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Background: The benefits of the application of basiliximab induction therapy in liver transplantation are not clear. The present meta-analysis was to evaluate the pros and cons of basiliximab use in liver transplantation., Data Sources: We searched the associated publications in English from July 1998 to December 2015 in the following databases: MEDLINE, PubMed, Ovid, EMBASE, Web of Science and Cochrane Library., Results: Basiliximab significantly decreased the incidence of de novo diabetes mellitus after liver transplantation (RR=0.56; 95% CI: 0.34-0.91; P=0.02). Subgroup analysis showed that basiliximab in combination with steroids-free immunosuppressant significantly decreased the incidence of biopsy-proven acute rejection (RR=0.62; 95% CI: 0.39-0.97; P=0.04) and new-onset hypertension (RR=0.62; 95% CI: 0.42-0.93; P=0.02)., Conclusions: Basiliximab may be effective in reducing de novo diabetes mellitus. What is more, basiliximab in combination with steroids-free immunosuppressant shows statistical benefit to reduce biopsy-proven acute rejection and de novo hypertension.

Poly(ethylene glycol) (PEG) is often attached to compounds to increase serum half-life, reduce immunogenicity, and enhance bioavailability. Accurate and sensitive quantification of PEG conjugates is critical for product development, pharmacokinetic measurements, and efficacy studies. However, PEGylated compounds can be difficult to quantify due to epitope masking by PEG. We previously generated two monoclonal antibodies to PEG (AGP3, IgM and E11, IgG) for quantitative detection of PEGylated proteins. We now report the identification of two second-generation mAbs to PEG (AGP4, IgM and 3.3, IgG) that bind to the repeating subunits of the PEG backbone and facilitate more sensitive quantification of a wider range of PEGylated compounds. A sandwich ELISA in which AGP4/3.3-biotin was employed as the capture/detection antibodies allowed quantification of PEG-Qdot 525 with 14-50-fold greater sensitivity than the original AGP3/E11 combination. Pegasys (PEG-interferon alpha-2a), PEG-Intron (PEG-interferon alpha-2b), Neulasta (PEG-G-CSF), and Lipo-Dox (PEGylated liposomal doxorubicin) could also be quantified with low ng/mL detection limits. The assay tolerated the presence of 50% human serum or 20% free PEG molecules. These new anti-PEG antibodies appear useful for qualitative and quantitative analysis of a wide range of PEGylated compounds.

Covalent attachment of poly(ethylene glycol) (PEG) molecules to drugs, proteins, and liposomes is a proven technology for improving their bioavailability, safety, and efficacy. Qualitative and quantitative analysis of PEG-derivatized molecules is important for both drug development and clinical applications. We previously reported the development of a monoclonal IgM antibody (AGP3) to PEG. We now describe a new IgG1 monoclonal antibody (E11) to PEG and show that it can be used in combination with AGP3 to detect and quantify PEG-derivatized molecules. Both antibodies bound the repeating subunits of the PEG backbone and could detect free PEG and PEG-modified proteins by ELISA, immunoblotting, and flow cytometry. Detection sensitivity increased with the length and the number of PEG chains on pegylated molecules. Both antibodies also efficiently accelerated the clearance of a PEG-modified enzyme in vivo. A sandwich ELISA in which E11/AGP3 were employed as the capture/detection antibodies was developed to detect PEG-modified proteins at concentrations as low as 1.2 ng/mL. In addition, the ELISA could also quantify, in the presence of 10% fetal bovine serum, free methoxy-PEG20,000, PEG2,000-quantum dots, and PEG2,000-liposomes at concentrations as low as 20 ng/mL (1.0 nM), 1.4 ng/mL (3.1 pM), and 2.4 ng/mL (3.13 nM phospholipids), respectively. Finally, we show that the sandwich ELISA could accurately measured the in vivo half-life of a PEG-modified enzyme. These antibodies should be generally applicable to the qualitative and quantitative analysis of all PEG-derivatized molecules.

Artificial recombinant receptors may be useful for selectively targeting imaging and therapeutic agents to sites of gene expression. To evaluate this approach, we developed transgenes to express highly on cells a single-chain antibody (scFv) against the hapten 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one (phOx). A phOx enzyme conjugate was created by covalently attaching phOx molecules to polyethylene glycol (PEG)-modified beta-glucuronidase. Cells expressing phOx scFv but not control scFv receptors were selectively killed after exposure to ss-glucuronidase derivatized with phOx and PEG (phOx-beta G-PEG) and a glucuronide prodrug (p-hydroxy aniline mustard beta-D-glucuronide, HAMG) of p-hydroxyaniline mustard. Targeted activation of HAMG produced bystander killing of receptor-negative cells in mixed populations containing as few as 10% phOx-receptor-positive cells. Functional phOx scFv receptors were stably expressed on B16-F1 melanoma tumors in vivo. Treatment of mice bearing established phOx-receptor-positive tumors with phOx-beta G-PEG and HAMG significantly (P< or =.0005) suppressed tumor growth as compared with treatment with beta G-PEG and HAMG or prodrug alone. phOx was unstable in the serum, suggesting alternative haptens may be more suitable for in vivo applications. Our results show that therapeutic agents can be targeted to artificial hapten receptors in vitro and in vivo. The expression of artificial receptors on target cells may allow preferential delivery of therapeutic or imaging molecules to sites of transgene expression.

Antibody-directed enzyme prodrug therapy (ADEPT) has displayed antitumor activity in animal models and clinical trials. We examined whether antitumor immunity is generated during ADEPT by employing an immunoenzyme composed of the monoclonal antibody (MAb) RH1 conjugated to beta-glucuronidase to target rat AS-30D hepatocellular carcinoma tumors. A glucuronide prodrug of p-hydroxyaniline mustard was used to treat malignant ascites after immunoenzyme localization at the cancer cells. ADEPT cured more than 96% of Sprague-Dawley rats bearing advanced malignant ascites, and all cured rats were protected from a lethal challenge of AS-30D cells. Immunization with radiation-killed AS-30D cells or AS-30D cells coated with immunoenzyme did not provide tumor protection. Likewise, ex vivo treatment of tumor cells by ADEPT before injection into rats did not protect against a tumor challenge. AS-30D and N1-S1 hepatocellular carcinoma cells but not unrelated syngeneic tumor cells were lysed by peritoneal exudate cells isolated from ADEPT-cured rats. Depletion of CD8(+) but not CD4(+) T cells or natural killer (NK) cells reduced the cytolytic activity of peritoneal lymphocytes. ADEPT did not cure tumor-bearing rats depleted of CD4(+) and CD8(+) T cells even though it was curative when given 7 days after tumor transplantation in rats with an intact immune system, indicating that ADEPT can synergize with host immunity to increase therapeutic efficacy. These results have important implications for the clinical application of ADEPT., (Copyright 2001 Wiley-Liss, Inc.)

The F(ab')(2) fragment of the anti-TAG-72 antibody, B72.3, was covalently linked to Escherichia coli-derived beta-glucuronidase that was modified with methoxypoly(ethylene glycol). The conjugate (B72.3-betaG-PEG) localized to a peak concentration in LS174T xenografts within 48 h after injection, but enzyme activity persisted in plasma such that prodrug administration had to be delayed for at least 4 days to avoid systemic prodrug activation and associated toxicity. Conjugate levels in tumors decreased to 36% of peak levels at this time. Intravenous administration of AGP3, an IgM mAb against methoxypoly(ethylene glycol), accelerated clearance of conjugate from serum and increased the tumor/blood ratio of B72. 3-betaG-PEG from 3.9 to 29.6 without significantly decreasing the accumulation of conjugate in tumors. Treatment of nude mice bearing established human colon adenocarcinoma xenografts with B72. 3-betaG-PEG followed 48 h later with AGP3 and a glucuronide prodrug of p-hydroxyaniline mustard significantly (p< or =0.0005) delayed tumor growth with minimal toxicity compared to therapy with a control conjugate or conventional chemotherapy.