51Cr release assay of antibody-dependent cell-mediated cytotoxicity (ADCC)
D L Nelson1, C C Kurman, D E Serbousek
1National Cancer Institute, Bethesda, Maryland, USA.
Insights
This study details an assay for measuring antibody-dependent cell-mediated cytotoxicity (ADCC), a key immune response. The assay quantifies effector cell immunocompetence and monoclonal antibody efficacy in target cell lysis.
Area of Science:
- Immunology
- Cellular Biology
- Assay Development
Background:
- Antibody-dependent cell-mediated cytotoxicity (ADCC) is a critical immune mechanism involving both humoral and cellular components.
- ADCC facilitates target cell lysis through the interaction of Fc receptors on effector cells with antibody-coated target cells.
Purpose of the Study:
- To describe a reliable assay for quantifying ADCC activity.
- To provide a method for assessing effector cell immunocompetence.
- To evaluate the ADCC-mediating potential of monoclonal antibodies.
Main Methods:
- The assay utilizes chromium-51 (51Cr)-labeled target cells, specific anti-target cell antibodies, and effector cells (e.g., peripheral blood mononuclear cells).
- Components are incubated in microtiter plates, and target cell lysis is measured by detecting 51Cr release into the supernatant.
- Supporting protocols cover the preparation of anti-target cell antiserum and 51Cr-labeled target cells.
Main Results:
- The described method effectively measures ADCC activity in lymphoid cell populations.
- The assay allows for the quantitative assessment of immune effector cell function.
- It provides a means to determine the efficacy of antibodies in mediating ADCC.
Conclusions:
- The developed ADCC assay is a valuable tool for evaluating immune function and antibody activity.
- This method aids in the study of cellular cytotoxicity and immune responses.
- The assay can be applied to assess immunocompetence and antibody performance in research and diagnostics.
Abstract:
Antibody-dependent cell-mediated cytotoxicity (ADCC) is an immunologic cytotoxic effector mechanism that is dependent on the cooperative interaction of humoral and cellular effector elements. This unit describes an assay of ADCC activity that can be used as a test for immunocompetence in effector cells or to test the activity of a monoclonal antibody to mediate ADCC. In this form of cytotoxicity, effector cells with receptors for the Fc portion of immunoglobulin produce target cell lysis by attachment to the Fc portion of antibodies that are bound to target cells via their antigen-combining sites. Therefore, an ADCC assay involves three essential components: labeled target cells, antibodies with specificity for target-cell surface antigens, and effector-cell populations. The basic protocol describes a method of measuring ADCC effector activity in lymphoid cells (peripheral blood mononuclear cells, or PBMC) that employs (51)Cr-labeled target cells. The three components are mixed in microtiter-plate wells and lysis of the target cells is detected by measuring the release of radioactivity into the cell supernatant. Support protocols describe procedures for preparing anti-target cell antiserum and (51)Cr-labeled target cells.
