TABLE 1.

Relative frequencies by ELISPOT analysis of total and ΔactA listeria-specific IgA ASC in gut lamina propria of GF and formerly GF BALB/c mice monoassociated with ΔactA L. monocytogenes for 21 and 28 days

Days after infection	Frequencya		% of specific cells
	Total IgA	ΔactA-specific IgA
0	1,066 ± 251
21	9,375 ± 3,346	47 ± 6	0.50
28	16,833 ± 2,608	82 ± 30	0.49

^aMean frequency ± standard deviation of number of spots formed in three replicate wells with cell suspensions from three mice per group. Fivefold dilutions were assayed, and the dilution yielding between 5 and 50 spots per well was used to estimate the number of ASC per 10⁶ mononuclear cells.