Time-lapse observation of cellular function with fluorescent probe reveals novel CTL-target cell interactions

Int Immunol. 2009 Oct;21(10):1145-50. doi: 10.1093/intimm/dxp080. Epub 2009 Aug 26.

Abstract

Fluorescent protein that detects caspase-3 activation was used for the time-lapse observation of CTL-target cell interaction. In the target cells transfected with SCAT3.1 (caspase-3-sensitive fusion protein) complementary DNA, caspase-3 activation can be detected significantly earlier than the commonly used annexin-V binding that detects membrane change in apoptotic cells. Moreover, during the cytolytic interaction between OE4 CTL and W3 tumor target cells, detachment of CTL from the target cells occurred prior to caspase-3 activation and death of the target cells, indicating very early sensing of apoptotic target cells by CTL. This early detachment of OE4 CTL from W3 target cells was inhibited by the expression of CD80 co-stimulatory molecule on the target cells. Taken together, time-lapse observation of cellular interaction with functional probe, SCAT3.1 provides new kinetic information and demonstrates that co-stimulatory molecules regulate the kinetics of CTL-target cell interaction.

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / immunology*
  • B7-1 Antigen / immunology
  • B7-1 Antigen / metabolism
  • B7-2 Antigen / immunology
  • B7-2 Antigen / metabolism
  • Caspase 3 / drug effects
  • Caspase 3 / immunology*
  • Caspase 3 / metabolism
  • Cell Line
  • Cell Line, Tumor
  • Fas Ligand Protein / pharmacology
  • Fluorescent Dyes / metabolism
  • Humans
  • Macrophages / drug effects
  • Macrophages / immunology*
  • Macrophages / metabolism
  • Microscopy, Confocal / methods
  • Phagocytosis / drug effects
  • Phagocytosis / immunology
  • Recombinant Fusion Proteins / immunology*
  • Recombinant Fusion Proteins / metabolism
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Cytotoxic / metabolism
  • Transfection

Substances

  • B7-1 Antigen
  • B7-2 Antigen
  • Fas Ligand Protein
  • Fluorescent Dyes
  • Recombinant Fusion Proteins
  • Caspase 3