Alli Rajshekhar S, Khar Ashok
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabd 500 007, India.
FEBS Lett. 2004 Feb 13;559(1-3):71-6. doi: 10.1016/S0014-5793(04)00026-2.
Dendritic cells (DCs) are known to modulate immune response by activating effector cells of both the innate and the adaptive immune system. In the present study, we demonstrate that co-culture of DCs with paraformaldehyde-fixed tumor cells augments the secretion of interleukin (IL)-12 by DCs and these activated DCs upon co-culture with naive NK cells enhance the cytolytic activity of NK cells against NK-sensitive target YAC-1. Similarly, DCs isolated from tumor-bearing animals also activated NK cells in vitro. For efficient activation of NK cells, the ratio of activated DCs to NK cells is crucial. Addition of anti-IL-12 antibody to the culture system completely abolished activation of NK cells by DCs, suggesting that IL-12 secreted by DCs is an essential factor in NK cell activation. Adoptive transfer of DCs isolated from tumor-bearing animals into normal rats also induced activation of NK cells in normal animals.
已知树突状细胞（DCs）可通过激活先天性和适应性免疫系统的效应细胞来调节免疫反应。在本研究中，我们证明，将DCs与多聚甲醛固定的肿瘤细胞共培养可增强DCs分泌白细胞介素（IL）-12，并且这些活化的DCs与未致敏的自然杀伤（NK）细胞共培养时可增强NK细胞对NK敏感靶细胞YAC-1的细胞溶解活性。同样，从荷瘤动物分离的DCs在体外也能激活NK细胞。为了有效激活NK细胞，活化的DCs与NK细胞的比例至关重要。向培养体系中添加抗IL-12抗体可完全消除DCs对NK细胞的激活作用，这表明DCs分泌的IL-12是NK细胞激活的关键因素。将从荷瘤动物分离的DCs过继转移到正常大鼠体内也可诱导正常动物体内NK细胞的激活。
