ONLINESUPPLEMENTARYMATERIALThelentiviralvectorLentivirusbasedexpressionsystems,initiallydevelopedforgenetherapypurposes,provideseveraladvantagesoverothervirus-basedinvivotransgeneexpressionstrategies.First,aswithallretroviruses,theyarecapableofstableintegrationintothegenomeofthehostcell,facilitatingthepotentialforlong-term,stabletransgeneexpression.Second,oncetheviral-transgenehasbeenstablyintegrated,continuedexpressionofviralproteins(andtheaccompanyingpotentialfordestructiveimmuneresponses)isavoided.Third,lenti-retrovirusesarecapableofgenomicintegrationintonon-dividingcells,suchasneuronsandotherterminallydifferentiatedcells.ThelentiviralexpressionvectorsusedintheprojectarederivedfromthepHR’expressionvectorsfirstdescribedbyNaldinietalADDINEN.CITE<EndNote><Cite><Author>Naldini</Author><Year>1996</Year><RecNum>34</RecNum><MDL><REFERENCE_TYPE>0</REFERENCE_TYPE><ACCESSION_NUMBER>8876144</ACCESSION_NUMBER><VOLUME>93</VOLUME><NUMBER>21</NUMBER><YEAR>1996</YEAR><DATE>Oct15</DATE><TITLE>Efficienttransfer,integration,andsustainedlong-termexpressionofthetransgeneinadultratbrainsinjectedwithalentiviralvector</TITLE><PAGES>11382-8</PAGES><AUTHOR_ADDRESS>SalkInstituteforBiologicalStudies,SanDiego,CA92186-5800,USA.</AUTHOR_ADDRESS><AUTHORS><AUTHOR>Naldini,L.</AUTHOR><AUTHOR>Blomer,U.</AUTHOR><AUTHOR>Gage,F.H.</AUTHOR><AUTHOR>Trono,D.</AUTHOR><AUTHOR>Verma,I.M.</AUTHOR></AUTHORS><SECONDARY_TITLE>ProcNatlAcadSciUSA</SECONDARY_TITLE><KEYWORDS><KEYWORD>Animals</KEYWORD><KEYWORD>Animals,GeneticallyModified</KEYWORD><KEYWORD>Brain/cytology/*metabolism</KEYWORD><KEYWORD>CellLine</KEYWORD><KEYWORD>Cytomegalovirus/genetics</KEYWORD><KEYWORD>*GeneTransferTechniques</KEYWORD><KEYWORD>Genes,Reporter</KEYWORD><KEYWORD>Genes,gag</KEYWORD><KEYWORD>Genes,pol</KEYWORD><KEYWORD>*GeneticVectors</KEYWORD><KEYWORD>Human</KEYWORD><KEYWORD>Kidney</KEYWORD><KEYWORD>LacOperon</KEYWORD><KEYWORD>Lentivirus/*genetics</KEYWORD><KEYWORD>Neurons/cytology/*metabolism</KEYWORD><KEYWORD>Rats</KEYWORD><KEY