Alzuguren Pilar, Hervas-Stubbs Sandra, Gonzalez-Aseguinolaza Gloria, Poutou Joanna, Fortes Puri, Mancheno Uxua, Bunuales Maria, Olagüe Cristina, Razquin Nerea, Van Rooijen Nico, Enguita Monica, Hernandez-Alcoceba Ruben
Division of Hepatology and Gene Therapy, CIMA, Foundation for Applied Medical Research, University of Navarra, Pamplona, Spain.
Liver Int. 2015 Apr;35(4):1274-89. doi: 10.1111/liv.12571. Epub 2014 May 10.
BACKGROUND & AIMS: Adenoviral (Ad) vectors are currently one of the most efficient tools for in vivo gene transfer to the liver. However, anti-Ad immune responses limit the safety and efficacy of these vectors. The initial inflammatory reaction is a concern in terms of toxicity, and it favours the development of cellular and humoral responses leading to short transgene persistence and inefficient vector re-administrations. Therefore, safe and simple ways to interfere with these processes are needed. Study ways to deplete specific immune cell populations and their impact on liver-directed gene transfer.
First-generation Ad vectors encoding reporter genes (luciferase or β-galactosidase) were injected intravenously into Balb/c mice. Kupffer cells and splenic macrophages were depleted by intravenous administration of clodronate liposomes. B lymphocytes, CD4(+) , CD8(+) T lymphocytes or NK cells were depleted by intraperitoneal injection of anti-M plus anti-D, anti-CD4, anti-CD8 or anti-asialo-GM1 antibodies respectively. Long-term evolution of luciferase expression in the liver was monitored by bioluminescence imaging.
The anti-CD4 monoclonal antibody impaired cellular and humoral immune responses, leading to efficient vector re-administration. Clodronate liposomes had no impact on humoral responses but caused a 100-1000 fold increase in liver transduction, stabilized transgene expression, reduced the concentration of inflammatory cytokines, and inhibited lymphocyte activation.
Transient CD4(+) T-cell depletion using antibodies is a clinically feasible procedure that allows efficient Ad redosing. Systemic administration of clodronate liposomes may further increase the safety and efficacy of vectors.
腺病毒（Ad）载体是目前体内基因转移至肝脏最有效的工具之一。然而，抗腺病毒免疫反应限制了这些载体的安全性和有效性。初始炎症反应在毒性方面令人担忧，并且它有利于细胞和体液反应的发展，导致转基因持续时间短和载体再次给药效率低下。因此，需要安全且简单的方法来干预这些过程。研究耗尽特定免疫细胞群体的方法及其对肝脏定向基因转移的影响。
将编码报告基因（荧光素酶或β-半乳糖苷酶）的第一代腺病毒载体静脉注射到Balb/c小鼠体内。通过静脉注射氯膦酸脂质体来耗尽枯否细胞和脾巨噬细胞。分别通过腹腔注射抗M加抗D、抗CD4、抗CD8或抗去唾液酸GM1抗体来耗尽B淋巴细胞、CD4(+)、CD8(+) T淋巴细胞或NK细胞。通过生物发光成像监测肝脏中荧光素酶表达的长期变化。
抗CD4单克隆抗体损害细胞和体液免疫反应，从而实现有效的载体再次给药。氯膦酸脂质体对体液反应没有影响，但使肝脏转导增加了100 - 1000倍，稳定了转基因表达，降低了炎症细胞因子的浓度，并抑制了淋巴细胞活化。
使用抗体短暂耗尽CD4(+) T细胞是一种临床可行的方法，可实现有效的腺病毒重新给药。全身给予氯膦酸脂质体可能会进一步提高载体的安全性和有效性。
