Non Coding Rna In Immunotherapies And Immune Regulation PDF Download

Genomic imprinting, a unique epigenetic regulation resulting in a parent-of-origin specificgene expression, is essential for normal mammalian development and growth. H19 is amaternally expressed long non-coding RNA that is a central regulator of the imprinting gene network controlling development and growth. H19 is expressed throughout embryonic development in multiple tissues including all hematopoietic cells. The role of H19 during embryonic development has only been documented for the placenta where it controls growthand the role of H19 in lymphopoiesis has not been investigated. The laboratory has previouslyfound H19 as the major differentially expressed transcript in two microarrays comparing fetalliver (FL) and bone marrow (BM) derived pro-B cells, as well as between early and latethymic settling progenitors. However, a role for imprinting gene H19 in B cell development,or even in immune system remains elusive. Here we sought to analyze mice where a large segment of the H19 locus has been deleted. In our work, we found that loss of H19 have specific impact on the FL B cell development byproducing increased numbers of BP1+ proB cell. Although BP1+ proB cells from H19-/- FLshowed impaired Ig heavy chain V-D-J rearrangement, that increase resulted in a net enlarged B cell compartment in the adult periphery of H19 mutant. In adult mice, although H19 is notexpressed in B lymphocytes after birth, B cells from H19-/- mice exhibited altered B cellsurface phenotype, represented by an upregulated B220 expression on all B cell subsets. After immunization with different T cell dependent antigens, H19-/- exhibits reduced GC B cells, and impaired specific IgM titer in the serum, indicating a defected B cell response in H19-/-mice. Competitive reconstitution analysis showed a B cell autonomous impairment in the Bcell response. Consistently we found a reduced BCR responsiveness of H19-/- naïve B cells that together with less efficient upregulation of MHCII and CD40 expression after immunization might be responsible for the impaired immune response in H19-/- mice. Genome-wide transcription analysis revealed differential expression of genes involved inregulating the intensity of B cell receptor signaling. This work brings new insights on the regulation role of long non-coding RNA H19 in the early B cell development and immune system.