Lymphocyte activation by purified carrageenan

Area of Science:

• Immunology
• Biochemistry

Background:

• Carrageenan (CGN) is a sulfated polysaccharide with known biological activities.
• The immunomodulatory effects of CGN, particularly its ability to induce antibody production, require further elucidation.

Purpose of the Study:

• To investigate the in vitro induction of polyclonal antibody production and mitogenic response by purified carrageenan (CGN).
• To determine the cellular targets and requirements for CGN-induced immune responses.

Main Methods:

• In vitro study using spleen cells from mice, hamsters, and rats.
• Assessment of polyclonal antibody production and mitogenic activity.
• Evaluation of CGN's effects after removal of T cells, adherent cells, and phagocytic cells.

Main Results:

• Purified kappa-, lambda-, and iota-CGN induced significant polyclonal antibody production and mitogenic responses in mice, hamsters, and rats.
• Less purified CGN also stimulated polyclonal antibody production in mice.
• Purified CGN demonstrated mitogenic action on B cells and, to a lesser extent, on thymocytes.
• CGN-induced polyclonal antibody responses were unaffected by the depletion of T cells, adherent cells, or iron powder phagocytic cells.

Conclusions:

• Carrageenan (CGN) effectively induces polyclonal antibody production.
• CGN exhibits direct mitogenic activity on B cells.
• These findings suggest that CGN activates B cells, leading to polyclonal antibody responses, independent of T cell mediation.