title: Inhibition of IgE antibody formation by plasmid DNA immunization is mediated by both CD4+ and CD8+ T cells.
abstract: BACKGROUND
  We previously showed that immunization of mice with plasmid DNA (pDNA) encoding the Escherichia coli beta-galactosidase gene (pCMV-LacZ) induces a Th1 response, whereas beta-galactosidase (beta-gal) in saline or alum induces a Th2 response. Furthermore, the Th1 response 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 beta2-microglobulin knockout (beta2-M KO) mice whether CD4+ and/or CD8+ cells from pDNA-immunized mice suppress IgE antibody production.
  
  
  METHODS
  BALB/c mice were injected 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 the IgE antibody formation was determined. Second, C57BL/6 wild-type (WT) or beta2-M KO mice were immunized with beta-gal orpCMV-LacZ, and the 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 from naive or beta-galin-alum immunized mice. beta2-M KO mice produced 3 times more IgE than the WT control mice both in the primary and secondary response.
  
  
  CONCLUSIONS
  Both CD4+ and CD8+ subsets of T cells from pDNA-immunized mice can suppress IgE antibody production by affecting the primary response and/or by propagating the Th1 memory response in a passive cell transfer system. Immunization with pDNA-encoding allergens may be an effective new form of immunotherapy for atopic diseases.
authors.affiliation: University of California, San Diego, School of Medicine, La Jolla 92093-0831, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Lee
authors.forename: H
authors.initials: H
authors.lastname: Tighe
authors.forename: M
authors.initials: M
authors.lastname: Corr
authors.forename: M
authors.initials: M
authors.lastname: Roman
authors.forename: D A
authors.initials: DA
authors.lastname: Carson
authors.forename: H L
authors.initials: HL
authors.lastname: Spiegelberg
authors.forename: E
authors.initials: E
authors.lastname: Raz
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D007114:Immunization; D007073:Immunoglobulin E / Q000096:biosynthesis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019444:Vaccines, DNA / Q000276:immunology*; D001616:beta-Galactosidase / Q000235:genetics*
chemical_list: D019444:Vaccines, DNA; D007073:Immunoglobulin E; D001616:beta-Galactosidase