ABSTRACT
Avoiding unwanted immunogenicity is of key importance in the development of therapeutic drug proteins. Animal models are of less predictive value because most of the drug proteins are recognized as foreign proteins. However, different methods have been developed to obtain immunotolerant animal models. So far, the immunotolerant animal models have been developed to assess one protein at a time and are not suitable for the assessment of combination products. Our aim was to develop an animal model for evaluating the impact of manufacturing and formulation changes on immunogenicity, suitable for both single protein and combination products. We constructed two lines of transgenic mice expressing the three human coagulation factors, II, VII, and X, by inserting a single vector containing the three coagulation factors encoding sequences separated by insulator sequences derived from the chicken beta-globin locus into the mouse genome. Immunization of transgenic mice from the two lines and their wild-type littermates showed that transgenic mice from both lines were immunotolerant to the expressed human coagulation factors. We conclude that transgenic mice immunotolerant to multiple proteins can be obtained, and that these mice are potentially useful as animal models in the assessment of immunogenicity in response to manufacturing changes.
Subject(s)
Factor VII/genetics , Factor VII/immunology , Factor X/genetics , Factor X/immunology , Prothrombin/genetics , Prothrombin/immunology , Animals , Antibodies/immunology , Chickens , Factor VII/administration & dosage , Factor X/administration & dosage , Female , Gene Expression , Humans , Immunization , Male , Mice , Mice, Transgenic , Models, Animal , Prothrombin/administration & dosage , Recombinant Proteins/administration & dosage , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Transgenes , beta-Globins/geneticsABSTRACT
The metabotropic glutamate receptor 5 (mGluR5) has been suggested to modulate energy balance. For example, mGluR5 antagonists inhibit food intake in rodents and mGluR5 knockout mice resist diet-induced obesity. However, nonspecific effects can reduce food intake. Thus, to further support the role of mGluR5 in feeding behaviour, we evaluated if the mGluR5 agonist (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG) would induce the opposite effect, i.e. increased food intake in rats. Intracerebroventricularly injected CHPG (0.5-1.5 micromol) induced a dose-dependent stimulation of food intake (349% increase at 2 h with 1.5 micromol). The mGluR5 antagonist 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-pyridine (10 mg/kg intraperitoneally) reduced 24 h food intake, without altering CHPG-induced feeding. These findings further support a physiologically relevant role of mGluR5 in appetite regulation.
Subject(s)
Eating/drug effects , Excitatory Amino Acid Agonists/pharmacology , Glycine/analogs & derivatives , Phenylacetates/pharmacology , Receptors, Metabotropic Glutamate/agonists , Animals , Catheterization , Dose-Response Relationship, Drug , Eating/physiology , Excitatory Amino Acid Agonists/administration & dosage , Excitatory Amino Acid Antagonists/pharmacology , Fasting , Glycine/administration & dosage , Glycine/pharmacology , Injections, Intraperitoneal , Male , Phenylacetates/administration & dosage , Pyridines/pharmacology , Rats , Rats, Wistar , Receptor, Metabotropic Glutamate 5 , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Receptors, Metabotropic Glutamate/metabolism , Thiazoles/pharmacology , Time FactorsABSTRACT
An 8-month-old Arabian-warmblood cross colt was evaluated for overt hematuria. The horse was severely anemic on presentation. A unilateral intrarenal vascular anomaly with unilateral pyelonephritis was diagnosed. Nephrectomy was attempted but was unsuccessful, and postmortem examination demonstrated the presence of an intrarenal pseudoaneurysm.
Subject(s)
Aneurysm, False/veterinary , Hematuria/virology , Horse Diseases/diagnosis , Kidney/blood supply , Aneurysm, False/complications , Aneurysm, False/diagnosis , Animals , Hematuria/etiology , Horse Diseases/urine , Horses , Kidney Diseases/diagnosis , Kidney Diseases/veterinary , MaleABSTRACT
Melanin-concentrating hormone (MCH) plays an important role in energy balance. The current studies were carried out on a new line of mice lacking the rodent MCH receptor (MCHR1(-/-) mice). These mice confirmed the previously reported lean phenotype characterized by increased energy expenditure and modestly increased caloric intake. Because MCH is expressed in the lateral hypothalamic area, which also has an important role in the regulation of the autonomic nervous system, heart rate and blood pressure were measured by a telemetric method to investigate whether the increased energy expenditure in these mice might be due to altered autonomic nervous system activity. Male MCHR1(-/-) mice demonstrated a significantly increased heart rate [24-h period: wild type 495 +/- 4 vs. MCHR1(-/-) 561 +/- 8 beats/min (P < 0.001); dark phase: wild type 506 +/- 8 vs. MCHR1(-/-) 582 +/- 9 beats/min (P < 0.001); light phase: wild type 484 +/- 13 vs. MCHR1(-/-) 539 +/- 9 beats/min (P < 0.005)] with no significant difference in mean arterial pressure [wild type 110 +/- 0.3 vs. MCHR1(-/-) 113 +/- 0.4 mmHg (P > 0.05)]. Locomotor activity and core body temperature were higher in the MCHR1(-/-) mice during the dark phase only and thus temporally dissociated from heart rate differences. On fasting, wild-type animals rapidly downregulated body temperature and heart rate. MCHR1(-/-) mice displayed a distinct delay in the onset of this downregulation. To investigate the mechanism underlying these differences, autonomic blockade experiments were carried out. Administration of the adrenergic antagonist metoprolol completely reversed the tachycardia seen in MCHR1(-/-) mice, suggesting an increased sympathetic tone.
