Dj. Lee et al., INHIBITION OF IGE ANTIBODY-FORMATION BY PLASMID DNA IMMUNIZATION IS MEDIATED BY BOTH CD4-CELLS( AND CD8+ T), International archives of allergy and immunology, 113(1-3), 1997, pp. 227-230
Background: We previously showed that immunization of mice with plasmi
d DNA (pDNA) encoding the Escherichia coli beta-galactosidase gene (pC
MV-LacZ) induces a Th1 response, whereas beta-galactosidase (beta-gal)
in saline or alum induces a Th2 response. Furthermore, the Th1 respon
se dominates over the Th2 response and downregulates preexisiting IgE
antibody formation. Here, we determined by passive transfer of CD4+ or
CD8+ lymphocytes and by immunizing beta(2)-microglobulin knockout (be
ta(2)-M KO) mice whether CD4+ and/or CD8+ cells from pDNA-immunized mi
ce suppress IgE antibody production. Methods: BALB/c mice were injecte
d with either CD4+ or CD8+ lymphocytes from naive beta-gal-in-alum or
pCMV-LacZ-immunized mice, then immunized with beta-gal in alum, and th
e IgE antibody formation was determined. Second, C57BL/6 wildtype (WT)
or beta(2)-M KO mice were immunized with beta-gal or pCMV-LacZ, and t
he IgE antibody production was assessed. Results: Passive transfer of
both CD4+ and CD8+ lymphocytes from pDNA-immunized mice suppressed the
IgE antibody response by 90% compared to transfer of CD4+ T cells fro
m naive or beta-gal in-alum immunized mice. beta(2)-M KO mice produced
3 times more IgE than the WT control mice both in the primary and sec
ondary response. Conclusion: Both CD4+ and CD8+ subsets of T cells fro
m pDNA-immunized mice can suppress IgE antibody production by affectin
g the primary response and/or by propagating the Th1 memory response i
n a passive cell transfer system. Immunization with pDNA-encoding alle
rgens may be an effective new form of immunotherapy for atopic disease
s.