the-use-carboxyfluorescein-diacetate-succinimidyl-ester-cfse-to

The Use of Carboxyfluorescein Diacetate Succinimidyl Ester (CFSE) to Monitor Lymphocyte Proliferation

Carboxyfluorescein succinimidyl ester (CFSE) is an effective and popular means to monitor lymphocyte division1-3.  CFSE covalently labels long-lived ...

the-use-fluorescent-target-arrays-for-assessment-t-cell-responses

The Use of Fluorescent Target Arrays for Assessment of T Cell Responses <em>In vivo</em>

The ability to monitor T cell responses in vivo is important for the development of our understanding of the immune response and the design of ...

John Curtin School of Medical Research, Australian National University

Australian National University

The use of carboxyfluorescein diacetate succinimidyl ester (CFSE) to measure lymphocyte proliferation by flow cytometry has become one of the most widely utilised assays for assessing lymphocyte responses. The properties of CFSE make it ideal for such a task, covalently labelling cells with a long-lived fluorescence of high intensity and low variance with minimal cell toxicity. No dye in the last 20 years has been capable of replicating CFSE in these respects. However, currently CFSE is limited to following a maximum of 7 cell divisions and is not compatible for use with ubiquitously available fluorescein conjugates or other fluorescent molecules with spectral properties similar to fluorescein, such as EGFP. Here we characterise two new fluorescent dyes for measuring lymphocyte proliferation, Cell Trace Violet (CTV) and Cell Proliferation Dye eFluor 670 (CPD), which have different excitation and emission spectra to CFSE and, consequently, are compatible with fluorescein conjugates. We found that while both CTV and CPD can label cells to a high fluorescence intensity, which is long-lived and has low variability and low toxicity and makes them ideal for long-term tracking of non-dividing lymphocytes in vivo, CTV offers possibly the best available alternative to CFSE in the analysis of cell divisions. We also describe how intercellular dye transfer and cell autofluorescence can affect division resolution with the three different dyes and describe labelling conditions for the three dyes that produce ultra-bright lymphocytes for in vivo tracking studies and allow up to 11 cell divisions to be detected when using CFSE and CTV as the fluorescent dyes.

New and improved methods for measuring lymphocyte proliferation in vitro and in vivo using CFSE-like fluorescent dyes.

Here we describe a multiplex, fluorescence-based, in vivo cytotoxic T-cell assay using the three vital dyes carboxyfluorescein diacetate succinimidyl ester, cell trace violet, and cell proliferation dye efluor 670. When used to label cells in combination, these dyes can discriminate >200 different target cell populations in the one animal due to each target population having a unique fluorescence signature based on fluorescence intensity and the different emission wavelengths of the dyes. This allows the simultaneous measurement of the in vivo killing of target cells pulsed with numerous peptides at different concentrations and the inclusion of many replicates. This fluorescent target array killing assay can be used to measure the fine antigen specificity and avidity of polyclonal cytotoxic T-cell responses in vivo, immunological parameters that were previously impossible to monitor.

Fluorescent target array killing assay: a multiplex cytotoxic T-cell assay to measure detailed T-cell antigen specificity and avidity in vivo.

CD4(+) T cells play a central role in regulating the immune response. Their effector function is commonly assessed by their capacity to secrete cytokines detected by ELISPOT and intracellular cytokine staining. However, one aspect of their effector function that is often overlooked is their ability to help activation of cognate B cells directly, a process that is initiated through the engagement of their T cell-receptor (TCR) with cognate peptide presented on major histocompatibility complex class II (MHC-II) molecules by B cells. Here we report a method to monitor CD4(+) T cell-mediated B cell help in vivo using a multiplex high throughput assay. This assay utilizes a fluorescent target array (FTA), which is composed of lymphocytes labeled with numerous (>200) unique fluorescence signatures that can be delineated in a single recipient animal based on combination labeling with the three vital dyes carboxyfluorescein diacetate succinimidyl ester (CFSE), CellTrace Violet (CTV) and Cell Proliferation Dye eFluor 670 (CPD). By pulsing different B cell populations in a FTA with titrated amounts of cognate MHC-II binding peptides, CD4(+) T cell help could be assessed by measuring induction of the B cell activation markers CD69 and CD44 by antibody labeling and flow cytometry. We call this the "FTA T helper assay", and have found it to be a robust and sensitive assay to measure CD4(+) T cell helper activity across a multitude of peptide-pulsed B "target" cells in real time in vivo. Furthermore, the technique can be used simultaneously with the FTA killing assay that measures cytotoxic T cell function, to provide a comprehensive tool for measuring both CD4(+) and CD8(+) T cell activity during an immune response in vivo.

Benjamin J. C. Quah

Department of Immunology

John Curtin School of Medical Research, Australian National University

The Use of Carboxyfluorescein Diacetate Succinimidyl Ester (CFSE) to Monitor Lymphocyte Proliferation

The Use of Fluorescent Target Arrays for Assessment of T Cell Responses In vivo

Benjamin J. C. Quah

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Immunology

John Curtin School of Medical Research, Australian National University

The Use of Carboxyfluorescein Diacetate Succinimidyl Ester (CFSE) to Monitor Lymphocyte Proliferation

The Use of Fluorescent Target Arrays for Assessment of T Cell Responses In vivo

Department of Immunology