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Abstract #21196 Published in IGR 10-2
Gpnmb(R150X) allele must be present in bone marrow derived cells to mediate DBA/2J glaucoma
Anderson MG; Nair KS; Amonoo LA; Mehalow A; Trantow CM; Masli S; John SWMBMC Genetics 2008; 9: 30
BACKGROUND: The Gpnmb gene encodes a transmembrane protein whose function(s) remain largely unknown. Here, we assess if a mutant allele of Gpnmb confers susceptibility to glaucoma by altering immune functions. DBA/2J mice have a mutant Gpnmb gene and they develop a form of glaucoma preceded by a pigment dispersing iris disease and abnormalities of the immunosuppressive ocular microenvironment. RESULTS: We find that the Gpnmb genotype of bone-marrow derived cell lineages significantly influences the iris disease and the elevation of intraocular pressure. GPNMB localizes to multiple cell types, including pigment producing cells, bone marrow derived F4/80 positive antigen-presenting cells (APCs) of the iris and dendritic cells. We show that APCs of DBA/2J mice fail to induce antigen induced immune deviation (a form of tolerance) when treated with TGFβ2. This demonstrates that some of the immune abnormalities previously identified in DBA/2J mice result from intrinsic defects in APCs. However, the tested APC defects are not dependent on a mutant Gpnmb gene. Finally, we show that the Gpnmb mediated iris disease does not require elevated IL18 or mature B or T lymphocytes. CONCLUSION: These results establish a role for Gpnmb in bone marrow derived lineages. They suggest that affects of Gpnmb on innate immunity influence susceptibility to glaucoma in DBA/2J mice.
Dr. S.W.M. John, The Jackson Laboratory, Bar Harbor, ME, USA. Simon.john@jax.org
Classification:
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
3.4.2 Gene studies (Part of: 3 Laboratory methods > 3.4 Molecular genetics)