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Biomedical subjects

B Sundquist

Publications and source records attributed to B Sundquist.

At least 19 recordsLinked to original sources
PubMed1997

Influence of Quillaja saponaria triterpenoid content on the immunomodulatory capacity of Epstein-Barr virus iscoms.

The immune responses to immunostimulating complexes (iscoms) containing recombinant Epstein-Barr virus (EBV) gp340 envelope protein was evaluated in BALB/c (H-2(d)) and CBA (H-2(k)) mice. Gp340-iscoms were used either with a low content of Quillaja triterpenoid adjuvant (L-iscoms) or supplemented with additional Quillaja adjuvant in the form of iscomatrix (S-iscoms). Class and subclass distribution of anti-gp340 antibodies, EBV-neutralizing antibodies, antigen-specific T cell proliferation and cytokine production were determined and these results compared to those obtained by immunization with non-adjuvated gp340. The H-2(d) and H-2(k) mice were characterized as low or high responders in respect to the level of specific anti-gp340 antibodies, secretion of IgG2a isotype, antigen-specific lymphoproliferative capacity, interferon-gamma (IFN-gamma) and interleukin-10 (IL-10) production in the basic immunizations with gp340. While presentation of the antigen in iscom formulations with low levels of Quillaja triterpenoids induces a moderate enhancement of the immune responses in the low responder H-2(d) mice, supplementation with high levels of iscomatrix immunomodulator was required to enhance the immune responses in the high responder H-2(k) mice. In both mouse strains subcutaneous immunization with S-iscoms resulted in a significant increase of IgG1- and IgG2a-specific antibodies, as well as in strong antigen-specific proliferative response confirmed by the simultaneous cytokine production. The enhanced antigen-specific secretion of IL-2 and IFN-gamma together with the abrogation of IL-10 and the absence of IL-4 indicates that the responses were driven towards a Th1-type rather than Th2-type immune response. The S-iscom formulations minimized the differences in immune responses between the two mouse strains, but the capacity of immune sera to neutralize EBV transformation in vitro remained completely strain-dependent. These data indicate that immune responses generated by iscoms can be manipulated by altering the triterpenoid composition of the iscoms and that the levels of triterpenoids can determine whether or not a Th1-type response is made.

Adjuvants, Immunologic↗
PubMed1996

Observations on the use of ELISA for detection of Babesia bigemina specific antibodies.

An indirect enzyme-linked immunosorbent assay (ELISA) was evaluated to study the cause of the high level of background reactions which hinders the application of ELISA as a field diagnostic test for Babesia bigemina. Different blockers to improve the specificity of the ELISA were compared. THe use of soya milk (25%), gelatin (2.5%) and chicken serum (2%) did not significantly improve the specificity of the test. It was noted that the presence of fibrinogen contributed to the positive ELISA results more than the presence of B. bigemina specific antigen. This conclusion was confirmed by testing bovine fibrinogen as a host protein antigen in ELISA which strongly responded against B. bigemina positive control sera. It is suggested that application of ELISA for B. bigemina is still unreliable until a more purified Babesia-specific antigen or specific monoclonal antibodies are available.

Animals↗
PubMed1994

Antigenicity and immunogenicity of experimental equine influenza ISCOM vaccines.

A comparison of the antigenicity and immunogenicity of ISCOM vaccines prepared from equine influenza viruses H3N8 and H7N7 was made with inactivated whole-virus vaccines containing equivalent amounts of virus haemagglutinin. ISCOMs stimulated superior antibody responses in terms of both amount and duration. As with conventional whole-virus vaccines, the levels of antibody to virus haemagglutinin induced by ISCOMs correlated with protection.

Animals↗
PubMed1994

Four-year study of caries inhibition of intensive Duraphat application in 11-15-year-old children.

The purpose of the study was to evaluate the caries preventive effect and cost of an intensive application of Duraphat varnish, added to the regular preventive program for 11-15-yr-old children in a Swedish Dental Community Clinic. In 1987, the 134 11-yr-old children in Floda were divided into two groups, every second child to each. Children with fixed orthodontic appliances were excluded. The test group received three applications of Duraphat varnish during 1 week, once a year, by a dental nurse. The control group received one application at the annual check-up. Both groups were included in the regular preventive program at the clinic. The total time cost for the clinic was estimated and used to calculate the cost per hour for dentists and nurses. The caries increment and progression were estimated both by routine diagnosis and by a careful study of radiographs taken at the beginning and end of the study period. There was a small caries increment and progression in the test group as compared to the control group. The difference was statistically significant for all aspects studied. The costs were about the same in both groups but more time was used in the test group. The administrative effort for the staff was considerable for the intensive Duraphat application.

Adolescent↗
PubMed1992

An immune stimulating complex (ISCOM) subunit rabies vaccine protects dogs and mice against street rabies challenge.

Dogs and mice were immunized with either a rabies glycoprotein subunit vaccine incorporated into an immune stimulating complex (ISCOM) or a commercial human diploid cell vaccine (HDCV) prepared from a Pitman Moore (PM) rabies vaccine strain. Pre-exposure vaccination of mice with two intraperitoneal (i.p.) doses of 360 ng ISCOM or 0.5 ml HDCV protected 95% (38/40) and 90% (36/40) of mice, respectively, against a lethal intracerebral (i.c.) dose with challenge virus strain (CVS). One 360 ng i.p. dose of ISCOM protected 87.5% (35/40) of mice against i.c. challenge with CVS. Three groups of five dogs were vaccinated intramuscularly (i.m.) with 730 ng of rabies ISCOM prepared from either the PM or the CVS rabies strains, and they resisted lethal street rabies challenge. Postexposure treatment of mice with three or four 120 ng i.m. doses of ISCOM protected 90% (27/30) and 94% (45/48), respectively, of mice inoculated in the footpad with street rabies virus, but three doses of HDCV conferred no protection. When four doses of HDCV were administered postexposure, 78% (32/41) of the mice died of anaphylactic shock; 21% (11/52) of mice had already died of rabies 4 days after the third vaccine dose was administered.

Animals↗
PubMed1991

Characterization of purified gp 51 from bovine leukemia virus integrated into iscom. Physicochemical properties and serum antibody response to the integrated gp51.

It is proposed that the envelope glycoprotein, gp 51, is the protective antigen of bovine leukemia virus (BLV). An experimental iscom vaccine has been prepared from immunoaffinity purified gp 51. To overcome the problem of integrating a nonamphipathic protein, gp 51 was partially denatured at pH 2.4 before integration into the iscom. The recovery of gp 51 into the iscom was calculated to be 85%. The gp 51 incorporated into iscom retained its physicochemical properties and the neutralizing epitopes F, G and H were found to be intact. The iscom preparation was shown to induce a specific immune response to gp 51 after inoculation into mice and calves, as tested by ELISA and Western blotting. Sera from the immunized calves specifically inhibited the VSV-(BLV) pseudotypes. Thus the gp 51-iscom preparations appear to be highly immunogenic and to induce a gp 51 specific response.

Animals↗
PubMed1991

Immunoaffinity purification of two major proteins of bovine leukemia virus (gp51 and p24) and their use for discrimination between vaccinated and infected animals.

The outer envelope glycoprotein gp51 and the core protein p24 of bovine leukemia virus (BLV), were purified from culture media of FLK-BLV cells by a single-step procedure, using immunoaffinity chromatography based on monoclonal antibodies to the respective proteins. About 90% of the envelope glycoprotein in the culture medium was recovered as a highly purified product. Both purified protein (gp51 and p24) preparations, were found to be highly specific antigens by ELISA, and did not cross-react with sera raised against the other antigen. The conformational epitopes on the purified gp51 were preserved as judged by their reactions with the corresponding monoclonal antibodies. The p24 ELISA reacted only with sera from naturally infected animals and not with sera from animals immunized with an experimental gp51-iscom vaccine. The p24 antigen is therefore useful for discriminating between BLV-infected animals and those immunized with a gp51 subunit vaccine.

Animals↗
PubMed1991

Protective effect of an ISCOM bovine virus diarrhoea virus (BVDV) vaccine against an experimental BVDV infection in vaccinated and non-vaccinated pregnant ewes.

Fifteen pregnant ewes were vaccinated twice with an experimental immunostimulating complex (ISCOM) subunit vaccine designed to contain the envelope proteins of a Danish cytopathic bovine virus diarrhoea virus (BVDV). The serological responses were measured in ELISA and virus neutralization (VN) tests. All ISCOM-vaccinated ewes developed high VN antibody titres to BVDV in contrast to the 14 non-vaccinated ewes. Both groups of ewes were challenged parenterally when 48-65 days pregnant with a Swedish cytopathic BVDV isolate. In the vaccinated group 26 fetuses out of 29 detected by ultrasound were liveborn, whereas only six out of 26 were liveborn in the non-vaccinated group. It is concluded that the ISCOM vaccine had the potential of eliciting high VN titres as well as protecting fetuses against transplacental infection after challenge with a virulent BVDV isolate.

Animals↗
PubMed1990

Protection against lethal equine herpes virus type 1 (subtype 1) infection in hamsters by immune stimulating complexes (ISCOMs) containing the major viral glycoproteins.

An experimental ISCOM vaccine has been prepared from gradient purified equine herpes virus type 1 (EHV-1). Radiolabelling studies demonstrated that this vaccine contained all the major viral glycoproteins in relative amounts similar to those found in non-detergent disrupted viral preparations. This EHV-1 ISCOM vaccine generated fully protective responses in hamsters challenged with an otherwise lethal dose of the hamster-adapted EHV-1 strain RACH.

Adjuvants, Immunologic↗
PubMed1989

Characterization and purification of Parafilaria bovicola antigens by chromatofocusing to enhance specificity in serodiagnosis.

A study was conducted to determine if the purification of Parafilaria bovicola antigens can increase the specificity of serodiagnosis of parafilariasis in enzyme-linked immunosorbent assay. Antigens released from adult worms of P. bovicola were separated by chromatofocusing on a polybuffer exchanger of the pH range 7.3-4.0 Polypeptide analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis showed the presence of four major polypeptides with MWs of 41, 36, 24 and 20 kDa. Additional biochemical characterization identified the 24- and 20-kDa polypeptides as hydrophobic glycoproteins. The chromatofocusing purification procedures were also applied for separation of a whole-worm extract. Again, the 41- and 36-kDa antigens were identified in separate peak fractions. Using ELISA, it was shown that the 41- and 35-kDa antigens were recognized by bovine antibodies specific for P. bovicola, but not by other sera collected from cattle infected by Onchocerca gutturosa, Onchocerca lienalis, Ostertagia ostertagi and Dictyocaulus viviparus. The serological evaluation strongly suggests that the 41- and 36-kDa antigens are P. bovicola specific.

Animals↗
PubMed1989

Equine herpes virus 1 (EHV-1) in liver, spleen, and lung as demonstrated by immunohistology and electron microscopy.

Ten aborted foals, diagnosed as infected with Equine Herpes Virus 1 (EHV-1) on histopathological criteria, were examined for the presence of EHV-1 using immunohistology as the investigative instrument. The primary reagent was an antiserum specific for viral envelope glycoproteins. Immunohistology localised EHV-1 to areas of liver necrosis and to the cytoplasm of infected Kupffer cells and hepatocytes. Cytoplasmic immunolabelling was also prominent in reticular cells of the red pulp of the spleen and in intact and degenerated bronchiolar epithelium. Cytoplasmic immunolabelling was seen in morphologically unchanged cells and in cells containing intranuclear inclusion bodies. Three aborted foetuses with no histological signs of EHV-1 infection were negative when immunostained for EHV-1. Detection by electron microscopy of EHV-1 virions confirmed the EHV-1 specificity of the immunolabelling procedure.

Abortion, Veterinary↗
PubMed1988

Influenza virus ISCOMs: biochemical characterization.

Immunostimulating complexes (ISCOMs) have been prepared from influenza A virus envelope glycoproteins, i.e. haemagglutinin (HA) and neuraminidase (NA). An ISCOM consists of a matrix, which is the micellar form of the glycoside, Quil A, in hydrophobic interaction with both the envelope glycoproteins (HA/NA). The Quil A bound to the ISCOM amounted to 50 micrograms mg-1 (5%) of ISCOM protein. ISCOMs were morphologically identified as symmetrical cage-like structures of approximately equal to 40 nm in diameter with hexagonal or pentagonal subunits of approximately equal to 12 nm. The sedimentation coefficient was approximately equal to 19 S as compared to 30 S for the glycoprotein micelles. The biological activities of the HA and NA are preserved in both ISCOMs and micelles.

Adjuvants, Immunologic↗
PubMed1988

Influenza virus ISCOMs: antibody response in animals.

A monovalent experimental ISCOM vaccine has been prepared with the envelope glycoproteins haemagglutinin and neuraminidase of the equine virus strain A/Solvalla/79 (H3N8). In vaccination trials on BALB/c mice the ISCOM vaccine induced more than ten times higher serum antibody titres measured in ELISA than a corresponding experimental micelle vaccine. Similarly, in guinea-pigs the ISCOMs induced about tenfold higher haemagglutination inhibition (HI) and neuraminidase inhibition (NI) titres than a micelle vaccine or a conventional killed influenza whole virus vaccine. Horses vaccinated with a divalent experimental ISCOM vaccine, containing the equine strains A/Prague/56 (H7N7) and A/Solvalla/79 (H3N8), responded with ELISA antibody titres against haemagglutinin which were higher and lasted considerably longer than those in horses vaccinated with conventional whole virus vaccine. ISCOMs induced complete immunoprotection in mice vaccinated with a dose of 1 microgram envelope glycoproteins of the mouse pathogenic strain A/PR/8/34 (H1N1).

Adjuvants, Immunologic↗
PubMed1988

Preparation and evaluation of the specificity of Parafilaria bovicola antigen for detection of specific antibodies by ELISA.

An enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies in bovine sera against Parafilaria bovicola nematodes was developed and its sensitivity was compared with the immunodiffusion (ID) method. An exoantigen of P. bovicola which was shown to contain four major polypeptides was used in these procedures. The serological reactivity of the antigen polypeptides was defined by using the enzyme-linked immunoelectrotransfer blot technique (EITB) and whole-worm extract proteins. It identified only four serologically reactive polypeptides with sera from one experimentally infected calf and a verified field case. These two positive sera reacted mainly with four major antigens which coincided in molecular weights of the polypeptides of the exoantigenic preparation, namely, 43, 39, 28 and 25 KDa. Calves experimentally infected with P. bovicola showed a positive reaction with ELISA at 4 months after inoculation, and after this period a rapid increase in serum antibody response occurred. In these cases the ID reaction was observed for the first time at 7 months after inoculation. The specificity of an ELISA method using crude exoantigen preparation of P. bovicola was tested for the diagnosis of bovine parafilariasis. No cross-reactivity was detected when the P. bovicola exoantigen preparation was tested against sera from calves experimentally infected with Onchocerca lienalis, as well as against the sera from cattle naturally infected with Dictyocaulus viviparus or from cattle chronically infected with Ostertagia ostertagi. In addition, testing of 740 field sera from cattle in areas non-endemic and endemic for P. bovicola indicated a specificity of the antigen preparation used. Forty sera from laboratory-confirmed field cases of P. bovicola infection were tested by ELISA and immunodiffusion. All of these sera were ELISA positive, whereas only 70% of these were positive in the ID test. Seven (2.1%) of 328 sera from 21 herds from non-endemic P. bovicola areas were ELISA positive, as opposed to none in the ID test. Of the 94 sera from six herds in areas endemic for P. bovicola infection, 51 (54%) were ELISA positive whereas only 24 (26%) were positive in the ID test. When 56 slaughtered cattle, with varying degrees of meat condemnations due to parafilariasis, were tested for P. bovicola specific antibody, 91% of the serum samples were positive by ELISA. These results suggest that the exoantigen of P. bovicola can be used in a sensitive and reliable serological detection of parafilariasis by ELISA.

Animals↗
PubMed1988

Measles virus fusion protein presented in an immune-stimulating complex (iscom) induces haemolysis-inhibiting and fusion-inhibiting antibodies, virus-specific T cells and protection in mice.

Immune-stimulating complexes (iscoms), which have recently been shown to be highly effective for the antigenic presentation of membrane proteins of viruses, were prepared with affinity-purified fusion (F) protein of measles virus (MV), using an adaptation of the standard method for iscom preparation. Immunization of monkeys with the F iscom preparation induced biologically active anti-F protein antibodies as was shown in haemolysis inhibition and cell-cell fusion inhibition tests. A whole MV iscom preparation, which also contained the haemagglutinin protein, induced not only also haemolysis-inhibiting antibodies, but, in contrast to the F iscom preparation, also haemagglutination-inhibiting and virus-neutralizing antibodies. In addition the F iscom preparation was shown to activate measles virus-specific T cells in mice. This was demonstrated by the generation of an MV-specific delayed type hypersensitivity response in F iscom-immunized animals and by the isolation of T cell clones specific for MV F protein with the T helper phenotype. Vaccination of mice with MV iscom or F iscom protected them from MV-induced fatal encephalopathy. The data concerning the immunogenicity of MV proteins presented in iscoms are discussed in relation to their potential for the development of an inactivated measles vaccine.

Animals↗
PubMed1987

Preparation and properties of immune-stimulating complexes containing hepatitis B virus surface antigen.

Immune-stimulating complexes (iscoms) have been prepared containing the major S gene products (HBsAg) of the hepatitis B virus genome. Immunization of BALB/c mice with a single dose of hepatitis B iscoms in saline resulted in a high titre antibody response to HBsAg. In contrast, the original HBsAg preparation required an adjuvant to produce equivalent amounts of antibody. Analysis of sera from mice immunized with hepatitis B iscoms revealed antibodies directed against the major a determinants of HBsAg. High secondary antibody responses were observed in immunized animals previously inoculated with a sub-immunogenic dose of HBsAg indicating that hepatitis B iscoms may represent a suitable immunogen for use in individuals in whom a course of immunization with currently licensed hepatitis B vaccines has failed to produce a significant anti-HBs response.

Animals↗
PubMed1985

Comparison of 252californium plasma desorption and fast atom bombardment mass spectrometry for analysis of small peptides.

The data obtained with 252Cf plasma desorption (PD) and fast atom bombardment mass spectrometry of eight tri-, tetra- and pentapeptides were compared. Good spectra were obtained with 1-10 nmol of peptide. In both techniques molecular weight information was obtained. The PD mass spectra are often dominated by the cationized molecular ions in contrast to the fast atom bombardment (FAB) mass spectra, where cationization is rarely observed. Amino acid content is reflected in the immonium ions equally well in both techniques. The fragmentation patterns observed with the two techniques are almost identical. However, practical sequencing of peptides based on either FAB or PD mass spectrometry of underivatized peptides alone is difficult. This is due to the unpredictable and sometimes absent cleavage yield at certain peptide bonds. Another difficulty is the many simultaneous fragmentation pathways. However, for many peptides enough information is present to allow sequence determination for at least a major part of the molecule.

Californium↗