title: The liposome-incorporating cell wall skeleton of Mycobacterium bovis bacillus Calmette-Guéin can directly enhance the susceptibility of cancer cells to lymphokine-activated killer cells through up-regulation of natural-killer group 2, member D ligands.
abstract: OBJECTIVE
  • To conduct a preclinical evaluation of the ability of natural killer cells to cytolyze bladder cancer cells that were modified to show enhanced expression of natural-killer group 2, member D (NKG2D) ligands by R8-liposome-bacillus Calmette-Guéin (BCG)-cell wall skeleton (CWS) treatment.
  
  
  METHODS
  • The T24 cells and RT-112 cells were co-cultured with R8-liposome-BCG-CWS and BCG for 2, 4, or 6 h, and then the surface expression of NKG2D ligands was analyzed using TaqMan real-time quantitative RT-PCR. • Peripheral blood mononuclear cells were obtained with a conventional preparation kit, and then lymphokine-activated killer (LAK) cells were generated from these purified peripheral blood mononuclear cells via interleukin-2 stimulation. • The anti-tumour effect of LAK cells against untreated and R8-liposome-BCG-CWS co-cultured with cells of the human bladder cancer cell lines T24 and RT-112 was analyzed using the cytotoxic WST-8 assay method at 4 h of culture at various effector/target (E : T) ratios.
  
  
  RESULTS
  • Major histocompatibility complex class I-related chain B (MICB) expression was increased ≈1.5-fold on T24 cells and RT-112 cells with BCG. • UL-16-binding protein (ULBP) 1 expression was also increased ≈1.5-fold on T24 cells and RT-112 cells with BCG. R8-liposome-BCG-CWS increased the surface expression of MICB 2.2-fold on T24 cells but did not increase it significantly on RT-112 cells. • ULBP1 expression was increased ≈2.2-fold on RT-112 cells, although no differences were observed between the expression of ULBP2 and 3 with R8-liposome-BCG-CWS. • T24 cells that were co-cultured with R8-liposome-BCG-CWS showed an ≈1.3-fold increase in sensitivity to cytolysis by LAK cells at an E : T ratio of 4 and RT-112 cells showed an ≈1.4-fold increase at an E : T ratio of 2.
  
  
  CONCLUSIONS
  • In the present study, the induction of surface NKG2D ligands by R8-liposome-BCG-CWS rendered cancer cells more susceptible to cytolysis by LAK cells. • T24 cells and RT-112 cells, even when cultured singly in the absence of immune cells, can directly respond to R8-liposome-BCG-CWS. • The results obtained in the present study may therefore indicate a novel adoptive immunotherapy against bladder cancers.
authors.affiliation: Graduate School of Comprehensive Human Sciences, Department of Urology, University of Tsukuba, Ibaraki, Japan. jmiyazaki@md.tsukuba.ac.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Miyazaki
authors.forename: Koji
authors.initials: K
authors.lastname: Kawai
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kojima
authors.forename: Takehiro
authors.initials: T
authors.lastname: Oikawa
authors.forename: Akira
authors.initials: A
authors.lastname: Joraku
authors.forename: Toru
authors.initials: T
authors.lastname: Shimazui
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nakaya
authors.forename: Ikuya
authors.initials: I
authors.lastname: Yano
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Hideyoshi
authors.initials: H
authors.lastname: Harashima
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Akaza
mesh_terms: D001500:BCG Vaccine / Q000494:pharmacology*; D017358:Cell Wall Skeleton / Q000494:pharmacology*; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology*; D007694:Killer Cells, Natural / Q000378:metabolism*; D008024:Ligands; D009163:Mycobacterium bovis / Q000737:chemistry; D060888:Real-Time Polymerase Chain Reaction; D014407:Tumor Cells, Cultured / Q000276:immunology; D015854:Up-Regulation; D001749:Urinary Bladder Neoplasms / Q000276:immunology*
chemical_list: D001500:BCG Vaccine; D017358:Cell Wall Skeleton; D015395:Histocompatibility Antigens Class I; D008024:Ligands; C099187:MHC class I-related chain A; C098080:MICB antigen