Protective ability and specificity of convalescent serum from calves with Haemophilus somnus pneumonia.

The ability of convalescent serum to passively protect calves against Haemophilus somnus-induced pneumonia was studied. Preimmune and convalescent serum were obtained from calves before or after recovery from experimental chronic H. somnus pneumonia. Passive protection was assessed in another group of calves by intrabronchial inoculation of H. somnus that had been incubated with preimmune or convalescent serum. Each calf was inoculated with each treatment in alternating caudal lung lobes. Twenty-four hours after inoculation almost no pneumonia was present in lungs inoculated with bacteria incubated with convalescent serum, whereas severe pneumonia was present in lungs inoculated with bacteria incubated with preimmune serum. Quantitation of calf pneumonia in both treatment groups indicated a significantly different protective capacity between convalescent serum and preimmune serum (P less than 0.0005). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western blotting of purified H. somnus lipopolysaccharide resulted in intense reactivity with convalescent serum, but no reactivity was detected with preimmune serum. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of H. somnus outer membrane-enriched fractions, Western blots with convalescent serum gave intense reactions against H. somnus outer membrane antigens with apparent molecular masses of 78 and 40 kilodaltons and weaker reactions with 60-, 34-, 31-, 29-, 18-, and 15-kilodalton outer membrane antigens. No reactivity was detected with preimmune serum. Antibodies eluted from H. somnus after adsorption of convalescent serum reacted almost identically to unadsorbed convalescent serum in Western blots against bacterial outer membrane-enriched fractions. Thus, most of the antigens recognized by convalescent serum are likely to be on the bacterial surface and accessible to antibody. Surface antigens recognized by protective convalescent serum are candidate antigens for a subunit vaccine against H. somnus pneumonia.     

Human serum antibodies reactive with dietary proteins. Antigenic specificity

The antigenic specificity of human serum IgG antibodies reactive with common dietary proteins has been evaluated by competitive binding using a solid-phase immunoassay (ELISA). Antibodies reactive with bovine milk antigens were shown to be reactive predominantly with casein, rather than alpha-lactalbumin, beta-lactoglobulin, gamma-globulin or albumin. Furthermore, sera containing antibodies reactive with bovine casein, wheat gliadin and chicken ovalbumin showed competitive binding only by each respective dietary protein antigen. IgG4 antibodies specifically reactive with ovalbumin, gliadin or casein were also not cross-reactive in competitive binding studies. Furthermore, both IgG2 and IgG4 anti-milk antibodies showed significant inhibition only with bovine casein, and not with alpha-lactalbumin or beta-lactoglobulin. These data are relevant to concepts regarding the immunobiological role of antibodies of the IgG4 isotype.     

Antigenic specificity of serum antibodies in mice fed soy protein

BACKGROUND: Soybean protein is used in a number of food products but unfortunately is also a common cause of food allergy. Upon ingestion of soy protein, healthy mice like other animals and humans generate a soy-specific antibody response in the absence of signs of illness. Not much is known about the relationship between the immunogenic proteins involved in this nondeleterious antibody response and the pathological response associated with food allergy.The objective of the present study was to characterize the antigenic specificity of the soy protein-specific antibody response generated in healthy mice ingesting soy protein. METHODS: Blood from mice fed a soy-containing diet was analyzed using ELISA and immunoblot for antibody reactivity towards various soy protein fractions and pure soy proteins/subunits. Mice bred on a soy-free diet were used as controls. RESULTS: The detectable antigenic specificity of the serum antibodies of soy-consuming mice comprised glycinin and beta-conglycinin. Immunoblots with soy protein extract demonstrated antibody reactivity towards both the basic and the acidic chains of glycinin and the beta-conglycinin subunits with an individual response pattern among mice. Moreover, antibody reactivity was found towards the native quaternary structure of glycinin. CONCLUSIONS: Mice ingesting soy protein generate an antibody response with reactivity towards glycinin and beta-conglycinin. Antibody reactivity found towards the native quaternary structure of glycinin indicates an oral immunogenicity of the highly processing-resistant oligomerized glycinin.     

Antigenic and genetic analyses of human rotavirus with dual subgroup specificity.

In our previous study (S. Urasawa, T. Urasawa, K. Taniguchi, F. Wakasugi, N. Kobayashi, S. Chiba, N. Sakurada, S. Morita, O. Morita, M. Tokieda, T. Kawamoto, K. Minekawa, and M. Oseto, J. Infect. Dis. 160:44-51, 1989) of antigenic characterization of about 300 human rotavirus (HRV) isolates collected at different localities in Japan, we found 4 HRV isolates having unique antigenic and genetic constructions. The four strains possessed both subgroup I and subgroup II antigens, serotype 3 antigen, and a long RNA electropherotype. The reactivity pattern of these four HRV isolates with three monoclonal antibodies (MAbs) directed to an outer capsid protein, VP4, and with one MAb directed to an inner capsid protein, VP2, was clearly different from those of usual subgroup II HRVs having serotype 1, serotype 3, or serotype 4 specificity and a long RNA pattern, whereas their reactivity pattern was similar to that of strain K8 (subgroup II, serotype 1), which possessed unique VP4 and VP2 proteins. RNA-RNA cross-hybridization analysis indicated that while the four isolates were genetically distinct from the two genetic groups of HRV reported previously, i.e., the Wa family (strains KU, S3, and YO) and the DS-1 family (strain S2), they were closely related to strain K8, a strain having unique antigenic and genetic properties (K. Taniguchi, K. Nishikawa, T. Urasawa, S. Urasawa, K. Midthun, A. Z. Kapikian, and M. Gorziglia, J. Virol. 63:4101-4106, 1989).     

Antigenic determinants of bovine serum albumin.

BACKGROUND: Bovine serum albumin (BSA) is one of the most widely studied proteins; its structure is well known and its antigenic characteristics have been described in several papers. The aim of this research was the identification of the BSA antigenic determinants. METHODS: This study was performed using limited proteolysis and an immunoblotting technique, in which a commercial murine antibody and sera from children sensitized to BSA were used. RESULTS: Findings suggest amino acids (aa) 524-598 as an epitopic area for human species. The most critical sequence seems to be aa 524-542, even if it must be included in a longer fragment to be recognized by antibodies. Murine IgG antibodies also recognize fragments contained in the first half (NH(2)-terminal portion) of BSA. CONCLUSIONS: The results presented in this study indicate that the epitopic sites of an antigenic protein can be different when different species are considered, so that data obtained with antibodies from animal species cannot be directly extrapolated to the behavior of human IgEs.     

Antigenic specificity of chlorpromazine-induced antinuclear antibodies

A few patients have been reported who developed systemic lupus erythematosus (SLE) in the course of prolonged treatment with chlorpromazine. Patients on this drug have also been found to have antinuclear antibodies (ANAs) although they do not develop lupus.

We have studied the antigenic specificity of ANAs in fifty-four patients on longterm chlorpromazine treatment and compared our findings with those on 175 patients on anticonvulsants, 215 patients on isoniazid, 109 SLE patients and fifty-four healthy subjects, sex and age matched to the chlorpromazine patients.

Thirty-nine per cent of patients on chlorpromazine had ANAs which were most frequently directed to single stranded (s)DNA. In contrast, patients on anticonvulsants as well as those on isoniazid had ANA directed to soluble nucleoprotein (sNP) most frequently and none of the patients on isoniazid had ANA to sDNA.

The mechanisms by which chlorpromazine, isoniazid or anticonvulsant intake results in ANAs probably differ. Our findings suggest that development of ANAs in patients on chlorpromazine may be initiated by interaction of the drug with denatured DNA.

     

Antigenic glycopolypeptides HA1 and HA2 of influenza virus haemagglutinin. III. Reactivity with human convalescent sera.

The immune reactivity to both haemagglutinin glycopolypeptides HA1 and HA2 [prepared from bromelain-released haemagglutinin of influenza virus A/Dunedin/4/73 (H3N2)], was demonstrated by both gel double immundiffusion and radioimmunoassay in human convalescent sera obtained after natural infection during influenza epidemics in 1974/75 and 1976/77. In gel double immunodiffusion, the precipitin line(s) corresponding to glycopolypeptide HA1 were always more distinct than precipin line(s) corresponding to glycopolypeptide HA2. In radioimmunoassay, human convalescent sera revealed higher titres for binding of 125-I-labelled HA2 than for 125-I-labelled HA1. Characterization of human convalescent sera was completed by haemagglutination-inhibition test.     

Foot-and-mouth disease virus carrier state in cells cultured from tissues of convalescent cattle

Summary Cultures were made from mucosal tissues of the pharynx, esophagus, rumen and tongue of cattle convalescent (7 days) from foot-and-mouth disease (FMD) infection. The persistence of FMD virus in the cell cultures was demonstrated by fluorescent antibody technique and by subcultures in primary swine kidney cells using cytopathic effect and plaque assay techniques.Virus persisted in the cell cultures and was found in the supernatant fluids, in washed and lysed cells, and in cells by fluorescent antibody reaction of the various samples for the number of weeks indicated, respectively: tongue — 3, 3, 5; rumen — 5, 5, 7; pharynx — 25, 25, 24; and esophagus — 25, 16 (intermittently), 24. Interferon was not detected in the supernatant fluids of any of the cultures.The virus-laden cultures did not show gross signs of infection, whereas mucosal cultures from similar areas of normal cattle were destroyed in about 18 hours after inoculation with stock virus. Both the infected cultures and noninfected normal cultures deteriorated after 25 to 26 weeks.The carrier virus isolated at 22 weeks from the esophageal and pharyngeal cultures showed decreased pathogenicity to different primary and cell line kidney cultures and to mice, as compared to the parent virus. The carrier viral isolates were infective for cattle. However, esophageal-pharyngeal (EP) fluids from steers inoculated with the carrier virus isolated from the esophageal culture at 22 weeks contained more virus at 7 and 14 days than the EP fluids from a steer inoculated with the carrier virus isolated from the pharyngeal cell cultures.     

The specificity of anti-actin serum.

The immunogenicity of smooth muscle actin is increased by ageing at 4 degrees for at least a week. Rabbits lacking natural smooth muscle antibodies were injected with 1 mg of aged purified actin in adjuvant. Fourteen out of thirty-six rabbits produced serum antibodies which precipitated with actin solution, but not with smooth muscle tropomyosin, myosin, light or heavy meromyosin or with other unidentified non-actin proteins in crude extracts. Analysis of crude actin extract before and after precipitation by antiserum (i) by Sephadex G-200 chromatography and (ii) for its stimulating effect on myosin ATPase activity showed that actin was selectively removed. The precipitate itself, analysed on SDS-polyacrylamide gel, showed one band in the actin position, and otherwise only bands representing immunoglobulins. The antiserum also inhibited the ability of actin to stimulate myosin ATPase activity, and prevented polymerization of G-actin to F-actin, as shown by viscosity and EM studies. On immunoflouresence with cryostat tissue sections or cell cultures, anti-actin serum stained smooth muscle fibres and many non-muscle cells, in the latter staining the microfilaments. The staining was prevented by absorbing the antiserum with actin (16 mug per 5 mul serum), and was abolished by pretreatment of the cells with cytochalasin B. No species specificity was demonstrated for these anti-actin antibodies.     

Antigenic variation of the viruses belonging to the tick-borne encephalitis complex as revealed by human convalescent serum and monoclonal antibodies

Solid-phase enzyme-linked immunoassay (ELISA) was used for the detection of antigenic relationships and/or differences among the viruses belonging to the tick-borne encephalitis (TBE) complex. Monoclonal antibodies of IgM class with haemagglutination-inhibiting activity to the Skalica strain of TBE virus were used to compare the TBE complex viruses. Antigenic analysis of 9 viruses of the TBE complex, isolated from Eurasia and America showed close relationships among them. Nevertheless, it was possible to differentiate the Skalica strain from Langat, louping-ill and Omsk haemorrhagic fever (OHF) viruses by ELISA when monoclonal antibodies and antigens were diluted 1:10,000. Monoclonal antibodies to the Russian spring-summer encephalitis virus did not react with the Skalica strain in immunofluorescence test. By the use of convalescent serum no reaction was found with louping-ill, Russian spring-summer encephalitis, Powassan and OHF viruses in haemagglutination-inhibition (HI) test.     

Comparison of abortion and infection after experimental challenge of pregnant bison and cattle with Brucella abortus strain 2308

A comparative study was conducted using data from naive bison (n = 45) and cattle (n = 46) from 8 and 6 studies, respectively, in which a standardized Brucella abortus strain 2308 experimental challenge was administered during midgestation. The incidence of abortion, fetal infection, uterine or mammary infection, or infection in maternal tissues after experimental challenge was greater (P < 0.05) in bison than in cattle. In animals that did abort, the time between experimental challenge and abortion was shorter (P < 0.05) for bison than for cattle. Brucella colonization of four target tissues and serologic responses on the standard tube agglutination test at the time of abortion did not differ (P > 0.05) between cattle and bison. The results of our study suggest that naive bison and cattle have similarities and differences after experimental exposure to a virulent B. abortus strain. Although our data suggest that bison may be more susceptible to infection with Brucella, some pathogenic characteristics of brucellosis were similar between bison and cattle.     

Antigenic specificity of two antibodies directed against the thymic hormone serum thymic factor (FTS)

Serum thymic factor (facteur thymique serique, FTS) induces in vitro differentiation of T-cell precursors into more mature cells with T-cell characteristics. As isolated from porcine serum, FTS is the nonapeptide GIp-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn. We have described two radioimmunoassays that detect FTS but not other thymic hormones [Ohga et al., (1982) J. Immun. Methods, in press]. One assay is based on a monoclonal antibody from a hybridoma derived by fusion of mouse myeloma cells and spleen cells from a mouse immunized with an FTS-mouse IgG conjugate. The second assay is based on the antiserum from a rabbit immunized with FTS bound to F(ab')₂ fragments of rabbit IgG. The detailed antigenic specificity of these anti-FTS antibodies was determined by measuring the ability of FTS and 12 synthetic FTS peptide analogues to compete with a radioiodinated FTS analogue in these radioimmunoassays. The mouse monoclonal antibody and the rabbit antiserum showed similar structural requirements for binding of the FTS peptides. Since FTS had been attached to the carrier proteins through the ε-amino group of Lys-3, both antibodies were relatively insensitive to omission of 1 or 2 N-terminal residues, replacement of Glp-1 with either Ala or Tyr-Ala, or substitution of Lys-3 with Ala. In contrast, binding of FTS to the antibodies was substantially decreased by omission of 3 or 4 N-terminal residues, omission of 2 or 3 C-terminal residues, or replacement of Gly-7 or Asn-9 with Ala. Relative to the mouse monoclonal antibody, the rabbit antiserum was more sensitive to the omission of 4 N-terminal residues and much more sensitive to replacement of Gln-5, Gly-6, or Asn-9 by Ala. Both antibodies were relatively specific for molecules ending in -Xxx-Xxx-Gly-Gly-Ser-Asn-OH, which corresponds to the biologically active region of FTS.     

Antigenic specificity and heterogeneity of lipopolysaccharides from pyocin-sensitive and -resistant strains of Neisseria gonorrhoeae

Homologous antisera were raised against lipopolysaccharides (LPSs) isolated from pyocin 103-sensitive JW31 strain Neisseria gonorrhoeae and its isogenic, pyocin-resistant variant, JW31R. Changes in immunochemical reactivity of LPS antigen associated with pyocin-resistance were examined by enzyme-linked immunosorbent assay, employing homologous and heterologous anti-LPS immune sera. The acquisition of pyocin 103 resistance is accompanied by a loss in LPS antigen reactivity with homologous anti-LPS. The variant LPS of pyocin 103-resistant mutants is immunogenic and displays a new, distinct antigenic specificity shared with other pyocin 103-resistant variant gonococcal strains. The acquisition of pyocin 103 resistance by JW31 strain gonococci is also accompanied by a striking loss of LPS cross-reactivity with antistreptococcal polysaccharide reagents having an antibody combining site specificity directed against the chemically defined lactose polymer from Streptococcus faecalis cell wall and pneumococcal type 14 capsular polysaccharide. When examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and sodium dodecyl sulfate-urea-polyacrylamide gel electrophoresis, JW31 and JW31R LPSs show banding patterns characteristic of microheterogeneous, rough-type LPS devoid of O-side chains. Immunoblot transfer analysis of gel-separated gonococcal LPS antigens shows a difference in the pattern of antibody binding by homologous versus cross-reactive anti-LPS, which suggests a heterogeneity in the distribution of cross-reactive determinants among LPS molecules.     

Antigenic specificity of serological response in Chlamydia trachomatis urethritis detected by immunoblotting.

Sera from 19 patients with Chlamydia trachomatis culture positive non-gonococcal urethritis were studied for the presence of antibodies to chlamydial proteins by immunoblotting. Ten C trachomatis negative patients with non-gonococcal urethritis and 10 healthy controls were also studied. Acute phase sera from C trachomatis positive patients with non-gonococcal urethritis reacted only with the major outer membrane protein whereas all the convalescent phase serum samples reacted with the major outer membrane protein and with a 60,000 and a 62,000 molecular weight protein. Some sera also reacted with a 45,000 molecular weight protein. Five of 10 convalescent phase samples from patients with C trachomatis negative non-gonococcal urethritis showed a reaction pattern comparable with that observed in convalescent sera from C trachomatis from C trachomatis positive patients with non-gonococcal urethritis. Sera from healthy seronegative subjects were negative by blotting.     

Species specificity of serum factors from rabbits with acute pancreatitis in stimulation of B-cell regeneration in pancreatic islets in experimental diabetes

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 115, No. 5, pp. 536–537, May, 1993     

Antigenic sites related to human serum proteins in HBsAg: isolation from normal human serum of a high-molecular-weight glycoprotein reacting with antialbumin.

A novel minor constituent was isolated from normal human serum by affinity chromatography on columns of insolubilized concanavalin A and antibodies to albumin, followed by rate zonal centrifugation. This component has the following properties: a sedimentation coefficient of approximately 31; a diameter of 14--22 nm, and a buoyant density of 1.302 gm/cu cm. It contains about 1% neutral sugars and is electrophoretically heterogeneous, since two populations of particles with isoelectric points of pH 4.95 and 5.75 were separated by isoelectric focusing. It contains a single major glycopeptide with an apparent molecular weight of 72,000 daltons. Its amino acid composition is distinct from that of albumin. It elicited the formation of antibodies that also reacted with HBsAg.