Sustained expression of human apo A-I following adenoviral gene transfer in mice.
Elevation of HDL cholesterol, following adenoviral apolipoprotein A-I (apo A-I) gene transfer, may delay or revert ischemic cardiovascular disease, provided transgene expression is persistent. The choice of promoter may have significant impact on persistence of transgene expression. Human apo A-I expression was compared after adenoviral gene transfer with a cytomegalovirus promoter (CMV) driven construct (AdCMV/A-I.gA-I) and with a construct (AdA-I.gA-I.4xapoE) containing the endogenous 256 bp apo A-I promoter (A-I), the genomic human apo A-I DNA (gA-I) and 4 human apo E enhancers (4xapoE) in three different mouse strains: C57BL/6, Balb/c and Fvb. After gene transfer with 5 x 10(8) p.f.u. of AdCMV/A-I.gA-I, human apo A-I expression was observed for 35 days in C57BL/6 mice, but declined below 1 mg/dl within 14 days both in Balb/c and Fvb mice, due to a strong humoral immune response against human apo A-I. In contrast, after transfer with AdA-I.gA-I.4xapoE, human apo A-I expression persisted for 6 months in all three strains and no antibodies against human apo A-I occurred in Fvb or Balb/c mice. Human apo A-I transgene DNA level 35 days after transfer with AdA-I.gA-I.4xapoE was 4.6- to 5.5-fold higher than with AdCMV/A-I.gA-I. CMV promoter attenuation occurred in all three strains, but promoter attenuation was not observed in any strain after transfer with AdA-I.gA-I.4xapoE. In conclusion, gene transfer with AdA-I.gA-I.4xapoE is associated with absence of an immune response against human apo A-I, improved transgene DNA persistence and absence of promoter shut-off, resulting in human apo A-I expression for up to 6 months in three different mouse strains. Possibly, the absence of human apo A-I expression in antigen-presenting cells with the liver-specific apo A-I promoter containing construct abrogated the immune response against human apo A-I in Balb/c and Fvb mice.
De Geest
B
B
Center for Molecular and Vascular Biology, University of Leuven, Belgium.
Van Linthout
S
S
Collen
D
D
D000256:Adenoviridae / Q000235:genetics*; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000917:Antibody Formation; D016632:Apolipoprotein A-I / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002455:Cell Division / Q000276:immunology; D003587:Cytomegalovirus / Q000235:genetics; D004247:DNA / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D011401:Promoter Regions, Genetic; D013045:Species Specificity; D013154:Spleen / Q000276:immunology; D019076:Transgenes
D016632:Apolipoprotein A-I; D004247:DNA; D000410:Alanine Transaminase