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Biomedical subjects

B M Goddeeris

Publications and source records attributed to B M Goddeeris.

At least 55 records · Page 3Linked to original sources
PubMed2002

[Avian pathogenic Escherichia coli (APEC)].

Escherichia coli infections are being increasingly detected among poultry flocks, indicating the growing importance of this pathogen to the industry. The infection begins as a respiratory infection of the trachea, followed by colonization of the air sacs and lungs, from where it invades the blood-stream, leading to infection of the deeper organs (liver, heart, oviduct, and peritoneum). A number of factors play a crucial role in the virulence and pathogenesis of infection. The F1 and P pili are particularly important in establishing the infection at the level of the tracheal epithelium cell. Other important factors are aerobactin, capsule, and serum resistance. Treatment is with antibiotics, but the growing bacterial resistance of avian E. coli and stricter regulations mean that attention is turning to prophylactic, preventative, measures, such as vaccination. Current vaccines provide limited homologous protection against the pathogen. Research is needed to develop a good, broad-spectrum vaccine.

Air Sacs↗
PubMed2002

Antigen dose modulates the immunoglobulin isotype responses of pigs against intramuscularly administered F4-fimbriae.

Parenteral immunisation normally induces a systemic antibody response characterised by high IgG and low IgA responses. In the present study, the effect of different doses of F4-fimbriae on the isotype-specific antibody response after intramuscular immunisation was studied in pigs. Pigs were injected twice with a 9 weeks interval with either 1, 0.1 or 0.01 mg of F4-ETEC fimbriae. The dose of 1mg F4 induced significantly lower primary F4-specific IgG and IgM responses than the doses of 0.1 and 0.01 mg F4, but primed for an enhanced F4-specific IgM serum antibody response after the booster immunisation. Furthermore, the dose of 0.1mg induced the highest F4-specific IgA serum response which was significantly higher than after injection with 0.01 and 1mg F4. Moreover, both lower doses (0.1 and 0.01 mg) showed a higher number of F4-specific IgA and IgG antibody secreting cells (ASC) in the local draining lymph nodes of the pigs. This study demonstrated that low doses of purified F4-ETEC fimbriae, especially the 0.1mg dose, are optimal for inducing F4-specific IgA responses after IM immunisation.

Animals↗
PubMed2002

Different kinetic of antibody responses following infection of newly weaned pigs with an F4 enterotoxigenic Escherichia coli strain or an F18 verotoxigenic Escherichia coli strain.

To develop a vaccine against Escherichia coli-induced post-weaning diarrhea and edema disease, insights in the induction of the protective immune response following infection with these pathogenic E. coli is needed. Therefore, the fimbriae-specific antibody response of newly weaned pigs following infection with the Shiga-like toxin type II variant (SLT-IIv) producing F18(+) verotoxigenic E. coli (VTEC) (strain 107/86) was compared with the response following an infection with LT producing F4(+) enterotoxigenic E. coli (ETEC) (strain GIS 26). F4(+) ETEC were able to colonize the gut very soon after infection, as peak excretion of F4(+) E. coli bacteria was seen 2 days post-infection (dpi), but had already disappeared 7dpi. On the other hand, F18(+) VTEC infection resulted in a slower colonization of the gut as the peak excretion of F18(+) E. coli was observed between 3 and 5dpi, but this colonization remained longer as F18(+) E. coli were detected till 9dpi in feces. Furthermore, this fast colonization pattern of F4(+) ETEC is accompanied with the presence of F4-specific antibodies in mucosal tissues and serum from 4dpi onward, with maximal amounts of F4-specific IgA in the jejunal lamina propria and serum 7dpi. In contrast, F18-specific IgA was only readily detected in the jejunal lamina propria 15dpi and showed a maximum serum titer 21dpi. Besides this faster induction and higher antibody response, the switch from IgM to IgA and IgG was also earlier following the F4(+) ETEC infection.

Animals↗
PubMed2002

CpG-oligodinucleotides as an effective adjuvant in pigs for intramuscular immunizations.

In this study, the effect of two oligodeoxynucleotide (ODN) sequences 5'GCT-AGA-CGT-TAG-CGT-3' (CpG-ODN) and 5'-GCT-AGA-GCT-TAG-GCT-3' (GpC-ODN) on the antigen-specific antibody and cellular immune response after intramuscular immunizations with OVA was analyzed in pigs. Pigs immunized with OVA supplemented with these ODNs showed a significantly enhanced primary antibody response in comparison with the control group which received OVA without ODN. This enhanced primary antibody response appeared ODN-sequence-independent as similar effects were seen in both ODN-groups. The OVA-specific antibody titers obtained after a single injection of antigen combined with either of both ODNs were as high as the titers in the control group after two injections. Furthermore, the ODN-supplemented animals showed significantly higher OVA-specific IgA antibodies in their saliva and nasal secretions at some time points after the first immunization. Proliferation assays showed that CpG- as well as GpC-ODN significantly enhanced the antigen-specific as well as the mitogen-induced proliferation in different lymphoid tissues. Furthermore, 48h after the third immunization the CpG-group showed a significantly decreased IL-6 mRNA expression in cells of the local draining lymph node but no significant difference in TGF-beta (Th3-like) and IL-10 (Th2-like). The ODN injected animals showed the tendency to have higher IFN-gamma (Th1-like) mRNA-expression in comparison with the control group. To our knowledge, these are the first in vivo studies in pigs, which demonstrate the appropriateness of CpG-ODN as immunostimulating adjuvants in vaccines for farm animals.

Adjuvants, Immunologic↗
PubMed2002

Stimulatory effect of CpG sequences on humoral response in chickens.

Oligonucleotides containing the dinucleotide CpG have an immunostimulatory effect in mammals. The CpG motif is interpreted as a signal of prokaryote invasion by the innate immune system and consequently activates defense mechanisms. The goal of this study was to investigate whether the immunostimulatory actions of CpG oligonucleotides take place in birds as well. To this end, birds were immunized with BSA and the serum antibody response was followed. A significantly higher BSA-specific response was observed in the CpG-treated group. Moreover, immunostimulatory DNA resulted in more persistent responses to immunization. After only one immunization, titers as high as in booster responses were observed in the CpG-treated birds. The effects were shown to depend on the presence of an unmethylated CpG core sequence in the DNA, because the reversal of CpG to GpC even caused a decrease in antibody response. These findings demonstrate that CpG oligonucleotides could be a valuable adjuvant for poultry vaccines.

Adjuvants, Immunologic↗
PubMed2002

Expression of RoTat 1.2 cross-reactive variable antigen type in Trypanosoma evansi and T. equiperdum.

The variable antigen type (VAT) RoTat 1.2 has been cloned from a T. evansi strain, isolated in 1982 from a water buffalo in Indonesia. All T. evansi isolates hitherto tested express this VAT. In a study on the differential diagnosis of T. equiperdum and T. evansi in horses, we investigated serological evidence for the expression of RoTat 1.2 in 11 T. evansi and six T. equiperdum populations originating from Asia, Europe, Africa, and the Americas. Preinfection sera and sera of days 7, 14, 25, and 35 post-infection (p.i.) were analyzed for the presence of antibodies reactive with RoTat 1.2 in immune trypanolysis, ELISA/T. evansi and CATT/T. evansi. Within the duration of the experiment, all rabbits infected with T. evansi became positive in the three serological tests. Five out of six rabbits infected with T. equiperdum also became positive in the three tests. Only one T. equiperdum strain (the OVI strain from South Africa) did not induce the production of antibodies reactive with RoTat 1.2 and thus might not contain or express a VSG that shares epitopes similar to those on the RoTat 1.2 VSG. The data lead to the conclusion that T. equiperdum can express VSGs containing epitopes serologically similar to those in the T. evansi RoTat 1.2 VAT. This explains, in part, why the antibody detection tests based on Ro Tat 1.2 VSG cannot reliably distinguish between the infections caused by T. evansi and those caused by T. equiperdum. There are no data that contradict the possibility that the putative T. equiperdum strains, which express VSGs with epitopes similar to those on RoTat 1.2, are actually T. evansi.

Animals↗
PubMed2001

The influence of T. evansi infection on the immuno-responsiveness of experimentally infected water buffaloes.

In order to define the immuno-suppressive capacity of Trypanosoma evansi infections in buffaloes on the induction of immune responses against heterologous antigens, infected and non-infected buffaloes were vaccinated against Pasteurella multocida (haemorrhagic septicemia) and were simultaneously immunised with a control antigen, human serum albumin (HSA). Antibody responses against HSA were significantly reduced in T. evansi-infected animals, but no conclusive data were obtained on the antibody responses against P. multocida. Conversely, the local inflammatory response at the site of Pasteurella vaccination, as measured by increase in size, was significantly reduced in T. evansi-infected animals. These results indicate that the inductive capacity to mount humoral and cell-mediated immune responses against heterologous antigens is suppressed in T. evansi-infected animals. Consequently, T. evansi infection might interfere with the development of protective immunity upon heterologous vaccinations and could explain the poor protection of Pasteurella-vaccinated buffaloes in T. evansi-endemic areas of Vietnam.

Animals↗
PubMed2001

Comparative analysis of porcine cytokine production by mRNA and protein detection.

To analyze the correlation between cytokine mRNA transcription and secretion, interleukin-10 (IL-10) and interferon-gamma (IFN-gamma) were quantified by enzyme-linked immunosorbent assay and IL-2 by bioassay and compared with their mRNA levels, determined by reverse transcription polymerase chain reaction (RT-PCR). For this purpose, peripheral blood monomorphonuclear cells (PBMC) were stimulated in vitro with the lectins pokeweed mitogen (PWM), phytohemagglutinin (PHA) and concanavalin A (ConA), respectively, and with F4 fimbriae in an antigen-specific assay. Analyses were performed 4, 8, 16, 24 and 48 h after stimulation on the stimulated PBMC for mRNA and on the respective culture supernatants for proteins. RT-PCR products were quantified by densitometric scanning of the electrophoresis bands and related to the band intensity of the housekeeping gene, cyclophilin. Low levels of IL-2, IL-4 and IFN-gamma mRNA were detected in unstimulated PBMC. Stimulation with all three mitogens (PWM, ConA, PHA) led to an increase in mRNA transcription. In contrast, substantial IL-10 mRNA levels were detected in both unstimulated and stimulated cells with practically no difference between the three mitogens used. IL-2 mRNA expression tended to peak after 8-16 h for all three mitogens. The cells stimulated with PWM and ConA showed higher levels of gene expression for IFN-gamma and lower for IL-4 then the cells stimulated with PHA, however, differences were not statistically significant. For cells stimulated with F4 fimbriae only the IFN-gamma mRNA expression increased with an early peak at 8h post-stimulation. The analysis of the culture supernatants for secreted cytokines revealed a correlation between the levels of mRNA transcription and the respective secreted cytokines during the first 24h of stimulation. After 24h of stimulation, however, a decrease in IFN-gamma and IL-2 mRNA levels was accompanied by an increase or a less pronounced decrease in cytokine concentration; only the ConA induced IL-2 mRNA and protein concentration slopes showed similar profiles. In conclusion, similar cytokine production profiles as defined by mRNA and protein, respectively are obtained only during the first 24h after stimulation of the cell cultures.

Animals↗
PubMed2001

Homologues of natural killer cell receptors NKG2-D and NKR-P1 expressed in cattle.

Partial transcripts of the homologues in cattle, of the genes encoding the NKR-P1 and NKG2-D natural killer cell lectin-like receptor families, were cloned by reverse transcriptase-PCR from bovine spleen. Three different cDNAs were partially sequenced for the NKG2-D homologue, and two for the NKR-P1 homologue. Identity to human nucleotide sequences was of 90 and 75%, respectively, and all structural residues of C-type lectin carbohydrate recognition domains were conserved. The identification of two of its members allows to hypothesise the existence of a bovine NK gene complex, prospectively located on chromosome 5.

Amino Acid Sequence↗
PubMed2001

Induction of cross-protection in mice against dolphin Erysipelothrix rhusiopathiae isolates with a swine commercial vaccine.

Erysipelothrix rhusiopathiae is well known to cause disease in dolphins. This disease occurs either in an peracute way, leading to mortality even before clinical signs are observed or in a sub-acute way, characterized by rhomboidal skin lesions, that can be treated with penicillin or its derivatives. Commercial swine vaccines, containing inactivated serotype 2 strains, are currently used for vaccination but it is not known whether these vaccines induce protection against E. rhusiopathiae isolates from dolphins. In the present study, it was demonstrated in a mouse model that vaccination with a commercial swine vaccine (Eurovac Ery, Eurovet, Belgium) containing inactivated serotype 2 E. rhusiopathiae strains induced protection against challenge with three E. rhusiopathiae isolates from dolphins. The duration of the protection varied, depending on the challenging isolate, between 8 and >23 weeks. There was however no positive correlation between the amount of antibodies at the moment of challenge and the observed protection. In conclusion, vaccination trials in mice indicate that commercial serotype 2 swine Erysipelothrix vaccines induce protection against erysipelas caused by dolphin pathogenic isolates.

Animals↗
PubMed2001

Enhanced induction of the IgA response in pigs by calcitriol after intramuscular immunization.

In this study, the immunomodulating effect of two steroid hormones namely 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and dehydroepiandrosterone (DHEA) was examined on the antigen-specific antibody responses by intramuscular immunization of pigs with human serum albumin alone (HSA) or supplemented with 2 microg of 1,25(OH)(2)D(3,) 40 microg of DHEA or the combination of both steroids. 1,25(OH)(2)D(3) significantly enhanced the antigen-specific IgA and IgM serum response. Higher HSA-specific IgA titers were also found in the mucosal secretions (saliva, feces and nasal) of the steroid treated animals, especially in the 1,25(OH)(2)D(3) group. Furthermore, 1,25(OH)(2)D(3) and DHEA increased the number of antigen-specific IgA and IgG antibody-secreting cells in the local draining lymph nodes, but only low numbers were detected in lymph nodes draining the mucosa. DHEA decreased the IgM serum response and had a tendency to enhance the IgG2 and IgG serum responses. Strong and comparable IgG, IgG1 and IgG2 serum responses were seen in all groups. Combining both steroids did not result in a higher IgA serum response. On the contrary DHEA seems to neutralize the effect of 1,25(OH)(2)D(3) on the IgA response. In conclusion, 1,25(OH)(2)D(3) significantly enhanced the antigen-specific IgA and IgM response in serum and the number of antigen-specific IgA and IgG ASC in the local draining lymph nodes following intramuscular immunization.

Adjuvants, Immunologic↗
PubMed2001

Generation of class-selective monoclonal antibodies against the penicillin group.

To develop a penicillin-specific ELISA, different attempts were made to obtain monoclonal antibodies specific for the common structure of penicillins. Ampicillin was coupled to different carrier proteins (bovine serum albumin, chicken ovalbumin, and thyroglobulin) to render it immunogenic. Different coupling methods were compared: two methods using a cross-linker (glutaraldehyde or a succinimide ester), one carbodiimide-mediated coupling method, and one method without any cross-linker or mediator molecule (physiological binding). Mice were immunized with the conjugates intraperitoneally or in the footpad. A screening ELISA was developed to detect anti-ampicillin antibodies in sera. Specificity and affinity of the antibodies were demonstrated by inhibiting their binding with a 10 mM solution of ampicillin. No difference could be observed using electrofusion or PEG-mediated fusion. For the production of the monoclonals, an intravenous final boost gave antibodies with better specificity and affinity than an intraperitoneal final booster injection. At least one anti-ampicillin monoclonal antibody (19C9) cross-reacts with penicillin G, oxacillin, dicloxacillin, and carbenicillin, and not with sulfanilamide, chloramphenicol, neomycin, and streptomycin, and is therefore considered interesting for developing a penicillin-specific ELISA.

Animals↗
PubMed2001

Genetic immunization for Chlamydia psittaci.

Plasmid DNA expressing the major outer membrane protein (MOMP) of an avian Chlamydia psittaci serovar A strain, has been tested for its ability to raise an immune response and induce protection against challenge with the same serovar. A combined parenteral (intramuscular injection) and mucosal route (DNA drops administered to the nares) of DNA inoculation was compared to gene gun-based immunization. The gene gun delivery of pcDNA1/MOMP as well as the intramuscular-intranasal DNA delivery primed both T-helper and B-cell memory although rMOMP-expressing cells did not induce high antibody responses. Evidence for the priming of the memory was provided by the fact that the pcDNA1/MOMP inoculations raised antibodies belonging to the IgG and not IgM isotype. However, in response to challenge only 5 out of 15 vaccinated turkeys showed four fold increases in serum IgG after challenge. By contrast, evidence for the priming of T-cell memory in response to challenge was found in all vaccinated turkeys as shown by the significantly heightened proliferative responses of peripheral blood lymphocytes following vaccination. Both immunization methods produced similar serological and lymphocyte proliferative responses. Notwithstanding the immunization method, a significant level of protection was observed in all pcDNA1/MOMP immunized turkeys. The efficacy of MOMP-based DNA vaccination as a means of preventing severe clinical signs, lesions and chlamydia excretion in a turkey model of Chlamydia psittaci infection was demonstrated.

Animals↗
PubMed2000

Identification of Ostertagia ostertagi specific cells in bovine abomasal lymph nodes.

To investigate the contribution of different bovine cell subpopulations in the development of in vitro induced responses by Ostertagia ostertagi third larval antigen extract (L3), bovine abomasal lymph node cell suspensions were depleted of specific cell populations. The depleted cell suspensions were subsequently assayed for their proliferative responses to O. ostertagi L3 antigen extract. Proliferative responses to O. ostertagi L3 antigen extract were restricted to a CD2+ CD4- CD8- cell population and MHC II+ cells different from B-cells were of major importance. Depletion of CD4, CD8, CD4CD8, IgM or CD21 positive cells did not decrease proliferation to L3 antigen extract. Depletion of gammadelta T-cells, which also comprise a subpopulation of CD2+ CD4- CD8- cells, reduced proliferation to L3 antigen extract only in one animal. The results suggest that either gammadelta T-cells could be involved in the proliferation or that another as yet unidentified population is important for proliferation. The precise role of these populations during infection with O. ostertagi and the mechanism by which these cells may influence the host immune response are important issues that remain to be elucidated.

Abomasum↗
PubMed2000

The F4 fimbrial antigen of Escherichia coli and its receptors.

F4 or K88 fimbriae are long filamentous polymeric surface proteins of enterotoxigenic Escherichia coli (ETEC), consisting of so-called major (FaeG) and minor (FaeF, FaeH, FaeC, and probably FaeI) subunits. Several serotypes of F4 have been described, namely F4ab, F4ac, and F4ad. The F4 fimbriae allow the microorganisms to adhere to F4-specific receptors present on brush borders of villous enterocytes and consequently to colonize the small intestine. Such ETEC infections are responsible for diarrhea and mortality in neonatal and recently weaned pigs. In this review emphasis is put on the morphology, genetic configuration, and biosynthesis of F4 fimbriae. Furthermore, the localization of the different a, b, c, and d epitopes, and the localization of the receptor binding site on the FaeG major subunit of F4 get ample attention. Subsequently, the F4-specific receptors are discussed. When the three variants of F4 (F4ab, F4ac, and F4ad) are considered, six porcine phenotypes can be distinguished with regard to the brush border adhesiveness: phenotype A binds all three variants, phenotype B binds F4ab and F4ac, phenotype C binds F4ab and F4ad, phenotype D binds F4ad, phenotype E binds none of the variants, and phenotype F binds F4ab. The following receptor model is described: receptor bcd is found in phenotype A pigs, receptor bc is found in phenotype A and B pigs, receptor d is found in phenotype C and D pigs, and receptor b is found in phenotype F pigs. Furthermore, the characterization of the different receptors is described in which the bcd receptor is proposed as collection of glycoproteins with molecular masses ranging from 45 to 70 kDa, the bc receptor as two glycoproteins with molecular masses of 210 an 240 kDa, respectively, the b receptor as a glycoprotein of 74 kDa, and the d receptor as a glycosphingolipid with unknown molecular mass. Finally, the importance of F4 fimbriae and their receptors in the study of mucosal immunity in pigs is discussed.

Animals↗
PubMed2000

Enhanced specific antibody response to bovine serum albumin in pigeons due to L-carnitine supplementation.

1. Thirty adult female pigeons (Columba livia domestica) were randomly divided into 3 equal groups; the 1st and 2nd groups were immunised with bovine serum albumin (BSA) at 0 and 20 d, the 2nd group also received 1 g L-carnitine per litre of drinking water from -5 to 25 d post-immunisation (dpi) and the 3rd group, a control group, received neither treatment. 2. Body weights and serum samples were taken at 0, 5, 10, 15, 20, 25, 30 and 35 dpi. 3. Both BSA-specific IgG and IgM responses were enhanced by about 10% by L-carnitine supplementation. 4. L-carnitine supplemented pigeons showed a higher water consumption. Body weight loss during the onset of the immune response showed a slight tendency to be counteracted by L-carnitine supplementation. 5. The impact of L-carnitine on resistance and resilience to an immunological challenge is discussed.

Animals↗
PubMed2000

Dietary L-carnitine supplementation increases antigen-specific immunoglobulin G production in broiler chickens.

The usefulness of supplementary dietary L-carnitine as an immunomodulator to increase antigen-specific antibody levels was analysed in 2-6-week-old broilers. The chickens received commercial feeds either unsupplemented (starter feed 17.8 mg carnitine/kg, finisher diet 22.9 mg carnitine/kg) or supplemented with L-carnitine (100 mg carnitine/kg added to feed). At 14 d of age, both groups were distributed in equal numbers and sex ratios over two environmentally controlled chambers where temperature (28 degrees) was either reduced immediately to 20 degrees, or gradually to 22 degrees at 36 d of age. Antigen-specific immunoglobulin (Ig)M, IgG, IgA and total Ig responses were measured following two immunizations with bovine serum albumin (BSA). The typical BSA-specific IgM responses followed by IgG responses to the primary immunization were boosted by the secondary immunization. The kinetics of these responses were not altered by L-carnitine treatment. However, BSA-specific total Ig and IgG, but not IgM, responses were significantly increased by dietary L-carnitine supplementation, after both the primary and the secondary immunization. No significant influence of the sex of the chicks or the imposed environmental temperature on Ig responses was found. Temperature treatment and sex, but not L-carnitine supplementation, did significantly influence body-weight gain: cockerels were heavier than females and this became most evident in the second half of the rearing period. Further, lowering the temperature increased body weight. In conclusion, dietary L-carnitine supplementation appeared to be beneficial in enhancing specific humoral responses on vaccination.

Animals↗