Figure 6. Gr1+ cells and IL-4 inhibit production of Th1-induced antibody isotypes.

A, B. 4Get mice were injected with 3K-Ova with or without alum and were treated with either control rat IgG or anti-Gr1 mAb as described in Materials and Methods. Splenocytes were stained for the presence of IA^b/3K specific CD4 T cells and gates were drawn around CD44^hi IA^b/3K+ CD4 cells as in Figs 4 and 5. A. Shown are the average +/−standard errors of the percentages of IA^b/3K+ CD44^hi CD4+ spleen cells that expressed GFP (IL-4 mRNA). The results are from three identically treated mice/group. B. Shown are the average numbers +/− standard errors of GFP+ IA^b/3K+ CD44^hi CD4+ cells/spleen from mice immunized as indicated. The results are from three identically treated mice/group. C, D. B6 mice were injected with Ova with or without alum or CFA. Mice were treated with IgG (white bars), anti-Gr1 (grey bars) or anti-IL-4 (black bars) on days one, three and five after primary immunization. On day nine mice were injected with Ova alone and on day twelve their sera were tested for Ova specific antibodies by ELISA as described in Materials and Methods. The results represent the mean relative units +/− standard error of Ova specific antibody detected from three individual mice per group. Asterisks indicate groups in which the amount of antibody detected was significantly different from that in similarly immunized mice that received control IgG. A single asterisk indicates p<0.05, double asterisk p<0.01, and triple asterisk indicates p<0.001. Results are representative of two independent experiments. E, F. Balb/c mice (E) or B6 mice (F) were injected with either alum (E) or Alhydrogel (F) adsorbed Ova and were treated with IgG (white bars) or αGr1 (black bars) antibody as above. On day 10, mice were boosted with alum adsorbed Ova and sera were tested for Ova specific isotypes 5 days later. Results are representative of 3 (E) and 2 (F) individual experiments.