Stress-induced Norepinephrine Downregulates CCL2 in Macrophages to Suppress Tumor Growth in a Model of Malignant Melanoma.

Psychological stressors have been implicated in the progression of various tumor types. We investigated a role for stress in tumor immune cell chemotaxis in the B16F10 mouse model of malignant melanoma. We exposed female mice to 6-hour periods of restraint stress (RST) for 7 days, then implanted B16F10 malignant melanoma tumor cells and continued the RST paradigm for 14 additional days. We determined serum corticosterone and liver catecholamine concentrations in these mice. To evaluate the tumor microenvironment, we performed IHC and examined cytokine expression profiles using ELISA-based analysis of tumor homogenates. We found that tumors in mice subjected to RST grew significantly slower, had reduced tumor C-C motif ligand 2 (CCL2), and contained fewer F4/80-positive macrophages than tumors from unstressed mice. We observed a concomitant increase in norepinephrine among the RST mice. An in vitro assay confirmed that norepinephrine downregulates CCL2 production in both mouse and human macrophages, and that pretreatment with the pan-ß-adrenergic receptor inhibitor nadolol rescues this activity. Furthermore, RST had no effect on tumor growth in transgenic CCL2-deficient mice. This study suggests that stress reduces malignant melanoma by reducing recruitment of tumor-promoting macrophages by CCL2.

Chronic Physical Stress Does Not Interact with Epstein-Barr Virus (EBV)-Encoded Dutpase to Alter the Sickness Response.

Most adult humans have been infected with Epstein-Barr virus (EBV), which is thought to contribute to the development of chronic fatigue syndrome. Stress is known to influence the immune system and can exacerbate the sickness response. Although a role for psychological stress in the sickness response, particularly in combination with EBV-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase) has been established, and the role of physical stressors in these interactions remains unspecified. In this study, we seek to determine the interaction of chronic physical (swim) stress and EBV-encoded dUTPase injection. We hypothesize that a chronic physical stressor will exacerbate the sickness response following EBV-encoded dUTPase injection. To test this hypothesis mice receive daily injections of EBV-encoded dUTPase or vehicle and are subjected to 15 min of swim stress each day for 14 days or left unmanipulated. On the final evening of injections mice undergo behavioral testing. EBV-encoded dUTPase injection alone produces some sickness behaviors. The physical swimming stress does not alter the sickness response.

Yoga and self-reported cognitive problems in breast cancer survivors: a randomized controlled trial.

OBJECTIVES: Cancer survivors often report cognitive problems. Furthermore, decreases in physical activity typically occur over the course of cancer treatment. Although physical activity benefits cognitive function in noncancer populations, evidence linking physical activity to cognitive function in cancer survivors is limited. In our recent randomized controlled trial, breast cancer survivors who received a yoga intervention had lower fatigue and inflammation following the trial compared with a wait list control group. This secondary analysis of the parent trial addressed yoga's impact on cognitive complaints. METHODS: Posttreatment stage 0-IIIA breast cancer survivors (n = 200) were randomized to a 12-week, twice-weekly Hatha yoga intervention or a wait list control group. Participants reported cognitive complaints using the Breast Cancer Prevention Trial Cognitive Problems Scale at baseline, immediately postintervention, and 3-month follow-up. RESULTS: Cognitive complaints did not differ significantly between groups immediately postintervention (p = 0.250). However, at 3-month follow-up, yoga participants' Breast Cancer Prevention Trial Cognitive Problems Scale scores were an average of 23% lower than wait list participants' scores (p = 0.003). These group differences in cognitive complaints remained after controlling for psychological distress, fatigue, and sleep quality. Consistent with the primary results, those who practiced yoga more frequently reported significantly fewer cognitive problems at 3-month follow-up than those who practiced less frequently (p < 0.001). CONCLUSIONS: These findings suggest that yoga can effectively reduce breast cancer survivors' cognitive complaints and prompt further research on mind-body and physical activity interventions for improving cancer-related cognitive problems.

Marital discord, past depression, and metabolic responses to high-fat meals: Interpersonal pathways to obesity.

BACKGROUND: Longitudinal studies have implicated both marital distress and depression in the development of the metabolic syndrome, a risk factor for diabetes and cardiovascular disease. This study addressed the impact of hostile marital interactions and a mood disorder history on obesity-related metabolic responses to high-fat meals. METHODS: This double-blind, randomized crossover study included serial assessments of resting energy expenditure (REE), fat and carbohydrate oxidation, triglycerides, insulin, glucose, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) before and after two high-fat meals. During two separate 9.5h visits, 43 healthy married couples, ages 24-61 (mean=38.22), received either a high saturated fat meal or a high oleic sunflower oil meal, both 930kcal and 60g fat. The Structured Diagnostic Interview for DSM-IV assessed mood disorder history. Couples discussed a marital disagreement during both visits; behavioral coding of these interactions provided data on hostile marital behaviors. RESULTS: Men and women who displayed more hostile behaviors and who also had a mood disorder history had significantly lower post-meal REE, higher insulin, and higher peak triglyceride responses than other participants, with nonsignificant effects for fat and carbohydrate oxidation. Participants with a mood disorder history had a steeper rise in postprandial IL-6 and glucose than those without a past history. Higher levels of hostile behaviors were associated with higher post-meal TNF-α. The two meals did not differ on any outcome assessed. CONCLUSIONS: People spend about 18 of every 24h in a postprandial state, and dining with one's partner is a common daily event. Among subjects with a mood disorder history, the cumulative 6.75-h difference between high and low hostile behaviors translates into 128kcal, a difference that could add 7.6pounds/year. Our findings illustrate novel pathways through which chronic marital stress and a mood disorder history synergistically heighten the risk for obesity, metabolic syndrome, and cardiovascular disease.

Omega-3 fatty acids and stress-induced immune dysregulation: implications for wound healing.

Stress-related immune alterations can be consequential for health; they can enhance susceptibility to infectious agents and influence the severity of infectious disease, diminish the strength of immune responses to vaccines, reactivate latent viruses, and slow wound healing. Furthermore, stressful events and negative emotions promote systemic proinflammatory cytokine production while reducing beneficial local production of proinflammatory cytokines at the wound site that are important for wound healing. Dietary omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) also influence systemic inflammation; high proportions of omega-6 to omega-3 boost inflammation, while omega-3 has anti-inflammatory properties. Additionally, the limited evidence thus far suggests that omega-3 PUFA may enhance local inflammatory responses at wound sites. Moreover, an individual's dietary proportion of omega-3 to omega-6 may influence the magnitude of inflammatory responses to stressful events. Thus, wound healing and surgery provide exemplars of how stress and depression can interact with the diet to influence important clinical outcomes.

Human herpesviruses-encoded dUTPases: a family of proteins that modulate dendritic cell function and innate immunity.

We have previously shown that Epstein-Barr virus (EBV)-encoded dUTPase can modulate innate immune responses through the activation of TLR2 and NF-κB signaling. However, whether this novel immune function of the dUTPase is specific for EBV or a common property of the Herpesviridae family is not known. In this study, we demonstrate that the purified viral dUTPases encoded by herpes simplex virus type 2 (HSV-2), human herpesvirus-6A (HHV-6A), human herpesvirus-8 (HHV-8) and varicella-zoster virus (VZV) differentially activate NF-κB through ligation of TLR2/TLR1 heterodimers. Furthermore, activation of NF-κB by the viral dUTPases was inhibited by anti-TLR2 blocking antibodies (Abs) and the over-expression of dominant-negative constructs of TLR2, lacking the TIR domain, and MyD88 in human embryonic kidney 293 cells expressing TLR2/TLR1. In addition, treatment of human dendritic cells and PBMCs with the herpesviruses-encoded dUTPases from HSV-2, HHV-6A, HHV-8, and VZV resulted in the secretion of the inflammatory cytokines IL-1ß, IL-6, IL-8, IL-12, TNF-α, IL-10, and IFN-γ. Interestingly, blocking experiments revealed that the anti-TLR2 Ab significantly reduced the secretion of cytokines by the various herpesviruses-encoded dUTPases (p < 0.05). To our knowledge, this is the first report demonstrating that a non-structural protein encoded by herpesviruses HHV-6A, HHV-8, VZV and to a lesser extent HSV-2 is a pathogen-associated molecular pattern. Our results reveal a novel function of the virus-encoded dUTPases, which may be important to the pathophysiology of diseases caused by these viruses. More importantly, this study demonstrates that the immunomodulatory functions of dUTPases are a common property of the Herpesviridae family and thus, the dUTPase could be a potential target for the development of novel therapeutic agents against infections caused by these herpesviruses.

Interpersonal stressors predict ghrelin and leptin levels in women.

OBJECTIVE: Stressful events enhance risk for weight gain and adiposity. Ghrelin and leptin, two hormones that are implicated in appetite regulation, may link stressful events to weight gain; a number of rodent studies suggest that stressors increase ghrelin production. The present study investigated the links among daily stressors, ghrelin and leptin, and dietary intake in humans. METHOD: Women (n=50) completed three study appointments that were scheduled at least 2 weeks apart. At each visit, women arrived fasting and ate a standardized breakfast and lunch. Blood samples were collected 45min after each meal. Women completed a self-report version of the Daily Inventory of Stressful Events (DISE) at each appointment. Two composites were created from the DISE data, reflecting the number of stressors that did and did not involve interpersonal tension. RESULTS: Women who experienced more stressors involving interpersonal tension had higher ghrelin and lower leptin levels than those who experienced fewer interpersonal stressors. Furthermore, women who experienced more interpersonal stressors had a diet that was higher in calories, fat, carbohydrates, protein, sugar, sodium, and fiber, and marginally higher in cholesterol, vegetables (but not fruits), vitamin A, and vitamin C. Stressors that did not involve interpersonal tension were unrelated to ghrelin and leptin levels or any of the dietary components examined. CONCLUSIONS: These data suggest that ghrelin and leptin may link daily interpersonal stressors to weight gain and obesity.

Epstein-Barr virus (EBV)-encoded dUTPase and chronic restraint induce impaired learning and memory and sickness responses.

Most adult humans have been infected with Epstein-Barr virus (EBV) and carry the latent virus. The EBV genome codes for several proteins that form an early antigen complex important for viral replication; one of these proteins is deoxyuridine triphosphate nucleotidohydrolase (dUTPase). The EBV-encoded dUTPase can induce sickness responses in mice. Because stress can increase latent virus reactivation, we hypothesized that chronic restraint would exacerbate sickness behaviors elicited by EBV-encoded dUTPase. Male Swiss-Webster mice were injected daily for 15 days with either saline or EBV-encoded dUTPase. Additionally, half of the mice from each condition were either restrained for 3h daily or left undisturbed. Restraint stress impaired learning and memory in the passive avoidance chamber; impaired learning and memory was due to EBV-encoded dUTPase injected into restrained mice. EBV-encoded dUTPase induced sickness responses and restraint stress interacts with EBV-encoded dUTPase to exacerbate the sickness response. These data support a role for EBV-encoded dUTPase and restraint stress in altering the pathophysiology of EBV independent of viral replication.

Attachment anxiety is related to Epstein-Barr virus latency.

Attachment theory provides a framework for understanding individual differences in chronic interpersonal stress. Attachment anxiety, a type of relationship insecurity characterized by worry about rejection and abandonment, is a chronic interpersonal stressor. Stress impacts cellular immunity, including herpesvirus reactivation. We investigated whether attachment anxiety was related to the expression of a latent herpesvirus, Epstein-Barr virus (EBV), when individuals were being tested for breast or colon cancer and approximately 1 year later. Participants (N=183) completed a standard attachment questionnaire and provided blood to assess EBV viral capsid antigen (VCA) IgG antibody titers. Individuals with more attachment anxiety had higher EBV VCA IgG antibody titers than those with less attachment anxiety. The strength of the association between attachment anxiety and antibody titers was the same at both assessments. This study is the first to show an association between latent herpesvirus reactivation and attachment anxiety. Because elevated herpesvirus antibody titers reflect poorer cellular immune system control over the latent virus, these data suggest that high attachment anxiety is associated with cellular immune dysregulation.

An ELISA method to compute endpoint titers to Epstein-Barr virus and cytomegalovirus: application to population-based studies.

Indirect fluorescence analysis (IFA), the gold standard for determining herpesvirus antibody titers, is labor-intensive and poorly suited for large population-based studies. The enzyme-linked immunosorbent assay (ELISA) is used widely for measuring antiviral antibodies but also suffers drawbacks such as reduced specificity and the qualitative nature of the results due to limited interpretation of the optical density (OD) units. This paper describes a method to titer herpesvirus antibodies using microplates coated with virally-infected cells in which a standard curve, derived from IFA-scored samples, allowed OD units to be converted into titers. A LOOKUP function was created in order to report the data as traditional IFA-based (i.e., 2-fold) titers. The modified ELISA correlated significantly with IFA and was subsequently used to compute endpoint antibody titers to Epstein-Barr virus (EBV)-virus capsid antigen (VCA) and cytomegalovirus (CMV) in blood samples taken from 398 pregnant Hispanic women. Four women were EBV negative (1%), while 58 women were CMV negative (14.6%). EBV VCA antibody titers were significantly higher than CMV antibody titers (p<0.001). This method allows titering of herpesvirus antibodies by ELISA suitable for large population-based studies. In addition, the LOOKUP table enables conversion from OD-derived titers into 2-fold titers for comparison of results with other studies.

Stress and anxiety effects on positive skin test responses in young adults with allergic rhinitis.

BACKGROUND: Anxiety and psychological stress affect allergy-related immune function. How these relations influence the evaluations of patients with allergic rhinitis is unknown. OBJECTIVE: To examine whether anxiety and stress exposure affect skin prick test (SPT) responses to common allergens for which patients with atopy showed no prior positive SPT response. METHODS: Patients with allergic rhinitis, evidenced by clinical history and SPT results, were admitted twice to a hospital research unit for 4 hours. In a crossover design, SPT wheals were assessed before and after the Trier Social Stress Test and then the following morning; for comparison, SPT wheals were assessed before and after a laboratory session without a stressor. Analyses focused on wheal responses for common allergens that tested negative (wheal size <3 mm larger than saline) from SPTs performed at multiple baseline assessments. RESULTS: After the Trier Social Stress Test, more anxious patients with atopy had a higher incidence of positive SPT reactions to antigens that previously tested negative. Anxiety was unrelated to positive SPT incidence under nonstressful conditions. Based on clinical symptom reports, newly positive SPT reactions after the stressor were apparently corrections of previously false-negative SPT reactions. The SPT wheal responses for allergens previously testing negative were enhanced after a stressor. Histamine (positive control) or saline (negative control) SPT responses were not affected. CONCLUSION: A laboratory stressor affected allergen SPT responses in more anxious patients with allergic rhinitis. In addition to clinical history, assessment of anxiety and current stress at the time of the SPT may provide valuable information about a patient's allergic status and aid in clinical decision making.

Social support predicts inflammation, pain, and depressive symptoms: longitudinal relationships among breast cancer survivors.

OBJECTIVE: Pain and depressive symptoms are commonly experienced by cancer survivors. Lower social support is linked to a variety of negative mental and physical health outcomes among survivors. Immune dysregulation may be one mechanism linking low social support to the development of pain and depressive symptoms over time. Accordingly, the goal of the present study was to examine the relationships among survivors' social support, pain, depressive symptoms, and inflammation. METHODS: Breast cancer survivors (N=164, stages 0-IIIA) completed two study visits, one before any cancer treatment and the other 6 months after the completion of surgery, radiation, or chemotherapy, whichever came last. Women completed self-report questionnaires assessing social support, pain, and depressive symptoms, and provided a blood sample at both visits. RESULTS: Survivors with lower social support prior to treatment experienced higher levels of pain and depressive symptoms over time than their more socially supported counterparts. Furthermore, women with lower pretreatment social support had higher levels of IL-6 over time, and these elevations in IL-6 predicted marginally larger increases in depressive symptoms. CONCLUSIONS: The results of this study suggest that social support at the time of diagnosis predicts the post-treatment development of pain, depressive symptoms, and inflammation. Consequently, early interventions targeting survivors' social networks could improve quality of life during survivorship.

Yoga's impact on inflammation, mood, and fatigue in breast cancer survivors: a randomized controlled trial.

PURPOSE: To evaluate yoga's impact on inflammation, mood, and fatigue. PATIENTS AND METHODS: A randomized controlled 3-month trial was conducted with two post-treatment assessments of 200 breast cancer survivors assigned to either 12 weeks of 90-minute twice per week hatha yoga classes or a wait-list control. The main outcome measures were lipopolysaccharide-stimulated production of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interleukin-1ß (IL-1ß), and scores on the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), the vitality scale from the Medical Outcomes Study 36-item Short Form (SF-36), and the Center for Epidemiological Studies-Depression (CES-D) scale. RESULTS: Immediately post-treatment, fatigue was not lower (P > .05) but vitality was higher (P = .01) in the yoga group compared with the control group. At 3 months post-treatment, fatigue was lower in the yoga group (P = .002), vitality was higher (P = .01), and IL-6 (P = .027), TNF-α (P = .027), and IL-1ß (P = .037) were lower for yoga participants compared with the control group. Groups did not differ on depression at either time (P > .2). Planned secondary analyses showed that the frequency of yoga practice had stronger associations with fatigue at both post-treatment visits (P = .019; P < .001), as well as vitality (P = .016; P = .0045), but not depression (P > .05) than simple group assignment; more frequent practice produced larger changes. At 3 months post-treatment, increasing yoga practice also led to a decrease in IL-6 (P = .01) and IL-1ß (P = .03) production but not in TNF-α production (P > .05). CONCLUSION: Chronic inflammation may fuel declines in physical function leading to frailty and disability. If yoga dampens or limits both fatigue and inflammation, then regular practice could have substantial health benefits.

Lower subjective social status exaggerates interleukin-6 responses to a laboratory stressor.

Growing evidence suggests that lower subjective social status (SSS), which reflects where a person positions himself on a social ladder in relation to others, is independently related to poor health. People who rate themselves lower in status also experience more frequent stressors and report higher stress than those who rate themselves higher in status, and chronic stress can enhance an individual's response to subsequent stressors. To address whether SSS predicted stress-induced interleukin-6 (IL-6) changes, we assessed 138 healthy adults at rest and following the Trier Social Stress Test (TSST). Participants completed the TSST at two study visits, separated by 4 months. People who placed themselves lower on the social ladder had larger IL-6 responses from baseline to 45 min post-stressor (p=0.01) and from baseline to 2h post-stressor (p=0.03) than those who placed themselves higher on the social ladder. Based on a ratio of subjective threat and coping ratings of the stress task, participants who viewed themselves as lower in status also tended to rate the speech task as more threatening and less manageable than those who viewed themselves as higher in status (p=0.05). These data suggest that people with lower perceived status experience greater physiological and psychological burden from brief stressors compared to those with higher perceived status. Accordingly, responses to stressors may be a possible mechanistic link among SSS, stress, and health.

Epstein-Barr virus encoded dUTPase containing exosomes modulate innate and adaptive immune responses in human dendritic cells and peripheral blood mononuclear cells.

We have recently demonstrated that Epstein-Barr virus (EBV)-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase) modulates innate immunity in human primary monocyte-derived macrophages through toll-like receptor (TLR) 2 leading to NF-κB activation and the production of pro-inflammatory cytokines. Our previous depletion studies indicated that dendritic cells (DCs) may also be a target of the EBV-encoded dUTPase. However, the role of EBV-encoded dUTPase in DC activation/function and its potential contribution to the inflammatory cellular milieu characteristic of EBV-associated diseases remains poorly understood. In the present study, we demonstrate that EBV-encoded dUTPase significantly altered the expression of genes involved in oncogenesis, inflammation and viral defense mechanisms in human primary DCs by microarray analysis. Proteome array studies revealed that EBV-encoded dUTPase modulates DC immune responses by inducing the secretion of pro-inflammatory TH1/TH17 cytokines. More importantly, we demonstrate that EBV-encoded dUTPase is secreted in exosomes from chemically induced Raji cells at sufficient levels to induce NF-κB activation and cytokine secretion in primary DCs and peripheral blood mononuclear cells (PBMCs). Interestingly, the production of pro-inflammatory cytokines in DCs and PBMCs was TLR2-dependent. Together these findings suggest that the EBV-encoded dUTPase may act as an intercellular signaling molecule capable of modulating the cellular microenvironment and thus, it may be important in the pathophysiology of EBV related diseases.

Marital distress prospectively predicts poorer cellular immune function.

OBJECTIVE: Distressed marriages enhance risk for a variety of health problems. Immune dysregulation is one potential mechanism; cross-sectional studies have demonstrated that marital distress is linked to maladaptive immune alterations. The current study filled an important gap in the literature by examining the ability of marital distress to prospectively predict immune alterations over a two-year period. METHOD: Participants were 90 couples (N=180 individuals; Mage=25.67) married less than a year at the time of their first study visit. Both members of a couple completed a baseline assessment of marital quality and provided blood samples at baseline and two years later. 63 couples (N=123 individuals) completed the follow-up assessment. RESULTS: Spouses in more distressed marriages had larger declines in cellular immune function over time than spouses in less distressed marriages. Furthermore, the results were highly consistent across two different indices, proliferative responses to two mitogens, concanavalin A (Con A) and phytohemagglutinin (PHA). CONCLUSIONS: Marital distress has a variety of negative health consequences. The current study provided important evidence that marital distress has longer-term immune consequences. Accordingly, the present results provide a glimpse into the pathways through which marital distress may impact health over time.

Stress-induced inflammatory responses in women: effects of race and pregnancy.

OBJECTIVE: African Americans experience preterm birth at nearly twice the rate of whites. Chronic stress associated with minority status is implicated in this disparity. Inflammation is a key biological pathway by which stress may affect birth outcomes. This study examined the effects of race and pregnancy on stress-induced inflammatory responses. METHODS: Thirty-nine women in the second trimester of pregnancy (19 African American, 20 white) and 39 demographically similar nonpregnant women completed an acute stressor (Trier Social Stress Test). Psychosocial characteristics, health behaviors, and affective responses were assessed. Serum interleukin (IL)-6 was measured at baseline, 45 minutes, and 120 minutes poststressor. RESULTS: IL-6 responses at 120 minutes poststressor were 46% higher in African Americans versus whites (95% confidence interval = 8%-81%, t(72) = 3.51, p = .001). This effect was present in pregnancy and nonpregnancy. IL-6 responses at 120 minutes poststressor tended to be lower (15%) in pregnant versus nonpregnant women (95% confidence interval = -5%-32%, p = .14). Racial differences in inflammatory responses were not accounted for by demographics, psychological characteristics, health behaviors, or differences in salivary cortisol. Pregnant whites showed lower negative affective responses than did nonpregnant women of either race (p values ≤ .007). CONCLUSIONS: This study provides novel evidence that stress-induced inflammatory responses are more robust among African American women versus whites during pregnancy and nonpregnancy. The ultimate impact of stress on health is a function of stressor exposure and physiological responses. Individual differences in stress-induced inflammatory responses represent a clear target for continued research efforts in racial disparities in health during pregnancy and nonpregnancy.

Loneliness promotes inflammation during acute stress.

Although evidence suggests that loneliness may increase risk for health problems, the mechanisms responsible are not well understood. Immune dysregulation is one potential pathway: Elevated proinflammatory cytokines such as interleukin-6 (IL-6) increase risk for health problems. In our first study (N = 134), lonelier healthy adults exposed to acute stress exhibited greater synthesis of tumor necrosis factor-alpha (TNF-α) and IL-6 by peripheral blood mononuclear cells (PBMCs) stimulated with lipopolysaccharide (LPS) than their less lonely counterparts. Similarly, in the second study (N = 144), lonelier posttreatment breast-cancer survivors exposed to acute stress exhibited greater synthesis of IL-6 and interleukin-1 beta (IL-1ß) by LPS-stimulated PBMCs than their counterparts who felt more socially connected. However, loneliness was unrelated to TNF-α in Study 2, although the result was in the expected direction. Thus, two different populations demonstrated that lonelier participants had more stimulated cytokine production in response to stress than less lonely participants, which reflects a proinflammatory phenotype. These data provide a glimpse into the pathways through which loneliness may affect health.