title: Immune modulation of CD4+CD25+regulatory T cells by zoledronic acid.
abstract: CD4+CD25+regulatory T (Treg) cells suppress tumor immunity by inhibiting immune cells. Manipulation of Treg cells represents a new strategy for cancer treatment. Zoledronic acid (ZA), a nitrogen-containing bisphosphonate, inhibits the expression of receptor activator of nuclear factor kappa-B ligand (RANKL) on osteoblasts to inhibit osteoclastogenesis. In a mouse model of bisphosphonate-related osteonecrosis of the jaw, administration of ZA suppressed Treg-cell activity and activated inflammatory Th17 cells. However, the interaction between ZA and Treg cells remained unclear. This study investigated the immune modulation of Treg cells by ZA.
  
  
  
  Flow cytometry was used to analyze the phenotypic and immunosuppressive characteristics of Treg cells treated with ZA. Chemotactic migration was evaluated using transwell assays. Quantitative real-time PCR (qRT-PCR) was used to investigate the effect of ZA on the expression of suppressive molecules by Treg cells.
  
  
  
  Proliferation of isolated Treg cells in culture was inhibited by ZA, although ZA did not induce apoptosis. qRT-PCR and flow cytometry showed that ZA significantly downregulated the expression of CCR4, CTLA4, PD-1 and RANKL on Treg cells. Chemotactic migration and immunosuppressive functions were also significantly attenuated in Treg cells pretreated with ZA, and these effects were dose-dependent. Co-culture with Treg cells significantly increased the migration rate of breast cancer cells, while pretreatment of Treg cells with ZA attenuated this effect.
  
  
  
  Our findings demonstrated that ZA acted as an immune modulator by significantly inhibiting the expansion, migration, immunosuppressive function and pro-metastatic ability of Treg cells. Immunomodulation of Treg cells by ZA represents a new strategy for cancer therapy.
authors.affiliation: Department of Surgery, Chi Mei Medical Center, Liouying, Tainan, Taiwan.|Department of Chemical Engineering & Institute of Biotechnology and Chemical Engineering, I-Shou University, Kaohsiung, Taiwan.
authors.forename: Hsien
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering & Institute of Biotechnology and Chemical Engineering, I-Shou University, Kaohsiung, Taiwan. shwang@isu.edu.tw.
authors.forename: Shih-Han
authors.initials: SH
authors.lastname: Wang
authors.affiliation: Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: Shin-Cheh
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Department of Medical Research, E-DA Hospital/I-SHOU University, Kaohsiung, Taiwan.
authors.forename: Ching-Ying
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, E-DA Hospital/I-SHOU University, Kaohsiung, Taiwan.
authors.forename: Jo-Lin
authors.initials: JL
authors.lastname: Lo
authors.affiliation: Department of Medical Laboratory Science, I-Shou University, Kaohsiung, Taiwan. ltmei@mail.ncku.edu.tw.|Department of Medical Research, E-DA Hospital/I-SHOU University, Kaohsiung, Taiwan. ltmei@mail.ncku.edu.tw.|Department of Laboratory Medicine, E-DA Hospital/I-SHOU University, Kaohsiung, Taiwan. ltmei@mail.ncku.edu.tw.
authors.forename: Tsun-Mei
authors.initials: TM
authors.lastname: Lin
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000276:immunology*; D015704:CD4 Antigens / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology*; D002465:Cell Movement; D002478:Cells, Cultured; D018920:Coculture Techniques; D004164:Diphosphonates / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology* / Q000627:therapeutic use; D007155:Immunologic Factors / Q000494:pharmacology* / Q000627:therapeutic use; D007167:Immunotherapy / Q000379:methods* / Q000639:trends; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008213:Lymphocyte Activation; D016328:NF-kappa B / Q000378:metabolism; D010012:Osteogenesis; D053245:RANK Ligand / Q000378:metabolism; D015398:Signal Transduction; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*; D000077211:Zoledronic Acid
chemical_list: D015704:CD4 Antigens; D019496:Cancer Vaccines; D004164:Diphosphonates; D007093:Imidazoles; D007155:Immunologic Factors; D053645:Interleukin-2 Receptor alpha Subunit; D016328:NF-kappa B; D053245:RANK Ligand; D000077211:Zoledronic Acid
keywords: Breast cancer; Immunomodulation; Regulatory T cells; Zoledronic acid