Human immunodeficiency virus type 1 Tat induces B7-H1 expression via ERK/MAPK signaling pathway

Cell Immunol. 2011;271(2):280-5. doi: 10.1016/j.cellimm.2011.07.005. Epub 2011 Jul 20.


In HIV-infected subjects, B7-H1 synthesis and expression are up-regulated, and the degree of dysregulation correlates with the severity of disease. HIV-1 Tat protein, the viral transactivating factor, represents a key target for the host immune response. However, the relationship between B7-H1 and Tat protein has not been addressed. Here, we chose human endothelial cells which provide costimulatory signals sufficiently to influence T cells. We used recombinant pcDNA3.1(+)-Tat plasmid to transfect human endothelial cells ECV304 to establish stable Tat-expressed cell strain, and found that HIV-1 Tat was able to induce B7-H1 expression in ECV304 cells by Real-time PCR and flow cytometry analysis, and inhibited lymphocyte proliferation in co-culture system. Moreover, by using pharmacological inhibitor of ERK pathway, HIV-1 Tat induces B7-H1 expression via ERK/MAPK signaling pathway was corroborated. In summary, our results indicate that HIV-1 Tat could induce B7-H1 synthesis in ECV304 cells through ERK/MAPK signaling pathway.

MeSH terms

  • B7-H1 Antigen / biosynthesis*
  • B7-H1 Antigen / genetics*
  • Base Sequence
  • Cell Line
  • Cell Proliferation
  • Coculture Techniques
  • DNA Primers / genetics
  • Endothelial Cells / immunology
  • Endothelial Cells / virology
  • HIV Infections / genetics
  • HIV Infections / immunology
  • HIV Infections / metabolism
  • HIV-1 / genetics
  • HIV-1 / immunology*
  • HIV-1 / pathogenicity
  • Humans
  • Lymphocytes / immunology
  • Lymphocytes / pathology
  • Lymphocytes / virology
  • MAP Kinase Signaling System / immunology*
  • Transfection
  • Up-Regulation
  • tat Gene Products, Human Immunodeficiency Virus / genetics
  • tat Gene Products, Human Immunodeficiency Virus / immunology*


  • B7-H1 Antigen
  • CD274 protein, human
  • DNA Primers
  • tat Gene Products, Human Immunodeficiency Virus