Fig. 5.

Mimotopes are recognized by human autoAbs and mimic MDA-LDL. (A–D) Correlation of mimotope and MDA-LDL-specific Ab titers in human plasma. Plasma of middle-aged healthy volunteers (n = 18) was obtained in a previous study (35) and Ab titers to P1, P2, and MDA-LDL were measured at 1:400 dilution by chemiluminescent ELISA as described in Materials and Methods. Correlation of IgM titers to MDA-LDL with IgM titers to P1 (A) and P2 (C). Correlation of IgG titer to MDA-LDL with IgG titers to P1 (B) and P2 (D). Values are given as relative light units (RLU) per 100 ms and represent the mean of triplicate determinations. Data points represent measurements of titers obtained from each of the 18 subjects at four different times: 0, 30, 120, and 210 days. Correlations were calculated by analyzing all data from all subjects using nonparametric Spearman's rank correlation (r = Spearman rank correlation coefficient). (E, F) Immunocompetition assays for specificity of IgG and IgM Abs to P1. Pooled human plasma was diluted 1:1,000 and incubated with or without increasing concentrations of BSA or MAA-BSA. Subsequently, samples were pelleted and binding of IgM (E) and IgG (F) Abs to coated P1 was determined in supernatants. Data are expressed as B/B₀ and represent the mean ± SD of triplicate determinations.