Modulating immune system development and function through microrna mir-146

Abstract

The present disclosure relates to the finding that microRNA-146 plays a role in modulating the development and function of the immune system. Immune cell development and function can be modulated by delivery of microRNA-146 (miR-146) or antisense miR-146 to target immune cells or precursor cells. For example, in some embodiments, activity and/or proliferation of certain immune cells is regulated by administering miR-146 oligonucleotides or anti-miR-146 oligonucleotides. In other embodiments, pro-inflammatory cytokine expression in immune cells is regulated by administering a miR-146 oligonucleotide or anti-miR-146. In further embodiments, methods of regulating macrophage activity using antisense miR-146 are provided. Additional methods and compositions for regulating immune system function and development using miR-146 are disclosed.

1 . A transgenic mouse, wherein the genome of the transgenic mouse comprises a homozygous disruption of the endogenous miRNA-146 gene. 
     
     
         2 . The transgenic mouse of  claim 1 , wherein the disruption comprises a deletion of at least a portion of the endogenous miRNA-146 gene. 
     
     
         3 . The transgenic mouse of  claim 1 , wherein the disruption comprises a replacement of at least a portion of the endogenous miRNA-146 gene with a PGK-Neo cassette flanked by loxP sites. 
     
     
         4 . The transgenic mouse of  claim 1 , wherein the disruption comprises a replacement of at least a portion of the endogenous miRNA-146 gene with a nucleotide sequence comprising a loxP site. 
     
     
         5 . The transgenic mouse of  claim 1 , wherein the endogenous miRNA-146 gene is replaced with a nucleotide sequence comprising a loxP site. 
     
     
         6 . The transgenic mouse of  claim 1 , wherein the transgenic mouse suffers from one or more autoimmune disorders. 
     
     
         7 . The transgenic mouse of  claim 6 , wherein one of the one or more autoimmune disorders is splenomegaly or lymphoadenopathy, 
     
     
         8 . The transgenic mouse of  claim 7 , wherein the transgenic mouse has an increased number of CD11b-positive cells as compared to a wild-type mouse. 
     
     
         9 . The transgenic mouse of  claim 1 , wherein the transgenic mouse exhibits severe inflammation or tissue damage in organs selected from the group consisting of liver, kidneys and lungs. 
     
     
         10 . The transgenic mouse of  claim 1 , wherein the transgenic mouse exhibits impaired T cell development as compared to a wild type mouse. 
     
     
         11 . The transgenic mouse of  claim 10 , wherein the impaired T cell development is impaired negative T cell selection or an increased number of activated T cells. 
     
     
         12 . The transgenic mouse of  claim 1 , wherein the transgenic mouse exhibits abnormal development in a cell of hematopoietic origin as compared to the wild type mouse. 
     
     
         13 . The transgenic mouse of  claim 12 , wherein the cell of hematopoietic origin is selected from the group consisting of a B1 B cell, a B2 cell, a marginal zone B cell, a CD8+ cell, a natural killer (NK) cell, and a CD8αα+ T cell. 
     
     
         14 . A transgenic mouse, wherein the transgenic mouse comprises a homozygous disruption of 295 base pairs of an endogenous sequence encoding pre-miR-146a. 
     
     
         15 . The transgenic mouse of  claim 14 , wherein the 295 base pairs of the endogenous sequence is replaced by a nucleotide sequence comprising a selection marker flanked by two or more recombinase recognition sites. 
     
     
         16 . The transgenic mouse of  claim 15 , wherein the selection marker is a PGK-Neo cassette. 
     
     
         17 . The transgenic mouse of  claim 15 , wherein the recombinase recognition site is a loxP site. 
     
     
         18 . The transgenic mouse of  claim 14 , wherein the 295 base pairs of the endogenous sequence is replaced by a sequence comprising a recombination recognition site. 
     
     
         19 . A cell from a transgenic mouse, wherein the transgenic mouse comprises a homozygous deletion of 295 base pairs of an endogenous sequence encoding pre-miR-146a. 
     
     
         20 . The cell of  claim 19 , wherein the cell is selected from the group consisting of a bone marrow derived macrophage (BMDM), a stem cell, a T cell, a B1 B cell, a marginal zone B cell, a CD8+ cell, a natural killer (NK) cell, and a CD8αα+ T cell. 
     
     
         21 . The cell of  claim 20 , wherein the cell is a BMDM. 
     
     
         22 . The cell of  claim 21 , wherein the BMDM secrets a higher level of a proinflammatory cytokine after lipopolysaccharide (LPS) stimulation as compared to a BMDM in a wild type mouse. 
     
     
         23 . The cell of  claim 22 , wherein the proinflammatory cytokine is selected from the group consisting of TNFα, IL-6 and IL-1β.