University of Iowa Research Foundation

Roger Williamson

Kevin P Campbell

Beverly L Davidson

Michael D Henry

Volker Straub

Franck Duclos

Leland E Lim

Michael Oldstone

Wei Cao

Rachelle Crosbie

Connie Lebakken

Ramon Coral

Hiroki Yamada

Madeleine Durbeej

Ronald Cohn

James L Clements

Kathleen H Holt

Gary A Koretzky

Disclosed is a method for treating a patient suffering from the disease sarcoglycan-deficient limb-girdle muscular dystrophy by gene replacement therapy. Sarcoglycan gene replacement therapy produces extensive long-term expression of the sarcoglycan species which restores the entire sarcoglycan complex, results in the stable association of alph&agr;-dystroglycan with the sarcolemma, and eliminates the morphological markers of limb-girdle muscular dystrophy. In another aspect, the invention relates to a method for determining a specific defective sarcoglycan species in the tissue of a patient. The method involves culture of muscle cells obtained from the patient, and the independent introduction of expression vectors encoding each of the sarcoglycan species, &agr;, &bgr;, &ggr;, and &dgr;, into the cultured cells with subsequent assaying for restoration of the dystrophin-glycoprotein complex. In another aspect, the invention relates to a mouse, and cells derived therefrom, homozygous for a disrupted &agr;-sarcoglycan gene. The disruption prevents the synthesis of functional &agr;-sarcoglycan in cells of the mouse and results in the mutant mouse having no detectable sarcospan, &bgr;-, &ggr;-, &dgr;-sarcoglycan, and reduced &agr;-dystroglycan in the sarcolemma of skeletal and cardiac muscles, and a reduction of dystrophin in skeletal muscle, when compared to tissue of a mouse lacking a disrupted &agr;-sarcoglycan gene. In another aspect, the invention relates to methods for screening for therapeutic agents useful in the treatment of sarcoglycan-deficient limb-girdle muscular dystrophy. The methods involve administering a candidate therapeutic agent to a mouse, or cells derived therefrom, and assaying for therapeutic effects on the mouse or cells, with the determination of therapeutic effects being a reduction or reversal in disease progression, or a restoration of the dystroglycan complex.

Gene replacement therapy for muscular dystrophy

Disclosed is a transgenic knockout mouse whose genome has a homozygous disruption in its endogenous sarcospan gene, wherein the disruption prevents the synthesis of functional sarcospan in cells of the mouse. The mouse is characterized as exhibiting from 1.4 to 6.8 fold larger epididymal fat pad deposits as compared to the epididymal fat pad deposits of a wild type mouse. Methods for production of the mouse are presented. Also disclosed are cells derived from the transgenic knockout mouse. The mouse can be used in a method for identifying therapeutic agents for the treatment of an individual diagnosed with a metabolic disorder associated with a reduction or loss of expression of wild-type sarcospan. An example of such a disorder is weight gain in the individual associated with a reduction or loss of expression of wild-type sarcospan. These specific methods are also provided.

Sarcospan-deficient mouse as a model for clinical disorders associated with sarcospan mutations

Disclosed is a mouse, cells derived therefrom, and methods for using the mouse, the mouse being homozygous for a disrupted &dgr;-sarcoglycan gene, the disruption in the gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage. The disruption prevents the synthesis of functional &dgr;-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of &bgr;- and &egr;-sarcoglycan and sarcospan, and a disruption of the sarcoglycan-sarcospan complex in smooth muscle of the mouse. Also disclosed is a mouse, cells derived therefrom, and methods for using the mouse, the mouse being homozygous for a disrupted &bgr;-sarcoglycan gene, the disruption in the gene having been introduced into the mouse or an ancestor of the mouse at an embryonic stage. The disruption prevents the synthesis of functional &bgr;-sarcoglycan in cells of the mouse and results in the mouse having a reduced amount of &dgr;-and &egr;-sarcoglycan and sarcospan and &agr;-dystroglycan in smooth muscle of the mouse.

Pathogenesis of cardiomyopathy

A nonhuman animal having somatic and germ cells in which at least one allele of an endogenous SLP-76 gene is functionally disrupted is provided. The animal may be heterozygous or, more preferably, homozygous for the SLP-76 gene disruption and is preferably a mouse. In homozygous animals, the percentage of peripheral T cells is substantially decreased compared to wildtype animals, whereas the percentage of B cells and macrophages in the periphery is substantially normal, indicating that SLP-76 disruption causes a profound block in T cell development. The animals of the invention can be used, for example, as controls to evaluate the efficacy of SLP-76 inhibitors and to identify disease conditions that can be treated with SLP-76 inhibitors. A transgenic nonhuman animal having a functionally disrupted endogenous SLP-76 gene but which has been reconstituted with an exogenous SLP-76 transgene (e.g., a human SLP-76 gene or a SLP-76 gene whose expression in targeted to a particular cell population) is also provided. An animal that has been reconstituted with a human SLP-76 gene can be used to identify agents that modulate human SLP-76 in vivo. Nucleic acid constructs for functionally disrupting an endogenous SLP-76 gene in a host cell, recombinant vectors including the nucleic acid construct, and host cells into which the nucleic acid construct has been introduced are also encompassed by the invention.

Non-human animal having a functionally disrupted SLP-76 gene

Disclosed is a method for inhibiting the binding of an arenavirus to a cellular receptor. The method involves providing, in soluble form, a reagent comprising .alpha.-dystroglycan or a portion thereof, the reagent being characterized by the ability to bind to the arenavirus thereby inhibiting the binding of the arenavirus to the cellular receptor. The reagent is contacted with an arenavirus particle prior to infection of a cell by the arenavirus particle. Also disclosed are methods for treating an arenavirus infection in a patient and preventing an arenavirus infection in an individual at risk. These methods involve providing a therapeutic composition comprising .alpha.-dystroglycan or a portion thereof which is characterized by the ability to bind to arenaviruses, thereby inhibiting the binding of arenaviruses to a cellular receptor; and administering the composition to the patient or individual at risk. Arenaviruses to which the methods of the present invention apply include, without limitation, Lymphocyte Choriomeningitis Virus, Lassa fever virus, Mobala, and Oliveros. In another aspect, the disclosure relates to an embryonic stem cell line, and cells derived therefrom, which is homozygous for a disrupted dystroglycan gene, wherein the disruption prevents the synthesis of functional dystroglycan in the cells. Applications of the dystroglycan null embryonic stem cells include producing dystroglycan or a portion thereof in the cells and also for identifying portions of dystroglycan necessary for arenavirus infection. Also disclosed is a method for identifying antiviral compounds which interfere specifically with the binding of arenavirus and .alpha.-dystroglycan, comprising providing a binding assay system for the determination of binding of arenavirus and .alpha.-dystroglycan. The candidate antiviral compounds are introduced into the binding assay system and antiviral compounds which substantially inhibit binding of arenavirus to .alpha.-dystroglycan are identified.

Arenavirus receptor and methods of use

Growing community of inventors

Iowa City, IA, United States of America

Roger Williamson