Glucocorticoids and the immune system in AIDS

HIV-1 Tat and morphine decrease murine inter-male social interactions and associated oxytocin levels in the prefrontal cortex, amygdala, and hypothalamic paraventricular nucleus

Many persons infected with HIV-1 (PWH) and opioid-dependent individuals experience deficits in sociability that interfere with daily living. Sociability is regulated by the prefrontal cortico-hippocampal-amygdalar circuit. Within this circuit HIV-1 trans-activator of transcription (HIV-1 Tat) and opioids can increase dendritic pathology and alter neuronal firing. Changes in sociability are also associated with dysregulation of hypothalamic neuropeptides such as oxytocin or corticotropin releasing factor (CRF) in the prefrontal cortico-hippocampal-amygdalar circuit. Accordingly, we hypothesized that the interaction of HIV-1 Tat and morphine would impair inter-male social interactions and disrupt oxytocin and CRF within the PFC and associated circuitry. Male mice were exposed to HIV-1 Tat for 8 weeks and administered saline or escalating doses of morphine twice daily (s.c.) during the last 2 weeks of HIV-1 Tat exposure. Tat attenuated aggressive interactions with an unknown intruder, whereas morphine decreased both non-aggressive and aggressive social interactions in the resident-intruder test. However, there was no effect of Tat or morphine on non-reciprocal interactions in the social interaction and novelty tests. Tat, but not morphine, decreased oxytocin levels in the PFC and amygdala, whereas both Tat and morphine decreased the percentage of oxytocin-immunoreactive neurons in the hypothalamic paraventricular nucleus (PVN). In Tat(+) or morphine-exposed mice, regional levels of CRF and oxytocin correlated with alterations in behavior in the social interaction and novelty tests. Overall, decreased expression of oxytocin in the prefrontal cortico-hippocampal-amygdalar circuit is associated with morphine- and HIV-Tat-induced deficits in social behavior.

Clinical and histopathologic predictors of therapeutic response to bronchial thermoplasty in severe refractory asthma

BACKGROUND

Phenotypes and endotypes predicting optimal response to bronchial thermoplasty (BT) in patients with severe asthma remain elusive.

OBJECTIVE

Our aim was to compare the clinical characteristics and hallmarks of airway inflammation and remodeling before and after BT in responder and partial responder patients with severe asthma refractory to oral steroids and to omalizumab.

METHODS

In all, 23 patients with severe refractory asthma were divided into BT responders (n = 15) and BT partial responders (n = 8), according to the decrease in asthma exacerbations at 12 months after BT. Clinical parameters were compared at baseline and 12 months after BT, and hallmarks of airway inflammation and remodeling were analyzed by immunohistochemistry in bronchial biopsy specimens before and 3 months after BT.

RESULTS

At baseline, the BT responders were around 8 years younger than the BT partial responders (P = .02) and they had a greater incidence of atopy, higher numbers of blood eosinophils (both P = .03) and IgE levels, higher epithelial IFN-α expression, and higher numbers of mucosal eosinophils and IL-33-positive cells (P ≤ .05). A reduction in blood eosinophil count, serum IgE level, type 2 airway inflammation, and numbers of mucosal IL-33-positive cells and mast cells associated with augmented epithelial MUC5AC and IFN-α/β immunostaining was noted after BT in responders, whereas the numbers of mucosal IL-33-positive cells were augmented in BT partial responders. Most of these changes were correlated with clinical parameters. Subepithelial membrane thickening and airway smooth muscle area were similar in the 2 patient groups at baseline and after BT.

CONCLUSION

By reducing allergic type 2 inflammation and increasing epithelial MUC5AC and anti-viral IFN-α/β expression, BT may enhance host immune responses and thus attenuate exacerbations and symptoms in BT responders. Instead, targeting IL-33 may provide a clinical benefit in BT partial responders.

Inhibition of HIV-1 envelope-dependent membrane fusion by serum antilymphocyte autoantibodies is associated with low plasma viral load

The HIV-1 envelope protein (Env) mediates the membrane fusion process allowing virus entry to target cells and the efficiency to induce membrane fusion is an important determinant of HIV-1 pathogenicity. In addition to virus receptors, other adhesion/signaling molecules on infected and target cells and virus particles can enhance fusion. The presence of antilymphocyte autoantibodies (ALA) in HIV patients' serum suggests that they may contribute to the inhibition of Env-mediated membrane fusion. Here, sera from 38 HIV-1 infected treatment-naïve men and 30 healthy donors were analyzed for the presence of IgG and IgM able to bind to CD4-negative Jurkat cells. The use of CD4-negative cells precluded the binding of virus-antibody immune complexes, and allowed detection of ALA different from anti-CD4 antibodies. IgG and IgM antibodies binding to Jurkat CD4-negative cells was detected in 74% and 84% of HIV-positive sera, respectively. Then, the activity of sera on fusion of CD4⁺ with HIV Env⁺ Jurkat cells was determined before and after their adsorption on CD4-negative Jurkat cells to remove ALA. Sera inhibited fusion at variable extents, and inhibitory activity decreased in 58% of serum samples after adsorption, indicating that ALA contributed to fusion inhibition in these sera (herein called fusion inhibitory ALA). The contribution of ALA to fusion inhibition in individual sera was highly variable, with an average of 33%. IgG purified from a pool of HIV⁺ sera inhibited fusion of primary CD4 T lymphocytes with Jurkat Env⁺, and adsorption of IgG on CD4-negative Jurkat cells diminished the fusion inhibitory activity. Thus, the inhibitory activity of sera was related to IgG ALA. Our observations suggest that fusion inhibitory ALA other than anti-CD4 antibodies may contribute significantly to the inhibition of Env-mediated cell-cell fusion. Fusion inhibitory ALA, but not total ALA levels, associated with low plasma viral loads, suggesting that specific ALA may participate in virus containment by inhibiting virus-cell fusion in a significant fraction of HIV-infected patients.

Probable boceprevir-induced hyponatremia in a patient with chronic hepatitis C

PURPOSE

A probable case of severe drug-induced hyponatremia associated with boceprevir use is reported.

SUMMARY

A 55-year-old woman was started on boceprevir (800 mg orally thrice daily) during week 5 of triple therapy for chronic hepatitis C. Her serum sodium concentration the morning before starting boceprevir use was 140 mmol/L. After the fourth dose of boceprevir, the patient developed progressive dizziness leading to eventual loss of consciousness. She was taken to the emergency department (ED), where her serum sodium concentration was measured as 126 mmol/L; boceprevir use was temporarily discontinued. The patient's symptoms improved with infusion of 0.9% sodium chloride injection, and she was discharged home the same day. After resuming boceprevir use that evening, the woman developed extreme dizziness and headache upon awakening the next morning. On her return to the ED later that day, she had a serum sodium value of 134 mmol/L and was admitted to the hospital for monitoring and evaluation. Over the next three days, her symptoms improved with additional infusion therapy and discontinuation of boceprevir. The patient continued to receive dual therapy (peginterferon alfa-2a and ribavirin) without further documented serum sodium instability. Using the adverse drug reaction probability scale of Naranjo et al., the case was assigned a score of 5, indicating a probable reaction to boceprevir.

CONCLUSION

Soon after initiating boceprevir use as part of hepatitis C triple therapy, a woman required hospitalization for probable drug-induced hyponatremia, which resolved with discontinuation of the medication.

Stress buffering effects of oxytocin on HIV status in low-income ethnic minority women

BACKGROUND

Elevated perceptions of psychosocial stress and stressful life events are linked to faster disease progression in individuals living with HIV and these associations may be stronger for women from ethnic minority populations. Levels of neurohormones such as oxytocin (OT), cortisol, and norepinephrine (NE) have been shown to influence the effects of psychosocial stress in different populations. Understanding how intrinsic neuroendocrine substances moderate the effects of stressors in minority women living with HIV (WLWH) may pave the way for interventions to improve disease management.

METHODS

We examined circulating levels of plasma OT as a moderator of the effects of stress on disease status (viral load, CD4+ cell count) in 71 low-income ethnic minority WLWH.

RESULTS

At low levels of OT, there was an inverse association between stress and CD4+ cell counts. Counter-intuitively, at high levels of OT there was a positive association between stress and CD4+ cell counts. This pattern was unrelated to women's viral load. Other neuroendocrine hormones known to down-regulate the immune system (cortisol, norepinephrine) did not mediate the effects of OT and stress on immune status.

CONCLUSIONS

OT may have stress buffering effects on some immune parameters and possibly health status in low income ethnic minority WLWH reporting elevated stress.

Individual exercise sessions alter circulating hormones and cytokines in HIV-infected men

Exercise has the potential to impact disease by altering circulating anabolic and catabolic factors. It was the goal of this study to determine how different regimens of low-intensity and moderate-intensity exercise affected circulating levels of these anabolic and catabolic factors in HIV-infected men. Exercise-naive, HIV-infected men, medically cleared for study participation, were randomized into one of the following groups: a moderate-intensity group (MOD, who completed 30 min of moderate-intensity aerobic training followed by 30 min of moderate-intensity resistance training; a low-intensity group (LOW), who completed 60 min of treadmill walking; or a control group (CON), who attended the clinic but participated in no activity. Blood and saliva samples were collected at selected time points before, during, and after each of the 3 required sessions. Compared with baseline, the MOD group (n=14) had a 135% increase in growth hormone (GH) (p<0.05) and a 34% decrease in cortisol (CORT) (p<0.05) at the post time point, a 31% increase in interleukin-6 (IL-6) (p<0.05) at 30-min post exercise, and a 23% increase in IL-6 (p<0.05) and a 13% decrease in soluble tumor necrosis factor receptor 2 (sTNFrII) (p<0.05) at 60-min post exercise. The LOW (n=11) group had a 3.5% decrease in sTNFrII (<0.05) at 30-min post exercise compared with baseline and a 49% decrease (p<0.05) in GH at 60-min post exercise. The CON group (n=13) had a decrease in GH at 30-min (62%, p<0.05) and 60-min (61%, p<0.05) post exercise compared with baseline. The increase in GH from baseline to post was greater in the MOD group (p<0.05) and the decrease in CORT from pre to post was greater in the MOD group (p<0.05) than in the other groups. These data suggest that individual sessions of both low-intensity and moderate-intensity exercise can alter circulating anabolic and catabolic factors in HIV-infected men. The changes in the MOD group present potential mechanisms for the increases in lean tissue mass seen with resistance exercise training.

Population levels of psychological stress, herpesvirus reactivation and HIV

Nearly 40,000 Americans are newly infected with Human Immunodeficiency Virus (HIV) each year. Recently, studies have demonstrated associations between group-level characteristics and the prevalence and incidence of HIV/Acquired Immune Deficiency Syndrome (AIDS) and other sexually transmitted diseases. Two mechanisms previously posited to explain these associations are neighborhood effects on risk behaviors and social or institutional policies. In this paper, we hypothesize that adversity at the population level, such as neighborhood poverty, also influences HIV risk through stress-mediated aberrations in immunological susceptibility by reviewing existing data examining each of these pathways. In particular, we review the evidence showing that: (1) Neighborhood ecologic stressors influence neighborhood- and individual-levels of mental health, psychosocial stress, and HIV/AIDS risk, (2) Individual-level psychosocial stressors influence progression from HIV to AIDS through stress-related hormonal changes, and (3) Individual-level psychosocial stressors influence HIV acquisition via stress-related reactivation of latent herpesviruses, specifically EBV and HSV-2. Our review indicates that further studies are needed to examine the joint pathways linking neighborhood-level sources of psychosocial stress, stress-related reactivation of HSV-2 and EBV, and increased acquisition rates of HIV. We suggest using a multi-level framework for targeting HIV prevention efforts that address not only behavioral risk factors, but structural, political, and institutional factors associated with neighborhood disadvantage, levels of psychosocial stress, and prevention or treatment of HSV-2 and EBV.

Disclosing HIV serostatus to family members: Effects on psychological and physiological health in minority women living with HIV

BACKGROUND

Directly disclosing a positive HIV serostatus to family members can have psychological and physiological health benefits. Perceptions that one is in a supportive family environment may enhance these benefits.

PURPOSE

We examined a mediated moderation model in which we expected interactions between serostatus disclosure to family members and HIV-specific family support to be associated with women's perceived stress, which in turn would explain depressive symptoms and 24-h urinary cortisol in women living with HIV (WLWH).

METHOD

Low-income ethnic minority WLWH (n = 82) reported the percentage of family members they had directly disclosed their serostatus to, perceptions of HIV-related support from family members, perceived stress, and depressive symptoms. Cortisol was measured via 24-h urinary collection.

RESULTS

Disclosure to spouses and children coupled with high levels of family support was associated with higher levels of depressive symptoms in women. For disclosure to spouses, this relationship was explained by higher perceived stress. Direct disclosure to mothers in tandem with high support was associated with lower cortisol, and this relationship was explained through higher levels of perceived stress.

CONCLUSION

The effects of serostatus disclosure on perceived stress and health in WLWH may depend, in part, on women's family environment and to whom they disclose to within that environment.

Immune modulation of the hypothalamic-pituitary-adrenal (HPA) axis during viral infection

Compelling data has been amassed indicating that soluble factors, or cytokines, emanating from the immune system can have profound effects on the neuroendocrine system, in particular the hypothalamic- pituitary-adrenal (HPA) axis. HPA activation by cytokines (via the release of glucocorticoids), in turn, has been found to play a critical role in restraining and shaping immune responses. Thus, cytokine-HPA interactions represent a fundamental consideration regarding the maintenance of homeostasis and the development of disease during viral infection. Although reviews exist that focus on the bi-directional communication between the immune system and the HPA axis during viral infection (188,235), others have focused on the immunomodulatory effects of glucocorticoids during viral infection (14,225). This review, however, concentrates on the other side of the bi-directional loop of neuroendocrine-immune interactions, namely, the characterization of HPA axis activity during viral infection and the mechanisms employed by cytokines to stimulate glucocorticoid release.

Increases in a marker of immune system reconstitution are predated by decreases in 24-h urinary cortisol output and depressed mood during a 10-week stress management intervention in symptomatic HIV-infected men

BACKGROUND

Stress management interventions reduce distress symptoms and hypothalamic-pituitary-adrenal (HPA) axis hormones such as cortisol, which has been related to a down-regulation of immune system components relevant to the human immunodeficiency virus (HIV) infection. We previously showed that HIV+ men assigned to a 10-week cognitive behavioral stress management (CBSM) intervention showed more CD4+CD45RA+CD29+ lymphocytes, an indicator of immune system reconstitution, at a 6- to 12-month follow-up compared with controls. Here, we tested whether reductions in urinary cortisol output and depressed mood during the 10-week CBSM intervention period mediated its effects on this immune system reconstitution marker at follow-up.

METHODS

Twenty-five HIV-infected men randomized to either a 10-week CBSM intervention or a wait-list control provided 24-h urine samples and psychological responses pre- to postintervention, which were related to changes in immune status over a 6- to 12-month follow-up period.

RESULTS

Greater reductions in cortisol output and depressed mood during CBSM appeared to mediate the effects of this intervention on this indicator of immune system reconstitution over the 6- to 12-month follow-up period. Changes in mood were maintained over the follow-up period, although these did not add explanatory information beyond the cortisol and mood changes that were observed during the 10-week intervention period. These findings were not explained by the changes in medications or health behaviors during follow-up.

CONCLUSION

A time-limited CBSM intervention may affect the rate of immune system reconstitution in HIV-infected men by modifying the stress of symptomatic disease. This intervention may work by decreasing depressed mood and normalizing HPA axis functioning.

Cognitive-behavioral stress management reduces distress and 24-hour urinary free cortisol output among symptomatic HIV-infected gay men

BACKGROUND

Stress management interventions can reduce symptoms of distress as well as modulate certain immune system components in persons infected with human immunodeficiency virus (HIV). These effects may occur in parallel with reductions in hypothalamic-pituitary-adrenal (HPA) axis hormones such as cortisol, which has been related in other work to a down-regulation of immune system components relevant to HIV infection. The present study tested the effects of a multimodal cognitive-behavioral stress management (CBSM) intervention on 24-hour urinary free cortisol levels and distressed mood in symptomatic HIV+ gay men.

METHODS

Symptomatic HIV-infected gay men who were randomized to either a 10-week group-based CBSM intervention or a 10-week wait-list period provided psychological responses and urine samples pre-post intervention.

RESULTS

Of the 59 participants providing matched questionnaire data, men assigned to CBSM (n = 40) showed significantly lower posttreatment levels of self-reported depressed affect, anxiety, anger, and confusion than those in the wait-list control group (n = 19). Among the 47 men providing urine samples (34 CBSM, 13 controls), those assigned to CBSM revealed significantly less cortisol output as compared to controls. At the individual level, depressed mood decreases paralleled cortisol reductions over this period across the entire sample.

CONCLUSION

A time-limited CBSM intervention reduced distress symptoms and urinary free cortisol output in symptomatic HIV+ gay men and greater reductions in some aspects of distress, especially depressed mood, paralleled greater decreases in cortisol over the intervention period. If persisting stressors and depressed mood contribute to chronic HPA axis activation in HIV-infected persons, then interventions such as CBSM, which teaches them to relax, alter cognitive appraisals, use new coping strategies, and access social support resources, may decrease distress and depressed mood and normalize HPA axis functioning.

Stimulating effect of HIV-1 coat protein gp120 on corticotropin-releasing hormone and arginine vasopressin in the rat hypothalamus: involvement of nitric oxide

Subjects with human immunodeficiency virus type 1 (HIV-1) infection display increased activity of the hypothalamo-pituitary-adrenal (HPA) axis, which may play a role in both HIV-related neurodegenerative processes and disease progression. It has been speculated that the HIV coat protein gp120 may be responsible for these changes, and previous experimental evidence in both transgenic and nontransgenic mice supports this view. We speculated that one of the effects of gp120 in the CNS is to act within the hypothalamus to affect both corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP), the principal regulators of HPA axis. We therefore administered i.p. gp120 (100 ng/rat) or vehicle to male Wistar rats and then detected Fos protein (an index of neuronal activation), CRH, and AVP immunoreactivity in the cellular compartments of the hypothalamic paraventricular nucleus (PVN). In addition, we tested the direct effect of various concentrations of gp120 on the release of CRH and AVP from rat hypothalamic explants maintained in vitro. Any modulation of gp120 effects by nitric oxide (NO) pathways was also sought by coadministering i.p. to rats or adding to the hypothalamic preparations the NO synthase inhibitor N(G)-methyl-l-arginine (l-NMMA). Gp120 induced the expression of Fos protein in both the parvo- and the magnocellular PVN, which was significantly attenuated by l-NMMA 10(-6) nM/L (P < 0.001 vs gp120 alone). Double immunochemistry showed costaining for Fos protein and CRH or AVP in the PVN following gp120; the number of double-labeled CRH and AVP cells for Fos protein was markedly reduced (P < 0.001) by coadministration of l-NMMA 10(-6) nM/L. In the in vitro studies, addition of gp120 to the hypothalamic explants in the dose range of 10 pM-1 nM resulted in a clear stimulation of both CRH and AVP release (P < 0.05-0.001 compared to control); in the presence of l-NMMA at 10-fold higher concentrations the stimulatory effect of gp120 on the release of both peptides was completely lost. It would therefore appear that gp120 activates CRH and AVP-producing neurons in the hypothalamic PVN and stimulates the release of both peptides in vitro via NO-dependent mechanisms. These findings, in line with previous evidence, further suggest that the increased activity of the HPA axis associated with HIV infection may be of central origin, due to the effects of gp120 on hypothalamic CRH and AVP release.

Effects of cytokines on glucocorticoid receptor expression and function. Glucocorticoid resistance and relevance to depression

Our data indicate that the proinflammatory cytokine, IL-1alpha inhibits GR translocation and hormone-induced GR-mediated gene transcription, and, in conjunction with previous in vivo and in vitro studies, can be interpreted to suggest that cytokines have the capacity to contribute to glucocorticoid resistance and thus the pathophysiology of depression. In addition, data from our mouse viral studies in glucocorticoid deficient animals demonstrate that endogenous glucocorticoids modulate a delicate balance between viral defense and cytokine toxicity. Finally, the antidepressant, DMI, has been found to enhance GR translocation and GR-mediated gene transcription and thus may provide a useful strategy for adjusting neuroendocrine setpoints in vivo. Taken together, these findings suggest that factors which modulate glucocorticoid action (e.g. cytokines and antidepressants) will be relevant contributors to disease expression including behavioral toxicity and sickness behavior.