Helicobacter pylori lipopolysaccharide modification, Lewis antigen expression, and gastric colonization are cholesterol-dependent

Table 3 Enhanced cell surface Lewis antigen expression is cholesterol-specific

	fold increase compared to parallel cholesterol-free culture
	Lewis X		Lewis Y
	mean ± SEM (n)	P value	mean ± SEM (n)	P value
cholesterol	2.96 ± 0.22 (5)	.0008	2.48 ± 0.10 (4)	.0007
β- sitosterol	1.80 ± 0.47 (4)	0.19	1.19 ± 0.13 (3)	0.28
taurocholate	0.64 ± 0.16 (4)	0.12	0.84 ± 0.20 (3)	0.52

Lewis antigens were quantitated in replicate whole-cell ELISA analyses of pairwise cultures of H. pylori G27 grown in the presence or absence of 130 μM cholesterol, or an equal concentration of β-sitosterol or sodium taurocholate. The antigen load was 300 ng cellular protein per well. Ratios for plus:minus cholesterol were calculated from duplicate net absorbance readings in each assay, and ratios determined in three to five independent ELISA runs were then averaged. P values were calculated in two-tailed Student t-tests for the null hypothesis that the ratio equals 1.

ISSN: 1471-2180