[Preparation and analysis of antiserum against light chains of human immunoglobulins]

Antisera to kappa chains were obtained in rabbits and sheep by immunization with monoclonal IgG or Bence-Jones proteins of kappa type. Antisera to lambda chains were obtained only in rabbits by immunization by lambda Bence-Jones proteins, but not with monoclonal IgG; sheep failed to produce antibodies to lambda chains. Antisera were evaluated by immunoelectrophoresis using Bence-Jones proteins of the same type and myeloma serum with monoclonal IgG of the other type. Unabsorbed antisera revealed two bands in the myeloma serum, one of which was formed by the monoclonal IgG reacting with antibodies to the gamma chain, the other -- by normal IgG reacting with both antibodies to the gamma and to the light chains. After adsorbtion with the monoclonal IgG of the other type only the normal IgG band was revealed by antibodies to the light chain. Comparative immunochemical analysis of antisera obtained at various stages of immunization with monoclonal IgG or Bence-Jones proteins showed that in the kappa chains the most antigenic were surface (accessable) determinants and in the lambda chains -- nonaccessable determinants.

The sub-type classification of strains of foot-and-mouth disease virus

Sixteen foot-and-mouth disease virus (FMDV) strains of type SAT 1 were compared in complement-fixation tests. With the test used, the range of antigenic variation within a type appeared to be greater than previously described. The concept of a sub-type group within which all strains are more closely related to each other than to any strain outside the group was not supported. Considering the group of strains studied, it is suggested that the classification of strains is best achieved by moninating a reference strain for each sub-type. Others are classified as related strains in one or more sub-type groups according to their relationships with the reference strains.

[Obtaining specific non-adsorbed sera to Haemophilus influenza for the agglutination test on glass]

Type-specific agglutinating sera to capsular antigenas of H. influenzae were recovered (from 1:3200 to 1:25600). With the given immunization scheme there formed mostly IgG immunoglobulins, and only insignificant amount of IgM (separation of G-200 Sephadex gel). IgG were found to be responsible for the type-specificity of the sera to bacteria, whereas the cross reactions within the H. influenzae genus were connected connected with the IgM. Use of the sera heated at various temperature regimens offered a possibility of obtaining highly specific agglutinating sera with the aid of which express serodiagnosis of the isolated H. influenzae strains was possible.

Distribution of troponin components in the thin filament studied by immunoelectron microscopy

1. The localization of specific antiboidies against troponin components, i.e., troponin T(TN-T), troponin I(TN-I, and troponin C(TN-C), was studied by the use of an electrom microscope. 2. Every antibody was distributed along the thin filament with a period of 38 nm. 3. Staining with anti-TN-I or anti-TN-C formed narrow striations. The location of the first striation was 26 nm from the free end of the thin filament. 4. The width of individual striations formed by anti-TN-T was 14--20nm The H-band-side end of each striation coincided with the location of anti-TN-I or anti-TN-C.

The hapten-carrier effect in teleost fish

The sea robin (Prionotus evolans), a representative teleost fish, was found to undergo the hapten-carrier effect, suggestive of T-B cell cooperativity, in vivo with dinitrophenyl as the hapten and bovine gamma-globulin or bovine serum albumin as carriers. In contrast to mammalian systems, the secondary anti-hapten response in the sea robin was found to involve exclusively high molecular weight antibody.

Serological classification of anti-I sera

Twelve anti-I sera were examined by means of broad panel of cells: OI, BI, OhI, Oicord, Oiadult, BI-F. Titration, fixation-elution, and haemagglutination-inhibition tests, and comparison of agglutination of untreated and neuraminidase-treated erythrocytes allowed to establish the specificity of the sera. For some sera the serological heterogeneity was revealed, which consisted in the following combinations of two or more kinds of specificity: anti-I-D plus anti-I-F, anti-I-D plus anti-i, anti-I-D plus anti-I-S, anti-I-D plus anti-I-F plus anti-I-S. Methodical problems of classification of anti-I sera are discussed.

Reference equine antisera to 33 human adenovirus types: homologous and heterologous titers

Equine antisera to human adenovirus types 1 to 33 were prepared and evaluated by hemagglutination-inhibition and serum neutralization tests. Detailed data on the potency and purity of the immunizing antigens were tabulated as one means of evaluating the antisera. Most of the 52 hemagglutination-inhibition and 25 serum neutralization major or minor heterotypic responses among the equine antisera were observed at similar levels in previous studies with rabbit antisera and appeared to represent genuine antigenic relationships among the human adenoviruses. Equine antisera to human adenoviruses 1 to 33 and a similarly packaged normal horse serum served as lots of fully tested sera for definitive typing of isolates and as reference standards for evaluating other antisera.

The development of radioimmunoassays for fibrinogen degradation products: fragments D and E

Fibrinogen degradation products, fragment D (FgD) and fragment E (FgE) have been measured in human serum by specific radioimmunoassays. In addition, the appearance of a neoantigenic determinant on FgD, revealed when fibrinogen is degraded by plasmin has been utilized to develop a specific radioimmunoassay for FgD in plasma (FgDneo). The reagents and conditions used in each assay are described in detail. The mean specific activity was 144 muCi/mug for 125I-labelled FgE and 82 muCi/mug for 125I-labelled FgD. Separation of antibody bound and free antigen was achieved using second antibody. The detection limits of the FgE, FgD and FgDneo assays were 0.8, 1.0 and 6.2 ng/ml respectively. The specificity of each assay with respect to fibrinogen and its degradation fragments has been assessed. Fibrinogen and fragment X cross-reacted markedly in both the FgE and FgD assays, whereas the cross-reaction of fibrinogen was abolished in the FgDneo assay, while the cross-reaction of fragment X was 10%, indicating gradual emergence of the neoantigenic site during digestion of fibriogen. The sensitivity, precision, and specificity of the radioimmunoassay systems described have major advantages over the existing procedures for the measurement of fibrinogen degradation products.

Quantitative determination of allotypic and idiotypic markers with antisera coupled to N-hydroxysuccinimide-activated sepharose

N-hydroxysuccinimide activated Sepharose beads (HAS) were used to immobilize allotypic and idiotypic antisera for use in radioimmunoassays. These HAS antisera were compared to antisera solidified with ethylchloroformate (ECF) with respect to their reactivity, specificity, and ability to detect subspecificities of the group a allotypes. The HAS antisera rated favorably in all comparisons with ECF antisera and are far superior with respect to ease of preparation and retention of antibody activity.

Double diffusion in gel tests with Paul-Bunnell antibodies of infectious mononucleosis sera

Double diffusion tests in gel were employed for studies of reactions between infectious mononucleosis sera and extracts of bovine, sheep and equine erythrocyte stromata. The extracts were obtained by ultrasonication of stromata prepared from trypsin-digested erythrocytes. The reaction with bovine stroma extract was composed, in many instances, of two lines. A single line was observed in reactions with sheep and equine stroma extracts. This line merged into a reaction of partial or complete identy with one of the lines formed with bovine stroma extract. Evidence was obtained that some infectioous mononucleosis sera may contain heterophile (Paul-Bunnell) antibodies belonging to IgG class in addition to those of IgM nature.

Infection of the mosquito Aedes aegypti with infectious West Nile virus-antibody complexes

Aedes aegypti fed through chick skin membranes on West Nile virus-homologous antiserum mixtures shown by an anti-globulin neutralization test to be highly infectious complexes (in terms of plaque formation in tissue culture) failed to become infected. Control mosquitoes fed on West Nile virus--normal rabbit serum mixtures containing similar or smaller amounts of infectious virus were shown to become infected. Mosquitoes ingesting suspensions of West Nile virus previously incubated with Murray Valley encephalitis or Ntaya antiserum became infected at significantly lower rates (P = less than 0-05) than controls ingesting West Nile virus-normal rabbit serum mixtures. West Nile virus--17D yellow fever or dengue--2 antiserum mixtures did not produce significantly reduced infection rates in Ae. aegypti when compared to controls.

Use of radioimmunoassays to determine the concentration of streptococcal group-specific antibodies in rabbit antisera

A radioimmunoassay was developed for the quantitation of antibodies to the Group A, A-variant, and C carbohydrates in rabbit streptococcal antisera. The assay employs radiolabeled purified Group carbohydrate which has been tyrosylated to allow for incorporation of 125-I. This assay has an advantage over the intitative precipitin test because it measures non-precipitating antibody in addition to precipitating antibody. Furthermore, 7S anti-IgG in rabbit antisera give a falsely elevated value for the antibody concentration in the quantitative precipitin test. This did not occur with the radioimmunoassay. The assay described is reproducible, sensitive, and uses little antisera.

A solid-phase radioimmunoassay for plasma progesterone

A detailed procedure is presented for the assay of plasma progesterone. The routine assay is based on the use of antiserum which is covalently linked to microcrystalline cellulose, the double-antibody method being used as a reference separation system. This procedure gives high precision accompanied by small and acceptable losses of antiserum titre but without loss of sensitivity when compared with the double-antibody method. Ethanol is first added to the plasma (10vol. of plasma+1vol. of ethanol) after which a single extraction with light petroleum yields a constant recovery [92.4+/-1.2 (s.d.)% of added [(3)H]progesterone] and obviates the need for tracer recoveries on each sample being assayed. Distortions of the response curve owing to solvent residues have been almost eliminated. The assay can measure progesterone at all stages of the menstrual cycle when volumes of 200mul of plasma are used and this permits the detection of the periovulatory rise at its inception. Detailed specificity studies are presented for the assay end point itself and these are related to the responses to be expected in extracts of plasma. Progesterone-like activity was found in urine and a fourfold increase in excretion rates was observed between the follicular and luteal phase of the normal menstrual cycle.

Autogenous immunity to endogenous RNA tumor virus: differential reactivities of immunoglobulins M and G to virus envelope antigens

The autogenous humoral immune response of mice to their endogenous leukemia virus has been examined in terms of the reactivities of individual classes of antibody present in normal B6C3F(1) serum. Whole serum and the immunoglobulin (Ig) M and IgG fractions of serum from animals of different age groups were compared by radioimmune precipitation assays and viral infectivity neutralization assays. Both IgM and IgG fractions were able to precipitate virus, although not as effectively as whole serum. Virus-specific antibody levels, as well as total antibody concentrations in whole serum, appeared to increase with age. Sodium dodecyl sulfate gel electrophoresis analysis was performed with immune precipitates obtained when whole serum or 19 or 7S fractions from animals of different age groups were reacted with disrupted virus. The 19S antibody fraction reacted with three antigenic determinants on the viral envelope. These antigens have apparent molecular weights of 17,000, 43,000, and 68,000. The last two appear to be glycoproteins and may correspond to the M(2) and M(1) antigens. In contrast, the 7S component reacted only with the 17,000-molecular-weight protein. Neutralization assays against BALB:virus-2, a xenotropic endogenous mouse type C virus, revealed that 19S and whole serum but not the 7S fraction possessed neutralizing activity. These findings indicate that there are differential reactivities of IgM and IgG antibodies in normal serum of B6C3F(1) mice, with respect to both recognition of viral envelope antigens and neutralization of endogenous MuLV. These results are consistent with the hypothesis that the autogenous humoral immune response is a systemic host function that may be important in the regulation of endogenous type C virus expression in vivo.