Petry H, Brooks A, Orme A, Wang P, Liu P, Xie J, Kretschmer P, Qian H S, Hermiston T W, Harkins R N
Department of Gene Technologies, Berlex Biosciences, Richmond, CA, USA.
Gene Ther. 2008 Jan;15(1):54-60. doi: 10.1038/sj.gt.3303037. Epub 2007 Oct 25.
Neutralizing antibodies (nAB) at the time of administration hamper the effectiveness of adeno-associated virus (AAV) as a clinical DNA delivery system. The present study was designed to investigate if AAV re-administration in muscle tissue is dependent on the nAB titer. Recombinant (r)AAV serotype 1, as a promising candidate for targeting skeletal muscle, was used for gene delivery. C57Bl/6 mice were infected intramuscularly with doses between 1 x 10(9) and 5 x 10(10) virus particles (vp) of AAV1-expressing luciferase (AAV1-luc) or human interferon-beta (AAV1-hIFNbeta). Increasing transgene expression was observed over the first 2 months and anti-AAV1 nAB titers peaked between weeks 4 and 8. Six months after the first administration, 5 x 10(10) vp of AAV1-IFNbeta were re-administered. Following re-administration, nAB titers increased but did not significantly affect transgene expression from the AAV vector that had been administered first. In contrast, hIFNbeta expression originating from the second vector administration was significantly diminished and reflected the nAB titer present at the day of re-administration. The present study extends earlier observations that preexisting nAB affects AAV1 re-administration. The level of nAB is proportional to the virus dose used for the first injection and transgene expression following re-administration is dependent on preexisting nAB titer.
给药时的中和抗体（nAB）会妨碍腺相关病毒（AAV）作为临床DNA递送系统的有效性。本研究旨在调查肌肉组织中AAV再次给药是否依赖于nAB滴度。重组（r）AAV血清型1作为靶向骨骼肌的有前景的候选物，用于基因递送。将表达荧光素酶（AAV1-luc）或人干扰素-β（AAV1-hIFNβ）的AAV1以1×10⁹至5×10¹⁰病毒颗粒（vp）的剂量肌肉注射感染C57Bl/6小鼠。在最初的2个月内观察到转基因表达增加，抗AAV1 nAB滴度在第4至8周达到峰值。首次给药6个月后，再次给予5×10¹⁰ vp的AAV1-IFNβ。再次给药后，nAB滴度增加，但未显著影响首次给药的AAV载体的转基因表达。相反，源自第二次载体给药的hIFNβ表达显著降低，反映了再次给药当天存在的nAB滴度。本研究扩展了先前的观察结果，即预先存在的nAB会影响AAV1再次给药。nAB的水平与首次注射所用的病毒剂量成正比，再次给药后的转基因表达取决于预先存在的nAB滴度。
