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3.
J Pharmacol Exp Ther ; 370(3): 703-714, 2019 09.
Article in English | MEDLINE | ID: mdl-31010843

ABSTRACT

With the advancement of medicine, the utility of protein therapeutics is increasing exponentially. However, a significant number of protein therapeutics suffer from grave limitations, which include their subpar pharmacokinetics. In this study, we have reviewed the emerging field of protein chimerization for improving the short circulatory half-life of protein therapeutics. We have discussed various aspects of protein therapeutics aiming at their mechanism of clearance and various approaches used to increase their short circulatory half-life with principal focus on the concept of chimerization. Furthermore, we have comprehensively reviewed various components of chimera, such as half-life extension partners and linkers, their shortcomings, and prospective work to be undertaken for developing effective chimeric protein therapeutics.


Subject(s)
Mutant Chimeric Proteins/pharmacokinetics , Mutant Chimeric Proteins/therapeutic use , Protein Engineering/methods , Animals , Humans , Mutant Chimeric Proteins/genetics , Protein Engineering/trends
5.
Biochem Soc Trans ; 44(3): 951-9, 2016 Jun 15.
Article in English | MEDLINE | ID: mdl-27284065

ABSTRACT

We studied safety and proof of concept of a phase I/II trial with chimeric antigen receptor (CAR) T-cells in patients with metastatic renal cell carcinoma (mRCC). The CAR was based on the G250 mAb that recognized an epitope of carboxy-anhydrase-IX (CAIX). Twelve patients with CAIX+ mRCC were treated in three cohorts with a maximum of 10 daily infusions of 2×10(7) to 2×10(9) CAR T-cells. Circulating CAR T-cells were transiently detectable in all patients and maintained antigen-specific immune functions following their isolation post-treatment. Blood cytokine profiles mirrored CAR T-cell presence and in vivo activity. Unfortunately, patients developed anti-CAR T-cell antibodies and cellular immune responses. Moreover, CAR T-cell infusions induced liver enzyme disturbances reaching CTC grades 2-4, which necessitated cessation of treatment in four out of eight patients (cohort 1+2). Examination of liver biopsies revealed T-cell infiltration around bile ducts and CAIX expression on bile duct epithelium, adding to the notion of on-target toxicity. No such toxicities were observed in four patients that were pretreated with G250 mAb (cohort 3). The study was stopped due to the advent of competing treatments before reaching therapeutic or maximum tolerated dose in cohort 3. No clinical responses have been recorded. Despite that, from this trial numerous recommendations for future trials and their immune monitoring could be formulated, such as choice of the target antigen, format and immunogenicity of receptor and how the latter relates to peripheral T-cell persistence.


Subject(s)
Carcinoma, Renal Cell/drug therapy , Carcinoma, Renal Cell/secondary , Kidney Neoplasms/drug therapy , Kidney Neoplasms/pathology , Receptors, Antigen, T-Cell/therapeutic use , T-Lymphocytes , Carcinoma, Renal Cell/immunology , Cytokines/blood , Humans , Kidney Neoplasms/immunology , Mutant Chimeric Proteins/therapeutic use , Treatment Outcome
6.
ACS Appl Mater Interfaces ; 8(8): 5070-81, 2016 Mar 02.
Article in English | MEDLINE | ID: mdl-26795060

ABSTRACT

Prevention of bacterial colonization and consequent biofilm formation remains a major challenge in implantable medical devices. Implant-associated infections are not only a major cause of implant failures but also their conventional treatment with antibiotics brings further complications due to the escalation in multidrug resistance to a variety of bacterial species. Owing to their unique properties, antimicrobial peptides (AMPs) have gained significant attention as effective agents to combat colonization of microorganisms. These peptides have been shown to exhibit a wide spectrum of activities with specificity to a target cell while having a low tendency for developing bacterial resistance. Engineering biomaterial surfaces that feature AMP properties, therefore, offer a promising approach to prevent implant infections. Here, we engineered a chimeric peptide with bifunctionality that both forms a robust solid-surface coating while presenting antimicrobial property. The individual domains of the chimeric peptides were evaluated for their solid-binding kinetics to titanium substrate as well as for their antimicrobial properties in solution. The antimicrobial efficacy of the chimeric peptide on the implant material was evaluated in vitro against infection by a variety of bacteria, including Streptococcus mutans, Staphylococcus. epidermidis, and Escherichia coli, which are commonly found in oral and orthopedic implant related surgeries. Our results demonstrate significant improvement in reducing bacterial colonization onto titanium surfaces below the detectable limit. Engineered chimeric peptides with freely displayed antimicrobial domains could be a potential solution for developing infection-free surfaces by engineering implant interfaces with highly reduced bacterial colonization property.


Subject(s)
Anti-Infective Agents/chemistry , Mutant Chimeric Proteins/chemistry , Peptides/chemistry , Prostheses and Implants/microbiology , Anti-Infective Agents/therapeutic use , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/therapeutic use , Biofilms/drug effects , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/therapeutic use , Drug Resistance, Multiple/drug effects , Escherichia coli/drug effects , Humans , Mutant Chimeric Proteins/therapeutic use , Peptides/therapeutic use , Protein Engineering , Staphylococcus/drug effects , Streptococcus mutans/drug effects , Titanium/chemistry , Titanium/therapeutic use
7.
Arterioscler Thromb Vasc Biol ; 32(12): 2847-54, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23087361

ABSTRACT

OBJECTIVE: The pathogenesis of atherosclerosis is associated with the early retention of low-density lipoproteins that are trapped in the extracellular matrix of the arterial intima by interaction with glycosaminoglycan side chains of proteoglycans. Mutant mouse/human chimeric antibodies of the murine monoclonal antibody P3, which react with N-glycolyl-containing gangliosides and sulfated glycosaminoglycans, were tested for their potentially antiatherogenic properties through the induction of an idiotypic antibody network that may specifically interfere with the binding of low-density lipoproteins to proteoglycan side chains, low-density lipoprotein modification, and foam cell formation. METHODS AND RESULTS: Apolipoprotein E-deficient mice fed a high-fat, high-cholesterol diet received 5 to 6 doses of chP3R99 or chP3S98 mutant antibodies, showing high and low reactivity, respectively, against their respective antigens. Both chimeric antibodies elicited an immunodominant anti-idiotypic response in the absence of adjuvant. A striking (40%-43%) reduction (P<0.01) in total lesion areas was observed in 18-week-old mice immunized with chP3R99, but not chP3S98, compared with PBS-treated mice. The antiatherosclerotic effect was associated with increased mice sera reactivity against heparin and sulfated glycosaminoglycans, including chondroitin and dermatan sulfate. In addition, purified IgG from chP3R99-immunized mice blocked the retention of apolipoprotein B-containing lipoproteins within the arterial wall of apolipoprotein E(-/-) mice. CONCLUSIONS: The present study supports use of active immunization and the mounting of an idiotypic antibody network response against glycosaminoglycans as a novel approach to target atherosclerosis.


Subject(s)
Antibodies, Anti-Idiotypic/therapeutic use , Apolipoproteins E/deficiency , Atherosclerosis/prevention & control , Glycosaminoglycans/immunology , Glycosaminoglycans/metabolism , Sulfates/metabolism , Animals , Antibodies, Anti-Idiotypic/immunology , Apolipoproteins E/genetics , Apolipoproteins E/metabolism , Arteries/metabolism , Atherosclerosis/etiology , Atherosclerosis/metabolism , Cholesterol, Dietary/adverse effects , Diet, High-Fat/adverse effects , Disease Models, Animal , Humans , Lipoproteins, LDL/metabolism , Male , Mice , Mice, Knockout , Mutant Chimeric Proteins/immunology , Mutant Chimeric Proteins/therapeutic use
8.
Ann N Y Acad Sci ; 1056: 344-58, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16387700

ABSTRACT

Gene therapy as an immunomodulatory approach has the potential to treat various inherited and acquired immune-based human diseases. However, its clinical application has several challenges, varying from the efficiency of gene transfer, control of gene expression, cell and tissue targeting, and safety concerns associated with the introduction of exogenous DNA into cells/tissues. Gene therapy is also a time- and labor-intensive procedure. As an alternative, we recently developed a novel technology, ProtEx, that allows for rapid, efficient, and durable display of exogenous proteins on the surface of cells, tissues, and organs without detectable toxicity. This technology exploits the strong binding affinity (Kd = 10(-15) M) of streptavidin with biotin and involves generation of chimeric molecules composed of the extracellular portions of immunological proteins of interest and a modified form of streptavidin, biotinylation of biological surfaces, and decoration of the modified surface with chimeric proteins. Biotin persists on the cell surface for weeks both in vitro and in vivo, thereby providing a platform to display exogenous proteins with extended cell surface kinetics. Two chimeric proteins, rat FasL (SA-FasL) and human CD80 (CD80-SA), were generated and tested for cell surface display and immunomodulatory functions. SA-FasL and CD80-SA molecules persisted on the surface of various cell types for extended periods, varying from days to weeks in vitro and in vivo. The cell surface kinetics, however, were protein and cell type dependent. SA-FasL showed potent apoptotic activity against Fas+ cells as a soluble protein or displayed on the cell surface and effectively blocked alloreactive responses. The display of CD80-SA on the surface of tumor cells, however, converted them into antigen-presenting cells for effective stimulation of autologous and allogeneic T-cell responses. ProtEx technology, therefore, represents a practical and effective alternative to DNA-based gene therapy for immunomodulation.


Subject(s)
Genetic Therapy/methods , Animals , Apoptosis/drug effects , Biotechnology/methods , Biotinylation , Cell Membrane/drug effects , Cell Membrane/physiology , Cloning, Molecular , DNA/genetics , Membrane Proteins/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mutant Chimeric Proteins/therapeutic use
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