Ge Y, Powell S, Van Roey M, McArthur J G
Cell Genesys, Dept of Preclinical Biology and Immunology, 342 Lakeside Dr., Foster City, CA 94404, USA.
Blood. 2001 Jun 15;97(12):3733-7. doi: 10.1182/blood.v97.12.3733.
The present study sought to determine the impact of the route of administration of an adeno-associated virus (AAV) vector encoding human factor IX (hFIX) on the induction of an immune response against the vector and its xenogenic transgene product, hFIX. Increasing doses of AAV-hFIX were administered by different routes to C57Bl/6 mice, which typically demonstrate significant immune tolerance to hFIX. The route of delivery had a profound impact on serum hFIX levels as well as the induction of an anti-hFIX humoral immune response. At all dose levels tested, delivery of AAV-hFIX by an intramuscular (IM) route induced an antibody response against the human FIX protein and no hFIX was detected in the serum of animals even at doses of 2 x 10(11) DNA viral particles (vp) of AAV-hFIX. This was in stark contrast to the mice that received AAV-hFIX by intraportal vein (IPV) administration. No anti-hFIX inhibitors were observed in any of these mice and therapeutic levels of hFIX were detected in the serum of all mice that received doses of 2 x 10(10) vp AAV-hFIX and higher. When pre-existing neutralizing immunity to AAV was established in mice, AAV-hFIX administration by either the IM or IPV routes did not result in detectable serum hFIX. Although hFIX expression was not observed in mice with pre-existing neutralizing immunity to AAV, an anti-hFIX response was induced in all of the animals that received AAV-hFIX by the IM route. This was not observed in the preimmune mice that received AAV-hFIX by IPV administration. These results suggest that the threshold of inducing an immune response against a secreted transgene product, in this case the xenoprotein hFIX, is lower when the vector is administered by the IM route even in animals with pre-existing immunity to AAV. (Blood. 2001;97:3733-3737)
本研究旨在确定编码人凝血因子IX（hFIX）的腺相关病毒（AAV）载体的给药途径对诱导针对该载体及其异种转基因产物hFIX的免疫反应的影响。将递增剂量的AAV-hFIX通过不同途径给予C57Bl/6小鼠，这些小鼠通常对hFIX表现出显著的免疫耐受性。给药途径对血清hFIX水平以及抗hFIX体液免疫反应的诱导有深远影响。在所有测试剂量水平下，通过肌肉内（IM）途径递送AAV-hFIX会诱导针对人FIX蛋白的抗体反应，即使在AAV-hFIX剂量为2×10¹¹ DNA病毒颗粒（vp）时，动物血清中也未检测到hFIX。这与通过门静脉内（IPV）给药接受AAV-hFIX的小鼠形成鲜明对比。在这些小鼠中均未观察到抗hFIX抑制剂，并且在所有接受2×10¹⁰ vp及更高剂量AAV-hFIX的小鼠血清中检测到治疗水平的hFIX。当在小鼠中建立了对AAV的预先存在的中和免疫时，通过IM或IPV途径给予AAV-hFIX均未导致可检测到的血清hFIX。尽管在对AAV具有预先存在的中和免疫的小鼠中未观察到hFIX表达，但通过IM途径接受AAV-hFIX的所有动物均诱导了抗hFIX反应。通过IPV给药接受AAV-hFIX的免疫前小鼠中未观察到这种情况。这些结果表明，即使在对AAV具有预先存在免疫的动物中，当通过IM途径给药载体时，诱导针对分泌的转基因产物（在这种情况下为异种蛋白hFIX）的免疫反应的阈值较低。（《血液》。2001年；97：3733 - 3737）
