Table 1. Antigen-specific cellular responses following mucosal vaccination.

IFN-γ Production		DAY 14						DAY 28
Post
Immunization		PBS		U112		U112ΔiglB		PBS		U112		U112ΔiglB
(pg/mL)		Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
I.T.	Spleen	<30	N/A	16258	1355	2234	329	<30	N/A	1051	28	54	10
	CLN	<30	N/A	1103	99	<30	N/A	<30	N/A	<30	N/A	<30	N/A
	MLN	540	526	3716	207	101	52	<30	N/A	<30	N/A	<30	N/A
Oral	Spleen	<30	N/A	29840	1158	151	83	<30	N/A	146	28	<30	N/A
	CLN	<30	N/A	2967	7	<30	N/A	<30	N/A	<30	N/A	<30	N/A
	MLN	<30	N/A	2766	31	32	N/A	<30	N/A	<30	N/A	<30	N/A

Rats were vaccinated either i.t. (top panel) or orally (bottom panel) with either 10⁵ CFU U112, 10⁷ CFU U112ΔiglB, or mock-vaccinated with PBS, and rested for 14 or 28 days. Rats were euthanized and spleens (10⁶ cells/well) and draining lymph nodes (CLN and MLN) collected (day 14: 5×10⁵ cells/well and day 28: 1×10⁵ cells/well). Single cells were cultured for 72 hr in the presence of approximately 1 µg of protein from either UV-inactivated U112 (for U112 and mock vaccinated groups), or UV-inactivated U112ΔiglB (for U112ΔiglB vaccinated group). Cells were then separated by centrifugation and supernatants were collected and assayed for IFN-γ production by ELISA (shown here in pg/mL, limit of detection is 30 pg/mL). Results are representative of two independent experiments at each time point. CLN = cervical lymph nodes, MLN = mesenteric lymph nodes, SD = standard deviation, NA = not applicable.