Table 2.

LTα^{− /}− Mice Cannot Mount a CH Response to Secondary Hapten Challenge but Retain a Sensitivity Response to Hapten Presented Subcutaneously

CH responses				Subcutaneous and CH responses to TMA
Strain	Sensitization	Elicitation	Swelling (%)	Strain	n	Priming dose and route	Swelling (mm)
LT+/+	FITC	Vehicle	9 ± 3	LTα+/−	5	10 mm, 50 μl s.c.	0.90 ± 0.23
LT+/+	FITC	FITC	61 ± 8	LTα+/−	6	10 mm, 50 μl s.c.	0.70 ± 0.12
LTα−/−	FITC	FITC	16 ± 8	Control	3	0	0.18 ± 0.02
LT+/+	Vehicle	0.3% oxazalone	5 ± 8.5	LTα−/−	5	10 mm, 50 μl e.c.	0.68 ± 0.16
LT+/+	0.3% oxazalone	0.3% oxazalone	31.6 ± 13.6	LTα−/−	6	10 mm, 50 μl e.c.	0.28 ± 0.11
LTα−/−	0.3% oxazalone	0.3% oxazalone	5.1 ± 4.3	Control	3	0	0.10 ± 0.03
LT+/+	2% oxazalone	0.3% oxazalone	40 ± 22
LTα−/−	2% oxazalone	0.3% oxazalone	4.7 ± 6.1
LT+/+	None	0.8% croton oil	23.5 ± 2.8
LTα−/−	None	0.8% croton oil	31.5 ± 9.7

For skin sensitization, mice were painted with 100 μl hapten. 10 d later, CH was elicited by painting the ears with 10 μl hapten. Ear thickness was measured and the average percent increase in thickness (n = 6, FITC; n = 8, oxazalone; n = 4, croton oil) was determined for each set of mice. FITC and oxazalone data are representative of four independent experiments. Croton oil responses were not statistically different from each other. For experiments using TMA, mice were sensitized on the shaved abdomen with 50 μl either by subcutaneous (s.c.) injection or skin painting (e.c.). Elicitation of the footpad was with 20 μl TMA presented either subcutaneously or by painting. Footpad swelling is thickness at site of challenge − thickness of contralateral control. The TMA experiments were performed three times with similar results.