Table 1.

Splenocyte proliferation, and IL-4 and IgE production in PDE4D^+/+ and PDE4D^−/− mice immunized with OVA

Parameter	PDE4D+/+ mice		PDE4D−/− mice
	Control	OVA	Control	OVA
Proliferation*	2,017 ± 479	35,427  ± 3,120	1,512 ± 354	36,577  ± 2,994
IL-4 (pg/ml)*	<31	393  ± 18	<31	430  ± 22
IgE (μg/ml)†	<0.001	414  ± 120	<0.001	401  ± 84

^*Spleens were removed from OVA-primed mice, and spleen cells were cultured at 5 × 10⁵ cells/well with or without 100 μg/ml OVA. Proliferation of OVA-specific cells was assessed by incorporation of [³H]thymidine in triplicate cultures over the last 18 h of a 4-day culture. IL-4 content in supernatants was determined after 4 days of culture by ELISA. Data are the mean of triplicate determinations. 

^† Serum IgE Ab levels were determined by ELISA. Data are the mean of triplicate determinations on ≥8 mice ± SD.