A SALL4 zinc finger missense mutation predicted to result in increased DNA binding affinity is associated with cranial midline defects and mild features of Okihiro syndrome

Truncating mutations of the gene SALL4 on chromosome 20q13.13–13.2 cause Okihiro and acro-renal-ocular syndromes. Pathogenic missense mutations within the SALL4 or SALL1 genes have not yet been reported, raising the question which phenotypic features would be associated with them. Here we describe the first missense mutation within the SALL4 gene. The mutation results in an exchange of a highly conserved zinc-coordinating Histidine crucial for zinc finger (ZF) structure within a C2H2 double ZF domain to an Arginine. Molecular modeling predicts that this exchange does not result in a loss of zinc ion binding but leads to an increased DNA-binding affinity of the domain. The index patient shows mild features of Okihiro syndrome, but in addition cranial midline defects (pituitary hypoplasia and single central incisor). This finding illustrates that the phenotypic and functional effects of SALL4 missense mutations are difficult to predict, and that other SALL4 missense mutations might lead to phenotypes not overlapping with Okihiro syndrome. This study has received approval by the institutional review board (Ethics committee) of the Medical Faculty, University of Freiburg, Germany. Jan Miertus and Wiktor Borozdin have equally contributed to this work.     

Effect of controlled inoculation with specific mycorrhizal fungi from the urban environment on growth and physiology of containerized shade tree species growing under different water regimes

The aim of this work was to evaluate the effects of selected mycorrhiza obtained in the urban environment on growth, leaf gas exchange, and drought tolerance of containerized plants growing in the nursery. Two-year-old uniform Acer campestre L., Tilia cordata Mill., and Quercus robur L. were inoculated with a mixture of infected roots and mycelium of selected arbuscular (maple, linden) and/or ectomycorrhiza (linden, oak) fungi and grown in well-watered or water shortage conditions. Plant biomass and leaf area were measured 1 and 2 years after inoculation. Leaf gas exchange, chlorophyll fluorescence, and water relations were measured during the first and second growing seasons after inoculation. Our data suggest that the mycelium-based inoculum used in this experiment was able to colonize the roots of the tree species growing in the nursery. Plant biomass was affected by water shortage, but not by inoculation. Leaf area was affected by water regime and, in oak and linden, by inoculation. Leaf gas exchange was affected by inoculation and water stress. V _cmax and J _max were increased by inoculation and decreased by water shortage in all species. F _v/F _m was also generally higher in inoculated plants than in control. Changes in PSII photochemistry and photosynthesis may be related to the capacity of inoculated plants to maintain less negative leaf water potential under drought conditions. The overall data suggest that inoculated plants were better able to maintain physiological activity during water stress in comparison to non-inoculated plants.     

Treatment with Oxiracetam or Choline Restores Cholinergic Biochemical and Pharmacological Activities in Striata of Decorticated Rats

Interruption of the corticostriatal pathway by undercutting the frontal cortex resulted after 2 weeks in a 40% reduction of basal acetylcholine (ACh) release in vivo, and in inhibition of the striatal sodium-dependent high-affinity uptake of choline (SDHACU) to the same extent. The lesion, too, completely prevented the rise (about 35%) in striatal ACh content induced by oxotremorine and apomorphine acting at muscarine and dopamine receptors, respectively. Acute intraperitoneal injections of 100 mg/kg of either oxiracetam or choline chloride resulted in time-dependent recovery of ACh output from the striata of decorticated rats to control levels. Oxiracetam also normalized the ex vivo striatal SDHACU activity of decorticated rats 2 h after administration without any effect in sham-operated rats. Oxiracetam or choline chloride administered before oxotremorine (0.8 mg/kg, i.p.) or apomorphine (1 mg/kg, i.p.) reinstated the ACh-increasing effect of these agonists. It is suggested that choline chloride acts directly simply by being the precursor for ACh, whereas oxiracetam may act indirectly, possibly by increasing the availability of choline chloride for ACh synthesis. Furthermore, the frontally decorticated rat could constitute a useful model for studying means to restore the deficit in striatal cholinergic neurotransmission.     

T-helper 17 cell cytokines and interferon type I: partners in crime in systemic lupus erythematosus?

Introduction

A hallmark of systemic autoimmune diseases like systemic lupus erythematosus (SLE) is the increased expression of interferon (IFN) type I inducible genes, so-called IFN type I signature. Recently, T-helper 17 subset (Th17 cells), which produces IL-17A, IL-17F, IL-21, and IL-22, has been implicated in SLE. As CCR6 enriches for Th17 cells, we used this approach to investigate whether CCR6⁺ memory T-helper cells producing IL-17A, IL-17F, IL-21, and/or IL-22 are increased in SLE patients and whether this increase is related to the presence of IFN type I signature.

Methods

In total, 25 SLE patients and 15 healthy controls (HCs) were included. SLE patients were divided into IFN type I signature-positive (IFN⁺) (n = 16) and negative (IFN^-) (n = 9) patients, as assessed by mRNA expression of IFN-inducible genes (IFIGs) in monocytes. Expression of IL-17A, IL-17F, IL-21, and IL-22 by CD4⁺CD45RO⁺CCR6⁺ T cells (CCR6⁺ cells) was measured with flow cytometry and compared between IFN⁺, IFN^- patients and HCs.

Results

Increased percentages of IL-17A and IL-17A/IL-17F double-producing CCR6⁺ cells were observed in IFN⁺ patients compared with IFN^- patients and HCs. IL-17A and IL-17F expression within CCR6⁺ cells correlated significantly with IFIG expression. In addition, we found significant correlation between B-cell activating factor of the tumor necrosis family (BAFF)–a factor strongly correlating with IFN type I - and IL-21 producing CCR6⁺ cells.

Conclusions

We show for the first time higher percentages of IL-17A and IL-17A/IL-17F double-producing CCR6⁺ memory T-helper cells in IFN⁺ SLE patients, supporting the hypothesis that IFN type I co-acts with Th17 cytokines in SLE pathogenesis.     

Increasing the affinity for tumor antigen enhances bispecific antibody cytotoxicity

We tested the hypothesis that bispecific Abs (Bsab) with increased binding affinity for tumor Ags augment retargeted antitumor cytotoxicity. We report that an increase in the affinity of Bsab for the HER2/neu Ag correlates with an increase in the ability of the Bsab to promote retargeted cytotoxicity against HER2/neu-positive cell lines. A series of anti-HER2/neu extracellular domain-directed single-chain Fv fragments (scFv), ranging in affinity for HER2/neu from 10(-7) to 10(-11) M, were fused to the phage display-derived NM3E2 human scFV: NM3E2 associates with the extracellular domain of human FcgammaRIII (CD16). The resulting series of Bsab promoted cytotoxicity of SKOV3 human ovarian carcinoma cells overexpressing HER2/neu by human PBMC preparations containing CD16-positive NK cells. The affinity for HER2/neu clearly influenced the ability of the Bsab to promote cytotoxicity of (51)Cr-labeled SKOV3 cells. Lysis was 6.5% with an anti-HER2/neu K(D) = 1.7 x 10(-7) M, 14.5% with K(D) = 5.7 x 10(-9) M, and 21.3% with K(D) = 1.7 x 10(-10) M at 50:1 E:T ratios. These scFv-based Bsab did not cross-link receptors and induce leukocyte calcium mobilization in the absence of tumor cell engagement. Thus, these novel Bsab structures should not induce the dose-limiting cytokine release syndromes that have been observed in clinical trials with intact IgG BSAB: Additional manipulations in Bsab structure that improve selective tumor retention or facilitate the ability of Bsab to selectively cross-link tumor and effector cells at tumor sites should further improve the utility of this therapeutic strategy.     

Mannose-binding lectin does not explain the course and outcome of pregnancy in rheumatoid arthritis

Introduction  

Rheumatoid arthritis (RA) improves during pregnancy and flares after delivery. It has been hypothesized that high levels of the complement factor mannose-binding lectin (MBL) are associated with a favourable disease course of RA by facilitating the clearance of pathogenic immunoglobulin G (IgG) lacking galactose sugar moieties. During pregnancy, increased galactosylation of IgG and simultaneously increased MBL levels can be observed, with the latter being strictly related to maternal MBL genotypes. Therefore, increased MBL levels in concert with increased IgG galactosylation may be associated with pregnancy-induced improvement of RA. The objective of this study was to investigate whether MBL genotypes are associated with changes in RA disease activity and with changes in IgG galactosylation during pregnancy and in the postpartum period. We also studied the association between MBL genotypes and pregnancy outcomes in RA.     

Effects of dimaprit, an H2 receptor agonist, on blood levels of corticosterone in the rat

These experiments were performed in order to further clarify the role played by hystamine in the control of hypothalamus-hypophisis-adrenal axis. To this aim we evaluated the effect of Dimaprit, a H2 agonist on plasma corticosterone levels. This drug was administered intraperitoneally or i.c.v. at the doses of 25, 50 and 100 mg/kg or 100 gamma/animal respectively. The administration i.p. at the dose of 100 mg/kg increased plasma-corticosterone levels whereas Dimaprit, injected intraventricularly did not modify plasma-corticosterone levels. These results seem to suggest that Dimaprit stimulates corticosterone secretion at a peripheral level.     

A xenogeneic monoclonal antibody recognizing specificities controlled by HLA-A and B alleles

In the present paper one reagent among the many prepared has been carefully studied. It is a xenogeneic monoclonal antibody, F10.13/13, obtained by immunizing mice with human peripheral blood lymphocytes. The splenocytes of the immunized mice were fused with a murine were fused with a murine myeloma and the supernatants of the resulting Ig-secreting hybridomas were tested against appropriate targets. --F10.13/13 behaves in a very peculiar manner from the serological point of view and we think that it reacts with maximal affinity with an epitope expressed most strongly on HLA glycoproteins controlled by genes B8, B7, and Aw19.