TABLE 2.

Genetic backgrounds of different mouse strains affect the serum (IgG) responses to flagellin and LPS after immunization with attenuated S. enterica serovar Dublin ICB5 delivered by the oral or i.p. route

Mouse strain	Ity allelea	Haplotype	IgG antibody titer in serumb
			Oral route		i.p. route
			LPS	FLA	LPS	FLA
C57BL/6	S	H2b	10,376 ± 1,350	345 ± 20	9,108 ± 978	25,053 ± 2,455
BALB/c	S	H2d	5,155 ± 495	<2	40,930 ± 6,300	32,180 ± 2,574
B10A	S	H2a	3,638 ± 436	<2	7,315 ± 790	13,977 ± 1,257
CBA/J	R	H2k	8,605 ± 798	160 ± 14	11,585 ± 1,056	150,132 ± 16,564
DBA/2	R	H2d	4,770 ± 548	<2	6,653 ± 678	152,568 ± 13,731
A/J	R	H2a	6,936 ± 716	<2	14,655 ± 1,575	207,522 ± 20,863
C3H/HePas	R	H2k	33,147 ± 3,140	2,312 ± 221	54,064 ± 6,100	108,948 ± 12,560
Biozi/High	R	Outbred	42,675 ± 4,050	10,613 ± 1,230	24,976 ± 2,789	312,837 ± 25,890
Biozi/Low	R	Outbred	7,634 ± 852	56 ± 8	1,081 ± 124	78,591 ± 9,683

^aAllele of the Ity (Nramp) gene conferring resistance (R) or susceptibility (S) to Salmonella infection.

^bImmunizations were carried out with three doses of 10¹⁰ CFU (p.o.) or 10⁷ CFU (i.n. or i.p.) on days 0, 21, and 35. Serum samples were collected 1 week after the last immunization dose. Titers were determined in ELISA plates treated with type d flagellin (FLA) or group D Salmonella LPS. Values are means of endpoint titers ± SEM of serum pools prepared from each mouse group. Data are based on two independent experiments.