A new strategy to induce effective antitumour response in vitro and in vivo

To induce Her2-specific cell immune response, we used xenogeneic antigen rat neu L2-S2 domains as the vaccine antigen. The antigenic protein was engineered as a chimeric protein with human IgG1 Fc region (neu-Fc). Neu-Fc could stimulate the cell proliferation in mixed lymphocyte reaction effectively. Simultaneous neu-Fc and IFN-gamma stimulation dramatically elevated IL-12 secretion and reduced IL-10 production in PBMC. To further augment the activating effects on Th1-type response, Bacille Calmette-Guerin (BCG) was utilized as a non-specific stimulus. Neu-Fc, IFN-gamma and BCG costimulation exhibited the most conspicuous effects on the reversal of the Th1-type inhibitory effects by MCF-7 cell supernatant compared with neu-Fc alone or IFN-gamma and BCG costimulation. The lytic activity of effector cells to Her2 overexpressing cells was greatly promoted by neu-Fc, IFN-gamma and BCG stimulation simultaneously. Neu-Fc led to considerable retardation in EMT6/Her2 tumour growth in Balb/c mice. IFN-gamma and BCG efficiently enhanced the antitumour activity. A large amount of inflammatory cells were found to be accumulated in the tumour tissues or surrounded tumours in mice treated with neu-Fc, IFN-gamma and BCG but no inflammatory cell infiltration was observed in control tumours, indicating that the strategy is potent enough to support the initiation and propagation of tumour-specific immune response in an established tumour and generate a proinflammatory environment.

Molecular characterization, expression and association analysis of the porcine CMYA4 gene with carcass traits

CMYA4 (cardiomyopathy-associated 4) gene plays an important role in thick filament assembly. In this study, we obtained the mRNA sequence including the full coding sequence and the partial 5' untranslated region of the porcine CMYA4 gene by using the rapid amplification of cDNA ends and reverse transcriptase polymerase chain reaction (RT-PCR) and the sequence was deposited in the GenBank nucleotide database (DQ_286571). The human (NM_173167) and mouse (NM_178680) homologues have a 91% and 87% identity with the porcine CMYA4 gene, respectively. The sequence contains an open reading frame encoding 930 amino acid residues, and the amino terminus of the predicted CMYA4 protein contains three tandem repeats belonging to the tetratricopeptide repeat family. Semi-quantitative RT-PCR results showed that the porcine CMYA4 gene is expressed exclusively in striated muscle tissue. An A558G single nucleotide polymorphism in the CMYA4 intron 15 detected as an MspI PCR-restriction fragment length polymorphism showed allele frequency differences among 225 unrelated pigs from six breeds. Association of the genotypes with growth and carcass traits showed that different genotypes of the CMYA4 gene were significantly associated with the backfat thickness of the area between sixth and seventh ribs (p < 0.05) and backfat thickness at the shoulder (p < 0.05).

Exendin-4 does not promote Beta-cell proliferation or survival during the early post-islet transplant period in mice

Current pancreatic islet transplantation protocols achieve remarkable short-term success, but long-term insulin independence remains elusive. Hypoxic and inflammatory insults cause substantial early posttransplant graft loss while allo/autoimmunity and immunosuppressive drug toxicity threaten long-term graft mass and function. Exendin-4 (Ex4) is a GLP-1 receptor agonist that promotes beta-cell proliferation, survival, and differentiation. To determine whether Ex-4 displays potential as a graft-supportive agent, we transplanted 500 murine islets under the kidney capsule of syngeneic or allogeneic streptozocin-treated recipient mice and immediately initiated daily treatment with vehicle or Ex4. Graft beta-cell proliferation, death, and vascularity were assessed at 1, 3, and 10 days after syngeneic islet transplantation. For allogeneic recipients, blood glucose and body weight were assessed until glycemic deterioration. Ex-4 did not promote graft beta-cell proliferation, reduce beta-cell death, or enhance graft vascularity over the first 10 days after syngeneic islet transplantation. A trend toward prolongation of posttransplant euglycemia was observed with Ex4 treatment in nonimmune-suppressed allograft recipients, but its use in this setting was associated with frequent, severe hypoglycemia over the first 2 posttransplant days. Our findings do not support a beneficial effect of Ex-4 on islet grafts during the critical early posttransplant period, further, they demonstrate a significant hypoglycemic potential of Ex-4 in the first days after islet transplantation in mice. Optimal application of GLP-1 receptor agonists for long-term proliferative and survival benefits in transplantation may require earlier intervention prior to and/or during islet isolation for peri-transplant cytoprotection and administration beyond the period of engraftment.

Overexpression, refolding, purification of Erbin PDZ domain from Escherichia coli and preparation of its polyclonal antibody

The Erbin was recently identified. The antibody against Erbin has not been commercially available. As a new member of peripheral protein LAP family and novel type of adaptor protein, its functions and binding partners are not completely known. In the present study, cDNA encoding PDZ domain of Erbin was inserted in a prokaryotic expression vector. His-tagged recombinant protein was overproduced in E. coli and purified by Ni-NTA column chromatography. About 14.4 mg of the purified protein was obtained from 500 mL of cell culture. The purity of the recombinant protein was higher than 90%. The polyclonal antibody against this protein was raised. The antibody can recognize both denatured and natural Erbin protein. It will be used to further identify the new binding partners of Erbin and study its unknown functions.

Investigation of Lpin1 as a candidate gene for fat deposition in pigs

Lpin1 deficiency prevents normal adipose tissue development and remarkably reduces adipose tissue mass, while overexpression of the Lpin1 gene in either skeletal muscle or adipose tissue promotes adiposity in mice. However, little is known about the porcine Lpin1 gene. In the present study, a 5,559-bp cDNA sequence of the porcine Lpin1 gene was obtained by RT-PCR and 3'RACE. The sequence consisted of a 111-bp 5'UTR, a 2,685-bp open reading frame encoding a protein of 894 amino acids and a 2,763-bp 3'UTR. Semi-quantitative RT-PCR analysis revealed that Lpin1 had a high level of expression in the liver, spleen, skeletal muscle and fat, a low level of expression in the heart, lung and kidney. The porcine Lpin1 gene was assigned to 3q21-27 by using the somatic cell hybrid panel (SCHP) and the radiation hybrid (IMpRH) panel. One C93T single nucleotide polymorphism (SNP) was identified and genotyped using the TaqI PCR-RFLP method. Association analysis between the genotypes and fat deposition traits suggested that different genotypes of the Lpin1 gene were associated with percentage of leaf fat and intramuscular fat.

Identification of a recombinant dengue virus type 1 with 3 recombination regions in natural populations in Guangdong province, China

Using recombination analysis, we identified a recombinant dengue virus type 1 strain, namely, GD23/95, with three recombination regions, located within the sequences of the prM/E junction, NS1, and NS3, respectively. The recombinant dengue virus was further confirmed by phylogenetic analysis based on its recombination and non-recombination regions. This appears to be the first study to confirm the existence of three recombination regions in a single dengue virus isolate and to report recombination between parent virus strains isolated from the same geographic area (Guangdong province, China). It is also the first to report breakpoints within the NS3 gene of dengue viruses.

Pre-Existing Cardiac Disease, Troponin I Elevation and Mortality in Patients with Severe Sepsis and Septic Shock

A prospective, observational study was undertaken to determine the frequency of troponin I elevation and the incidence of pre-existing cardiac disease in patients with severe sepsis and septic shock, and to determine their relationship to mortality.

The setting was the surgical intensive care unit of a tertiary care medical centre. Sixty-six consecutive patients admitted with severe sepsis or septic shock requiring pulmonary artery catheterisation for haemodynamic monitoring were studied. Measurement of troponin I was done at the time of pulmonary artery catheterisation and every six to eight hours if there was ongoing tachycardia, hypotension or arrhythmias requiring treatment. Preexisting cardiac disease was determined from the patient and/or family members as well as from the medical record. Significant cardiac history was defined as prior myocardial infarction; abnormal treadmill report, nuclear medicine study or coronary angiogram; history of congestive heart failure or arrhythmia requiring treatment.

Forty-two patients (64%) had elevated troponin I at study entrance and 23 patients (35%) had pre-existing cardiac disease. History of cardiac disease was associated with reduced cardiac index and oxygen delivery, and a nearly three-fold increase in mortality (44% vs. 16%, P=0.03), irrespective of elevated troponin I levels. Troponin I elevation alone was not associated with increased mortality.

We conclude that pre-existing cardiac disease and elevated troponin I are commonly found in surgical patients with severe sepsis and septic shock. In our study, pre-existing cardiac disease, and not troponin I elevation, was associated with increased mortality.

Mechanisms underlying B-cell tolerance induction by antigen-immunoglobulin G gene transfer

Previous studies on the mechanisms underlying tolerance induction in diabetes have mainly focused on T cells, however B cells also have an important role in diabetes. Based on our previous studies that splenocytes, transduced with glutamic acid decarboxylase (GAD) 65 fused to immunoglobulin (Ig) G carrier, reduced antibody-mediated response in non-obese diabetic (NOD) mice, here we examined the mechanisms underlying B-cell tolerance in this system. We found that GAD-IgG-transduced splenocytes did not reduce CD40 expression on B-cells in NOD mice, but they did downregulate CD40 ligand (CD40L) expression. Furthermore, anti-CD40L injection reduced autoantibody levels in NOD mice and in vitro experiments demonstrated that CD40L blockade reduced the antigenpresenting capability of B-cells. In conclusion, the results of this study suggest that downregulation of CD40L may be one mechanism underlying the induction of B-cell tolerance in GAD-IgG-treated NOD mice.

Assignment of solute carrier family 2 (facilitated glucose transporter), members <i>SLC2A2</i>, <i>SLC2A3</i>, <i>SLC2A5</i>, <i>SLC2A8</i> and <i>SLC2A12</i> to porcine chromosomes by somatic cell and radiation hybrid panel mapping (Brief report)

Abstract. The transport of glucose plays an important role in cellular glucose homeostasis and metabolism [1]. Due to the hydrophilic character of glucose, the transport of glucose in and out of cells requires specific carrier proteins. The mammalian facilitative glucose transport family, which contains the energy-independent transporters (gene symbol SLC2A, protein symbol GLUT), catalyzes the entry of glucose into mammalian cells by facilitative diffusion down a concentration gradient. Thirteen members of mammalian GLUT family have been now characterized [1]. In swine, the chromosomal locations for the five genes (SLC2A2, SLC2A3, SLC2A5, SLC2A8 and SLC2A12) have not yet been determined. In this study, as the first step to better understand of the roles of these GLUTs in pigs which could subsequently be beneficial for pig production, we report the mapping of the five genes using both porcine somatic cell hybrid panel (INRA-SCHP) and radiation hybrid panel (IMpRH).

Mechanisms of regulatory T-cell induction by antigen-IgG-transduced splenocytes

Our previous studies have demonstrated that splenocytes, transduced with glutamate decarboxylate 65 (GAD) and IgG fusion construct, protect non-obese diabetes (NOD) mice from diabetes. However, the mechanism by which this strategy prevents diabetes is not well understood. Here, we found that CD4(+)Foxp3(+)Treg cells, in vitro induced by GAD-IgG-transduced splenocytes, after transfer, were responsible for prevention of diabetes in NOD mice. Further studies suggested that GAD-IgG-transduced B cells could secrete high level of TGF-beta and stimulated CD4(+)T cells to secrete high level of IFN-gamma. Finally, we found that when TGF-beta and/or IFN-gamma were blocked, CD4(+)Foxp3(-)T cells were not converted into CD4(+)Foxp3(+)Treg cells. The results suggest that GAD-IgG-transduced B cells via TGF-beta and IFN-gamma in vitro induce the CD4(+)Foxp3(+)Treg cells which are responsible for prevention of diabetes in NOD mice by GAD-IgG-gene transfer.

Changes of CSF and spinal pathomorphology after high-concentration ozone injection into the subarachnoid space: an experimental study in pigs

BACKGROUND AND PURPOSE

Our aim was to explore the changes of CSF and spinal pathomorphology after high-concentration ozone injection into a pig's subarachnoid space.

MATERIALS AND METHODS

Eight experimental pigs were randomly divided into 4 groups (n=2 in each group). In groups A, B, C, and D, animals were sacrificed for pathology 1 day, 1 week, 1 month, and 3 months after the injection, respectively. Ozone (10 mL, 90 microg/mL) was injected along the lumbar 4-5 interspace into the subarachnoid space with a 21-ga Chiba needle under fluoroscopy. CSF collection and CT and MR imaging were performed before injection and 30 minutes, 1 week, 1 month, and 3 months after injection, respectively. The spinal cords were observed macroscopically and microscopically.

RESULTS

No serious behavior abnormalities were observed in any animals. There were no abnormalities in CSF and spinal cords pathologically and radiologically after injection.

CONCLUSION

Our initial study suggests that high-concentration ozone injection into a pig's subarachnoid space will not cause serious sequelae such as chemical arachnoiditis and necrosis of the spinal cord, and this finding provides evidence of the safety of ozone inadvertently injected into subarachnoid space in the clinical treatment of disk herniation.