Rabbit anti-human beta 2 microglobulin antibodies: a T-cell mitogen

Area of Science:

• Immunology
• Cell Biology

Background:

• Rabbit anti-beta 2 microglobulin antibodies were previously considered potent mitogens for human B lymphocytes.
• Fractionation after activation revealed that only the T-cell enriched population exhibited active division.

Purpose of the Study:

• To investigate the selective activation of T cells by anti-beta 2 microglobulin antibodies.
• To identify the factors required for anti-beta 2-induced T cell proliferation.

Main Methods:

• Fractionation of activated lymphocytes to isolate T-cell populations.
• Co-culture experiments using purified T cells and non-T cells (including Daudi cells).
• Addition of interleukin 2, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), or teleocidin B to assess their effect on T cell division.

Main Results:

• Purified T cells required non-T cells for proliferation induced by anti-beta 2 antibodies.
• Daudi cells produced 'macrophage replacing factors' that supported anti-beta 2-induced T cell division.
• Interleukin 2, TPA, or teleocidin B could replace the need for non-T cells, indicating selective T cell activation.

Conclusions:

• Anti-beta 2 microglobulin antibodies selectively activate T cells.
• The proliferation of T cells induced by anti-beta 2 antibodies is dependent on specific helper factors.
• Unlike other T cell mitogens, anti-beta 2 antibodies did not induce secondary immunoglobulin production in B cells.