Human lymphoblast cell lines: antibody-dependent cytotoxicity

Area of Science:

• Immunology
• Cell Biology

Background:

• Human buffy coat leukocytes can be cultured long-term to establish cell lines.
• Lymphoblast cell lines are morphologically similar to lymphocytes stimulated by antigens or mitogens.
• One established line contained Epstein-Barr virus-like particles.

Purpose of the Study:

• To investigate the functional properties of established human lymphoblast cell lines.
• To compare the antibody-dependent cell-mediated cytotoxicity (LADC) of lymphoblasts with normal peripheral blood lymphocytes (PBL).

Main Methods:

• Isolation and prolonged culture of human buffy coat leukocytes to establish cell lines.
• Morphological characterization of the established cell lines.
• Quantitative assessment of antibody-dependent cell-mediated cytotoxicity (LADC) mediated by lymphoblasts and PBL.
• Inhibition assays using human IgG subclasses (IgG1, IgG2, IgG3, IgG4) to analyze LADC mechanisms.

Main Results:

• Five lymphoblast cell lines were successfully established.
• All established lymphoblast lines demonstrated LADC quantitatively comparable to normal PBL.
• LADC mediated by both lymphoblasts and PBL was inhibited by all tested human IgG subclasses.

Conclusions:

• Established lymphoblast cell lines retain the capacity to mediate antibody-dependent cell-mediated cytotoxicity (LADC).
• The LADC function of these lymphoblasts is consistent with that of their precursor peripheral blood lymphocytes (PBL).
• These findings indicate that long-term culture and lymphoblast differentiation do not abolish LADC effector functions.