COLD SPRING HARBOR, N.Y. (Mon., Feb. 2, 2009) -- By using OP9-DL1 cells as a support system, researchers can study the differentiation of embryonic stem cells into mature components of the immune system. This month's issue of Cold Spring Harbor Protocols (www.cshprotocols.org/TOCs/toc2_09.dtl) features a set of methods from Juan Carlos Zúñiga-Pflücker's laboratory at the University of Toronto (http://www.immunology.utoronto.ca/faculty/directory/zunigapflucker.htm) detailing "The OP9-DL1 System: Generation of T-Lymphocytes from Embryonic or Hematopoietic Stem Cells In Vitro." The article contains a series of protocols describing the establishment, maintenance, and storage of OP9 and OP9-DL1 cells; the co-culture of these cells with embryonic stem cells or hematopoietic stem cells from fetal liver or bone marrow; and the in vitro differentiation of the stem cells into lymphocytes. The OP9-DL1 system has been useful in addressing questions about the cellular and molecular regulation of T-lymphocyte lineage commitment, pre-T cell receptor signaling (beta-selection), functional characteristics of progenitor T cells, and maturation of functional CD8 T cells. The article is freely accessible on the website for Cold Spring Harbor Protocols (http://www.cshprotocols.org/cgi/content/full/2009/2/pdb.prot5156).
The second featured article for February comes from S.P. Dinesh-Kumar and colleagues at Yale University (http://plantfunctionalgenomics.yale.edu/). RNA interference (RNAi) has become an effective tool for the down-regulation of genes in plants. The most effective means of accomplishing this gene silencing is through the use of viral vectors, with the Tobacco Rattle Virus (TRV) providing the most robust results. "Virus-Induced Gene Silencing as a Tool for Delivery of dsRNA into Plants" outlines a simple procedure for introducing TRV-based vectors into commonly studied plants such as Arabidopsis and tomato. This method is freely accessible on the website for Cold Spring Harbor Protocols (http://www.cshprotocols.org/cgi/content/full/2009/2/pdb.prot5139).
Source: Cold Spring Harbor Laboratory