title: Enhanced Induction of T Cell Immunity Using Dendritic Cells Pulsed with HIV Tat and HCMV-pp65 Fusion Protein In Vitro.
abstract: BACKGROUND
  Cytotoxic T lymphocytes (CTLs) appear to play an important role in the control and prevention of human cytomegalovirus (HCMV) infection. The pp65 antigen is a structural protein, which has been defined as a potential target for effective immunity against HCMV infection. Incorporation of an 11 amino acid region of the HIV TAT protein transduction domain (Tat) into protein facilitates rapid, efficient entry into cells.
  
  
  METHODS
  To establish a strategy for the generation of HCMV-specific CTLs in vitro, recombinant truncated N- and C-terminal pp65 protein (pp65 N&C) and N- and C-terminal pp65 protein fused with Tat (Tat/pp65 N&C) was produced in E.coli system. Peripheral blood mononuclear cells were stimulated with dendritic cells (DCs) pulsed with pp65 N&C or Tat/pp65 N&C protein and immune responses induced was examined using IFN-γ ELISPOT assay, cytotoxicity assay and tetramer staining.
  
  
  RESULTS
  DCs pulsed with Tat/pp65N&C protein could induce higher T-cell responses in vitro compared with pp65N&C. Moreover, the DCs pulsed with Tat/pp65 N&C could stimulate both of CD8(+) and CD4(+) T-cell responses. The T cells induced by DCs pulsed with Tat/pp65 N&C showed higher cytotoxicity than that of pp65-pulsed DCs against autologous lymphoblastoid B-cell line (LCL) expressing the HCMV-pp65 antigen.
  
  
  CONCLUSIONS
  Our results suggest that DCs pulsed with Tat/pp65 N&C protein effectively induced pp65-specific CTL in vitro. Tat fusion recombinant protein may be useful for the development of adoptive T-cell immunotherapy and DC-based vaccines.
authors.affiliation: Catholic Hematopoietic Stem Cell Bank, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea.
authors.forename: Jung-Sun
authors.initials: JS
authors.lastname: Park
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Hyun-Il
authors.initials: HI
authors.lastname: Cho
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Sohn
authors.forename: Tai-Gyu
authors.initials: TG
authors.lastname: Kim