/26 patients with NANB chronic active hepatitis. The homologous antibody was detected in the serum of these 14 patients. Behaving like HBc Ag and cross reacting with it by immunofluorescence, the new antigen was termed NANBc Ag. Anti NANBc also became detectable in serial acute phase and convalescence sera from 5/5 NANB Ag-positive posttransfusion hepatitis cases. Further characterization of NANBe and NANBc antigens achieved by fractionation of a NANB virus-infected liver showed NANBc Ag to be expressed on 22-25 nm HB core-like particles containing DNA polymerase activity. Cross-reactivity between NANBc and HBc antigens was confirmed by immunodiffusion. Liver-derived NANBe Ag identical to serum NANBe Ag exhibited the same physical properties as HBe/3 Ag and could be similarly released by disruption of the non-A, non-B, virus cores. These results indicate that hepatitis B and NANB virions not only share the same structure and DNA polymerase activity but are also antigenically related and belong to the same new class of DNA viruses.

ADCC (K-cell) lysis of human erythrocytes sensitized with rhesus alloantibodies. II. Investigation into the mechanism of lysis.

The mechanism of lysis of anti-D coated human erythrocytes by human mononuclear K-cells was investigated. Red cell lysis was measurable after 30 min incubation and reached a maximum by 18--20 h. Cell-to-cell contact was necessary for lysis, phagocytosis was not a prerequisite, and intact microfilament function was required. The divalent cations Ca2+ and Mg2+ were both required for lysis to occur. Studies with metabolic inhibitors indicate that some RNA and protein synthesis is required for maximum expression of ADCC and intact microtubule function is essential. In the present system lysis was mediated by IgG1 anti-D antibodies and was significantly inhibited by IgG1 and IgG3 subclasses with some inhibition by IgG2 but not by IgG4, IgA or IgM. This suggests that the K-cell receptor is specific for IgG but that there is major cross-reactivity between IgG1 and IgG3. The inhibiting effect of hydrocortisone suggests that ADCC inhibition may be one mode of action of corticosteroids in ameliorating autoimmune haemolytic anaemia.

The agglutination reactions of Haemophilus paraphrophilus and H. paraphrohaemolyticus, and some observations on the agglutination of H. Aphrophilus and H. haemoglobinophilus (H. canis).

Agglutination tests were used to study the surface antigens of two recently described species of the genus Haemophilus, H. paraphrophilus and H. paraphrohaemolyticus, and their antigenic relationship to other members of the genus. The results obtained with a few strains of H. haemoglobinophilus and H. aphrophilus are also reported. The species H. paraphrophilus appears to be homogeneous; no major cross-reactions were observed. The species H. paraphrohaemolyticus contains at least three serotypes, of which two have been defined in terms of agglutination reactions. Cross-agglutinations occurred between one strain of H. paraphrohaemolyticus and strains of the other V-dependent species, H. parainfluenzae and H. parahaemolyticus. Of the X-dependent species, H. haemoglobinophilus seems to be homogeneous, and the species H. aphrophilus is not. A non-specific antibody against horse blood in the medium occurred erratically and was present in only two antisera, those raised to H. aphrophilus strain Khairat and H. haemoglobinophilus strain no. NCTC8540.

Inhibition of the Metabolism of Streptococci and Salmonella by Specific Antisera

Streptococcal and salmonella antisera inhibited carbohydrate metabolism for groups A, B, C, and D streptococci and group E salmonella, as measured by the formation of [(14)C]dioxide from [(14)C]glucose metabolism. For salmonella, the inhibition was type specific since group E salmonella were inhibited only by salmonella E antisera and not by anti-salmonella A or C(1). For streptococci, quantitative differences were demonstrated, but major cross-reactivity was observed. At high concentrations, the antisera were bactericidal; at more dilute concentrations, for both salmonella and streptococci, carbohydrate metabolism was suppressed, but subculture on chocolate agar showed abundant growth. Cross-reacting antibodies could be absorbed by incubation with either antigen, e.g., streptococcal antisera versus heat-killed salmonella. The results suggest that the radiometric technique can be more sensitive than either capillary flocculation or visual detection of bacterial growth for detecting the inhibition of streptococci and salmonella by specific antibodies. The use of specific antisera may prove useful for bacterial species identification in an automated system for detection of bacterial growth.

A study of the serotyping of Proteus rettgeri

An approach to the serotyping of Proteus rettgeri through flagellar (H) and somatic (O) antigens is described. Major cross-reactions amongst strains with unlike H or O antigens were shown to be due to a common thermolabile capsular (or envelope) antigen. Absorption of antibodies against the thermolabile antigen resulted in specificity of the typing sera. Eighteen O, twelve H, and one K antigen are defined and their distribution among 83 strains is shown. Typing sera with reliable specificity may now be used in epidemiological investigations of infections with P. rettgeri.

Predicted and unpredicted cross-reactions of an acetylphosphogalactan of Sporobolomyces yeast. II.

The teichoic acid of streptococcal Group N, with end groups of galactose phosphate, had been shown to cross-react with antipneumococcal sera of types VI, XIV, XVI, and XXVII. End groups of D-galactose-1-phosphate in the phosphogalactans of Sporobolomyces yeasts made it predictable that these galactans would precipitate the same antipneumococcal sera and also antisera to streptococcal Group N. The predictions were verified, and other unpredicted reactions were found. Precipitation of much of the antibody in an antipneumoccal type XVIII horse serum was shown to be due to O-acetyl-D-galactose residues in the phosphogalactan, in accord with earlier information that an O-acetyl sugar was a principal determinant of S XVIII. The new results identify this sugar as D-galactose. Since it is linked 1,3- in S XVIII, the O-acetyl group in the Sporobolomyces galactan is probably also on a 1,3-linked residue. Another major cross-reaction in anti-S. paratyphi A serum characterizes the galactose residues in the "O" polysaccharide of the bacillus as members of the D-series probably linked in tandem 1,6-, 1,6-; 1,6-, 1,3-; 1,3-, 1,6-; or 1,3-, 1,3-. Reactions of periodate-oxidized-reduced products confirm the conclusions stated above. Quantitative data are given.

Predicted and unpredicted cross-reactions of an acetylphosphogalactan of Sporobolomyces yeast.

The teichoic acid of streptococcal Group N, with end groups of galactose phosphate, had been shown to cross-react with antipneumococcal sera of types VI, XIV, XVI, and XXVII. End groups of D-galactose-1-phosphate in the phosphogalactans of Sporobolomyces yeasts made it predictable that these galactans would precipitate the same antipneumococcal sera and also antisera to streptococcal Group N. The predictions were verified, and other unpredicted reactions were found. Precipitation of much of the antibody in an antipneumoccal type XVIII horse serum was shown to be due to O-acetyl-D-galactose residues in the phosphogalactan, in accord with earlier information that an O-acetyl sugar was a principal determinant of S XVIII. The new results identify this sugar as D-galactose. Since it is linked 1,3- in S XVIII, the O-acetyl group in the Sporobolomyces galactan is probably also on a 1,3-linked residue. Another major cross-reaction in anti-S. paratyphi A serum characterizes the galactose residues in the "O" polysaccharide of the bacillus as members of the D-series probably linked in tandem 1,6-, 1,6-; 1,6-, 1,3-; 1,3-, 1,6-; or 1,3-, 1,3-. Reactions of periodate-oxidized-reduced products confirm the conclusions stated above. Quantitative data are given.

Cross-Reactions in the Ouchterlony Plate: Analysis of Native and Halogenated Bovine Serum Albumins

Summary Cross-reactions in the Ouchterlony plate were studied by means of native and halogenated bovine serum albumins and several of their antisera. The following observations were made: The comparison of two immunologically related antigens yielded a major cross-reaction for that antigen which possessed a closer affinity to the reference antibody. The degree of cross-reactivity between the antigens was reflected by the length of the spur.When both antigens possessed nearly the same degree of immunologic affinity to the antibody, their precipitate lines would fuse.Identical pairs of cross-reacting antigens yielded different precipitate patterns with different reference antibodies.The formation of separate specific precipitates by cross-reacting antigens in mixtures depended on the relative concentrations of the antigens in the mixture, on the degree of immunologic affinity between these antigens, and on the antibody concentration.The immunologic distinction between related antibodies was much less pronounced than the distinction between the corresponding cross-reacting antigens.Variable precipitate patterns were obtained when cross-reacting antigens were analyzed by means of mixtures of their respective antisera and when immunologically related antisera were analyzed by means of mixtures of their respective antigens. From findings in this and in a preceding paper (9) it was concluded that the basic precipitate patterns described by Ouchterlony do not always indicate immunologic identity, partial identity, or nonidentity; these patterns can be considerably modified by changes in the relative concentrations of the immune systems, by the degree of immunologic affinity between the reagents, by the choice of the reference reagent, and by the degree of immunologic purity of the reference reagent.

Anti-Virus Antibody Studies Following Induced Infection of Man with West Nile, Ilhéus, and Other Viruses

Summary and Conclusions Serial specimens of human serum were studied for the presence of anti-virus antibodies following the intentional inoculation of viruses as part of a clinical experimental study of the effects of these virus infections upon advanced cancer. Included in the study are sera from 20 patients following the inoculation of Smithburn's isolate of West Nile virus, and 50 patients following inoculation of the Egypt 101 isolate of West Nile virus; 20 patients following Ilhéus virus, 10 patients following Newcastle disease virus, and 1 or more patients following inoculation of Bunyamwera, Semliki Forest, Br I, Rabies, and R viruses, and the Egypt 19 and Egypt 21 isolates of West Nile virus. Almost all sera were studied by complement fixation technique, and many were studied by neutralization techniques. Sera from 3 patients were also studied for anti-hemagglutinating antibodies against West Nile virus. All of the techniques included in this study appeared to be approximately equivalent in their capacity to detect and quantitate antibody formation. In general, these viruses caused production of detectable antibodies in a majority of patients between 3 and 4 weeks after virus inoculation. Thereafter neutralizing antibody titers remained generally stable for the duration of this study, which rarely exceeded 6 months, but complement-fixation antibody titers often fell after 3 to 4 months. Newcastle disease virus differend from the other viruses studied in that the onset of complement-fixing antibody formation was more rapid and the titer of serum antibodies was greater than seen with the other viruses studied. This difference, however, was not observed when the neutralization technique was used. These data are in agreement with the conclusion that Egypt 101 virus and West Nile virus are antigenically identical, and data from a single patient is compatible with the view that Egypt 21 virus is also identical with West Nile virus. No satisfactory data were available for any conclusion concerning the Egypt 19 virus. There was no major cross-reaction between the West Nile viruses and Ilhéus virus. Antibodies against Japanese encephalitis virus were demonstrated in 2 patients following inoculation of Egypt 101 and Ilhéus virus. These same sera did not react with Western equine encephalitis virus. There were no data which suggested that any of the patients included in this study had had any previous exposure to West Nile or any antigenically similar virus. A few patients showed suggestive, but not conclusive, evidence of previous contact with antigenic material similar to Ilhéus and Newcastle disease viruses. Antibody formation occurred following inoculation of virus whether the virus propagated or not. Among patients inoculated with a single virus, there was no apparent correlation between the amount of virus propagation and the magnitude of the antibody response. However, when comparing different viruses, it appeared that those viruses which were more infective for man also stimulated greater antibody production. There were suggestive data to indicate that antibody formation in patients with lymphomatous neoplasms is poorer than in patients with other types of neoplastic disease. There was no apparent relationship between antibody forming ability and various types of cancer other than lymphoma.