TABLE 2.

Cytokine profile of LACK-reactive T cells recruited in the draining lymph node on day 3 after L. major infection in LACK-L. monocytogenes-immunized B10.D2 or BALB/c mice^a

Cytokine secreted	Inoculum	Cytokine secretion (pg/ml)
		B10.D2 mice			BALB/c mice
		No antigen	Peptide	Protein	No antigen	Peptide	Protein
IFN-γ	LACK-L. monocytogenes	121 ± 4	1,743 ± 309*	1,895 ± 773*	109 ± 50	1,374 ± 113*	1,856 ± 290*
	None (control)	61 ± 10	303 ± 207	638 ± 84	88 ± 39	162 ± 27	433 ± 107
	NP-L. monocytogenes	61 ± 8	138 ± 59	189 ± 87	<49	<49	74 ± 16
IL-4	LACK-L. monocytogenes	<49	<49	<49	72 ± 11	121 ± 35	197 ± 39*
	None (control)	<49	<49	<49	197 ± 51	<49	68 ± 19
	NP-L. monocytogenes	<49	<49	<49	221 ± 28	<49	<49
IL-2	LACK-L. monocytogenes	121 ± 4*	103 ± 49	84 ± 35	447 ± 62*	478 ± 168	572 ± 151
	None (control)	<49	<49	<49	255 ± 24	328 ± 35	313 ± 54
	NP-L. monocytogenes	60 ± 8	<49	<49	70 ± 13	<49	52 ± 2

^aStationary-phase promastigotes (5 × 10⁵) were inoculated s.c. in the right hind footpad 15 days after a single LACK-L. monocytogenes inoculation. Nonimmunized (controls) or NP-L. monocytogenes-immunized mice were used as negative controls. Popliteal lymph node cells were reactivated ex vivo (2 × 10⁵ to 4 × 10⁵ cells per well) in the presence of the LACK_158–173 peptide (7.5 μM) or the LACK protein (2.5 μg/ml). IFN-γ, IL-2, and IL-4 secretion levels in the supernatants were quantified by ELISA as described in Materials and Methods. Results are expressed as means of results of triplicate experiments ± SEM. The asterisk indicates statistical significance (P < 0.05) versus results with nonimmunized controls.