Evidence for Immune Activation and Resistance to Glucocorticoids Following Childhood Maltreatment in Adolescents Without Psychopathology.

Early-life stress (ELS) increases the risk for psychopathology. Immune and endocrine changes have been reported in adults and are associated with maladaptation of stress-responsive systems. Here we investigated the effects of ELS on endocrine and immune pathways in adolescents without psychopathology. Thirty adolescents with a history of childhood maltreatment and 27 adolescents without ELS history were recruited. Blood and hair samples were obtained from all participants. Lymphocytes were isolated and stimulated in vitro. Flow cytometry was used to evaluate lymphocyte subsets, Th1/Th2/Th17 cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB) signaling pathways, as well as lymphocyte sensitivity to dexamethasone. Brain-derived neurotrophic factor (BDNF) and hair cortisol were assessed with enzyme-linked immunosorbent assays (ELISAs). Adolescents with a history of ELS had increased percentages of T-cell activation markers (CD3+CD4+CD25+ and CD3+CD69+) and senescent T cells (CD8+CD28- and CD4+CD28-), as well as decreased percentages of NK (CD3-CD56+) and NK T cells (CD3+CD56+). Following stimulation, lymphocytes of ELS+ adolescents produced significantly more IL-2, IL-4, IFN-γ, and IL-17 and engaged more MAPK ERK and NF-κB signaling. ELS was associated with increased hair cortisol levels in parallel with increased lymphocyte resistance to dexamethasone and low plasma BDNF levels. These data provide the first indication of the presence of immune activation and pro-inflammatory profiles in healthy adolescents exposed to ELS, which could contribute to increased vulnerability of trauma-related psychopathology later in life. The underlying mechanisms of this impairment may include the enhanced activation of both MAPK and NF-κB signaling in parallel to partial resistance to glucocorticoids.

The impact of childhood maltreatment on redox state: Relationship with oxidative damage and antioxidant defenses in adolescents with no psychiatric disorder.

Early life stress (ELS) has been associated with biological and psychosocial alterations due to developmental reprogramming. Here, we investigated whether childhood maltreatment is associated with an imbalance between the production of oxidative markers and antioxidant defenses. Thirty adolescents with no psychiatric disorder but reporting childhood maltreatment and twenty-seven adolescents with no psychiatric disorder and no history of ELS were recruited for the study. Childhood maltreatment was investigated by the Childhood Trauma Questionnaire (CTQ). Redox state was estimated by plasma levels of protein carbonylation, total thiol content (SH), superoxide dismutase (SOD), glutathione peroxidase (GPx), as well as total reactive antioxidant potential (TRAP). Childhood maltreatment was associated with oxidative stress as shown by increased protein carbonylation. Interestingly, adolescents exposed to maltreatment also displayed higher SOD levels, TRAP kinetics and reduced GPx levels when compared with adolescents who had not undergone childhood maltreatment. No significant differences were observed for SH levels. Taken together, we provide novel evidence indicating that childhood maltreatment is associated with increased oxidative stress markers in otherwise healthy adolescents.

Toll-like receptor expression and function in type I bipolar disorder.

Bipolar disorder (BD) has been associated with immune imbalance and low-grade inflammation. The underlying mechanisms remain largely obscure but may involve changes in cell signaling. Toll-like receptors (TLRs) are widely expressed by immune cells. Specific binding of TLRs to pathogen- or danger-associated signals leads to inflammatory responses. Here, we analyzed the frequencies of TLR-1, TLR-2, TLR-4, TLR-5 and TLR-6 in monocytes, regulatory T cells (Tregs) and activated T cells from type I BD euthymic patients and healthy controls (HCs). Monocytes were stimulated in vitro with specific TLR agonists (flagellin, LPS, LTA, BLP and PGN) and immunophenotyped. Cytokines (IL-8, IL-1beta, IL-6, IL-10, TNF-alpha and IL-12p70) were assessed with cytometric bead arrays. At baseline, increased percentages of TLR-1+ and TLR-2+ monocytes and reduced expression of TLR-5 were observed in BD. Following stimulation, the percentage of TLR-1+, TLR-2+, and TLR-6+ monocytes was higher in BD subjects than in HCs. Increased levels of IL-8, IL-12p70 and TNF were observed following stimulation with TLR-1, TLR-2 and TLR-6 agonists, suggesting increased signaling via these receptors in BD. In contrast to HCs, BD patients exhibited no changes in TLR-5 expression following stimulation. The percentage of TLR-2+ Treg cells as well as activated T cells expressing both TLR-2 and TLR-5 increased in BD patients. Given the importance of TLRs in triggering immune responses, our data indicate a role for these receptors in the low-grade inflammatory profile documented in BD.

Pro-inflammatory cytokines and soluble receptors in response to acute psychosocial stress: differential reactivity in bipolar disorder.

Mounting evidence suggests a chronic pro-inflammatory state in individuals with bipolar disorder (BD). Stress exposure is known to exacerbate several inflammatory conditions as well as psychiatric disorders. Here, we analyzed plasma levels of pro-inflammatory cytokines and their soluble receptors to realistic acute psychosocial stress challenge in BD. Thirteen euthymic type 1 BD patients and 15 matched controls underwent the Trier Social Stress Test protocol (TSST). Blood samples were collected before and after TSST and plasma cytokines interleukin IL-2, IL-6, IL-33, and tumor necrosis factor alpha (TNF-α) were measured. In addition TNF-α soluble receptors TNFR1 and TNFR2, and IL-33 soluble receptor sST2 were assessed. Increased IL-33 and reduced sST2 levels were observed in BD subjects as compared to controls, independently of stress exposure. Following TSST, there were higher levels of IL-2 and reduced levels of sTNFR1 in both groups. However, the magnitude change for both cytokines was found higher in controls than BD subjects. Our data suggest that BD patients have differential stress reactivity as compared to controls, possibly related to an immunologic imbalance and failure of regulatory mechanisms.

Patients with systemic lupus erythematosus and secondary antiphospholipid syndrome have decreased numbers of circulating CD4⁺CD25⁺Foxp3⁺ Treg and CD3⁻CD19⁺ B cells.

INTRODUCTION: CD4+CD25+Foxp3+ regulatory T (Treg) cell depletion has been reported in systemic lupus erythematosus (SLE) and, recently, in primary antiphospholipid syndrome (APS); the issue has not been studied in SLE patients with secondary APS (SLE/APS) so far. OBJECTIVE: To quantify total lymphocytes, Treg cells, CD3+CD19- T cells and CD3-CD19+ B cells in SLE/APS patients and healthy controls. METHODS: Cell subtypes underwent immunophenotyping using specific monoclonal antibodies (anti-CD3 CY5, anti-CD4 FITC, anti-CD25, anti-Foxp3, anti-CD19 PE) and flow cytometry. RESULTS: Twenty-five patients with SLE/APS (mean age 43.5 years, 96% females, 96% caucasians, mean duration of disease 9.87 years, mean SLEDAI 10 ± 5.77) and 25 age and sex-matched controls entered the study. It was realized that the numbers of Treg and CD3- CD19+ B cells were significantly lower in SLE/APS patients than in controls (all p < 0.05).Treg and CD3-CD19+ B cells remained numerically low after controlling (ANCOVA) for percentage of total lymphocytes (p < 0.05). Decreasing levels of circulating Treg and CD3-CD19+ B cells correlated to higher scores of lupus activity (rs = -0.75, p < 0.0001; rs = -0.46, p = 0.021, respectively). Number of Treg cells and CD3-CD19+ B lymphocytes did not significantly differ in users or nonusers of chloroquine, azathioprine and corticosteroids (all p > 0.05). CONCLUSIONS: In this preliminary study, patients with SLE and secondary APS showed depletion of Treg and CD3-CD19+ B cells; decreasing numbers of both subtypes correlated to a higher SLEDAI. Treg cells depletion might contribute to the autoimmune lesion seen in patients with SLE/APS. The reduced number of CD3-CD19+ B cells seen in these patients deserves more studies in order to get further elucidation.

Immunosenescence is associated with human cytomegalovirus and shortened telomeres in type I bipolar disorder.

OBJECTIVE: Bipolar disorder (BD) has been associated with persistent low-grade inflammation and premature cell senescence, as shown by reduced telomere length (TL). The human cytomegalovirus (CMV) has increasingly been implicated in accelerated immunosenescence in aging studies. Here, we compared CMV serology and its relationships with cell senescence markers, including TL and lymphocyte subsets, in patients with type I BD and healthy controls. METHODS: Twenty-two euthymic female patients with BD type I and 17 age-matched healthy controls were selected for the study. A sample of blood was collected and mononuclear cells and DNA were isolated and TL measured. CMV immunoglobulin M (IgM) and IgG titers were measured using chemiluminescent assays. Lymphocyte subsets [T, natural killer (NK) and NKT] were phenotyped by flow cytometry. RESULTS: Individuals with BD had shorter TLs but higher CMV IgG levels than controls (both p < 0.01). CMV IgG level was inversely correlated with TL. None of the subjects showed IgM reactivity for CMV, excluding acute viral infection. CMV IgG level was associated with expansion of senescent CD8+CD28- T cells and NK cells, which are involved in viral control. CONCLUSIONS: These data support the hypothesis of accelerated aging in BD, as shown by shortened telomeres, higher seropositivity for CMV, and expansion of senescent T cells.

Differential neuroendocrine and immune responses to acute psychosocial stress in women with type 1 bipolar disorder.

Bipolar disorder (BD) has been associated with immune imbalance, including lymphocyte activation and increased pro-inflammatory cytokines. Immune activation is part of stress response, and psychosocial stress has been implicated in the pathogenesis of psychiatric disorders. Here, we investigated the neuroendocrine and immune responses to acute psychosocial stress challenge in BD. Thirteen euthymic participants with type 1 BD and 15 healthy controls underwent the Trier Social Stress Test protocol (TSST). Blood samples were collected before and after TSST. Lymphocytes were isolated and stimulated in vitro to assess lymphocyte activation profile, lymphocyte sensitivity to dexamethasone, mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling by flow cytometry. Heart rate and salivary cortisol levels were monitored across the task. BD participants exhibited blunted stress responses as shown by reduced heart rate and salivary cortisol levels in comparison to healthy controls. BD was also associated with reduction in the percentage of regulatory T cells, but with expansion of activated T cells. When compared to controls, patients showed increased lymphocyte MAPK p-ERK and p-NF-κB signaling after the stress challenge, but exhibited a relative lymphocyte resistance to dexamethasone. In conclusion, stress-related neuroendocrine responses are blunted, associated with increased immune activation and lower sensitivity to glucocorticoids in BD. An inability in reducing NF-κB and MAPK signaling following TSST could be underlying the immune imbalance observed in BD.

Decreased levels of circulating CD4+CD25+Foxp3+ regulatory T cells in patients with primary antiphospholipid syndrome.

INTRODUCTION: CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cell dysfunction has been documented in various autoimmune disorders, but not in antiphospholipid syndrome (APS) so far. METHODS: In this cross-sectional study, we aim to investigate CD4(+)CD25(+)Foxp3(+) Treg cells, CD3(+)CD19(-) T cells and CD3(-)CD19(+) B cells in patients with primary APS and healthy controls. Cell subtypes were immunophenotyped using specific monoclonal antibodies (anti-CD3 CY5, anti-CD4 FITC, anti-CD25, anti-Foxp3, anti-CD19 PE) and flow cytometry. RESULTS: Twenty patients with APS and 20 age- and sex-matched controls were studied. The percentage of total lymphocytes, activated Th cells (CD4+CD25+), Treg cells and CD3(-)CD19(+) B cells were found significantly lower in APS patients as compared to controls (all p < 0.05). CONCLUSION: A dysfunction in CD4(+)CD25(+)Foxp3(+) Treg cells may represent one of the mechanisms leading to autoimmunity in APS patients. The decreased number of CD3(-)CD19(+) B cells of APS patients warrants further elucidation.

Reduced regulatory T cells are associated with higher levels of Th1/TH17 cytokines and activated MAPK in type 1 bipolar disorder.

Bipolar disorder (BD) has been associated with an immunologic imbalance shown by increased peripheral inflammatory markers. The underlying mechanisms of this phenomenon may include changes in circulating cells and differential activation of mitogen-activated protein kinases (MAPKs). Twenty-seven euthymic female subjects with BD type I (all medicated) and 24 age- and sex-matched controls were recruited in this study. Lymphocytes were isolated and stimulated in vitro to assess Th1/Th17/Th2 cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ and TNF-α) and MAPK phosphorylation. The expression of phospho-MAPKs, a large panel of lymphocyte subsets and cytokines were assessed by multi-color flow cytometry. BD patients had reduced proportions of natural T regulatory cells (CD4+ CD25+ FoxP3+) (p<0.01) in parallel to higher cytokine production (all p<0.01) than healthy controls. In particular, BD was associated with a strong bias to Th1 rather than Th2 profile. There was an expansion of senescence-associated cells (CD8+ CD28-) in BD (p<0.0001). T cells of BD patients had an increased p-ERK signaling (p<0.0001), indicating lymphocyte activation. Our data suggest that multiple molecular and cellular mechanisms may contribute to the immunologic imbalance observed in BD. In addition, our data concur to an early senescence process in these patients.