Ligation of CD3 triggers transmembrane proximity between LFA-1 and cortical microfilaments in a cytotoxic T cell clone derived from tumor infiltrating lymphocytes: A quantitative resonance energy transfer microscopy study
✍ Scribed by Haryoung Poo; Bernard A. Fox; Howard R. Petty
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 554 KB
- Volume
- 159
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
We have explored the transmembrane associations of leukocyte function associated antigen-1 (LFA-1) in response to T cell receptor ligation using resonance energy transfer (r.e.t.) microscopy to detect receptor to microfilament proximity. R.e.t. was detected using both imaging and photon counting techniques. T cells were labeled with fluorescein-conjugated F(ab'), fragments of an anti-LFA-1 monoclonal antibody. Cells were incubated at 37°C on unmodified glass surfaces and surfaces coated with anti-CD3 or anti-H-9 antibodies. Microfilaments of fixed cells were labeled with rhodamine-phalloidin. R.e.t. was not affected on unmodified (blank) or irrelevant antibody-treated (H-9) surfaces. However, both fluorescence images and photon count rates were significantly enhanced when cells bound to anti-CD3-coated surfaces. This enhancement was not due to a general effect of T cell activation on transmembrane cytoskeletal proximity since CD45phalloidin r.e.t. was not affected by CD3 ligation. These experiments provide direct physical evidence that ligation of the CD3 complex specifically increases the proximity of LFA-1 and microfilarnents, which may be relevant to T cell mediated adherence reactions.