Figure 1.

Interleukin-6 (IL-6) levels in non-Huntington’s disease (HD) and HD individuals. (A) Plasma was isolated from whole blood of individuals, and plasma IL-6 was measured by ELISA (n = 5). (B) Peripheral blood mononuclear cells (PBMCs) were stimulated with CpG in the presence and absence of anti-IL-6 neutralizing antibody (n = 7 non-HD individuals, n = 6 HD individuals). For a few subjects, a comparison between CpG and lipopolysaccharide (LPS) was made to optimize IL-6 stimulation conditions because it was noted that CpG-induced IL-6 levels were relatively low. * p < 0.05 as compared to the other treatment groups. (C) In follow-up studies, PBMCs from non-HD and HD individuals were stimulated with LPS or were left untreated (naïve) in the presence and absence of IL-6 neutralizing antibody or IgG isotype control; n = 6 for all treatments, except for those treatments that utilized LPS alone (n = 2). * p < 0.05 as compared to LPS + Iso of same treatment group, ** p < 0.05 as compared to Iso, *** p < 0.05 as compared to Naïve. For (B,C), IL-6 was detected in supernatants by ELISA and normalized to mg protein in the culture well. Differences between groups and treatments were assessed by Student’s t-test (A) and two-way analysis of variance (B,C).