S. Behboudi et al., Quillaja saponin formulations that stimulate proinflammatory cytokines elicit a potent acquired cell-mediated immunity, SC J IMMUN, 50(4), 1999, pp. 371-377
We examined the ability of various Quillaja saponins in iscom-matrix formul
ations to induce proinflammatory cytokines, such as interleukin (IL)-1 alph
a and IL-6, and to stimulate acquired immune responses to influenza virus e
nvelope proteins. The A-fraction of Quillaja saponins (QH-A) was shown to s
timulate antigen-presenting cells (APC) to produce proinflammatory cytokine
s, and elicited a high primary antigen-specific antibody response and poten
t cell-mediated responses, as measured by T-cell proliferation, production
of cytokines and cytotoxic T-lymphocyte (CTL) activity. The C-fraction of Q
uillaja saponins (QH-C) was shown to have a low capacity to stimulate proin
flammatory cytokines and elicited low primary antibody and T-cell responses
. However, the QH-C iscom-matrix mediated a potent booster effect, resultin
g in a high secondary antibody response. The ability of APC to discriminate
and to respond to QH-A formulations more efficiently than to QH-C with rel
ease of proinflammatory cytokines, which precedes a potent acquired immune
response, identifies an important mechanism through which some adjuvants ma
y exert their immunoenhancing activities.