Distribution of human adult lactase phenotypes in the population of Austria

Summary A total of 528 unrelated, apparently healthy, adult and adolescent Austrians (270 females, 258 males, mean age 22.1 years) were examined for lactose absorption capacity employing a noninvasive field test based on breath hydrogen (H₂) determination. Subjects exhibiting a change of breath hydrogen concentration of less than 15 volumes per million (vpm) after a load of 50 g lactose (n=422) were classified as lactorse absorbers, 106 probands (20.1%) showing increases of breath hydrogen concentration between 16 and 111 vpm were diagnosed as lactose malabsorbers. The distribution of the lactase phenotypes was independent of age and sex. Intolerance symptoms after lactose administration were significantly more frequent in lactose malabsorbers. Grouping of probands according to the birth-places of their grandparents revealed significant differences in the distribution of the lactase phenotypes in East and West Austria (East 25%, West 15% lactose malabsorbers). These differences are discussed in the light of the population history of these regions.     

Influence of organically or conventionally produced wheat on health, performance and mycotoxin residues in tissues and bile of growing pigs

From 1999-2001 three different varieties of wheat [Contur (susceptible to Fusarium), Batis and Petrus (less susceptible to Fusarium)] were cultivated under organic and conventional conditions in order to determine mycotoxin burden. Soil quality, preceding crop and weather conditions were comparable in the different production systems. The wheat batches were analysed for moulds, and the contents of zearalenone (ZEN) and deoxynivalenol (DON). Feeding trials were carried out with growing pigs (n = 96; average initial live weight 22.2 +/- 1.5 kg [mean +/- SD]) to examine a possible influence on the animal performance and on mycotoxin residues. The data recorded were clinical conditions, performance, biochemical and hematological data. Residues of ZEN, alpha- and beta-zearalenol (ZEL) and of DON were determined in bile, liver and muscle after slaughtering. Conventionally cultivated wheat was more frequently contaminated with Fusarium and contained more frequently ZEN and DON in higher concentrations than the organically produced wheat. Hematological and biochemical parameters of pigs fed with organically cultivated diets were not different from those of conventionally fed pigs. Pigs fed with organically produced wheat showed a slightly higher daily weight gain, but a lower carcass yield than the conventionally fed animals. The highest residues of DON and total-ZEN (ZEN + alpha-ZEL + beta-ZEL) were found in bile. Bile samples of organically fed pigs contained lower concentrations of total-ZEN than those of conventionally fed pigs. Altogether, these data suggest that wheat from an organic farming does not have higher mycotoxin-contamination than wheat from the conventional farming system.     

Dual role of CCR2 during initiation and progression of collagen-induced arthritis: evidence for regulatory activity of CCR2+ T cells

Chemokines play an important role in the recruitment of leukocytes and have recently been shown to also attract regulatory T cells. Using blocking mAbs, we analyzed the role of the chemokine receptor CCR2 during initiation and progression of collagen-induced arthritis in mice. Blockade of CCR2 from days 0 to 15 markedly improved clinical signs of arthritis and histological scores measuring leukocyte infiltration, synovial hyperplasia, and bone and cartilage erosion. CCR2 blockade during disease initiation significantly reduced plasma titers of collagen Abs in vivo. In vitro CCR2 blockade also interfered with collagen-specific activation and proliferation of T cells. Surprisingly, CCR2 blockade from days 21 to 36 markedly aggravated clinical and histological signs of arthritis and increased the humoral immune response against collagen. We show that CCR2 is expressed on regulatory T cells. Purified CCR2+ T cells are fully anergic toward polyclonal and collagen-specific activation and potently suppress activation of other T and B cells. The subpopulation of CCR2+ CD25+ regulatory T cells increases approximately 5-fold in the progression phase, while CCR2 expression on other leukocyte populations remains unchanged. These findings identify CCR2+ T cells as regulatory T cells and indicate that CCR2 also plays an important role in down-modulating an inflammatory response.     

Selection of T-cell epitopes from foot-and-mouth disease virus reflects the binding affinity to different cattle MHC class II molecules

The major histocompatibility complex (MHC)-restricted selection of T-cell epitopes of foot-and-mouth disease virus (FMDV) by individual cattle MHC class II DR (BoLA-DR) molecules was studied in a direct MHC-peptide binding assay. By in vitro priming of T lymphocytes derived from animals homozygous for both MHC class I and II, five T-cell epitopes were analyzed in the context of three MHC class II haplotypes. We found that the presentation of these T-cell epitopes was mediated by DR molecules, since blocking this pathway of antigen presentation using monoclonal antibody TH14B completely abolished the proliferative responses against the peptides. To study the DR-restricted presentation of these T-cell epitopes, a direct MHC-peptide binding assay on isolated cattle DR molecules was developed. Purified cattle MHC class II DR molecules of the BoLA-DRB3*0201, BoLA-DRB3*1101, and BoLA-DRB3*1201 alleles were isolated from peripheral blood mononuclear cells. For each allele, one of the identified T-cell epitopes was biotinylated, and used as a marker peptide for the development of a competitive MHC-peptide binding assay. Subsequently, the T-cell epitopes of FMDV with functionally defined MHC class II specificity were analyzed in this binding assay. The affinity of the epitopes to bind to certain DR molecules was significantly correlated to the capacity to induce T-cell proliferation. This demonstrated at the molecular level that the selection of individual T-cell epitopes found at the functional level was indeed the result of MHC restriction.     

In vivo cervical cancer growth inhibition by genetically engineered cytotoxic T cells

Purpose: The CD44 v7/8 splice variant that is frequently expressed in cervical carcinoma and rarely expressed in normal tissues displays promising properties as a target antigen for cancer immune therapy. In this study, cytotoxic T lymphocytes (CTLs) were genetically engineered to gain CD44v7/8 target specificity. Methods: Clone 96 (CI96), an established murine cytotoxic T-cell line, and naïve murine T cells were retrovirally transduced with a fusion gene construct encoding for the single chain fragment scFv of the monoclonal antibody VFF17 and for the chain of the T-cell receptor (TCR). The therapeutic potential of genetically engineered T cells was tested in vitro and in vivo. Results: Surface expression of the chimeric TCR on infected Cl96 and naïve T cells was shown by FACS analysis. CD44v7/8-positive target cells were efficiently lysed by transduced Cl96 and naïve T cells, demonstrating the functionality and specificity of the chimeric TCR. In a xenograft BALB/c mouse model, efficient growth retardation of CD44v7/8-positive tumours was mediated by genetically engineered Cl96(VFF17)cyYZ cells. Conclusions: We were able to reprogramme the target specificity of recombinant Cl96 and naïve CTLs resulting in efficient cytolysis of CD44v7/8-positive cervical cancer cells. High transduction rates and the specific cytolysis of CD44v7/8-redirected CTLs are promising tools for an immune gene therapy approach for advanced cervical cancer.Abbreviations Ab Antibody - CTL Cytolytic T lymphocyte - mAb Monoclonal antibody - TCR T-cell receptor     

Lamins A and C are differentially dysfunctional in autosomal dominant Emery-Dreifuss muscular dystrophy

Mutations in the LMNA gene, which encodes nuclear lamins A and C by alternative splicing, can give rise to Emery-Dreifuss muscular dystrophy. The mechanism by which lamins A and C separately contribute to this molecular phenotype is unknown. To address this question we examined ten LMNA mutations exogenously expressed as lamins A and C in COS-7 cells. Eight of the mutations when expressed in lamin A, exhibited a range of nuclear mislocalisation patterns. However, two mutations (T150P and delQ355) almost completely relocated exogenous lamin A from the nuclear envelope to the cytoplasm, disrupted nuclear envelope reassembly following cell division and altered the protein composition of the mid-body. In contrast, exogenously expressed DsRed2-tagged mutant lamin C constructs were only inserted into the nuclear lamina if co-expressed with any EGFP-tagged lamin A construct, except with one carrying the T150P mutation. The T150P, R527P and L530P mutations reduced the ability of lamin A, but not lamin C from binding to emerin. These data identify specific functional roles for the emerin-lamin C- and emerin-lamin A- containing protein complexes and is the first report to suggest that the A-type lamin mutations may be differentially dysfunctional for the same LMNA mutation.     

Performance of seedlings from natural and afforested populations of Cupressus sempervirens under different temperature and moisture regimes

For successful afforestation programs seed quality is crucial, but seedlings are susceptible to climatic stress. Therefore, to improve afforestation success it is necessary to compare performance of seedlings from natural and cultivated populations under different climatic conditions. We investigated growth performance in seedlings of three natural and four afforested Syrian Cupressus sempervirens L. populations under different temperature and moisture regimes. A “warm” climate chamber approximately simulated current mean annual temperatures (day/night: 20/10°C) while a “hot” chamber simulated an average increase of 5°C (day/night: 25/15°C). Seedlings were irrigated twice (drier) or thrice (moist) weekly. Seedlings from natural provenances outperformed those from afforested stands in all growth variables in both chambers. In the warm chamber, root length and biomass were not affected by irrigation for both population types, but shoot height decreased for afforested seedlings under drier treatment while it slightly increased in natural seedlings. In the hot chamber, shoot height decreased but root length and biomass increased for population types under the drier treatment. Comparison between the two chambers showed that under the drier treatment shoot height and biomass decreased at higher temperatures, but root length and biomass were not significantly different. The same response to higher temperatures was observed under the moist treatment, but root biomass decreased too. Our results emphasize the necessity to protect the remaining natural forest of C. sempervirens in Syria and recommend systematic collection of seed material from natural stands for afforestation programs. This might also hold for ex situ cultivation of retrieving rare and endangered plant species.     

Xmrk‐induced melanoma progression is affected by Sdf1 signals through Cxcr7

Chemokine signals mediated by Sdf1/Cxcl12 through the chemokine receptor Cxcr4 are thought to play an instructive role in tumor migration and organ‐specific metastasis. We have used a small aquarium fish model to contribute to a better understanding of how the course of melanoma development is influenced by Sdf1 signals in vivo. We studied oncogene‐induced skin tumor appearance and progression in the transgenic medaka (Oryzias latipes) melanoma model. Similar to humans, invasive medaka melanomas show increased levels of sdf1, cxcr4, and cxcr7 gene expression. Stable transgenic fish lines overexpressing sdf1 exclusively in pigment cells showed a reduction in melanoma appearance and progression. Remarkably, diminished levels of functional Cxcr7, but not of Cxcr4b, resulted in strongly reduced melanoma invasiveness and a repression of melanoma. Our results thereby indicate that Sdf1 signals via Cxcr7 are able to constrain melanoma growth in vivo and that these signals influence tumor outcome.