title: Class II transactivator expression in melanoma cells facilitates T-cell engulfment.
abstract: OBJECTIVE
  Melanoma cells express high levels of HLA class II, cell surface antigen-presenting proteins, which is an anomalous phenotype among solid tumors. There has never been a satisfying explanation for how this HLA class II-positive phenotype is related to tumor development. Lugini and colleagues demonstrated that melanoma cells have the capacity to engulf T-cells. We considered the possibility that this capacity could be dependent on HLA class II expression.
  
  
  METHODS
  We co-cultured melanoma and CD4-positive, labeled, Jurkat-C T-cells. The melanoma cells were transformed with an expression vector for CIITA, the obligate HLA class II gene transactivator. We then assayed for the transfer of label to the melanoma cells.
  
  
  RESULTS
  CIITA expression facilitated engulfment of the T-cell material but not material from B-cells.
  
  
  CONCLUSIONS
  The results suggest a possible mechanism for HLA class II-positive melanoma cells in blunting an anti-tumor response and suggest a possible target for melanoma therapy.
authors.affiliation: Analytic Microscopy Core, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, U.S.A. Biological Sciences Department, Ecology and Evolution division, University of Illinois at Chicago, Chicago, IL, U.S.A.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Lloyd
authors.affiliation: Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, U.S.A.
authors.forename: Karoly
authors.initials: K
authors.lastname: Szekeres
authors.affiliation: Biological Sciences Department, Ecology and Evolution division, University of Illinois at Chicago, Chicago, IL, U.S.A.
authors.forename: Joel S
authors.initials: JS
authors.lastname: Brown
authors.affiliation: Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, U.S.A. Immunology Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, U.S.A. gblanck@health.usf.edu.
authors.forename: George
authors.initials: G
authors.lastname: Blanck
mesh_terms: D018920:Coculture Techniques; D006801:Humans; D019169:Jurkat Cells; D008545:Melanoma / Q000276:immunology* / Q000473:pathology; D009687:Nuclear Proteins / Q000378:metabolism*; D010587:Phagocytosis; D015534:Trans-Activators / Q000378:metabolism*
chemical_list: C083728:MHC class II transactivator protein; D009687:Nuclear Proteins; D015534:Trans-Activators
keywords: CIITA; HLA class II; Jurkat-C; T-cell; immune response; melanoma