Altered immunoglobulin profiles in children with Tourette syndrome

BACKGROUND: Post-infectious autoimmunity and immune deficiency have been implicated in the pathogenesis of Tourette syndrome (TS). We asked here whether B cell immunity of patients with TS differs from healthy subjects. METHODS: In two independent cross-sectional samples, we compared serum levels of IgG1, IgG2, IgG3, IgG4, IgM, IgA, and IgE in 21 patients with TS from Yale University (17 males, 4 females, 8–16 years) versus 21 healthy controls (13 males, 8 females, 7–17 years); and in 53 patients with TS from Groningen University (45 males, 8 females, 6–18 years) versus 53 healthy controls (22 males, 31 females, 6–18 years), respectively. We also investigated correlations between Ig concentrations and symptom severity. In 13 additional patients (9 males, 4 females, age range 9–14), we established Ig profiles at time points before, during, and after symptom exacerbations. RESULTS: IgG3 levels were significantly lower in Yale patients compared to healthy children (medians 0.28 versus 0.49 mg/ml, p = .04), while levels of IgG2, IgG4, and IgM in patients were lower at trend-level significance (p ≤ .10). Decreased IgG3 (medians 0.45 versus 0.52 mg/ml; p = .05) and IgM (medians 0.30 versus 0.38 mg/ml; p = .04) levels were replicated in the Groningen patients. Ig levels did not correlate with symptom severity. There was a trend-level elevation of IgG1 during symptom exacerbations (p = .09). CONCLUSION: These pilot data indicate that at least some patients with TS have decreased serum IgG3, and possibly also IgM levels, though only few subjects had fully expressed Ig immunodeficiency. Whether these changes are related to TS pathogenesis needs to be investigated

Risperidone-Related Improvement of Irritability in Children with Autism Is not Associated with Changes in Serum of Epidermal Growth Factor and Interleukin-13

Risperidone has been shown to improve serious behavioral problems in children with autism. Here we asked whether risperidone-associated improvement was related to changes in concentrations of inflammatory molecules in the serum of these subjects. Seven molecules were identified as worthy of further assessment by performing a pilot analysis of 31 inflammatory markers in 21 medication-free subjects with autism versus 15 healthy controls: epidermal growth factor (EGF), interferon-gamma (IFN-gamma), interleukin (IL)-13, IL-17, monocyte chemoattractant protein-1 (MCP-1), IL-1 and IL-1-receptor antagonist. Serum concentrations of these markers were then established in a different set of subjects that participated in a double-blind, clinical trial and an expanded group of healthy subjects. In the first analysis, samples obtained from subjects with autism at baseline visits were compared to visits after 8-week treatment with placebo (n = 37) or risperidone (n = 40). The cytokine concentrations remained stable over the 8-week period for both risperidone and placebo groups. In the second analysis, we explored further the differences between medication-free subjects with autism (n = 77) and healthy controls (recruited independently; n = 19). Serum levels of EGF were elevated in subjects with autism (median = 103 pg/mL, n = 75) in comparison to healthy controls (75 pg/mL, n = 19;

PPARγ Negatively Regulates T Cell Activation to Prevent Follicular Helper T Cells and Germinal Center Formation

<div><p>Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that regulates lipid and glucose metabolism. Although studies of PPARγ ligands have demonstrated its regulatory functions in inflammation and adaptive immunity, its intrinsic role in T cells and autoimmunity has yet to be fully elucidated. Here we used CD4-PPARγ^KO mice to investigate PPARγ-deficient T cells, which were hyper-reactive to produce higher levels of cytokines and exhibited greater proliferation than wild type T cells with increased ERK and AKT phosphorylation. Diminished expression of IκBα, Sirt1, and Foxo1, which are inhibitors of NF-κB, was observed in PPARγ-deficient T cells that were prone to produce all the signature cytokines under Th1, Th2, Th17, and Th9 skewing condition. Interestingly, 1-year-old CD4-PPARγ^KO mice spontaneously developed moderate autoimmune phenotype by increased activated T cells, follicular helper T cells (T_FH cells) and germinal center B cells with glomerular inflammation and enhanced autoantibody production. Sheep red blood cell immunization more induced T_FH cells and germinal centers in CD4-PPARγ^KO mice and the T cells showed increased of Bcl-6 and IL-21 expression suggesting its regulatory role in germinal center reaction. Collectively, these results suggest that PPARγ has a regulatory role for T_FH cells and germinal center reaction to prevent autoimmunity.</p></div

PPARγ deficiency induces hyper-reactivity in T cells.

<p>CD4⁺CD25⁻ T cells from the spleens of 6- to 8-week-old female littermate control (Cre−) and CD4-PPARγ^KO (Cre+) mice were stimulated for 24 h with plate-bound anti-CD3 and soluble anti-CD28 antibodies. (A) IFN-γ, (B) IL-4, (C) IL-17, and (D) IL-2 levels in culture supernatants were measured by ELISA. (E) Proliferation of 3-day-anti-CD3/CD28 stimulated cells was measured by H³-thymidine incorporation. Values represent the mean ± SEM of counts per minute (CPM) in triplicate wells. CD4⁺25⁻ T cells were differentiated under Th1, Th2, Th17, and Th9 differentiation conditions. (F) After 5 days, the culture supernatants were collected and cytokine levels (IFN-γ, IL-13, IL-17, and IL-9) were measured by ELISA. Values represent the mean ± SEM, n = 4–6. *<i>P</i><0.05. (G) Flow cytometric analysis for lineage-specific cytokines (IFN-γ, IL-4, IL-17, and IL-9) of Th1, Th2, Th17 and Th9 were determined by intracellular staining. Representative data were shown from five independent experiments.</p

Increase of CD4⁺CD62L^low, CD4⁺CD69⁺ and CD4⁺IL-7Rα^high cells in 1-year-old CD4-PPARγ^KO mice.

<p>Lymphocytes from spleen (SPL) and mesenteric lymph nodes (MLN) were isolated from 1-year-old control (Cre−) and CD4-PPARγ^KO (Cre+) mice and then stained with anti-CD4, anti-CD62L, anti-CD69 and anti-IL-7Rα antibodies for flow cytometric analysis. (A, B) CD4⁺CD62L^low cells, (C, D) CD4⁺CD69⁺ cells, and (E, F) CD4⁺IL-7Rα^high cells were analyzed. Values represent the mean ± SEM, n = 5-6. *<i>P</i><0.05.</p

PPARγ deficiency in T cells results in spontaneous autoimmune phenotypes.

<p>(A) Percentages of CD4, CD8, CD19, and NK in the spleen of 6-month-old control (Cre−) and CD4-PPARγ^KO (Cre+) mice. Values represent the mean ± SEM, n = 10. *<i>P</i><0.05. (B, C) Comparison of the frequency of CD19⁺CD138⁺ plasma cells in female control (Cre−) and CD4-PPARγ^KO (Cre+) splenocytes. Values represent the mean ± SEM, n = 6. *<i>P</i><0.05. (D) The level of anti-nuclear antibody in the serum of 6-month-old mice was examined by immunofluorescence of pre-fixed NIH3T3 cells stained with diluted (1:100) sera followed by Alexa Fluor 488-conjugated anti-mouse Ig antibody. (E) Quantitation of anti-dsDNA antibody in serum of 1-year-old mice by ELISA, n = 8. (F) Hematoxylin and eosin staining of kidney from 1-year-old mice. (G) The severity of inflammation in 1-year-old mice, n = 16–19. *<i>P</i><0.05; ** <i>P</i><0.01; *** <i>P</i><0.001.</p

PPARγ deficiency in T cells spontaneously increases follicular helper T cell and germinal center formation.

<p>(A) Representative flow cytometric gating strategy for the identification of follicular helper T cells, which were identified as CD4⁺TCRβ⁺CD62L^lowCD44^highPSGL-1^lowCXCR5⁺PD-1⁺ cells in the spleen of 1-year-old mice. (B, C) Flow cytometric analysis of T_FH cells from 1-year-old mice. Values represent the mean ± SEM, n = 10. *<i>P</i><0.05. (D) Germinal centers of frozen 7-µm sections from spleen of 1-year-old mice were visualized by confocal microscopy. Slides were stained for PNA (green), IgD (red), and CD4 (blue) to detect germinal centers, B cells, and T cells, respectively. (E) The number of PNA⁺ germinal centers per spleen section was quantitated, n = 5. (F) The frequency of B220⁺GL7⁺CD95⁺ germinal center B cells from splenocytes and (G) amount of IgM and IgG1 from the sera of 1-year-old control (Cre−) and CD4-PPARγ^KO (Cre+) mice was analyzed. Values represent the mean ± SEM, n = 8–11. *<i>P</i><0.05.</p

PPARγ expression in T cells and generation of CD4-PPARγ^KO mice.

<p>(A) Expression of PPARγ in FACS-purified CD4⁺, CD8⁺, and CD19⁺ cells from female wild type C57BL/6J mice was analyzed by quantitative real-time PCR and normalized to β-actin. Values represent the mean ± SEM, n = 4. **<i>P</i><0.01 when CD19 and CD8 were compared. (B) MACS-purified naïve (CD4⁺CD25⁻CD62L^highCD44^low) T cells from female wild type C57BL/6J mice were stimulated with plate-bound anti-CD3 and soluble anti-CD28 antibodies for the indicated times. PPARγ expression was determined by quantitative real-time PCR. Relative PPARγ expression level was calculated as the fold-change relative to 0 h. Values represent the mean ± SEM, n = 4. *<i>P</i><0.05, **<i>P</i><0.01 when 0 h, 24 h, and 48 h were compared. (C) FACS-sorted cells from female littermate control (Cre-) and CD4-PPARγ^KO (Cre+) mice were harvested and PPARγ expression was determined by quantitative real-time PCR. Values represent the mean ± SEM, n = 3. *<i>P</i><0.05. (D) Cre-mediated PPARγ deletion in cell lysate prepared from CD4⁺ T cells was confirmed by western blot analysis.</p