title: IL-12 regulates B7-H1 expression in ovarian cancer-associated macrophages by effects on NF-κB signalling.
abstract: OBJECTIVE
  B7-H1, a co-inhibitory molecule of the B7 family, is found aberrantly expressed in ovarian cancer cells and infiltrating macrophage/dendritic-like cells, and plays a critical role in immune evasion by ovarian cancer. IL-12, an inducer of Th1 cell development, exerts immunomodulatory effects on ovarian cancer. However, whether IL-12 regulates B7-H1 expression in human ovarian cancer associated-macrophages has not been clarified. Therefore, we investigated the effects of IL-12 on the expression of B7-H1 in ovarian cancer-associated macrophages and possible mechanisms.
  
  
  METHODS
  PMA induced THP-1-derived macrophages or human monocyte-derived macrophages were treated with recombinant IL-12 (rIL-12) or infected with adenovirus carrying human IL-12 gene (Ad-IL-12-GFP) for 24 h, then cocultured with the SKOV3 ovarian cancer cell line for another 24 h. Macrophages were collected for real-time PCR and Western blot to detect the expression of B7-H1, and activation of the NF-κB signaling pathway. Moreover, supernatants were collected to assay for IL-12, IFN-γ and IL-10 by ELISA. In addition, monocyte-derived macrophages treated with IFN-γ were cocultured with SKOV3 and determined for the expression of B7-H1. Furthermore, the expression of B7-H1 in monocyte-derived macrophages was also evaluated after blocking NF-κB signaling.
  
  
  RESULTS
  The expression of B7-H1 was significantly upregulated in monocyte-derived macrophages treated with rIL-12 or Ad-IL-12-GFP compared with the control groups (p<0.05), accompanied by a remarkable upregulation of IFN-γ (p<0.05), a marked downregulation of IL-10 (p<0.05) and activation of NF-κB signaling. However, the upregulation of B7- H1 was inhibited by blocking the NF-κB signaling pathway (p<0.05). Expression of B7-H1 was also increased (p<0.05) in monocyte-derived macrophages treated with IFN-γ and cocultured with SKOV3. By contrast, the expression of B7-H1 in THP-1-derived macrophages was significantly decreased when treated in the same way as monocyte-derived macrophages (p<0.05), and IL-10 was also significantly decreased but IFN-γ was almost absent.
  
  
  CONCLUSIONS
  IL-12 upregulates the expression of B7-H1 in monocyte-derived macrophages, which is possible though inducing the secretion of IFN-γ and further activating the NF-κB signal pathway. However, IL-12 downregulates the expression of B7-H1 in THP-1-derived macrophages, associated with a lack of IFN-γ and inhibition of expression of IL-10.
authors: College of Laboratory Medicine, Key Laboratory of Laboratory Medical Diagnostics of Education Ministry, Chongqing Medical University, Chongqing, China E-mail : tuzhiguang@aliyun.com.
authors: Hai-Yu
authors: HY
authors: Xiong
authors: Ting-Ting
authors: TT
authors: Ma
authors: Bi-Tao
authors: BT
authors: Wu
authors: Yan
authors: Y
authors: Lin
authors: Zhi-Guang
authors: ZG
authors: Tu
mesh_terms: D060890:B7-H1 Antigen / Q000096:biosynthesis* / Q000276:immunology; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000276:immunology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology / Q000494:pharmacology*; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000276:immunology* / Q000473:pathology; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019139:Tumor Escape / Q000276:immunology
chemical_list: D060890:B7-H1 Antigen; C423236:CD274 protein, human; C508609:IL10 protein, human; C498143:RELA protein, human; D051996:Transcription Factor RelA; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma