Dendritic cells （DCs） are the most potent antigen-presenting cells （APCs） for the initiation of antigen （Ag）-specific immune responses. In most studies, mature DCs are generated from bone marrow cells or periphe...Dendritic cells （DCs） are the most potent antigen-presenting cells （APCs） for the initiation of antigen （Ag）-specific immune responses. In most studies, mature DCs are generated from bone marrow cells or peripheral monocytes; in either case, the harvested cells are then cultured in medium containing recombinant GM-CSF, IL-4 and TNF-α for 7-10 days and stimulated with lipopolysaccharide （LPS）. However, this approach is time-consuming and expensive. There is another less cost approach of using immobilized DC cell lines, which can easily grow in the medium. A disadvantage with the immobilized DC cell lines, however, is that they are immature DCs and lack expression of MHC class Ⅱ and costimulatory CD40 and CD80 molecules. This, therefore, limits their capacity for inducing efficient antitumor immunity. In the current study, we investigated the possible efficacy of various stimuli （IL-1β, IFN-γ, TNF-α CpG and LPS） in converting the immature dendritic cell line DC2.4 to mature DCs. Our findings were quite interesting since we demonstrated for the first time that IFN-γ was able to stimulate the maturation of DC2.4 cells. The IFN-γ-activated ovalbumin （OVA）-pulsed DC2.4 cells have capacity to upregulate MHC class Ⅱ, CD40, CD80 and CCR7, and to more efficiently stimulate in vitro and in vivo OVA-specific CD8^＋ T cell responses and antitumor immunity. Therefore, IFN-γ-activated immortal DC2.4 ceils may prove to be useful in the study of DC biology and antitumor immunity.展开更多
文摘Dendritic cells （DCs） are the most potent antigen-presenting cells （APCs） for the initiation of antigen （Ag）-specific immune responses. In most studies, mature DCs are generated from bone marrow cells or peripheral monocytes; in either case, the harvested cells are then cultured in medium containing recombinant GM-CSF, IL-4 and TNF-α for 7-10 days and stimulated with lipopolysaccharide （LPS）. However, this approach is time-consuming and expensive. There is another less cost approach of using immobilized DC cell lines, which can easily grow in the medium. A disadvantage with the immobilized DC cell lines, however, is that they are immature DCs and lack expression of MHC class Ⅱ and costimulatory CD40 and CD80 molecules. This, therefore, limits their capacity for inducing efficient antitumor immunity. In the current study, we investigated the possible efficacy of various stimuli （IL-1β, IFN-γ, TNF-α CpG and LPS） in converting the immature dendritic cell line DC2.4 to mature DCs. Our findings were quite interesting since we demonstrated for the first time that IFN-γ was able to stimulate the maturation of DC2.4 cells. The IFN-γ-activated ovalbumin （OVA）-pulsed DC2.4 cells have capacity to upregulate MHC class Ⅱ, CD40, CD80 and CCR7, and to more efficiently stimulate in vitro and in vivo OVA-specific CD8^＋ T cell responses and antitumor immunity. Therefore, IFN-γ-activated immortal DC2.4 ceils may prove to be useful in the study of DC biology and antitumor immunity.
