Antioxidants & Immunity: Action of DL-lipoic acid Among Antigen-specific T Cells

Speaker: Tyler F. Creelan

Abstract: Our aim is to determine why some immune responses are ephemeral
whereas others are long-lasting, in order to define and improve
therapy for people suffering from immune diseases. Our model system is
the evaluation of antigen-specific T cell responses in mice under
conditions that mimic infection and disease. In healthy individuals
the immune system is tolerant to self antigens yet maintains the
ability to attack and remove foreign pathogens. Normally self reactive
or autoreactiveT cells are deleted or killed, yet during the
progression of autoimmune disease tolerance induction is circumvented
by these cells. Thus understanding how autoreactive T cells survive
provides insight into improving therapeutic intervention for people
suffering from autoimmune disease.

These studies may be exemplfied by a recently undertaken effort to
elucidate how immunity works using chemicals of reducing ability, that
is antioxidants. In murine T cells, the survival effects of the
bacterial cell wall component lipopolysaccharide may be signaled via
reactive oxygen species, such as hydrogen peroxide (H202). This may be
tested by administration of antioxidants, such as lipoic acid
(6,8-Dithiooctanoic acid), or NAC (N-acetyl-cystine). The action of
this antioxidant among active T cells may suggest beneficial dietary
qualities of antioxidants.