Allaway G P, Ryder A M, Beaudry G A, Maddon P J
Progenics Pharmaceuticals, Inc., Tarrytown, New York 10591.
AIDS Res Hum Retroviruses. 1993 Jul;9(7):581-7. doi: 10.1089/aid.1993.9.581.
CD4-based molecules were tested in combination with HIV-1-neutralizing antibodies directed against the V3 loop of gp120 or against gp41, for inhibition of HIV-1 envelope-mediated cell fusion. A virus-free cell fusion assay was developed, using Chinese hamster ovary cells that stably express HIV-1 gp120/gp41. These cells were incubated with dilutions of CD4-based molecules, antibodies, or mixtures of both, then overlaid with C8166 CD4+ T cells. Syncytia were counted and the degree of inhibition of cell fusion was determined. Synergy, additivity, or antagonism was calculated by the combination index (CI) method. The CD4-based molecules included soluble human CD4 as well as fusion proteins composed of CD4 linked to human immunoglobulin gamma 1 or gamma 2 heavy chains. Combinations of CD4-based molecules and monoclonal or polyclonal anti-V3 loop antibodies were synergistic in blocking HIV-1 envelope-mediated cell fusion (CI = 0.21-0.91 at 95% inhibition). Synergy was also observed with combinations of the CD4-based molecules and a broadly neutralizing anti-gp41 monoclonal antibody (2F5) (CI = 0.29-0.65 at 95% inhibition). These results demonstrate that molecules inhibiting HIV attachment act synergistically with molecules inhibiting HIV-1 fusion. The results suggest that CD4-based therapeutics would be more effective in patients with naturally occurring anti-V3 loop or anti-gp41 antibodies. In addition, there may be an advantage in coadministering CD4-based molecules and antibodies that block fusion, especially broadly neutralizing anti-gp41 antibodies, as a combination therapy for HIV-1 infections.
基于CD4的分子与针对gp120的V3环或gp41的HIV-1中和抗体联合进行测试，以抑制HIV-1包膜介导的细胞融合。利用稳定表达HIV-1 gp120/gp41的中国仓鼠卵巢细胞开发了一种无病毒细胞融合试验。将这些细胞与基于CD4的分子、抗体或两者的混合物的稀释液孵育，然后覆盖C8166 CD4+ T细胞。对多核巨细胞进行计数，并确定细胞融合的抑制程度。通过联合指数（CI）法计算协同、相加或拮抗作用。基于CD4的分子包括可溶性人CD4以及由与人类免疫球蛋白γ1或γ2重链连接的CD4组成的融合蛋白。基于CD4的分子与单克隆或多克隆抗V3环抗体的组合在阻断HIV-1包膜介导的细胞融合方面具有协同作用（在95%抑制率时CI = 0.21 - 0.91）。基于CD4的分子与一种广泛中和的抗gp41单克隆抗体（2F5）的组合也观察到协同作用（在95%抑制率时CI = 0.29 - 0.65）。这些结果表明，抑制HIV附着的分子与抑制HIV-1融合的分子具有协同作用。结果表明，基于CD4的疗法在具有天然抗V3环或抗gp41抗体的患者中可能更有效。此外，联合给予基于CD4的分子和阻断融合的抗体，特别是广泛中和的抗gp41抗体，作为HIV-1感染的联合疗法可能具有优势。
