Biomedical subjects

P Hultman

Publications and source records attributed to P Hultman.

At least 19 recordsLinked to original sources

PubMed2006

Alteration of the spontaneous systemic autoimmune disease in (NZB x NZW)F1 mice by treatment with thimerosal (ethyl mercury).

Inorganic mercury may aggravate murine systemic autoimmune diseases which are either spontaneous (genetically determined) or induced by non-genetic mechanisms. Organic mercury species, the dominating form of mercury exposure in the human population, have not been examined in this respect. Therefore, ethyl mercury in the form of thimerosal, a preservative recently debated as a possible health hazard when present in vaccines, was administered in a dose of 0.156-5 mg/L drinking water to female (NZB x NZW)F1 (ZBWF1) mice. These mice develop an age-dependent spontaneous systemic autoimmune disease with high mortality primarily due to immune-complex (IC) glomerulonephritis. Five mg thimerosal/L drinking water (295 microg Hg/kg body weight (bw)/day) for 7 weeks induced glomerular, mesangial and systemic vessel wall IC deposits and antinuclear antibodies (ANA) which were not present in the untreated controls. After 22-25 weeks, the higher doses of thimerosal had shifted the localization of the spontaneously developing renal glomerular IC deposits from the capillary wall position seen in controls to the mesangium. The altered localization was associated with less severe histological kidney damage, less proteinuria, and reduced mortality. The effect was dose-dependent, lower doses having no effect compared with the untreated controls. A different effect of thimerosal treatment was induction of renal and splenic vessel walls IC deposits. Renal vessel wall deposits occurred at a dose of 0.313-5 mg thimerosal/L (18-295 microg Hg/kg bw/day), while splenic vessel wall deposits developed also in mice given the lowest dose of thimerosal, 0.156 mg/L (9 microg Hg/kg bw/day). The latter dose is 3- and 15-fold lower than the dose of Hg required to induce vessel wall IC deposits in genetically susceptible H-2s mice by HgCl2 and thimerosal, respectively. Further studies on the exact conditions needed for induction of systemic IC deposits by low-dose organic mercurials in autoimmune-prone individuals, as well as the potential effect of these deposits on the vessel walls, are warranted.

Animals↗

PubMed2006

The effect of xenobiotic exposure on spontaneous autoimmunity in (SWR x SJL)F1 hybrid mice.

F1 hybrids of SWR (H-2(q)) and SJL (H-2(s)) mice spontaneously develop a lupuslike condition in an age-dependent manner, and these two H-2 haplotypes also confer susceptibility to induction of systemic autoimmunity by heavy metals such as mercury, silver, and gold with anti-fibrillarin antibodies (AFA) as marker. The aim of this study was to determine how the mixing of two susceptible genomes might influence expression of idiopathic and induced autoimmunity over a period of 14 mo of exposure to mercury and silver. Spontaneous autoimmunity first appeared as antinuclear antibodies (ANA) in females at 10 wk of age and in males at 10 mo of age, and was followed by development of anti-chromatin antibodies. Antibodies to double-stranded DNA developed in 60% of males and 20% of females. Thirty percent of males and 10% of females developed a coarsely speckled ANA pattern associated with high titers of anti-Sm antibodies. Glomerular immune complex (IC) deposits and a proliferative glomerulonephritis were seen at 17 mo of age. The F1 hybrids treated with metals showed no exaggeration of spontaneous autoimmunity. However, the metals suppressed the spontaneous development of anti-Sm and antichromatin antibodies. The metal-induced AFA, linked to the H-2(s) and H-2(q) haplotype, reached a maximum after 3-4 mo of treatment and then declined; 33% of the silver-treated hybrids finally became AFA-negative, despite continuous treatment. The decline in ANoA during metal treatment is contrary to the situation in metal-treated SJL mice. This indicates that dominant SWR background genes suppressed induction of certain autoimmune traits in the (SWR x SJL)F1 hybrid mice.

Age Factors↗

PubMed2006

The role of Fc-receptors in murine mercury-induced systemic autoimmunity.

Inorganic mercury (Hg) in genetically susceptible mouse strains induces a T cell-dependent, systemic autoimmune condition (HgIA) characterized by immunostimulation, anti-nuclear antibodies (ANA) and systemic immune-complex (IC) deposits. The exact phenotypic expression of HgIA in different strains depends on H-2 and non-H-2 genes. Fc receptors (FcRs) are important in the development of many autoimmune diseases. In this study, the effect of targeted mutations for activating and inhibiting FcRs in the BALB/c model of HgIA was examined. Hg-treated BALB/c mice without mutation (wild-type, wt) showed heavy IC deposits in the renal glomerular mesangium, as well as in renal and splenic vessel walls. The renal mesangial IC deposits were severely reduced in Hg-treated BALB/c mice without the gamma-chain (lack of the activating receptors FcgammaRI, FcgammaRIII and FcinRI), but unchanged in mice lacking the inhibitory FcgammaRIIB. The Hg-induced vessel wall IC deposits present in wt mice were abolished and reduced in the FcRgamma and FcgammaRIIB strains, respectively. Hg-treated BALB/c wt mice and mice without the gamma-chain showed an increase in serum IgE, while the increase in IgG1 was attenuated in the latter strain. In contrast, absence of the inhibiting FcgammaRIIB augmented the Hg-induced increase of both serum IgG1 and IgE. In conclusion, FcRs are important mainly for the induction of systmeic IC deposits in the HgIA model, but also affects serum IgG1 and IgE levels.

Animals↗

PubMed2005

Immunosuppressive and autoimmune effects of thimerosal in mice.

The possible health effects of the organic mercury compound thimerosal (ethylmercurithiosalicylate), which is rapidly metabolized to ethylmercury (EtHg), have recently been much debated and the effect of this compound on the immune system is largely unknown. We therefore studied the effect of thimerosal by treating A.SW (H-2s) mice, susceptible to induction of autoimmunity by heavy metals, with 10 mg thimerosal/L drinking water (internal dose ca 590 microg Hg/kg body weight/day) for up to 30 days. The lymph node expression of IL-2 and IL-15 mRNA was increased after 2 days, and of IL-4 and IFN-gamma mRNA after 6 and 14 days. During the first 14 days treatment, the number of splenocytes, including T and B cells as well as Ig-secreting cells decreased. A strong immunostimulation superseded after 30 days treatment with increase in splenic weight, number of splenocytes including T and B cells and Ig-secreting cells, and Th2- as well as Th-1-dependent serum immunoglobulins. Antinucleolar antibodies (ANoA) targeting the 34-kDa nucleolar protein fibrillarin, and systemic immune-complex deposits developed. The H-2s strains SJL and B10.S also responded to thimerosal treatment with ANoA. The A.TL and B10.TL strain, sharing background genes with the A.SW and B10.S strain, respectively, but with a different H-2 haplotype (t1), did not develop ANoA, linking the susceptibility to H-2. Thimerosal-treated H-2s mice homozygous for the nu mutation (SJL-nu/nu), or lacking the T-cell co-stimulatory molecule CD28 (B10.S-CD28-/-), did not develop ANoA, which showed that the autoimmune response is T-cell dependent. Using H-2s strains with targeted mutations, we found that IFN-gamma and IL-6, but not IL-4, is important for induction of ANoA by thimerosal. The maximum added renal concentration of thimerosal (EtHg) and inorganic mercury occurred after 14 days treatment and was 81 microg Hg/g. EtHg made up 59% and inorganic mercury 41% of the renal mercury. In conclusion, the organic mercury compound thimerosal (EtHg) has initial immunosuppressive effects similar to those of MeHg. However, in contrast to MeHg, thimerosal treatment leads in genetically susceptible mice to a second phase with strong immunostimulation and autoimmunity, which is T-cell dependent, H-2 linked and may at least partly be due to the inorganic mercury derived from the metabolism of ethyl mercury.

Administration, Oral↗

PubMed2005

Interleukin-10 in murine metal-induced systemic autoimmunity.

Systemic autoimmune diseases have a complicated and largely unknown aetiology and pathogenesis, but they are at least partly obeying the rules of an ordinary immune response. Cytokines are therefore important in the pathogenesis as demonstrated by the recent success in treating rheumatoid arthritis with anti-cytokine agents. The suppressive functions in the immune system have lately received much interest. One of the cytokines in focus in this respect is interleukin (IL)-10. We recently observed that in heavy-metal induced systemic autoimmunity, genetically resistant mice show a strong increase in IL-10 mRNA expression, which was not seen in susceptible mice. We have therefore examined the possible regulating effect of IL-10 on the induction and manifestation of systemic autoimmunity in this model. We took two approaches: a targeted mutation of the IL-10 gene in a strain resistant to heavy metal-induced autoimmunity, and treatment with recombinant IL-10 in the genetically susceptible A.SW strain during the induction of autoimmunity by metals. The wild-type C57BL/6 J (B6-WT) strain did not react with lymphoproliferation, polyclonal B cell activation, anti-nucleoar autoantibodies (ANoA) or tissue immune-complex (IC) deposits in response to inorganic mercury (Hg) or silver (Ag). However, serum IgG1 and IgE showed a modest increase during Hg treatment, while Ag caused a weak increase in IgE and IgG2a. The B6.129P2-Il10(tm1Cgn)/J strain (IL-10-deficient mice) did not develop antinucleolar antibodies (ANoA) during Hg treatment, but showed a higher median titre of homogeneous ANA compared with Hg-treated B6-WT mice. Both control and Hg-treated (but not Ag-treated) IL-10-deficient mice showed an increase in splenic weight and serum IgG1 compared with B6-WT control and Hg-treated mice. An early, significant increase in serum IgE was seen in Hg-treated IL-10-deficient and WT mice compared with the controls; the increase was 42- and sixfold, respectively. During ongoing intense treatment with rIL-10 in combination with Hg the susceptible A.SW mice showed a reduced development of ANoA and antichromatin antibodies, as well as serum IgE, compared with mice receiving Hg but not rIL-10. In conclusion, IL-10 suppresses several aspects of HgIA, but is not crucial for resistance to heavy metal-induced autoimmunity. Peroral silver treatment suppresses the spontaneous immune activation seen in IL-10-deficient mice.

Animals↗

PubMed2005

Acute glomerulonephritis associated with streptococcus pyogenes with concomitant spread of streptococcus constellatus in four rural families.

We studied history, renal histopathology and microbiology of an epidemic of acute glomerulonephritis associated with throat infections and uncommon culture results in four neighbour families. A 40-year-old man (index patient) was referred to a university hospital for dialysis and kidney biopsy due to a suspected acute glomerulonephritis. An acute tonsillitis had preceded the condition. Penicillin treatment had been started four days before the discovery of renal failure. Throat swabs were positive for beta-hemolytic streptococci, group C (GCS). GCS were also found in throat cultures from his wife and two of their children. The bacteria were typed as Streptococcus constellatus. A third child had S. constellatus expressing Lancefield antigen group G. A neighbour and two of his children fell ill the following week with renal involvement. Throat swabs from both these children were positive for S. constellatus. His third child had erythema multiforme and S. constellatus in the throat while a fourth child had beta-hemolytic streptococci group A; Streptococcus pyogenes. Kidney biopsies on the index patient and his neighbour showed an acute diffuse prolipherative glomerulonephritis compatible with acute post-streptococcal nephritis and microbiological analysis of renal tissue revealed in both cases S. pyogenes and S. constellatus. The families had had much contact and had consumed unpasteurized milk from our index patient's farm. In four of seven persons in two additional neighbouring families S. constellatus was found in throat swabs during the same month while two persons carried Streptococcus anginosus expressing the Lancefield C antigen. In conclusion spread of S. constellatus coincided with the occurrence of four cases of acute glomerulonephritis. The two biopsied patients had both S. pyogenes and S. constellatus present in renal tissue. The epidemic either suggested that the outbreak of glomerulonephritis was due to S. pyogenes but coincided with the transmission and colonization of S. constellatus or that the S. constellatus strains were highly pathogenic or nephritogenic and that this organism can be transmitted in such cases.

Acute Disease↗

PubMed2004

Dose-response study of thimerosal-induced murine systemic autoimmunity.

The organic compound ethylmercurithiosalicylate (thimerosal), which is primarily present in the tissues as ethylmercury, has caused illness and several deaths due to erroneous handling when used as a disinfectant or as a preservative in medical preparations. Lately, possible health effects of thimerosal in childhood vaccines have been much discussed. Thimerosal is a well-known sensitizing agent, although usually of no clinical relevance. In rare cases, thimerosal has caused systemic immune reactions including acrodynia. We have studied if thimerosal might induce the systemic autoimmune condition observed in genetically susceptible mice after exposure to inorganic mercury. A.SW mice were exposed to 1.25-40 mg thimerosal/l drinking water for 70 days. Antinucleolar antibodies, targeting the 34-kDa protein fibrillarin, developed in a dose-related pattern and first appeared after 10 days in the two highest dose groups. The lowest observed adverse effect level (LOAEL) for antifibrillarin antibodies was 2.5 mg thimerosal/l, corresponding to an absorbed dose of 147 microg Hg/kg bw and a concentration of 21 and 1.9 microg Hg/g in the kidney and lymph nodes, respectively. The same LOAEL was found for tissue immune-complex deposits. The total serum concentration of IgE, IgG1, and IgG2a showed a significant dose-related increase in thimerosal-treated mice, with a LOAEL of 5 mg thimerosal/l for IgG1 and IgE, and 20 mg thimerosal/l for IgG2a. The polyclonal B-cell activation showed a significant dose-response relationship with a LOAEL of 10 mg thimerosal/l. Therefore, thimerosal induces in genetically susceptible mice a systemic autoimmune syndrome very similar to that seen after treatment with inorganic mercury, although a higher absorbed dose of Hg is needed using thimerosal. The autoimmune syndrome induced by thimerosal is different from the weaker and more restricted autoimmune reaction observed after treatment with an equipotent dose of methylmercury.

Animals↗

PubMed2003

Effects of deviating the Th2-response in murine mercury-induced autoimmunity towards a Th1-response.

T-helper cells type 1 (Th1) and type 2 (Th2) play an important role in the pathogenesis of autoimmune diseases. In many Th1-dependent autoimmune models, treatment with recombinant interleukin-12 (rIL-12) accelerates the autoimmune response. Mercury-induced autoimmunity (HgIA) in mice is an H-2 regulated condition with antinucleolar antibodies targeting fibrillarin (ANoA), systemic immune-complex (IC) deposits and transient polyclonal B-cell activation (PBA). HgIA has many characteristics of a Th2 type of reaction, including a strong increase of IgE, but disease induction is critically dependent on the Th1 cytokine IFN-gamma. The aim of this study was to investigate if a strong deviation of the immune response in HgIA towards Th1 would aggravate HgIA. Injections of both rIL-12 and anti-IL-4 monoclonal antibody (alpha-IL-4) reduced the HgCl2-(Hg-)induced concentration of the Th2-dependent serum IgE and IgG1, but increased the Th1-dependent serum IgG2a. The IgG-ANoA developed earlier and attained a higher titre after combined treatment, and the ANoA titre of the IgG1 isotype decreased while the ANoA titre of the Th1-associated IgG2a, IgG2b and IgG3-ANoA isotypes increased. Treatment with rIL-12 alone increased the Hg-induced IgG2a and IgG3 ANoA titres, the PBA, and the IC deposits in renal and splenic vessel walls, while treatment with alpha-IL-4 + Hg inhibited renal but not splenic vessel wall IC deposits. We conclude that manipulating the cytokine status, by altering the Th1/Th2 balance, will influence autoimmune disease manifestations. This might be an important way of modulating human autoimmune diseases.

Animals↗

PubMed2003

Cytokine production, lymphocyte proliferation and T-cell receptor Vbeta expression in primary peripheral blood mononuclear cell cultures from nickel-allergic individuals.

BACKGROUND: Clinical history and patch test constitute the two cornerstones in the diagnosis of nickel (Ni) allergy. Due to technical and interpretative limits of the patch test, the in vitro lymphocyte transformation test (LTT) has been developed for confirming contact allergy; however, most studies show an overlap in lymphocyte proliferation between Ni-allergic and nonallergic subjects using the LTT. The aim of this study was to see if the secretion of cytokines, especially interleukin (IL)-10 and IL-17, or the use of T-cell receptor (TCR) Vbeta families in Ni-stimulated primary peripheral blood mononuclear cell (PBMC) cultures might be more useful for discriminating between allergic and nonallergic subjects. METHODS: Ni(2+)-stimulated primary PBMC cultures derived from female subjects diagnosed as Ni-allergic (n = 5) or nonallergic (n = 5) on the basis of a positive or negative patch test were assessed for cell proliferation by tritiated thymidine incorporation and for production of interferon-gamma, IL-4, IL-10 and IL-17 in the culture supernatant by ELISA. The immunophenotype and TCR-Vbeta family affiliation of the Ni(2+)-induced lymphoblasts were determined by flow cytometry. RESULTS: Lymphocytes from Ni-allergic individuals challenged with a high and a low concentration of Ni showed significantly higher cell proliferation than lymphocytes from nonallergic individuals, but all subjects showed a positive LTT result (stimulation index >2). We found a significantly higher release of IL-10 in Ni(2+)-treated cultures from Ni-allergic compared with nonallergic subjects that provided better separation between individuals in the two groups than did lymphocyte proliferation. The proliferating lymphoblasts were predominantly CD4+, and in 2 of the 5 Ni-allergic subjects, but in none of the 5 nonallergic subjects, the CD4+ lymphoblasts showed a dominance of TCR-Vbeta17. CONCLUSIONS: Determination of IL-10 production in primary PBMC cultures is a potentially promising in vitro method for discrimination of Ni allergy in females, as compared with cell proliferation.

Adult↗

PubMed2001

Resistance to xenobiotic-induced autoimmunity maps to chromosome 1.

Although evidence indicates that environmental factors play a major role in precipitating systemic autoimmunity in genetically susceptible individuals, little is known about the mechanisms involved. Certain heavy metals, such as mercury, are potent environmental immunostimulants that produce a number of immunopathologic sequelae, including lymphoproliferation, hypergammaglobulinemia, and overt systemic autoimmunity. Predisposition to such metal-induced immunopathology has been shown to be influenced by both MHC and non-MHC genes, as well as susceptibility to spontaneous lupus, in mice and other experimental animals. Among the various mouse strains examined to date, the DBA/2 appears to uniquely lack susceptibility to mercury-induced autoimmunity (HgIA), despite expressing a susceptible H-2 haplotype (H-2d). To define the genetic basis for this trait, two genome-wide scans were conducted using F2 intercrosses of the DBA/2 strain with either the SJL or NZB strains, both of which are highly susceptible to HgIA. A single major quantitative trait locus on chromosome 1, designated Hmr1, was shown to be common to both crosses and encompassed a region containing several lupus susceptibility loci. Hmr1 was linked to glomerular immune complex deposits and not autoantibody production, suggesting that DBA/2 resistance to HgIA may primarily involve the later stages of disease pathogenesis. Identification and characterization of susceptibility/resistance genes and mechanisms relevant to the immunopathogenesis of mercury-induced autoimmunity should provide important insights into the pathogenesis of autoimmunity and may reveal novel targets for intervention.

Animals↗

PubMed2001

The effect of dose, gender, and non-H-2 genes in murine mercury-induced autoimmunity.

We have studied the effect of dose, treatment time, gender and non-H-2 genes on immune parameters and toxicokinetics in murine mercury-induced autoimmunity (HgAI). The partly-proven mechanism for HgAI is the modification of the autoantigen fibrillarin by mercury, followed by a T cell-dependent immune response driven by the modified fibrillarin. In the H-2 congenic (H-2(S)) mouse strains A.SW and B10.S given (203)HgCl(2) in a dose of 0.25-8 mg Hg/l drinking water for up to 10 weeks, the internal dose measured as the whole-body retention of mercury reached steady state within 5 weeks. Fifty percent of the steady state level was reached already after 2 days. Conditions therefore exist for a rapid modification of fibrillarin, followed by a T cell-dependent immune response, which is consistent with the presence of anti-fibrillarin antibodies (AFA) in serum after 2 weeks. AFA developed in a dose-dependent pattern. Serum IgE showed a dose-dependent increase with a maximum after 1-2.5 weeks followed by a distinct decline towards the baseline level. Substantial polyclonal B-cell activation (PBA) developed in the highest dose groups only. Since AFA developed using lower doses too, PBA can be excluded as a general mechanism for induction of AFA. Tissue immune-complex (IC) deposits were present in the highest dose groups only, indicating a possible causality between PBA and IC deposits. The substantially lower whole body and organ mercury level needed to induce AFA in the A.SW strain as compared with the H-2 congenic B10.S strain, demonstrates that genetic factors outside the H-2 region, and not related to toxicokinetics, modifies the autoimmune response. In contrast, the difference in mercury thresholds for induction of IgE was only slight between A.SW and B10.S mice, indicating basically different mechanisms for induction of AFA and serum IgE.

Animals↗

PubMed2001

Murine metal-induced systemic autoimmunity: baseline and stimulated cytokine mRNA expression in genetically susceptible and resistant strains.

Cytokines play an important and complex role in the pathogenesis of systemic autoimmune diseases. In susceptible H-2s mice, inorganic mercury (Hg) induces lymphoproliferation, antinucleolar antibodies against the 34-kDa-protein fibrillarin, and systemic immune-complex (IC) deposits. Here, we report extensive analysis of cytokine mRNA levels in susceptible A.SW (H-2s) and resistant A.TL (H-2tl) mice under unstimulated conditions and during oral treatment with Hg and/or silver nitrate (Ag). Cytokine mRNA expression in lymphoid tissues was assessed using the ribonuclease protection assay and phosphorimaging. Baseline expression of IL-2 and IFN-gamma mRNA was higher in A.SW than in A.TL mice. In A.SW mice, Hg treatment caused early up-regulation of IL-2 and IFN-gamma levels, followed by substantial expression of IL-4 mRNA, which was significant compared to control A.SW and Hg-treated A.TL mice. Hg-exposed A.TL mice exhibited unchanged IFN-gamma, reduced IL-2 and greatly increased IL-10 mRNA expression. Ag-treated A.SW mice, which develop antifibrillarin antibodies (AFA) but exhibit minimal immune activation and no IC deposits, showed an early increase in IL-2 and IFN-gamma mRNA, but only a small and delayed rise in IL-4 mRNA. In conclusion, H-2-linked resistance to Hg-induced AFA is characterized by low constitutive expression of IL-2 and IFN-gamma mRNA, which is not increased by Hg, and a marked increase in IL-10 expression. Conversely, the key features of H-2-linked susceptibility to Hg- and Ag-induced AFA are up-regulation of IL-2, IFN-gamma and IL-4 mRNA expression, and down-regulation of IL-10 expression.

Animals↗

PubMed2001

Xenobiotic acceleration of idiopathic systemic autoimmunity in lupus-prone bxsb mice.

The diverse genetic backgrounds of lupus-prone murine models, which produce both quantitative and qualitative differences in disease expression, may be a valuable resource for studying the influence of environmental exposure on autoimmune disease in sensitive populations. We tested this premise by exposing autoimmune-prone BXSB and the nonautoimmune C57BL/6 mice to the heavy metal mercury. Although both strains express a nonsusceptible H-2 haplotype, exposure to mercury accelerated systemic autoimmunity in both male and female BXSB mice, whereas the C57BL/6 mice were resistant. The subclasses of antichromatin antibodies elicited in BXSB mice by mercury exposure were more consistent with the predominant Th1-type response of idiopathic disease than with the Th2-type response found in mercury-induced autoimmunity (HgIA). The appearance and magnitude of both humoral and cellular features of systemic autoimmunity correlated with the mercury dose. Furthermore, environmentally relevant tissue levels of mercury were associated with exacerbated systemic autoimmunity. These studies demonstrate that xenobiotic exposure can accelerate spontaneous systemic autoimmunity, and they support the possibility that low-level xenobiotic exposure enhances susceptibility to systemic autoimmunity in genetically susceptible individuals.

Animals↗

PubMed2000

Characterization of primary recall in vitro lymphocyte responses to bacampicillin in allergic subjects.

BACKGROUND: Antigen-specific cell lines or clones are often used as models of drug-specific allergy. However, cloning procedures are time consuming, and the repeated antigen stimulation cycles as well as the addition of various growth enhancers may affect the in vivo relevance of these systems. OBJECTIVE: Using bacampicillin-allergic subjects, we wanted to investigate the applicability of primary recall in vitro lymphocyte responses to characterize type I and type IV allergy. The sensitivity and specificity of LTT (Lymphocyte transformation test), when used as an in vitro diagnostic tool, were also assessed. METHODS: A total of 39 patients with symptoms of type I (rhinitis) or type IV (allergic contact dermatitis, ACD) allergy following occupational exposure to bacampicillin, were included. Ten individuals without penicillin allergy or occupational exposure to bacampicillin served as controls. All subjects were LTT tested. Four patients with rhinitis and two patients with ACD were available for studying the immunophenotype and the TCR-Vbeta repertoire of bacampicillin induced lymphoblasts as well as the cytokine profiles and expression of the activation markers CD23 and CD134 in primary PBMC cultures. RESULTS: LTT was positive in 87% and at least one of the skin tests was positive in 85% of the patients with allergic symptoms. 69% of the patients with type I allergies were patch test-positive. Results from LTT and skin test correlated in 87% of the cases. The combined sensitivity of LTT and skin tests was 92%. The specificity of LTT was 90% in healthy controls. Bacampicillin induced lymphoblasts were mainly CD4 + in both ACD and rhinitis patients. The TCR-Vbeta profiles of the predominant CD4 + lymphoblasts were heterogeneous with individual skewing towards Vbeta2, Vbeta3, Vbeta5.1 and/or Vbeta14. An increased expression of IFNgamma was detected in bacampicillin treated PBMC cultures from the ACD but not from rhinitis patients. IL-5 was detected in bacampicillin exposed PBMC cultures from all patients but not from healthy controls. This Th2 environment could also be verified by CD23 and CD134 expression. CONCLUSION: LTT and skin tests are equally sensitive in identifying bacampicillin allergic subjects. When the two tests are combined, the sensitivity increases. The patch test is useful not only for detection of type IV but also for the identification of type I allergies. When using primary PBMC cultures, IFNgamma is the most suitable cytokine to discriminate between type I and type IV allergy. IL-5 can possibly be used as a general marker for bacampicillin induced allergy. Thus, primary cell cultures may be considered as an alternative to T-cell lines or clones for the study of drug induced allergy.

Ampicillin↗

PubMed2000

Characterization of mercuric mercury (Hg2+)-induced lymphoblasts from patients with mercury allergy and from healthy subjects.

Hg2+ induces lymphocyte proliferation when added to cell cultures from both healthy and mercury-allergic subjects. Consequently, when measuring DNA synthesis a possible Hg2+-specific response, resulting from proliferating memory cells, cannot be discriminated from a non-allergic response. The mechanism behind this non-allergic response is unknown but a superantigenic effect of Hg2+ has been suggested. In this study, five mercury-allergic patients, with oral lichen planus (OLP) lesions adjacent to dental amalgam and a positive patch test to Hg0, and five healthy subjects without amalgam were examined. The immunophenotype and the T cell receptor Vbeta (TCR Vbeta) repertoire of Hg2+-induced lymphoblasts as well as the expression of the lymphocyte activation markers CD23 and CD134 were analysed for possible differences between healthy and allergic subjects. The mechanism of Hg2+-induced proliferation was examined by comparing the TCR Vbeta expression of Hg- and staphylococcal enterotoxin B (SEB)-activated lymphoblasts, the latter used as a positive superantigen control. It was not possible to discriminate between mercury-allergic and healthy subjects using the immunophenotype or the TCR Vbeta profile of the Hg2+-induced lymphoblasts or the expression of CD23 and CD134. However, Hg2+-induced CD4+ lymphoblasts showed a skewing towards Vbeta2. This relative increase in Vbeta2 was only detected in the CD4+ but not in the CD8+ lymphoblast population. In conclusion, Hg2+ induced a proliferation-dependent skewing towards CD4+ but not CD8+ lymphocytes expressing Vbeta2. In this respect Hg2+ differs from the classical bacterial superantigen SEB, which also stimulates unique TCR Vbeta families among CD8+ cells.

Adult↗

PubMed1999

Methyl mercury-induced autoimmunity in mice.

Female SJL/N, A.SW, B10.S (H-2s), BALB/C, DBA/2 (H-2d), A.TL and B10. TL (H-2t1) mice were treated with sc injections of 1.0 mg CH3HgCl/kg body weight every third day for 4 weeks. Controls were given sterile, isotonic NaCl. CH3HgCl (MeHg) induced in SJL, A.SW and B10.S mice antinucleolar antibodies (ANoA) targeting the nucleolar 34-kDa protein fibrillarin. The susceptibility to develop ANoA in response to MeHg was linked to the mouse major histocompatibility complex (H-2), since H-2s but not H-2t1 mice sharing background (non-H-2) genes developed ANoA. However, the background genes decided the strength of the ANoA response in the susceptible H-2s mice, and the ANoA titer was in the order: A.SW > SJL > B10.S. Although MeHg as well as inorganic mercury induced ANoA, the two forms of mercury differed both quantitatively and qualitatively in their effect on the immune system. MeHg induced in H-2s mice a weaker general (polyclonal) and specific (ANoA) B-cell response than HgCl2, probably due to weaker activation of Th2 cells with lower IL-4 production, as indicated by the minimal increase in serum IgE. The A. TL strain with a susceptible genetic background, but a H-2 haplotype resistant to HgCl2, responded to MeHg with a modest polyclonal B-cell response dominated by Th1-associated Ig isotypes. H-2s mice treated with MeHg showed in contrast to HgCl2-treated mice no systemic immune-complex (IC) deposits, which may be due to the weaker immune activation after MeHg treatment. The increase in serum IgE concentration and ANoA titer 2-6 weeks after stopping treatment with MeHg is identical to reactions during the first 2-3 weeks of HgCl2 treatment. Therefore, demethylation of MeHg probably increased the concentration of inorganic mercury in the body sufficiently to reactivate the immune system. This reactivation indicated that genetically susceptible mice are not resistant to challenge with mercury, making them distinctly different from rats.

Animals↗

PubMed1999

In vitro lymphoproliferative assays with HgCl2 cannot identify patients with systemic symptoms attributed to dental amalgam.

Dental amalgam is suspected, by some exposed individuals, to cause various systemic psychological, sensory, and neurological symptoms. Since not all amalgam-bearers experience such reactions, an individual characteristic--for example, a susceptible immune system--might explain these conditions. In vitro lymphocyte proliferation is a valuable tool in the diagnosis of allergy. With HgCl2 as the antigen, however, the test is hampered, because Hg2+ can cause unspecific lymphocyte proliferation, optimal at 1.4 to 9.5 micrograms HgCl2/mL. Recently, the use of suboptimal HgCl2 concentrations (< or = 0.5 microgram/mL) has been suggested to circumvent these problems. The main aim of this study was to investigate whether patients with systemic symptoms alleged to result from the presence of dental amalgam differ from healthy controls, with reference to in vitro lymphoproliferative responses to HgCl2 < or = 0.5 microgram/mL. Three different test protocols--lymphocyte transformation test (LTT) in micro- and macro-cultures, and the memory lymphocyte immunostimulation assay (MELISA)--were used. Other immune parameters--such as a standard patch test for dental materials, the number of T- and B-lymphocytes, monocytes, granulocytes, and NK cells in peripheral blood, allergic symptoms, and predisposition--were also investigated. Twenty-three amalgam patients, 30 healthy blood donors with amalgam, ten healthy subjects without amalgam, and nine patients with oral lichen planus (OLP) adjacent to dental amalgam and a positive patch test to Hg0 were tested. None of the investigated immune parameters revealed any significant differences between amalgam patients and controls. The sensitivity of in vitro lymphocyte proliferation ranged from 33 to 67%, with the OLP patients as a positive control group, and the specificity from 0 to 70% for healthy controls with a negative patch test to Hg0. Thus, despite the use of HgCl2 < or = 0.5 microgram/mL, a high frequency of positive results was obtained among healthy subjects with or without dental amalgam. Consequently, in vitro lymphocyte proliferation with HgCl2 cannot be used as an objective marker for mercury allergy in dental amalgam-bearers.

Adjuvants, Immunologic↗

PubMed1999

Lupus-prone mice as models to study xenobiotic-induced acceleration of systemic autoimmunity.

The linkage between xenobiotic exposures and autoimmune diseases remains to be clearly defined. However, recent studies have raised the possibility that both genetic and environmental factors act synergistically at several stages or checkpoints to influence disease pathogenesis in susceptible populations. These observations predict that individuals susceptible to spontaneous autoimmunity should be more susceptible following xenobiotic exposure by virtue of the presence of predisposing background genes. To test this possibility, mouse strains with differing genetic susceptibility to murine lupus were examined for acceleration of autoimmune features characteristic of spontaneous systemic autoimmune disease following exposure to the immunostimulatory metals nickel and mercury. Although NiCl(2) exposure did not exacerbate autoimmunity, HgCl(2) significantly accelerated systemic disease in a strain-dependent manner. Mercury-exposed (NZB X NZW)F1 mice had accelerated lymphoid hyperplasia, hypergammaglobulinemia, autoantibodies, and immune complex deposits. Mercury also exacerbated immunopathologic manifestations in MRL+/+ and MR -lpr mice. However, there was less disease acceleration in lpr mice compared with MRL+/+ mice, likely due to the fact that environmental factors are less critical for disease induction when there is strong genetic susceptibility. Non-major histocompatibility complex genes also contributed to mercury-exacerbated disease, as the nonautoimmune AKR mice, which are H-2 identical with the MRL, showed less immunopathology than either the MRL/lpr or MRL+/+ strains. This study demonstrates that genetic susceptibility to spontaneous systemic autoimmunity can be a predisposing factor for HgCl(2)-induced exacerbation of autoimmunity. Such genetic predisposition may have to be considered when assessing the immunotoxicity of xenobiotics. Additional comparative studies using autoimmune-prone and nonautoimmune mice strains with different genetic backgrounds will help determine the contribution that xenobiotic exposure makes in rendering sensitive populations susceptible to autoimmune diseases.

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