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P J van der Heijden

Publications and source records attributed to P J van der Heijden.

At least 19 recordsLinked to original sources
PubMed1995

The use of a double antibody sandwich ELISA and monoclonal antibodies for the assessment of porcine IgM, IgG and IgA concentrations.

Double antibody sandwich enzyme-linked immunosorbent assays (DAS-ELISA) have been developed for the assessment of IgM, IgG and IgA concentrations in porcine serum. Isotype-specific monoclonal antibodies (mAb) were used for coating and detection. The DAS-ELISAs were examined for their ability to detect each isotype and for the assay variations. A computer programme was used to verify the parallelism of the slope of each serum sample with the slope of standard/reference serum, a prerequisite for reliable estimation of Ig concentrations. The DAS-ELISAs are easy to perform and highly specific, have adequate detection levels (ranging from 7 to 50 ng ml-1) and are very reproducible, as illustrated by the inter- and intra-assay variation coefficients (ranging between 4.9 and 7%). To illustrate the applicability of the ELISAs we assessed Ig concentrations in pig sera sampled from birth to young adulthood.

Aging↗
PubMed1994

Antigen presenting cells and B-cells in the pig.

The central position of antigen presenting cells (APC) in the immune system and the heterogeneity of the APC family are discussed; both aspects are illustrated with data from species other than the pig. Thereafter the limited work on porcine APC is reviewed. The section on B-cells, the effector cells of the humoral immune system, exclusively focuses on 'porcine data'.

Animals↗
PubMed1994

Conversion of orally induced suppression of the mucosal immune response to ovalbumin into stimulation by conjugating ovalbumin to cholera toxin or its B subunit.

Oral pretreatment of mice with ovalbumin (OVA) not only suppressed a subsequently induced systemic immune response ('oral tolerance') but also suppressed, even more effectively, a subsequently induced intestinal IgA response. In contrast, pretreatment with OVA conjugated to cholera toxin (CT) or its B subunit (CTB) resulted in a stimulative effect. The stimulative effect was enhanced when unconjugated OVA and polymerized OVA were removed from the OVA-CT (B) conjugate mixtures by affinity chromatography. Thus, the effect of oral pretreatment depends on the balance between tolerizing and stimulating components in the conjugate mixture. As OVA-CTB conjugates were at least as effective as OVA-CT conjugates in stimulation of the intestinal immune response, we concluded that the ability of the OVA conjugates to bind to the intestinal mucosa is a prerequisite in inducing the stimulative effect. These observations further demonstrate that conjugation of a protein antigen to an appropriate carrier can convert the nature of the immunization from suppressive into stimulative.

Administration, Oral↗
PubMed1992

Comparison of an indirect haemagglutination assay and an ELISA for diagnosing Fasciola hepatica in experimentally and naturally infected sheep.

An enzyme-linked immunosorbent assay (ELISA) with somatic (S) or excretory-secretory antigens (ES) was compared with an indirect haemagglutination assay (IHA) for ability to detect antibodies against Fasciola hepatica in sheep. The specificity of both assays was determined by testing sera collected from sheep experimentally or naturally mono-infected with Fasciola hepatica, Haemonchus contortus, Ostertagia circumcincta, Cooperia curticei, Taenia ovis, Eimeria spp., Trichostrongylus vitrinus, Trichostrongylus colubriformis or Nematodirus battus respectively. With S or ES antigens the specificity of the ELISA was 98% or 95% respectively, whereas the specificity of the IHA was 86%. Antibodies directed against Fasciola hepatica were detected by the ELISA with S or ES antigens from 2 weeks after infection until the end of the experiment, whereas the IHA detected antibodies from week 3. We conclude that the ELISA with S antigens compares favourably with the IHA and can be used for the serodiagnosis of ovine fasciolosis in the Netherlands.

Animals↗
PubMed1990

[Mucosal immunity].

The mucosal immune system protects against infections that enter the body via the mucosae. This article describes how the mucosal immune system functions and how mucosal immune responses can be induced by vaccination. It also discusses various vaccination regimens that maximize the induction of mucosal immune responses against bacterial and viral infections. One paragraph of the article discusses the possibilities of developing vaccines that induce a mucosal immune response against parasite infections.

Animals↗
PubMed1989

Background (spontaneous) immunoglobulin production in the murine small intestine before and after weaning.

The ontogeny of the murine intestinal B-cell compartment before and after weaning was studied by quantitative analysis of immunoglobulin-secreting cells (Ig-SC) in the small intestine (SI). Before weaning, few Ig-SC were detected in the SI, whereas spleen and bone marrow already contained many Ig-SC. The number of Ig-SC in the SI started to increase immediately after weaning. Comparing early-weaned mice with non-weaned mice of the same age clearly demonstrated that weaning brought on the development of Ig-SC in the SI. The influence of a gut flora on the number of Ig-SC in the SI was examined by comparing the number of Ig-SC in the SI of conventionally housed, specific pathogen free (SPF) and germ-free mice. A bacterial flora was apparently needed for the normal development of Ig-SC in the SI. Comparing mice containing an aerobic Gram-negative bacterial flora with mice containing only an anaerobic Gram-positive bacterial flora demonstrated that the type of bacterial flora is relatively unimportant. No evidence was found that circulating maternal antibodies suppressed the development of the "spontaneous" intestinal and systemic B cell response. The results show that bacterial colonization of the intestine plays a pivotal role in the development of the Ig-SC compartment in the SI.

Animals↗
PubMed1987

Contribution of immunoglobulin-secreting cells in the murine small intestine to the total 'background' immunoglobulin production.

In this study we investigated the contribution of the small intestine of C3H/He mice to the spontaneous ('background') immunoglobulin (Ig) production in terms of the number of Ig-secreting cells (Ig-SC), and compared the results with the numbers of Ig-SC found in various lymphoid organs (spleen, bone marrow, mesenteric lymph nodes and Peyer's patches). The results show that in C3H/He mice of 20 weeks of age, on average 16 x 10(6) Ig-SC can be isolated from the small intestine. Almost all of these Ig-SC produce IgA. Compared to the other lymphoid organs, the small intestine contains more than 80% of all Ig-SC present in adult C3H/He mice. These results are in agreement with the need to maintain relatively high levels of Ig at the mucosal surfaces, especially of secretory IgA, for the prevention of penetration of these surfaces by micro-organisms. In man and mouse most of these Ig are supposed to be produced locally in the underlying mucosal tissues and subsequently transported across the epithelium. Although the IgM and IgG levels in serum are predominantly maintained by non-mucosae associated lymphoid organs, the results of this study clearly indicate that the mucosal tissues are the major site of 'background' Ig-production.

Animals↗
PubMed1986

The influence of a water-in-oil emulsion on humoral immunity.

A strategy for research of immunostimulants is best served choosing a way by which the immune response can be studied without being complicated by a combination of effects originating both in adjuvant and antigen. This means that adjuvant and antigen preferably are applied with an interval and by different routes. In our model an adjuvant (a W/O emulsion) was applied intraperitoneally, whereas the antigen was injected intravenously. The stimulatory effect on the splenic plaque forming B-cell response depended on the dose of antigen, on the interval between adjuvant and antigen application, on the mouse strain used, and on the quality of the antigen with respect to the intrinsic adjuvanticity of the antigens.

Adjuvants, Immunologic↗
PubMed1986

Research of the application of a water-in-oil emulsion for the prevention of post-weaning diarrhoea and oedema disease in piglets.

A stable water-in-oil emulsion was injected intraperitoneally (i.p.) in piglets about 5 days before weaning to prevent post-weaning diarrhoea (PWD) and oedema disease (OD). So far more than 200,000 piglets have been treated with this adjuvant on a number of farms. On these farms the mortality rate due to PWD and OD decreased, whereas the need for antibiotic treatment declined. Experiments involving alternate application of adjuvant and physiological saline, or adjuvant treatment and no treatment at all, showed a statistically significant positive effect of adjuvant application. The effect of i.p. adjuvant application on specific and non-specific defence mechanisms were examined in well defined rat- and mouse-models, to throw light upon the mechanisms behind the observed adjuvant effect in piglets.

Adjuvants, Immunologic↗
PubMed1986

Separate application of adjuvant and antigen: the effect of a water-in-oil emulsion on the splenic plaque-forming cell response to sheep red blood cells in mice.

The effect of a non-immunogenic adjuvant on the murine splenic plaque-forming cell (PFC) response against sheep red blood cells (SRBC) was studied. The adjuvant, a stable water-in-oil (W/O) emulsion, was injected intraperitoneally at the same time as or prior to the intravenous (i.v.) injection of SRBC. Enhancement of the SRBC-specific IgM-, but not IgG- and IgA-responses was observed. The stimulatory effect depended on the dose of both adjuvant and antigen and on the interval between their application. The minimal dose of adjuvant needed to induce maximal stimulation increased with the interval between the injections. Administration of an optimal adjuvant dose one week before antigen application still resulted in a clear stimulation of the response to the antigen. In adjuvant-treated animals, the primary PFC response did not exceed the maximum level reached after i.v. injection of a high dose of SRBC. Adjuvant therapy also resulted in polyclonal B cell-activation, since the number of spontaneous Ig-secreting cells in the spleen was increased. The kinetics and isotype distribution of the SRBC-specific and polyclonal responses, however, were different. Therefore, the observed stimulatory effect on the SRBC-specific PFC-response cannot be explained by the polyclonal activation of the immune system. From this study it appears that injection of a W/O emulsion provokes an active stimulation of the immune system, which demonstrates that the adjuvant effect of W/O emulsions is not only passively obtained by prolonged antigen presentation by depot formation.

Adjuvants, Immunologic↗
PubMed1985

Modification of immune induction by adjuvant.

The role of adjuvanticity in the modification of the immune induction was studied by separate application of antigen and adjuvant in mice. An antigen specific plaque forming cell (PFC) test and a delayed type hypersensitivity (DTH) assay were used for these studies. Antigen (SRBC) and adjuvant were applied separately in time and place. A stable well defined water-in-oil emulsion without antigen was used as adjuvant. Our studies have shown that intraperitoneal (i.p.) injection of this adjuvant stimulates the intravenous (i.v.) induced PFC response, while the DTH response is suppressed. This effect can be demonstrated even when adjuvant has been injected i.p. 5 days prior to i.v. antigen injection. The stimulation of the PFC response depends on the dosage of i.v. injected antigen.

Adjuvants, Immunologic↗