Gene transfer and expression of a non-viral polycation-based vector in CD4(+) cells

CD4-selective targeting of an antibody-polycation-DNA complex was investiga ted The complex was synthesized with the anti-CD4 monoclonal antibody B-F5, polylysine(268) (pLL) and either the pGL3 control vector containing the lu ciferase reporter gene or the pGeneGrip vector containing the green fluores cent protein (GFP) gene. B-F5-pLL-DNA complexes inhibited the binding of I- 125-B-F5 to CD4(+) Jurkat cells, while complexes synthesised either without B-F5 or using a non-specific mouse IgG1 antibody had little or no effect E xpression of the luciferase reporter gene was achieved in Jurkat cells usin g the B-F5-pLL-pGL3 complex and was enhanced in the presence of PMA. Neglig ible luciferase activity was defected with the non-specific antibody comple x in Jurkat cells or with the B-F5-pLL-pGL3 complex in the CD4(-) K-562 cel ls. Using complexes synthesised with the pGeneGrip vector, the transfection efficiency in Jurkat and K-562 cells was examined using confocal microscop y. More than 95% of Jurkat cells expressed GFP and the level of this expres sion was markedly enhanced by PMA. Negligible GFP expression was seen in K- 562 cells or when B-F5 was replaced by a nonspecific antibody. Using flow c ytometry, fluorescein-labelled complex showed specific targeting to CD4(+) cells in a mixed cell population from human peripheral blood. These studies demonstrate the selective transfection of CD4(+) T-lymphoid cells using a polycation-based gene delivery system. The complex may provide a means of d elivering anti-HIV gene therapies to CD4(+) cells in vivo.