FIG. 3.

COPD patients who developed more broadly cross-reactive and internally directed antibody responses to different LOS epitopes. Shown are data from an evaluation of levels of IgG against various truncated LOS molecules in sera from COPD patients. The OS used as antigens are listed along the x axis. Patient 7 (A) was infected with 7P33B1 (serotype A), patient 7 (B) was infected with 7P94B1 (serotype C), patient 18 (C) was infected with 18P7B1 (serotype B), and patient 51 (D) was infected with 51P9B1 (serotype A). ELISAs were used to test the level of IgG antibody in sera of COPD patients in response to truncated LOS obtained from a panel of glycosyltransferase mutants and full-length wild-type structures representing serotype A (25238), serotype B (7169), and serotype C (26391). Serum samples obtained preacquisition and postclearance of the infecting M. catarrhalis strain were incubated in a 96-well plate coated with 20 to 30 μg of LOS per well. The bars represent the mean differences in absorbance for at least three independent ELISAs of serum samples taken postclearance of the exacerbating strain to preacquisition of that strain, with the error bars representing the standard errors of the means. Asterisks indicate a P value of ≤0.05 as determined by a one-sided paired t test.