Enhancement of tumoricidal activity of microglial cell via CD40-CD40 ligand interaction

目的)CD40-CD40配体（CD40L）相互作用在巨噬细胞和树突状细胞等小胶质细胞的细胞介导免疫中起着关键作用。因此，我们研究了CD40诱导的小胶质细胞与CD40L转染的203株胶质瘤细胞株共培养是否能增强小胶质细胞的抗肿瘤活性。结果)LPS和干扰素(IFN)-g联合刺激新生小鼠小胶质细胞克隆诱导CD40。随后刺激可溶性cd40配体可增强小胶质细胞TNF-a和NO的生成。与LPS + IFN-g或LPS + IFN-g刺激相比，通过CD40结扎刺激的小胶质细胞上清液对CD40转染的203胶质瘤细胞系有杀伤作用。在CD40结扎期间单独应用，抗CD40配体，拮抗剂TNF-a或L-MNNA，或成对使用（抗TNF-a和L-MNNA）可抑制受刺激小胶质细胞上清的杀伤活性。提示TNF-a和NO的混合作用，或TNF-a、NO等因子介导了肿瘤细胞的显著凋亡。这些发现表明，小胶质细胞通过CD40参与至少两种细胞毒性因子诱导肿瘤细胞凋亡。

Purpuse) It has been reported that CD40-CD40 ligand (CD40L) interaction plays key role for cell mediated immunity on microglial cell as macropharge and dendritic cell. So we examined whether antitumor activity of microglial cell could be enhanced via CD40 induced microglial cell cocultured with CD40L transfected 203 glioma cell lines.Result) Microglial clone derived form neoborn mouse induced CD40 by combined stimulation of LPS and Interferon (IFN)-g. The following stimulation of soluble CD 40 ligand enhanced TNF-a and NO production of microglia. The supernatants from stimulated microglia via CD 40 ligation mediated killing effect against CD40 transfected 203 glioma cell line as compared to that of the stimulation by LPS, IFN-g, or LPS and IFN-g. Individually applied during CD40 ligation, anti CD40 ligand, antagonists TNF-a, or L-MNNA, or as pairs (anti TNF-a and L-MNNA) inhibited killing activity of the supernatants from stimulated microglia. This indicate that a mixture of the TNF-a and NO, or TNF-a, NO, and other factor(s) mediated significant apoptosis in tumor cell. These findings demonstrate that microglial cells induce apoptosis in tumor cells by at least two of these cytotoxic factors via CD40 engagement.