Presented at:
60th Meeting AAAAI, Denver, CO, Mar 3-7, 2003
Enhanced IL-10 Secretion by PBMC During the Ragweed Season: Effect of AIC Immunotherapy vs Placebo
P. S. Creticos,
S. S. Lighvani, A. P. Bieneman,
S. L. Balcer-Whaley,
P. S. Norman,
L. M. Lichtenstein,
J. T. Schroeder
Allergy and Clinical Immunology, Johns Hopkins University School of Medicine,
Baltimore, MD; Allergy and Clinical Immunology, Johns Hopkins University School of Medicine,
Baltimore, MD;Allergy and Clinical Immunology, Johns Hopkins University School of Medicine,
Baltmore, MD.
Since IL-10 production by allergen-stimulated PBMCs is reported to increase in subjects receiving convention immunotherapy, we monitored the ex vivo secretion of this cytokine following ragweed (RW) immunotherapy with immunostimulatory DNA conjugated with Amb a 1 (AIC).
METHODS: 19 RW allergic subjects randomized in a blinded fashion to a 6-injection treatment regimen [RW AIC (n=10) vs placebo (n=9)], which ended approximately 2 weeks prior to the RW season, had PBMCs isolated at 4 time points [pretreatment (V1)/2 weeks post-treatment (V2)/post-RW season (V3)/3 months post-RW season (V4)]. Cells were cultured ×16 hours in medium alone, and medium containing either antigen (Amb a 1) or tetanus toxoid (TT). Supernatants were assayed for IL-10 protein by ELISA.
RESULTS: The AIC group demonstrated a sequential rise in IL-10 in response to antigen stimulation [V1:8.3; V2:14.4; V3:43.7 pgx106] (p=0.009) with a decline toward baseline at V4 (8.7 pgx106). Similar increases were observed in the placebo group [V1:5.9; V2:27.9; V3:52.6 pgx106] (p=0.011) with a decline observed at 3 months post season [V4:7.8 pgx106]. No difference was observed between groups.
CONCLUSIONS: These data suggests that seasonal exposure to RW alone can induce systemic effects leading to the production of large quantities of IL-10 by circulating immune cells. Furthermore, we note that AIC did not alter the production of this cytokine.