Module based antibody engineering: a novel synthetic REDantibody

We describe the facile generation of a stable recombinant antibody with intrinsic red fluorescent properties for qualitative and potentially quantitative immunofluorescence analysis. The REDantibody based on the X-ray crystallographic structures of the anti-sialyl-Tn antibody B72.3 and 3D model of the monomeric red fluorescent protein was designed to retain optimal spatial geometry between the C- and N-termini of the V(H) and V(L) chains respectively to mimic the domains interface pairing in antibody Fab fragments and to incorporate the red fluorescent protein as a bridging scaffold. The model was further validated by assembling a REDantibody based on CA19.9 the anti-sialylated Lewis (Le)(a) blood group antigen and 4D5-8 the anti-p185(HER2) antibodies. The chimeric heavy and light chains containing red fluorescent protein as a bridge were correctly processed and secreted into Escherichia coli periplasm for assembly and disulphide bond formation, further analysis revealed the molecules to be exclusively monomers. Purified anti-glycan proteins were used for an immunofluorescent analysis of Trypanosoma cruzi epimastigotes, and the anti-p185(HER2) used to determine the binding properties. The REDantibody platform facilitates rapid generation of scFv chimeras that could be used for screening antibodies against cell surface markers. Furthermore, such modular assembly should permit the interchange of binding sites and of fluorophores to create robust panels of coloured antibodies.     

Evaluation of cerebral autoregulation following diffuse brain injury in rats

Abstract

The normal cerebral circulation has the ability to maintain a stable cerebral blood flow over a wide range of cerebral perfusion p(essures and this is known as cerebral autoregulation. This autoregulation may be impaired in the injured brain. Closed head injury was induced in 28 Sprague-Dawley rats weighing 400-450 g. Four groups were studied: control group, head injured rat from meter height using 350 g, 400 g and 450 g respectively. CBF, volume velocity was monitored using laser-Doppler flowmetry together with monitoring of ICP and arterial blood pressure. Correlation to assess the relationship between CBF and CPP was done in each animal every hour. If correlation coefficient was> 0.85 and CPP was within normal range, loss of autoregulation was hypothesized. Chi square test, ANOVA test and unpaired Studen(s t-test were done and significant level of p < 0.05 was established. Mean CBF in injured rats was significantly lower than controls (p = 0.028) at the fifth hour. CBV was lower in the group of 450 g 1 m impact than in controls at 3 h (p = 0.04). Velocity in the group ofall injured rats, was significantly lower than in controls at 3 h (p = 0.032) and at 4 h (p = 0.027). Loss ofautoregulation was seen during first four hours after trauma in all groups of rats who sustained injury. Statistical significant difference (p = 0.041) in loss of autoregulation between injured and control animals was seen. No loss of autoregulation was observed in the control group. In conclusion CBF and CPP provide information about loss of autoregulation in diffuse brain injury. Decrease in CBF and increase of ICP is observed as a result ofloss of cerebral autoregulation. Knowledge of loss of autoregulation could give important information and help in the management of head injured patients. [Neural Res 1997; 19: 393-402]     

Predictive value of cytokine gene polymorphisms for the development of end-stage renal disease

BACKGROUND: Cytokines play a crucial role in different immunopathological conditions. Cytokine secretion is reported to be determined by polymorphisms in the cytokine genes. Since TNF-alfa and IL-10 are involved in regulation of inflammation, and TGF-beta 1 can induce fibrosis and renal insufficiency - dominant features of end-stage renal disease (ESRD), we explored the hypothesis that polymorphisms of these cytokine genes may be possible genetic susceptibility factors for the progression of renal failure. METHODS: We studied the IL-10 (-1082), TNF-alfa (-308), TGF-beta 1 (codon 10;25) gene single nucleotide polymorphisms in 118 healthy donors and 103 patients with ESRD (44 hemodialysis patients with diabetic nephropathy and 59 hemodialysis patients with glomerulonephritis) using PCR-SSP. RESULTS: Significant associations of ESRD with the TGF-beta 1 (codon 10) TT (odds ratio [OR] = 5.31; 95% confidence interval [95% CI], 3.77-7.02; p<0.001) and IL-10 (-1082) GG (OR=2.35; 95% CI, 1.67-3.15; p<0.01) genotypes were found. Statistical analysis of genotype frequencies made separately for the underlying renal disease (diabetes or glomerulo-nephritis) revealed the same linkage trend: TGF-beta 1 (codon 10) TT and IL-10 (-1082) GG were associated with type 2 diabetic nephropathy (p<0.001 and p<0.05, respectively) and chronic glomerulonephritis (p<0.001 and p<0.01, respectively). No significant differences in the TNF-alfa , TGF-beta 1 (codon 25) genotype distribution between healthy controls and patients with diabetic nephropathy- or glomerulonephritis-associated ESRD were detected. CONCLUSIONS: Carriage of the TGF-beta 1 (codon 10) TT and IL-10 (-1082) GG genotypes may increase susceptibility to ESRD in German patients with type 2 diabetes or glomerulonephritis.     

Beyond the genome and proteome: targeting protein modifications in cancer

Nearly all proteins are modified in post translational events, indeed, understanding the control and function of post translational modifications (PTMs) is arguably the 'next frontier' for cancer cell biologists. The most well understood PTMs include glycosylation, phosphorylation, ubiquitination, methylation and palmitylation. Each of these modifications has been observed to be altered in cancer, affecting key cellular pathways including signal transduction, cell membrane receptor function, and protein-protein interactions. A number of strategies have been proposed that aim to target the modified proteins themselves, the enzymes that construct them, or that boost host-cellular immunity against modified residues aberrantly expressed in cancer.     

Immunocytochemical staining of endogenous nuclear proteins with the HIS-1 anti-poly-histidine monoclonal antibody: A potential source of error in His-tagged protein detection

Histidine-tagged proteins are widely used in biochemical studies and frequently detected with antibodies specific for the histidine tag. Immunocytochemistry is widely used in studies with overexpressed proteins to determine cellular localization and in the case of histidine-tagged proteins can be carried out with anti-polyhistidine antibodies. Recent studies have suggested that polyhistidine sequences are present within a small number of human proteins and may direct expression to the nucleus and nuclear speckles compartments of the cell. In this study immunocytochemical staining of human SH-SY5Y neuroblastoma cell lines with the HIS-1 anti-polyhistidine monoclonal antibody were determined. Results showed that the HIS-1 anti-polyhistidine monoclonal antibody stained endogenous nuclear proteins in SH-SY5Y cells. The stained proteins were contained within the nuclear membrane, but were not directly linked to DNA. In a histidine-tagged catalase overexpressing cell line the HIS-1 anti-polyhistidine monoclonal antibody showed nuclear staining, whilst staining with the CAT-505 anti-catalase monoclonal antibody showed primarily cytoplasmic staining. These results suggest that anti-polyhistidine antibody staining shows significant cross-reactivity with endogenous nuclear proteins in SH-SY5Y neuroblastoma cells and may not be suitable for localization studies of histidine-tagged proteins. Immunocytochemical studies with anti-polyhistidine antibodies and localization of histidine-tagged proteins must be confirmed with protein specific antibodies or other methodology.     

Accessing of recombinant human monoclonal antibodies from patient libraries by eukaryotic ribosome display

What are effective antibodies and when do they arise to prevent or delay disease onset during a natural infection or in the course of vaccination? To address these questions at a molecular level requires longitudinal studies, capturing and analyzing the antibody repertoire at regular intervals following exposure or sero-conversion. Such studies require a method that allows the rapid generation and evaluation of monoclonal antibodies from relatively small volumes of blood. Here we describe an approach for rapidly generating human monoclonal antibodies in vitro by directly screening single-chain antibody repertories derived from donor peripheral blood mononuclear cells using ribosome display. Two single-chain antibody libraries were constructed using RNA extracted from peripheral blood mononuclear cells of two HIV-1 long-term non-progressor donors (K530 and M325). Both libraries were subjected to a single round of in vitro ribosome display for enrichment of human monoclonal antibodies against recombinant gp120^{K530}, derived from virus isolated from donor K530. This study has validated a novel, in vitro method for the rapid generation of human monoclonal antibodies. An antibody library could be constructed from as little as 3 μg of total RNA, the equivalent of 3-5 mL of human blood.     

Efficacy of Ukrain in the treatment of pancreatic cancer

BACKGROUND: This monocentric study evaluated the effect of ukrain in the treatment of pancreatic cancer. MATERIAL AND METHODS: Between January 1996 and December 1999 we treated 21 patients with 10 mg ukrain every second day x10. The control group received supportive treatment only. RESULTS: Ukrain treatment was well tolerated. Mean values on pain measure and Karnofsky index were significantly better in the ukrain group than in controls ( P<0.05). One-year survival was 76% in the ukrain group, compared to 9.5% in the control group. Median survival after treatment with ukrain was 574 days, compared to 197 days in the control group. CONCLUSIONS: Our data demonstrate that ukrain improves quality of life in patients suffering from advanced pancreatic cancer and significantly prolongs survival time in these patients.     

Properties of Concretes Incorporating Recycling Waste and Corrosion Susceptibility of Reinforcing Steel Bars

In this paper, properties of concretes incorporating recycling waste and corrosion susceptibility of reinforcing steel bars were studied. It was established that fineness of ground granulated blast furnace slag (GGBFS) and fly ash (FA) and their simultaneous combination have an influence on the kinetics of strength development of Portland cements and concretes. The compressive strength of concrete containing 10% by mass of GGBFS and 10% by mass of FA even exceeds the compressive strength of control concrete by 6.5% and concrete containing 20% by mass of GGBFS by 8.8% after 56 days of hardening. The formation of the extra amount of ettringite, calcium hydrosilicates as well as hydroaluminosilicates causes tightening of a cement matrix of concrete, reducing its water absorption, and improving its resistance to freezing and thawing damage.