Development of a novel anti-human aspartyl-(asparaginyl) β-hydroxylase monoclonal antibody with diagnostic and therapeutic potential

Human aspartyl-(asparaginyl)-β-hydroxylase (HAAH) has recently been the subject of several studies, as it was previously observed to be overexpressed in numerous types of carcinoma cells and tissues in patient tumor samples. HAAH has been implicated in tumor invasion and metastasis, indicating that it may be an important target and biomarker for tumor diagnosis and treatment. However, the immunological tools currently available for the study of this protein, including monoclonal antibodies, are limited, as is the present knowledge regarding the role of HAAH in tumor therapy and diagnosis. In the present study, a recombinant C-terminal domain of HAAH was expressed in Pichia pastoris and a novel monoclonal antibody (mAb) targeting HAAH (HAAH-C) was constructed. Immunofluorescence and antibody-dependent cellular cytotoxicity (ADCC) assays were used to demonstrate the specificity and ADCC activity of this antibody. The results demonstrated that this anti-C-terminal HAAH mAB, in combination with an existing anti-N terminal HAAH mAb, exhibited a high response to native HAAH from carcinoma cell culture supernatant, as measured with a double antibody sandwich enzyme-linked immunosorbent assay. This validated novel mAB-HAAH-C may prompt further studies into the underlying mechanisms of HAAH, and the exploration of its potential in tumor diagnosis and therapy.

Inhibition of human natural killer cell functional activity by human aspartyl β-hydroxylase

Natural killer (NK) cells are a key component of the innate immune system and play pivotal roles as inflammatory regulators and in tumor surveillance. Human aspartyl β-hydroxylase (HAAH) is a plasma membrane and endoplasmic reticulum protein with hydroxylation activity, which is over-expressed in many malignant neoplasms and can be detected from the sera of tumor patients. HAAH is involved in regulating tumor cell infiltration and metastasis. Escaping from immune surveillance may help tumor cell infiltration and metastasis. However, the effects of HAAH on tumor immune surveillance have not yet been investigated carefully. The present study investigated the potential use of HAAH as an immune regulator of human NK cells. We assessed the effects of recombinant HAAH (r-HAAH) on primary human NK cell morphology, viability, cytotoxicity, apoptosis, receptors expression and cytokine/cytolytic proteins production. Our results demonstrated that r-HAAH negatively affects NK cell activity in a time and dose-dependent manner. It noticeably reduces the viability of the NK cells by increasing apoptosis and necrosis via caspase signaling pathways. Moreover, r-HAAH reduces the NK cell cytotoxicity by inhibiting surface expression of NKG2D, NKp44 and IFN-γ secretion. These findings suggest that one of the ways by which HAAH actively promotes tumor formation and proliferation is by inhibiting NK cell-surveillance activity.

Recent advances in the development of inhibitors targeting hepatitis C virus NS3/4A serine protease and NS5B RNA polymerase

Hepatitis C virus (HCV) NS3/4A serine protease and NS5B RNA-dependent RNA polymerase are vital for the processing and maturation of viral protein precursors and RNA replication. Recently, many studies focus on developing inhibitors targeting these two enzymes to fight against HCV infection. In this article, we will review the recent advances in the development of inhibitors targeting HCV NS3/4A protease and NS5B polymerase.

Characteristics of bacterial and viral contamination of urban waters: a case study in Xi'an, China

In order to gain knowledge on the presence of bacteria and viruses in urban waters, the authors started a long-term study on the microbiological quality of urban lakes and rivers in Xi'an, China. In the current study, enteroviruses were chosen as typical viruses and RT-nested PCR was conducted for their detection. Universal primers were designed for simultaneous detection of poliovirus, coxsackievirus, and enterovirus 71 which are the most frequently encountered enteroviruses in China. The RT-nested PCR protocol established in this study showed high sensitivity and specificity. The detection limit was equivalent to 0.038 CCID50 per litre by applying a modified adsorption-elution concentration method. No cross-reactivity was observed using the genome of pathogenic bacteria as of PCR template. The occurrence of enteroviruses was compared with fecal coliform count in a 6-month period from July to December 2006 for the urban waters. As a result, it was noticed that the presence of enteroviruses might not relate to the fecal coliform count so much. Statistical analysis also indicated that there was no significant correlation between the presence of enteroviruses and that of total bacteria, total coliform, and fecal coliform.

Study on the Application of PEI for Gene Transfer in Mouse Skin Tissue

A reliable, low-cost, and highly efficient nonviral gene delivery system using lower molecular weight polyethylenimine (LMW-PEI) is provided. LMW-PEI was linked to an expressing plasmid with green fluorescence protein gene (gfp), the transfection activity mediated by PEIs were examined in the CM7721 cell line and the skin tissue of mouse, respectively. The cytotoxicity of PEIs, the localization and continuance time of gfp expressed in the skin tissue of mouse were also studied. Results showed that the transfection rate of gfp mediated by LMW-PEI in the CM7721 cell line was about 55% . However, with the increasing PEI molecular weight, the cytotoxicity of PEI increased, but its transfection activity decreased. The tissue transfection results showed that LMW-PEI induced a significant expression of the gfp in the cells of hair vesicle and sweat gland of mouse skin tissues following transfection of 24 h, and the expression of gfp lasted 7 - 9 d. When the tissue of mouse was treated with retinoic acid and nitrogenous ketone, respectively, gfp was transferred to the granule layer of mouse skin tissue. The LMW-PEI described here is a new, highly efficient vector; it would be a useful nonviral vector for gene delivery technology.

[Preparation of specific monoclonal antibody against nucleocapsid protein of SARS coronavirus]

AIM

To express nucleocapsid(N) protein of SARS coronavirus and produce monoclonal antibody(mAb) to N protein.

METHODS

N protein gene was amplified by RT-PCR. After being confirmed by DNA sequencing, the gene was subcloned into prokaryotic expression vector. N protein expressed in E.coli was recovered from SDS-PAGE gel and served as immunogen in the preparation of the mAb.

RESULTS

DNA sequencing confirmed that the amplified fragment was N protein gene. SDS-PAGE analysis showed that the M(r) of the expressed protein was approximately 43 kd. This expressed protein could be further confirmed in Western blot by using serum from a convalescent SARS patient as primary antibody. Western blot analysis proved that three mAbs obtained could react specifically to the recombinant N protein.

CONCLUSION

The prepared recombinant N protein and mAbs against N protein lay the foundation for further development of early diagnosis assays for SARS coronavirus infection.

Application of a virological tracer method for the assessment of pathogen removal by physicochemical treatment and chemical disinfection

Coxsackie B3 (CoxB3) virus was used as a virological tracer for an assessment of the efficiency of pathogen removal by several typical physicochemical treatment and chemical disinfection processes, such as coagulation-filtration, ultra-filtration, and disinfection using chlorine and ozone, with regard to the pathogenic quality of the treated domestic wastewater for reuse purposes. The CoxB3 virus was seeded to sterilized secondary effluent to make a raw water of known pathogenic level. After applying the raw water to each treatment or disinfection process, the residual virus in the finished water was concentrated, and virus assay was carried out by the Tissue Culture Infectious Dose technique. TCID50 was used as an indicative parameter of CoxB3 virus in the raw and treated water. Parallel experiments were also conducted to evaluate the effectiveness of each process for the removal of coliform bacteria. It was noticed from the experiment that both coagulation-filtration and ultrafiltration could achieve substantial removal of TCID50 at about the same level (2-log removal). However, the effect of the two processes on the removal of coliform bacteria was much different: 2-log removal by coagulation-filtration and 4 to 5-log removal by ultrafiltration. The TCID50 removal correlates more closely with the removal of turbidity than that of coliform bacteria. Chlorine was found to be effective in coliform removal but almost had no effect on TCID50. As ozone was applied, a high removal of both coliform bacteria and TCID50 could be obtained.

[Detection and significance of succinate dehydrogenase of sperm mitochondria]

OBJECTIVE

To detect succinate dehydrogenase (SDH) of sperm mitochondria by an improved method, and to evaluate the relationship between SDH and the motility and viability of sperm.

METHODS

In 46 fertile and infertile men (aged from 25 to 36), the motility, viability and mitochondrial SDH of sperm were detected by computer-assisted semen analysis system, dead/live sperm molecular fluorescent probe and an improved cytochemical method. Then, the correlation between the motility and viability of sperm and the positive percentage of sperm mitochondrial SDH were analyzed.

RESULTS

In the 46 fertile and infertile men, the motility and viability of sperm were (67.33 +/- 7.37)% and (79.78 +/- 7.65)%, and the positive percentage of sperm mitochondrial SDH was (74.74 +/- 8.29)%. The motility and viability of sperm and positive percentage of sperm mitochondrial SDH had significant correlation (r = 0.901, P < 0.01; r = 0.876, P < 0.01; r = 0.917, P < 0.01).

CONCLUSIONS

Detection of sperm mitochondrial SDH has significance in evaluation of sperm mitochondrial function and may serve as an assisted marker of sperm viability.

[Determination of partially cellular and local immune function in patients with spleen deficiency syndrome]

The immune function status as reflected by the peripheral blood OKT system T cell subset classification and the lymphocyte in vitro interleukin 2 (IL2) secretory function were determined in 30 patients with Spleen deficiency syndrome and 20 normal subjects in this study. Experimental results decreased cellular immune function and disturbance of immune regulatory mechanism in the patients. Its manifestations were decreased number of total T lymphocytes and helper T cells (Th), relatively increased suppressor T cells (Ts), abnormal rate of Th to Ts, no marked change of IL2 secretory function of T cell in vitro, increased SIgA level before stimulating with acid but marked decreased SIgA level after stimulating. All these suggest the compensatory stage of local immune function.