Summary. Background: Adenoviral-based methods of gene therapy have been ineffective at providing sustained factor (F)VIII expression in outbred populations of large animal hemophilic models primarily due to the immunogenicity of these vectors. Improvements have been made in vector design leading to the development of the helper-dependent adenoviral (HD) system. Unfortunately, it remains unclear whether these modi®cations are suf®cient to circumvent the induction of inhibitor formation associated with adenoviral gene transfer. Objective: To develop an HD vector capable of mediating sustained FVIII expression and to determine the variables that in¯uence inhibitor development. Methods: HD vectors were constructed encoding the canine FVIII B-domain deleted transgene under the control of either the cytomegalovirus (CMV) promoter or a tissue-restricted hybrid element consisting of ®ve HNF-1 binding sites, located upstream of the human FVIII proximal promoter. Inbred and outbred populations of hemophilic mice were treated, and monitored for vector-induced toxicity, therapeutic ef®cacy, and inhibitor formation. Results: When HD vectors utilizing the CMV promoter were administered, all hemophilic mice developed high levels of FVIII inhibitors. In contrast, vectors under the control of the HNF/FVIII element were capable of achieving sustained elevations of FVIII for over 6 months. Strain-speci®c differences were also observed, with outbred animals showing a greater propensity towards inhibitor development in response to treatment. Conclusions: HD vectors can be used to provide long-term FVIII expression in hemophilic animals, but treatment outcome and the induction of inhibitors is dependent on a number of variables including the transgene promoter, the vector dose, and the genetic background of the host.

Summary. Background: The development of anti-factor VIII (FVIII) neutralizing antibodies (inhibitors) is a significant obstacle to FVIII replacement therapy. Objective: As mucosal administration of an antigen may induce immune tolerance we have evaluated the efficacy of mucosal antigen exposure to achieve tolerance to FVIII. Methods: We investigated the effects of oral and nasal administration of the purified FVIII C2 domain (FVIII-C2) to FVIII-deficient BALB/c mice prior to FVIII protein challenge. Mice received oral or nasal doses of FVIII-C2, followed by a subcutaneous challenge of either FVIII-C2 or FVIII. The development of anti-FVIII inhibitors, cytokine production by splenocytes in vitro, and adoptive transfer assays were analyzed. Results and Conclusions: Mucosal administration of FVIII-C2 decreases the titer of anti-FVIII-C2 inhibitors after FVIII-C2 challenge, and decreases the percentage of FVIII-C2 specific antibodies after challenge with full-length FVIII. Tolerance induction to FVIII-C2 is associated with increased IL-10 production by splenocytes in vitro, and can be adoptively transferred to naı¨ve mice. This study is the first to demonstrate that tolerance to the FVIII-C2 domain can be induced via the mucosal route. Based on these results, the potential use of FVIII-specific mucosal tolerance induction as an immunotherapy treatment for anti-FVIII inhibitor development warrants further investigation.

Our results indicate that the genetic background of the murine model of hemophilia A influences FVIII expression levels, the development of anti-FVIII inhibitors, clearance of transduced cells, and the severity of vector-mediated hepatotoxicity.

Hemophilia A and B are excellent candidate disorders for the application of somatic cell gene therapy. One of the major advantages in the preclinical development of hemophilia gene therapy strategies has been the availability of several animal models for both hemophilia A and B. These models recapitulate many of the phenotypic aspects of human hemophilia and have proven to be very informative in exploring the efficacy and safety of gene therapy. Considerable progress has been made in the design of gene therapy protocols, and over the last 5 years it has been shown that long-term phenotypic correction, with sustained therapeutic levels of factor VIII (FVIII) and factor IX (FIX), can be attained in FVIII- and FIX-deficient mice and dogs using various viral vector-mediated gene therapy approaches. These animal models also have elucidated potential complications of gene therapy protocols, including acute vector-associated toxicities and the induction of neutralizing antibodies to the FVIII and FIX transgene products. Nevertheless, although the preclinical paradigm of hemophilic mouse followed by hemophilic dog studies has proven to be extremely helpful in evaluating the efficacy and safety of potential clinical gene therapy protocols, several limitations to these animal models still exist. This review presents a summary of the animal models available for hemophilia gene therapy, and highlights the various strengths and weaknesses of these models.

Curriculum mapping can be used to document, align, visualize, and assess curricular data, such as learning outcomes, assessment materials, instructional techniques, and student pre-and post-testing scores. A cross-disciplinary Curriculum Mapping Initiative currently underway at the University of Toronto Mississauga aims to: (1) develop guidelines for the curriculum mapping process; (2) develop cross-disciplinary curriculum mapping templates and samples to guide departments through the curriculum mapping process; (3) communicate narratives for how to use curriculum mapping to inform curricular change; (4) develop visualization strategies for curricular data; (5) initiate a plan for dissemination and sustainability; and (6) initiate a plan for informing students about how to use curricular maps in their academic experiences. Through this curriculum mapping initiative, we have discovered that discipline-specific differences exist in approaches to curriculum mapping. The purpose of this paper is to communicate these cross-disciplinary similarities and differences in purpose, process, and utilization of curriculum mapping strategies. We found that different departments had some common ground in the curriculum mapping process, but also key differences. The differences could be categorized according to: purpose for initiating the curriculum mapping process; approach to curriculum mapping; dissemination of completed maps; dealing with pedagogical jargon; and faculty buy-in.